CN115151229B

CN115151229B - Absorbent article

Info

Publication number: CN115151229B
Application number: CN202180010652.1A
Authority: CN
Inventors: 菊池响; 请川一夫; 国友照夫; 合田裕树; 正木俊介
Original assignee: Unicharm Corp
Current assignee: Unicharm Corp
Priority date: 2020-01-31
Filing date: 2021-01-07
Publication date: 2023-06-02
Anticipated expiration: 2041-01-07
Also published as: JP7353999B2; CN115151229A; WO2021153184A1; JP2021122325A

Abstract

An absorbent article (1) has an absorbent main body (4) having an absorbent core (41) and a core wrap sheet (42) covering the absorbent core (41). The absorbent core (41) includes a superabsorbent polymer in an amount of 70% by mass or more. The absorbent body (4) has a superabsorbent polymer-existing region (PR) in which a superabsorbent polymer is present. The absorbent article has a Bonding Region (BR) located at the central portion in the longitudinal direction and the outer side in the width direction of the superabsorbent polymer-existing region (PR). In each bonding region, the inner surface of the core wrap sheet (42) in the thickness direction is bonded to itself with an additional sheet-like member (43) interposed or partially interposed.

Description

Absorbent article

Technical Field

The present invention relates to an absorbent article.

Background

Conventionally, there are absorbent articles (such as disposable diapers) that include an absorbent body that absorbs liquid. As such an absorbent body, SAP sheets comprising superabsorbent polymers (so-called SAP) without comprising wood pulp fibers are known. The use of such SAP sheets tends to reduce the thickness of the absorbent body compared to absorbent bodies comprising wood pulp fibers, and thus SAP sheets are suitable for forming thin absorbent bodies. For example, patent document 1 discloses a disposable absorbent article having an absorbent core (SAP sheet) that does not substantially include cellulose, and wherein an absorbent particulate polymer material is wrapped with a core wrap sheet.

CITATION LIST

Patent literature

Patent document 1: japanese patent application laid-open (translation of PCT application) No. 2010-529900

Disclosure of Invention

Technical problem

Conventional SAP sheets (absorbent bodies) are typically sheets in which a large number of SAP particles are wrapped with a core wrap sheet, molded into a strip-like (substantially rectangular) shape. However, in such SAP sheets, the crotch portion has a wide width, and when the absorbent article is worn, the SAP sheet is sandwiched between the legs of the wearer (for example, at the groin), and may cause discomfort in the crotch portion. Furthermore, being sandwiched between the legs of the wearer makes the SAP particles more easily compressed in the width direction of the crotch portion and causes the SAP sheet (absorbent main body) to be deformed. Therefore, there is a risk that the absorbency and fit will be poor.

The present invention has been made in view of the conventional problems such as those described above, and an aspect of the present invention is to improve the fit of the crotch portion while suppressing shape aliasing in an absorbent body (SAP sheet) having a high superabsorbent polymer content.

Solution to the problem

One main aspect of the present invention for achieving the above aspect is an absorbent article having a longitudinal direction, a width direction, and a thickness direction orthogonal to each other, comprising: an absorbent body including an absorbent core and a core wrap sheet covering the absorbent core, the absorbent core including superabsorbent polymer in an amount of 70% or more of the mass of the absorbent core, the absorbent body having a superabsorbent polymer arrangement region in which superabsorbent polymer is arranged, the absorbent body having a connection region at a central portion in a longitudinal direction and outside the superabsorbent polymer arrangement region in a width direction, the connection region being a region in which inner surfaces in a thickness direction of the core wrap sheet are connected to each other in a state in which additional sheet members are interposed between the inner surfaces or in a state in which no additional sheet members are present.

Other features of the invention, in addition to those described above, will become apparent upon reading the description of the present specification and upon reference to the drawings.

Advantageous effects of the invention

According to the present invention, in an absorbent body having a high superabsorbent polymer content, the fit of the crotch portion can be improved while suppressing shape failure.

Drawings

Fig. 1: is a plan view and a cross-sectional view of the diaper 1 in the unfolded and stretched state.

Fig. 2: is a plan view of the absorbent main body 4 in a stretched state.

Fig. 3: fig. 3A is a schematic cross-sectional view of the absorbent body 4 taken along the line A-A shown in fig. 2. Fig. 3B is a schematic cross-sectional view of the absorbent body 4 taken along line B-B shown in fig. 2.

Fig. 4: fig. 4A is a schematic cross-sectional view of the absorbent main body 4 in a state before the central portion in the longitudinal direction absorbs moisture. Fig. 4B is a schematic cross-sectional view of the absorbent body 4 in a state after absorbing moisture from the state in fig. 4A.

Fig. 5: fig. 5A is a schematic cross-sectional view of the absorbent main body 4 in a state before the two end portions in the longitudinal direction absorb moisture. Fig. 5B is a schematic cross-sectional view of the absorbent body 4 in a state after absorbing moisture from the state in fig. 5A.

Fig. 6: is a table showing experimental results for the permeability of superabsorbent polymer particles (SAP) to sheet members.

Fig. 7: is a plan view of the absorbent main body 4 of the modified example in a stretched state.

Fig. 8: fig. 8A is a schematic cross-sectional view of the absorbent body 4 taken along line C-C shown in fig. 7. Fig. 8B is a schematic cross-sectional view of the absorbent body 4 taken along line D-D shown in fig. 7.

Detailed Description

At least the following matters will become clear from the description of the present specification and the accompanying drawings.

An absorbent article having a longitudinal direction, a width direction, and a thickness direction that are orthogonal to each other, the absorbent article comprising: an absorbent body including an absorbent core and a core wrap sheet covering the absorbent core, the absorbent core including superabsorbent polymer in an amount of 70% or more of the mass of the absorbent core, the absorbent body having a superabsorbent polymer arrangement region in which superabsorbent polymer is arranged, the absorbent body having a connection region at a central portion in a longitudinal direction and outside the superabsorbent polymer arrangement region in a width direction, the connection region being a region in which inner surfaces in a thickness direction of the core wrap sheet are connected to each other in a state in which additional sheet members are interposed between the inner surfaces or in a state in which no additional sheet members are present.

According to the absorbent article, in the center portion (crotch portion) in the longitudinal direction, the connecting region is provided outside the superabsorbent polymer arrangement region in the width direction, which suppresses outward movement of the superabsorbent polymer in the width direction, so that the width of the superabsorbent polymer arrangement region can be kept narrow. Thus, the two side portions of the absorbent core are less prone to interference with the groin of the wearer and fit can be improved. Furthermore, even in the case where the absorbent main body is sandwiched between the legs of the wearer, or even in the case where the superabsorbent polymer absorbs the excreta and swells, the absorbent core (superabsorbent polymer placement area) is less prone to shape-off. Thus, an absorbent body having good fit in the crotch portion can be realized while suppressing shape failure.

In such an absorbent article, it is desirable that the width of the connecting region at the central portion in the longitudinal direction is larger than the width of the connecting regions at the both end portions in the longitudinal direction.

According to the absorbent article, the center portion (crotch portion) of the width of the superabsorbent polymer arrangement region (absorbent core) in the longitudinal direction is kept narrow, which makes it possible to improve fit. Further, in both end portions (front and rear) in the longitudinal direction, when the superabsorbent polymer expands and increases its volume, the connection region is peeled off, and the space surrounded by the core wrap sheet or the like becomes wider. This makes the expansion of the superabsorbent polymer less susceptible to obstruction. Therefore, the water absorbing capacity of the entire absorbent main body can be improved while enhancing the fit of the absorbent main body in the crotch portion.

In such an absorbent article, it is desirable that the boundary between the superabsorbent polymer arrangement region and the connection region has a curved shape that narrows from an outer position in the longitudinal direction to a center position in the longitudinal direction in the width direction.

According to the absorbent article, in the crotch portion, both side ends in the width direction of the absorbent core are more likely to follow the shape of the wearer's legs and fit the groins. In addition, shape failure of the absorbent core is less likely to occur even with the absorbent core sandwiched between the legs of the wearer.

In such an absorbent article, it is desirable that the absorbent core includes: a skin-side core layer provided on the skin side in the thickness direction, and a non-skin-side core layer provided on the non-skin side with respect to the skin-side core layer, and each of the skin-side core layer and the non-skin-side core layer is sandwiched between the sheet-like members from both sides in the thickness direction.

According to the absorbent article, the thickness of the layer of the absorbent core can be reduced, which increases the flexibility of the absorbent core, making the absorbent article more prone to conform to uneven shapes of the wearer's body. Further, the core layers are sandwiched between the respective sheet-like members, which makes the positions of the superabsorbent polymer particles arranged in each core layer less likely to move, so that shape-shifting of the absorbent core (core layer) less likely to occur. Further, when the superabsorbent polymer particles absorb moisture and have expanded, the amount of expansion of the volume of each core layer is limited, which makes it possible to suppress excessive expansion of the core layer and makes it difficult for the sheet-like member (core wrap sheet or the like) covering the core layer to break.

In such an absorbent article, it is desirable that the absorbent article further comprises: an intermediate layer sheet located between the skin-side core layer and the non-skin-side core layer in the thickness direction; and a portion in which the intermediate layer sheet and the core wrap sheet are connected to each other, the portion being located outside in the width direction with respect to the skin-side core layer and the non-skin-side core layer.

According to this absorbent article, the intermediate layer sheet is reliably fixed to the core wrap sheet at both end portions in the width direction. Therefore, even in the case where the superabsorbent polymer particles absorb moisture and swell, the core layer can be stably fixed by the intermediate layer sheet. This suppresses shape-shifting of the core layer, making it easier for the absorbent body to maintain a favorable fit.

In such an absorbent article, it is desirable that the fiber density of the core wrap sheet is greater than that of the intermediate layer sheet.

According to the absorbent article, the superabsorbent polymer particles more easily pass through the intermediate layer sheet and move to the opposite side in the thickness direction, rather than moving from the superabsorbent polymer arrangement region to the outside of the core wrap sheet (to the outside of the absorbent body). This may make it easier to suppress leakage of superabsorbent polymer particles to the outside of the absorbent body.

In such an absorbent article, it is desirable that at least one of the skin-side core layer and the non-skin-side core layer has a slit in which the weight per unit area of the superabsorbent polymer is zero, the slit extends in the longitudinal direction, and the absorbent article further includes a portion in which the core wrap sheet and the intermediate layer sheet are connected to each other in the thickness direction, and the portion is located in the slit.

According to the absorbent article, the absorbent core is folded at the slit portion, so that the absorbent core is more easily deformed along the uneven shape of the wearer's body, enhancing fit. Further, the core wrap sheet and the intermediate layer sheet are connected to each other in the thickness direction in the slit portion, and therefore the superabsorbent polymer contained in the absorbent core is fixed in a state of being reliably wrapped by the core wrap sheet and the intermediate layer sheet on both sides in the width direction of the slit. This may make shape-shifting of the absorbent core less likely to occur.

In such an absorbent article, it is desirable that the width of the slit is smaller than the maximum value of the width of the connection region at the central portion in the longitudinal direction.

According to the absorbent article, the connection strength between the core wrap sheet and the intermediate layer sheet in the slit is weaker than the connection strength between the core wrap sheet and the intermediate layer sheet in the connection region. Therefore, when the superabsorbent polymer absorbs moisture and swells, the connection between the core wrap sheet and the intermediate layer sheet in the slit is easily peeled off first. Therefore, in the slit portion, the space sandwiched between the core wrap sheet and the intermediate sheet becomes wider, which makes the expansion of the superabsorbent polymer less susceptible to being hindered. Thus, the water absorbing capacity is enhanced.

In such an absorbent article, it is desirable that the thickness of the absorbent body at the center portion in the longitudinal direction when the superabsorbent polymer absorbs moisture and swells to a saturated state is smaller than the maximum value of the width of the connection region.

According to the absorbent article, the connecting area can have a sufficiently large connecting area in the central portion (crotch portion) in the longitudinal direction, and even in the case where the superabsorbent polymer swells, the thickness of the absorbent body can be prevented from becoming excessively thick. Thus, this can make it easier to further suppress shape-aliasing of the absorbent main body.

In such an absorbent article, it is desirable that at least a part of the connecting region is peeled off at both end portions in the longitudinal direction when the superabsorbent polymer absorbs moisture to reach a saturated state.

According to the absorbent article, since the space surrounded by the core wrap sheet (and the intermediate sheet) becomes wider, the expansion of the superabsorbent polymer is less likely to be hindered. This allows the water absorption properties of the superabsorbent polymer to be more readily and fully exhibited, as well as the water absorption properties of the entire absorbent core.

In such an absorbent article, it is desirable that the core wrap sheet includes a first core wrap sheet which is a sheet covered with a superabsorbent polymer from one side in the thickness direction and a second core wrap sheet which is a sheet covered with a superabsorbent polymer from the other side in the thickness direction, the first core wrap sheet having a folded back portion, wherein the first core wrap sheet is folded back inwardly at an outer end in the width direction of the absorbent main body, the folded back portion and the second core wrap sheet having an overlapping portion in which the folded back portion and the second core wrap sheet overlap when viewed in the thickness direction, and in at least a part of the overlapping portion, the folded back portion and the second core wrap sheet are connected to each other.

According to the absorbent article, the first core wrap sheet and the second core wrap sheet are connected to each other in a state of containing the absorbent core, and the entire absorbent core is completely covered with the core wrap sheet. This suppresses leakage of the superabsorbent polymer particles contained in the absorbent core out of the core wrap sheet, and also suppresses deterioration of the water absorption of the absorbent body and occurrence of shape failure of the absorbent body.

In such an absorbent article, it is desirable that the absorbent core includes: the absorbent article further includes an intermediate layer sheet disposed between the skin-side core layer and the non-skin-side core layer in the thickness direction, at least one of the skin-side core layer and the non-skin-side core layer having a slit in which the weight per unit area of the superabsorbent polymer is zero, the slit extending in the longitudinal direction, and a non-skin-side core layer disposed on the non-skin side with respect to the skin-side core layer, wherein the intermediate layer sheet and the core wrap sheet are connected to each other, and wherein a width of a portion where the folded-back portion and the second core wrap sheet are connected to each other is larger than a width of the slit.

According to the absorbent article, when the superabsorbent polymer absorbs moisture and has swelled, the connecting portion in the slit between the first core wrap sheet and the intermediate layer sheet is more easily peeled off before the connecting portion between the folded-back portion and the second core wrap sheet is peeled off. Therefore, even when the space between the first core wrap sheet and the intermediate sheet becomes wider and the superabsorbent polymer expands, the force of pulling the connecting portion between the folded-back portion and the second core wrap sheet does not easily act. This can more easily further suppress leakage of superabsorbent polymer particles out of the absorbent body and occurrence of shape failure.

In such absorbent articles, it is desirable that the absorbent core not include wood pulp fibers.

According to the absorbent article, the absorbent core is formed of only superabsorbent polymer, and the thickness of the absorbent body can be reduced as compared with the case where the absorbent core includes wood pulp fibers. This makes it easier for the absorbent body to deform to conform to the body shape of the wearer, and to achieve an advantageous fit.

Examples

An embodiment of an absorbent article according to the present invention will be described below by taking a bonded disposable diaper 1 (hereinafter also referred to as "diaper") as an example. However, the invention is not limited thereto, but is also applicable to other types of absorbent articles, such as pant-type disposable diapers, light incontinence pads, etc.

Basic structure 1 of adhesive disposable diaper

Figure 1 is a plan view and a cross-sectional view of a diaper 1 in an unfolded and stretched state. The stretched state of the diaper 1 refers to a state in which the wrinkles of the diaper 1, which are unfolded and stretched into the diaper 1, are substantially no longer visible, i.e., a state in which the diaper 1 is stretched until the dimensions of the constituent members of the diaper 1 (e.g., the topsheet 2, the outer sheet 5, and the like described later) conform to or approximate the dimensions of these members themselves.

The diaper 1 of the present embodiment is a so-called open type disposable diaper having longitudinal directions, width directions and thickness directions which are staggered (in the present embodiment, are mutually orthogonal). In the diaper 1, the first waist portion 1a, the crotch portion 1b, and the second waist portion 1c are arranged in order from one side in the longitudinal direction. Generally, after the diaper is put on, the first waist portion 1a covers the back of the wearer and the second waist portion 1c covers the abdomen of the wearer. However, the diaper may also be worn in reverse. Hereinafter, in the longitudinal direction, the side of the first waist portion 1a will also be referred to as the "back side" of the diaper 1, and the side of the second waist portion 1c will also be referred to as the "front side" of the diaper 1.

As shown in fig. 1, the diaper 1 comprises an absorbent body 4 which is located between a liquid permeable topsheet 2 and a liquid impermeable backsheet 3. The absorbent main body 4 extends from the first waist portion 1a to the second waist portion 1c in the longitudinal direction, and includes an absorbent core 41 formed of an absorbent material (e.g., superabsorbent polymer) that absorbs and retains excrement, and a liquid-permeable core wrap sheet 42 (e.g., cotton paper sheet and spunbond nonwoven sheet) that covers the absorbent core 41. In addition to these components, the absorbent body 4 may also include some constituent elements, such as an intermediate layer sheet 43 described later. On the non-skin side of the backsheet 3, an outer sheet 5 (e.g. a nonwoven sheet) is provided, which forms the outside of the entire diaper 1. It should be noted that, for example, in order to improve the fit around the waist, the first waist portion 1a may include an elastic member (e.g., an elastic sheet-like member or a string-like elastic member) capable of stretching and contracting in the width direction.

The first waist portion 1a has a pair of back side flaps 13 extending outwardly in the width direction beyond the crotch portion 1b, and the second waist portion 1c also has a pair of front side flaps 14 (side flaps) extending outwardly in the width direction beyond the crotch portion 1b. Each of the side flaps 13 and 14 is formed by overlapping the back film 3 and a later-described barrier cuff sheet 21. The pair of fastening tapes 10 extends outward in the width direction from the pair of rear side flaps 13 (the first waist portion 1 a).

The fastening tape 10 includes a base material 11 and a hook tab 12. The hook piece 12 is provided on the skin-side surface of the base material 11 in the thickness direction. When the hook sheet 12 is folded toward the second waist portion 1c, the hook sheet 12 faces the outer sheet 5 (non-skin-side surface) of the second waist portion 1c, being joined with the outer sheet 5. Thus, the hook sheet 12 (e.g., a sheet comprising the male member of a hook and loop fastener) is configured to be able to engage with and disengage from the outer sheet 5 (e.g., nonwoven fabric). It should be noted that this configuration is not limited to a configuration in which the hook sheet 12 is directly engaged with the outer sheet 5. For example, a target sheet (for example, a sheet including a female member of a hook-and-loop fastener) to which the hook sheet 12 can be engaged may be provided on the outer sheet 5 so that the hook sheet 12 is engaged with the target sheet.

When the diaper 1 is to be put on, the diaper 1 is first pressed against the wearer and folded in the longitudinal direction, and then the pair of rear side flaps 13 are folded inward in the width direction. Then, a pair of fastening tapes 10 are joined with the outer sheet 5 of the second waist portion 1 c. Thereby, a waist opening portion and a pair of leg opening portions are formed.

Further, leg elastic members 6 stretchable in the longitudinal direction are provided at both end portions in the width direction of the diaper 1. The leg elastic members 6 are fixed between the back film 3 and a sheet such as the top sheet 2 and the release cuff sheet 21 so as to be stretched in the longitudinal direction. Thus, in the diaper 1 in a natural state, the leg elastic members 6 contract to form leg gathers at the peripheral edge portions of the leg openings, and the leg openings fit around the legs of the wearer.

It should be noted that, in the present embodiment, as the leg elastic members 6, string-like elastic members (e.g., string-like polyurethane stretchable fibers and string-like natural rubber) are used, and each end portion of the diaper 1 in the width direction has two leg elastic members 6 arranged side by side in the width direction. However, the number of leg elastic members 6 is not limited thereto. Further, the leg elastic members 6 may be sheet-like elastic members (e.g., stretchable films formed by forming molten thermoplastic elastomer resins into film shapes, or stretchable nonwoven sheets formed of stretchable fibers).

Further, a pair of barrier cuffs 20 raised toward the skin side (toward the wearer) are provided at both end portions in the width direction of the diaper 1, respectively. Each of the isolation cuffs 20 includes an isolation cuff sheet 21 and an isolation cuff elastic member 22. The widthwise outer ends of the barrier cuff sheet 21 and the outer sheet 5 are aligned with each other (see fig. 1). The inner end portions of the barrier cuff sheets 21 in the width direction are folded toward the top sheet 2 (non-skin side), respectively. The isolation cuff elastic member 22 (one string-like elastic member in this embodiment) is fixed between the isolation cuff pieces 21 of the two-layer structure so as to be stretched in the longitudinal direction. Further, although not shown, both end portions in the longitudinal direction of the release cuff sheet 21 are connected to the top sheet 2 with an adhesive or the like. The portion of the barrier cuff sheet 21 other than the connected both end portions in the longitudinal direction in the width direction is connected to the top sheet 2 from one end in the longitudinal direction to the other end in the longitudinal direction. The isolation cuff 20 rises from the connecting portion (bottom end portion) due to the contraction of the isolation cuff elastic member 22.

Features of the absorbent body 4

Fig. 2 is a plan view of the absorbent main body 4 in a stretched state. Fig. 3A is a schematic cross-sectional view of the absorbent body 4 taken along the line A-A shown in fig. 2. Fig. 3B is a schematic cross-sectional view of the absorbent body 4 taken along line B-B shown in fig. 2.

The absorbent core 41 included in the absorbent main body 4 of the present embodiment includes superabsorbent polymer. The superabsorbent polymer is not particularly limited as long as it can absorb and retain moisture, and examples thereof include starch-based, acrylic-based, and amino-based superabsorbent polymers (SAP) in particulate or fibrous form. The content of the superabsorbent polymer included in the absorbent core 41 is 70% or more of the mass of the absorbent core 41. It should be noted that the "mass of the absorbent core 41" does not include the mass of the core wrap sheet 42, the intermediate layer sheet 43, and the joining material (such as a hot melt adhesive for joining these sheets) which will be described later. On the other hand, the absorbent core 41 of the present embodiment includes substantially no wood pulp fibers. In particular, the wood pulp fibers included in the absorbent core 41 are present in an amount of less than 30% by mass of the absorbent core 41, preferably less than 5%, more preferably 0%. That is, it is desirable that the absorbent core 41 is a so-called wood-free SAP sheet, which is formed of only superabsorbent polymer.

According to this configuration, the thickness of the absorbent body 4 can be reduced as compared with the case where the absorbent core includes wood pulp fibers, so that the absorbent body 4 is more easily deformed to conform to the body shape of the wearer, achieving advantageous fitting. It should be noted that the average particle diameter of the superabsorbent polymer particles (SAP) included in the absorbent core 41 in a state before absorbing moisture and swelling is about 300 to 400 μm.

The absorbent core 41 is divided into a plurality of layers in the thickness direction. In fig. 3A and 3B, the absorbent core 41 includes: a skin-side core layer 411 arranged on the skin side in the thickness direction; and a non-skin side core layer 412 arranged on the non-skin side with respect to the skin side core layer 411. Although the core layers 411 and 412 basically have a common configuration (although the content of superabsorbent polymer and the like is common), their planar shapes and areas are different from each other.

In particular, the skin-side core layer 411 has a substantially hourglass shape in the plan view shown in fig. 2, and is narrowed inward in the width direction at the central portion in the longitudinal direction. That is, in the skin-side core layer 411, the superabsorbent polymer particles are arranged such that the width of the portion between the two end portions 411ef and 411eb in the longitudinal direction is narrower than the width at the two end portions 411ef and 411eb in the longitudinal direction. Further, the central portion of the skin-side core layer 411 in the width direction has a low basis weight region L411 extending in the longitudinal direction, the low basis weight region L411 being a region in which the basis weight of the superabsorbent polymer is lower than that of the other regions. Fig. 3 shows a state in which the weight per unit area of the superabsorbent polymer is zero in the low weight per unit area region L411. That is, the skin-side core layer 411 has a slit-shaped portion in which the superabsorbent polymer is not disposed, the portion extending in the longitudinal direction and being located in the central portion in the width direction. Further, a portion corresponding to the low basis weight region L411 (slit) may be provided in the non-skin side core layer 412. In such a low basis weight region, since the rigidity of the absorbent core 41 is partially low, the absorbent core 41 is easily deformed along the uneven shape of the wearer's body when the diaper 1 is put on, and the fit can be improved. However, the low basis weight region L411 is not necessarily provided, and the superabsorbent polymer may be uniformly disposed in the entire region of the skin-side core layer 411.

On the other hand, the non-skin side core layer 412 has a rectangular shape in plan view, and has a uniform width from one side in the longitudinal direction to the other side in the longitudinal direction. That is, in the non-skin-side core layer 412, the superabsorbent polymer particles are arranged in a region having a uniform width in the entire region in the longitudinal direction. It should be noted that in fig. 2, the minimum values of the width of the non-skin-side core layer 412 and the width of the skin-side core layer 411 are equal to each other.

An intermediate layer sheet 43 is provided between the skin side core 411 and the non-skin side core 412. The intermediate layer sheet 43 is a sheet-like member formed of a cotton paper sheet, a spunbond nonwoven sheet or the like. The intermediate sheet 43 makes it possible to maintain a state in which the skin-side core layer 411 and the non-skin-side core layer 412 are arranged to be separated in the thickness direction.

It should be noted that in the absorbent main body 4, the absorbent core 41 may have only one layer in the thickness direction, or may have three or more layers. Furthermore, the intermediate layer sheet 43 is not necessarily provided.

The absorbent core 41 (and the intermediate layer sheet 43) is covered with a core wrap sheet 42. Similar to the intermediate layer sheet 43, the core wrap sheet 42 is a sheet member formed of a cotton paper sheet, a spunbond nonwoven fabric sheet, or the like. In fig. 3A and 3B, a first core wrap 421 covering the absorbent core 41 from one side in the thickness direction (e.g., the skin side) and a second core wrap 422 covering the absorbent core 41 from the other side in the thickness direction (e.g., the non-skin side) are provided. The core wrap sheet 42 is provided to extend outward beyond at least both end portions of the absorbent core 41 in the width direction. In the present embodiment, both end portions in the width direction of the first core wrap sheet 421 are folded back inward in the outer ends 4eo and 4eo of the absorbent main body 4, and the folded back

portions

421f and 421f are each connected in a state of being covered on the non-skin-side surface of the second core wrap sheet 422. Thereby, the particles of the absorbent core 41 are covered with the core wrap sheet 42, and are prevented from leaking to the outside of the absorbent main body 4.

The

members

41, 42, and 43 constituting the absorbent main body 4 are connected with their adjacent members adjacent in the thickness direction, respectively, with a connecting material such as a hot melt adhesive (indicated by broken lines in fig. 3A and 3B). Therefore, the sheet-like members facing each other in the thickness direction are fixed to each other. Furthermore, this makes it less likely that the superabsorbent polymer particles arranged to be sandwiched between the facing sheet members are displaced.

Hereinafter, when the absorbent body 4 is viewed in the thickness direction, the region where the superabsorbent polymer (absorbent core 41) exists will also be referred to as "superabsorbent polymer arrangement region PR". It should be noted that the low basis weight region L411 provided in the skin-side core layer 411 exists in the superabsorbent polymer arrangement region PR. In fig. 2, the region indicated by hatching is a superabsorbent polymer arrangement region PR. Further, in the region outside the superabsorbent polymer arrangement region PR in the width direction, a portion in which the core wrap sheet 42 is connected in the thickness direction is also referred to as a "connection region BR". In the present specification, the joining region BR refers to a region (area) in which a joining material such as a hot melt adhesive is applied by a well-known coating method (e.g., spiral coating). Thus, strictly speaking, the region in which no connecting material is present (e.g., the gap between spirals) is also included in the connecting region BR.

In the absorbent core 41 of the present embodiment, at the central portion in the longitudinal direction, the width WPR1 of the portion where the length (width) in the width direction of the superabsorbent polymer arrangement region PR is narrowest is narrower than the width WPR2 of the superabsorbent polymer arrangement region PR at both end portions in the longitudinal direction (WPR 1> WPR 2). That is, in the crotch portion 1b of the diaper 1 and its surroundings, the absorbent core 41 has a narrower width than in the first waist portion 1a (rear portion) and the second waist portion 1c (front portion) (see fig. 1 and 2). Therefore, when the diaper 1 is put on, both side portions in the width direction of the absorbent core 41 are less likely to interfere with the leg roots (groins) of the wearer, and the fitting degree can be improved. It should be noted that the central portion in the longitudinal direction of the absorbent core 41 is a region including the central position in the longitudinal direction and having a predetermined length in the longitudinal direction.

The conventional absorbent core (SAP sheet) formed of only superabsorbent polymer has a rectangular shape, and generally has a shape in which the width of the region in which the superabsorbent polymer is disposed is uniform (substantially rectangular shape). Therefore, the two side portions in the width direction of the absorbent core and the groin of the wearer are more likely to interfere with each other at the crotch of the wearer, and in some cases, the fit may be deteriorated or cause discomfort to the wearer.

In contrast, in the present embodiment, in the central portion (crotch portion 1 b) in the longitudinal direction, the connection regions BR and BR are disposed outside the superabsorbent polymer arrangement region PR in the width direction, and the inner surface in the thickness direction of the core wrap sheet 42 is connected to each other with the intermediate layer sheet 43 interposed therebetween. Thereby, the superabsorbent polymer particles are prevented from moving outward in the width direction and from the superabsorbent polymer arrangement region PR into the connection region BR side. That is, this suppresses widening of the superabsorbent polymer arrangement region PR in the width direction, and can keep the width WPR1 of the superabsorbent polymer arrangement region PR narrow in the crotch portion 1 b. Therefore, at the crotch of the wearer, the two side portions of the absorbent core 41 are less likely to interfere with the groin of the wearer, and the fit can be improved.

The connection region BR makes it difficult for the superabsorbent polymer particles to move outward in the width direction, which makes it easier to maintain the shape of the superabsorbent polymer arrangement region PR in the central portion (crotch portion 1 b) in the longitudinal direction. Therefore, even in the case where the absorbent main body 4 is sandwiched between the legs of the wearer when the diaper 1 is worn, or even in the case where the superabsorbent polymer absorbs the excreta and swells, the absorbent core 41 (superabsorbent polymer arrangement region PR) is less prone to shape-deformation. Therefore, the fit of the crotch portion can be improved, and the shape of the absorbent main body 4 can be suppressed from being deformed.

Further, in the absorbent main body 4 of the present embodiment, the maximum value WBR1 of the width of the connection region BR at the central portion in the longitudinal direction is wider than the maximum value WBR2 of the width of the connection region BR at both end portions in the longitudinal direction (WBR 1> WBR 2). That is, the area of the portion where the core wrap sheet 42 (and the intermediate layer sheet 43) is connected at the center portion in the longitudinal direction is larger than the area of the portion where the core wrap sheet 42 (and the intermediate layer sheet 43) is connected at both end portions in the longitudinal direction (see fig. 2). This makes it possible to increase the connection strength of the connection region BR at the center portion in the longitudinal direction and to decrease the connection strength of the connection region BR at both end portions in the longitudinal direction. Therefore, the water absorbing capacity of the absorbent main body 4 can be improved.

Fig. 4A is a schematic cross-sectional view of the absorbent main body 4 in a state before the central portion in the longitudinal direction absorbs moisture, and is a view corresponding to fig. 3A. Fig. 4B is a schematic cross-sectional view of the absorbent body 4 in a state after absorbing moisture from the state in fig. 4A. Fig. 5A is a schematic cross-sectional view of the absorbent main body 4 in a state before both end portions in the longitudinal direction absorb moisture, and is a view corresponding to fig. 3B. Fig. 5B is a schematic cross-sectional view of the absorbent body 4 in a state after absorbing moisture from the state in fig. 5A. It should be noted that in fig. 4 and 5, the scales in the width direction and the thickness direction are modified for convenience of explanation.

At the central portion in the longitudinal direction, the thickness T4c of the absorbent main body 4 is made to be T4c before the absorbent core 41 absorbs moisture such as urine, and in fig. 4A, the thickness T4c is kept thin because the super absorbent polymer does not swell. When the absorbent core 41 absorbs moisture from this state, each superabsorbent polymer disposed in the superabsorbent polymer disposition region PR expands, which increases the thickness of the absorbent body 4 to T4c '(T4 c' > T4 c) shown in fig. 4B. At this time, since the connection regions BR provided on both sides in the width direction of the superabsorbent polymer arrangement region PR have sufficient connection strength (connection area), this makes the connection regions BR less liable to peel off even after the superabsorbent polymer absorbs moisture and swells. Therefore, as described above, this suppresses outward movement of the superabsorbent polymer in the width direction, and the width WPR1 of the superabsorbent polymer placement area (absorbent core 41) in the crotch portion 1b can be kept narrow. That is, the fit of the crotch portion can be enhanced.

On the other hand, at both end portions in the longitudinal direction, the absorbent main body 4 is made to have a thickness T4b before the absorbent core 41 absorbs moisture (such as urine), and in fig. 5A, the thickness T4b is kept thin because the superabsorbent polymer does not swell as in the case of fig. 4A. When the absorbent core 41 absorbs moisture from this state, each superabsorbent polymer disposed in the superabsorbent polymer disposition region PR expands, which increases the thickness of the absorbent body 4 to T4B '(T4B' > T4B) as shown in fig. 5B. In addition, in the case of fig. 5B, in the connection regions BR provided at both side portions in the width direction of the superabsorbent polymer arrangement region PR, the area of the portion where the first core wrap sheet 421 and the intermediate layer sheet 43 are connected is smaller than in fig. 4B, and therefore, the connection strength is weaker. This makes the sheet-like member easier to peel off in this portion. That is, as the expansion and volume of the super absorbent polymer increases, a tensile force that pulls the first core wrap sheet 421 and the intermediate layer sheet 43 toward opposite sides in the thickness direction acts, so that the connection portion between the first core wrap sheet 421 and the intermediate layer sheet 43 is more easily peeled off.

Therefore, at both end portions in the longitudinal direction, the space enclosed between the first core wrap sheet 421 and the intermediate layer sheet 43 becomes wider. This makes it less likely to hinder the expansion of the superabsorbent polymer and makes it easier for the superabsorbent polymer to move outward in the width direction. This increases the amount of moisture that the superabsorbent polymer can absorb (the amount of water absorption), and makes it easier to sufficiently exhibit the water absorption performance of the skin-side core layer 411. Thus, the water absorbing performance of the entire absorbent core 41 can be improved.

It should be noted that the superabsorbent polymer is more prone to swelling in both end regions in the longitudinal direction, i.e. the rear and front portions of the diaper 1. Therefore, in these two end regions, the superabsorbent polymer arrangement region PR is more apt to widen toward both sides in the width direction and become thicker in the thickness direction (T4 b '> T4 c') during the water absorption. However, in the rear portion and the front portion, the problem that both side portions in the width direction of the absorbent core 41 interfere with the legs (groins) of the wearer is less likely to occur. Further, the uneven shape of the wearer's body is smaller in the rear and front portions than in the crotch portion, and therefore, even if the thickness of the absorbent core 41 is increased, the fit to the body is less likely to deteriorate, and the shape is less likely to be distorted. This enables both good water absorption and good fit in the crotch portion.

Further, with regard to the superabsorbent polymer arrangement region PR, it has been described that the width WPR1 at the central portion in the longitudinal direction is narrower than the width WPR2 at both end portions in the longitudinal direction. However, it is desirable that the width of the superabsorbent polymer arrangement region PR widens outwardly from the central portion in the longitudinal direction in an arcuate manner, as shown in fig. 2. In other words, it is desirable that in the center portion (crotch portion 1 b) in the longitudinal direction, the boundary between the superabsorbent polymer arrangement region PR and the connecting region BR is curved (parabolic), so that the boundary narrows inwardly in the width direction in the direction from the longitudinal outer side toward the longitudinal center. In such a configuration, both side portions in the width direction of the absorbent core 41 in the crotch portion 1b are more likely to follow the shape of the wearer's legs and fit the groin. In addition, even in the case where the absorbent core 41 is sandwiched between the legs of the wearer, shape-shifting of the absorbent core 41 is less likely to occur.

Further, the absorbent core 41 of the present embodiment is divided into a plurality of layers, and each layer is arranged in a state sandwiched between sheet-like members from both sides in the thickness direction. In fig. 3 and the like, the absorbent core 41 is divided into a skin-side core layer 411 and a non-skin-side core layer 412. The skin-side core layer 411 is sandwiched between the first core wrap sheet 421 and the intermediate sheet 43 in the thickness direction, and the non-skin-side core layer 412 is sandwiched between the intermediate sheet 43 and the second core wrap sheet 422 in the thickness direction. As described above, the absorbent core 41 includes a plurality of layers, which makes it possible to reduce the thickness of each layer. This increases the flexibility of the absorbent core 41, making the diaper more prone to conform to the uneven shape of the wearer's body. Further, each core layer is sandwiched between the sheet-like members, which makes the positions of the superabsorbent polymer particles arranged in each core layer less likely to move, so that shape-shifting of the absorbent core (each core layer) is less likely to occur. Further, when the superabsorbent polymer particles absorb moisture and have expanded, the amount of expansion of the volume of each core layer is limited, which makes it possible to suppress excessive expansion of the core layer and makes it difficult for the sheet-like members (the core wrap sheet 42 and the intermediate layer sheet 43) covering the core layer to break.

Further, as shown in fig. 3 and the like, the intermediate sheet 43 provided between the skin-side core layer 411 and the non-skin-side core layer 412 in the thickness direction is connected with the core wrap sheet 42 (421, 422) in the connection region BR outside the absorbent core 41 (411, 412) in the width direction. Therefore, at both end portions in the width direction, the intermediate layer sheet 43 is reliably fixed between the

core wrap sheets

421 and 422, and therefore, even in the case where the superabsorbent polymer particles absorb moisture and have expanded, the skin-side core layer 411 and the non-skin-side core layer 412 can be stably fixed by the intermediate layer sheet 43. This suppresses the shape of the core layers 411 and 412 from being deformed when the absorbent core 41 absorbs water, making it easier for the absorbent main body 4 to maintain an advantageous fit.

Further, in the absorbent main body 4 of the present embodiment, it is desirable that the fiber density of the intermediate layer sheet 43 is smaller than that of the core wrap sheet 42 (421, 422). In other words, it is desirable that the average value of the inter-fiber distances of the nonwoven fabric sheets or the like constituting the intermediate sheet 43 is larger than the average value of the inter-fiber distances of the nonwoven fabric sheets or the like constituting the core wrap sheets 42 (421, 422). In such a configuration, the probability of movement of the superabsorbent polymer (SAP) particles in the thickness direction through the inter-fiber spaces of the core wrap sheet 42 can be made lower than the probability of movement of the superabsorbent polymer (SAP) particles in the thickness direction through the inter-fiber spaces of the intermediate layer sheet 43. That is, the superabsorbent polymer particles are made to pass through the intermediate layer sheet 43 more easily and move to the other side in the thickness direction, rather than from the superabsorbent polymer arrangement region PR to outside the core wrap sheet 42 (outside the absorbent body 4). This makes it easier to suppress leakage of superabsorbent polymer particles to the outside of the absorbent body 4.

In particular, an average density of 50.4g/m for the intermediate layer 43 is desired ³ Or less and the average density of the core wrap sheet 42 is 89.5g/m ³ Or larger. FIG. 6 is a graph showing superabsorbent polymer particles (SAP) versus sheetTable of experimental results of permeability of the shape member. In the experiment, first, samples 1 to 9 were prepared by cutting nine nonwoven fabric sheets having different densities into predetermined sizes (120 mm×120 mm), and the weight of each sample (weight a in fig. 6) was measured. Next, superabsorbent polymer particles (average particle diameter: 300 to 400 μm) were uniformly dispersed on each of the samples 1 to 9 placed on the horizontal plane in a region of 100 mm×100 mm, and then the samples were placed for a predetermined time (for example, 1 minute). Next, the samples are turned over in air, and the superabsorbent polymer particles attached to the surface of each sample are allowed to fall by placing the samples for a predetermined time (e.g., 1 minute). Finally, the weight of each sample (weight B in fig. 6) was measured again, and the increased weight was calculated, so that the amount of superabsorbent polymer remaining in each sample could be obtained. Thus, the proportion of superabsorbent polymer that has entered and entangled between the fibers of each sample relative to 1 g of superabsorbent polymer was calculated as the entanglement proportion of superabsorbent polymer ((weight B-weight a)/1.0 g).

The experimental results showed that in samples 1 to 7 (having a density of 209.1 to 89.5g/m ³ ) The superabsorbent polymers (SAP) in these samples had entanglement ratios of 0.2% to 2.8%, and the superabsorbent polymers in these samples were less likely to be entangled and entered between the fibers of the nonwoven sheet. That is, it is apparent that the superabsorbent polymer is less likely to move in the thickness direction relative to the nonwoven fabric sheet. On the other hand, it is evident that in samples 8 and 9 (density 50.4 to 46.1g/m ³ ) In which the entanglement ratio of the superabsorbent polymer (SAP) is 22.5% or more, about one quarter of the dispersed superabsorbent polymer enters the spaces between the fibers of the nonwoven sheet and is entangled. That is, it is apparent that the superabsorbent polymer is relatively easy to move in the thickness direction with respect to the nonwoven fabric sheet.

Therefore, in the absorbent main body 4 of the present embodiment, the density of the intermediate sheet 43 is set to 50.4g/m ³ Or smaller, so that the superabsorbent polymer is more likely to migrate between the fibers of the intermediate ply 43. On the other hand, the core material is wrapped around the sheet 42The degree was set to 89.5g/m ³ Or higher, making the superabsorbent polymer less prone to migration between the fibers of the core wrap sheet 42. This makes it easier to prevent the superabsorbent polymer from passing through the core wrap sheet 42 and falling outside the absorbent body 4.

In addition, in the skin-side core layer 411 of the absorbent core 41, a low basis weight region L411 is provided. In the present embodiment, the low weight per unit area L411 has zero weight per unit area, and is formed in a so-called slit shape. Therefore, when the diaper 1 is put on, the absorbent core 41 is folded in the portion of the low basis weight region L411 and is easily deformed along the uneven shape of the wearer's body. That is, the low basis weight region L411 functions as a folding guide portion for folding and deforming the absorbent core 41. It should be noted that in the region where the low basis weight region L411 is provided, the first core wrap sheet 421 and the intermediate layer sheet 43 are connected to each other in the thickness direction (see fig. 3A and the like). Therefore, the superabsorbent polymer constituting the skin-side core layer 411 is fixed in a state reliably surrounded by the first core wrap sheet 421 and the intermediate layer sheet 43 on both sides in the width direction of the low basis weight region L411 (slit). Therefore, even when the slit having a zero basis weight is provided, the shape of the absorbent core 41 (the skin-side core layer 411) is less likely to be deformed, and the deterioration of the fit of the absorbent main body 4 is suppressed.

Further, at this time, it is desirable that the length (width) WL411 in the width direction of the low weight-per-area region L411 (slit) is smaller than the maximum value of the length (width) WBR1 in the width direction of the connection region BR (WL 411 < WBR 1) at the central portion in the longitudinal direction. In this case, the area of the portion where the first core wrap sheet 421 and the intermediate layer sheet 43 are connected to each other in the low basis weight region L411 is smaller than the area of the portion where the first core wrap sheet 421 and the intermediate layer sheet 43 are connected to each other in the connection region BR. That is, the connection strength between the first core wrap sheet 421 and the intermediate layer sheet 43 in the low basis weight region L411 is weaker than the connection strength between the first core wrap sheet 421 and the intermediate layer sheet 43 in the connection region BR. In such a configuration, as shown in fig. 4A and 4B, when the absorbent core 41 (skin-side core layer 411) absorbs moisture and has swelled, the connection between the first core wrap sheet 421 and the intermediate layer sheet 43 in the low basis weight region L411 is liable to peel before the connection in the connection region BR peels off. Therefore, in the central portion in the width direction of the absorbent main body 4, the space surrounded by the first core wrap sheet 421 and the intermediate sheet 43 becomes wider, which makes the expansion of the superabsorbent polymer included in the skin-side core layer 411 less prone to be hindered. Furthermore, the force pulling the connection region BR is less likely to act even in the case of swelling of the superabsorbent polymer due to the widening of the space. This suppresses leakage of the superabsorbent polymer out of the absorbent body 4 and shape-shifting of the absorbent core 41.

Further, it is desirable that the thickness T4c 'of the absorbent body 4 when the superabsorbent polymer absorbs moisture and swells to a saturated state is smaller than the maximum value WBR1 of the width of the connection region BR (T4 c' < WBR 1) at the central portion in the longitudinal direction. In such a configuration, a sufficiently large connecting region can be ensured in the connecting region BR of the crotch portion 1b, and even in the case where the superabsorbent polymer swells, the thickness of the absorbent main body 4 can be prevented from becoming excessively thick. Therefore, the connection of the core wrap sheet 42 is less likely to be peeled off, and the shape of the absorbent main body 4 can be suppressed from being deformed.

Further, in the absorbent main body 4, when the superabsorbent polymer absorbs moisture and has swelled, at least a part of the connection region BR is peeled off at both end portions in the longitudinal direction. In the present embodiment, as shown in fig. 5B, when the superabsorbent polymer has been expanded, the connection between the first core wrap sheet 421 and the intermediate layer sheet 43 in the connection region BR becomes more easily peeled off. Accordingly, the space surrounded by the first core wrap sheet 421 and the intermediate sheet 43 becomes wider, which makes the expansion of the superabsorbent polymer less susceptible to being hindered. This makes it easier for the water absorption properties of the superabsorbent polymer to be sufficiently exhibited, and the water absorption properties of the entire absorbent core 41 can be improved.

Further, when viewed in the thickness direction, the folded-back portion 421f of the second core wrap sheet 422 and the first core wrap sheet 421 has an overlapped portion, and in at least a part of the overlapped portion, the folded-back portion 421f and the second core wrap sheet 422 are connected to each other (see fig. 3 and the like). As a result, the first core wrap sheet 421 and the second core wrap sheet 422 are connected to each other in a state of containing the absorbent core 41, and the entire absorbent core 41 is completely covered with the core wrap sheet 42. This suppresses leakage of the superabsorbent polymer particles included in the absorbent core 41 to the outside of the core wrap sheet 42, and also suppresses deterioration of the water absorbency of the absorbent body 4 and occurrence of shape failure of the absorbent body 4.

Further, in such a configuration, it is desirable that the length (width) WBRf in the width direction of the portion where the folded-back portion 421f of the first core wrap sheet 421 and the second core wrap sheet 422 are connected to each other (see fig. 3A) is larger than the length (width) WL411 in the width direction of the slit (low basis weight region L411) provided in the skin-side core layer 411 (WBRf > WL 411). As described above, in the state before the superabsorbent polymer absorbs moisture and swells, the first core wrap sheet 421 and the intermediate layer sheet 43 are connected to each other in the portion of the skin-side core layer 411 where the slit L411 is provided. Therefore, in the case of WBRf > WL411, the connection strength (connection area) between the folded-back portion 421f of the first core wrap sheet 421 and the second core wrap sheet 422 is greater than the connection strength (connection area) of the first core wrap sheet 421 and the intermediate sheet 43 in the slit L411.

From this state, when the superabsorbent polymer absorbs moisture and has swelled, the connecting portion of the first core wrap sheet 421 and the intermediate layer sheet 43 in the slit L411 is more easily peeled off before the connecting portion between the folded-back portion 421f and the second core wrap sheet 422 is peeled off. Thus, the space between the first core wrap sheet 421 and the intermediate sheet 43 becomes wider, making the superabsorbent polymer more susceptible to swelling. That is, even in the case where the space between the first core wrap sheet 421 and the intermediate layer sheet 43 is widened and the volume thereof is increased due to the expansion of the superabsorbent polymer, the tensile force acting on the core wrap sheet 42 is small. Therefore, the force acting on the connection portion between the folded-back portion 421f and the second core wrap sheet 422 (the force of pulling apart the connection portion) becomes weak, which makes the connection portion between the folded-back portion 421f and the second core wrap sheet 422 less prone to be peeled off. This may make it easier to further suppress the occurrence of leakage of superabsorbent polymer particles out of the absorbent body 4 and shape-shifting.

Modified examples

The absorbent main body 4 of the diaper 1 can be deformed in the following manner. Fig. 7 is a plan view of the absorbent main body 4 of the modified example in a stretched state. Fig. 8A is a schematic cross-sectional view of the absorbent body 4 taken along line C-C shown in fig. 7. Fig. 8B is a schematic cross-sectional view of the absorbent body 4 taken along line D-D shown in fig. 7.

The basic construction of the absorbent main body 4 according to this modified example is substantially the same as that of the absorbent main body 4 described in fig. 2. However, in this modified example, the shape of the non-skin-side core layer 412 in the absorbent core 41 is different. In particular, the width of the non-skin-side core layer 412 in the modified example is wider than the width of the non-skin-side core layer 412 in fig. 2, and the low basis weight region L412 is provided in the non-skin-side core layer 412. Widening the width of the non-skin side core layer 412 increases the amount of superabsorbent polymer disposed, which can increase the water absorption of the absorbent core 41. In addition, providing the low basis weight region L412 in the non-skin-side core layer 412 prevents the stiffness of the non-skin-side core layer 412 from being excessively high, so that the absorbent core 41 (the non-skin-side core layer 412) can be flexibly deformed according to the body shape of the wearer when the diaper 1 is put on. It should be noted that the unit area weights of the low unit area weight region L411 and the low unit area weight region L412 may be different from each other. For example, in the low basis weight region L411 and the low basis weight region L412, one may be formed in a slit shape (basis weight is zero), and the other may be formed in a non-slit shape.

Further, two low basis weight regions L412 are provided in the non-skin-side core layer 412, and it is desirable to arrange the low basis weight regions L412 at positions offset in the width direction with respect to the low basis weight regions L411 provided in the skin-side core layer 411 (see fig. 8A and the like). In the case where the low basis weight region L411 on the skin side and the low basis weight region L412 on the non-skin side are disposed to overlap each other in the width direction, there is a risk that when the absorbent core 41 absorbs moisture (such as urine), the moisture excessively permeates the low basis weight regions L411 and L412 in the thickness direction and easily leaks to the non-skin side of the absorbent main body 4. In the present modified example, since the positions of the low basis weight region L411 and the low basis weight region L412 are shifted in the width direction, leakage of moisture to the non-skin side is more easily suppressed.

In the absorbent main body 4 as in the modified example, the width of the superabsorbent polymer arrangement region PR is limited by a connection region BR of the connection portion of the core wrap sheet 42 (intermediate sheet 43) which is located outside in the width direction of the superabsorbent polymer arrangement region PR in which the superabsorbent polymer is arranged. Therefore, the fit of the crotch portion can be improved while suppressing the shape of the absorbent main body 4 from being deformed. Further, at least the skin-side core layer 411 has a so-called narrow shape in which the width of both end portions in the longitudinal direction is wide and the width of the center portion in the longitudinal direction is narrow, which makes it possible to improve the fit of the crotch portion and enhance the water absorption of the entire absorbent main body.

Other embodiments

Although the above-described embodiments of the present invention have been described, the above-described embodiments are for the convenience of understanding the present invention, and are not to be construed as limiting the explanation of the present invention. Further, it is needless to say that the present invention can be modified or improved without departing from the gist thereof, and the present invention includes equivalents thereof.

List of reference numerals

1: bonded disposable diapers (absorbent articles),

1a: first waist portion, 1b: crotch portion, 1c: the second waist portion is provided with a pair of waist portions,

2: the top sheet is provided with a plurality of layers,

3: the back-film is provided with a back-film,

4: absorbent body, 4eo: the outer end of the inner tube is provided with a groove,

5: the outer sheet is provided with a pair of side panels,

6: the elastic members of the leg portions,

10: fixing adhesive tape, 11: a base material, 12: the hook sheet is provided with a hook plate,

13: rear side flap, 14: the front side flap is provided with a front side flap,

20: isolation cuffs, 21: barrier cuff sheet, 22: an elastic member for the isolation cuff,

41: absorbent core, 411: skin side core, 412: a non-skin side core layer,

42 the core material is wrapped by the sheet,

421: first core wrap sheet, 421f: the folded-back portion is formed in such a manner that,

422: the second core material is wrapped on the sheet,

43: the intermediate layer sheet is provided with a plurality of layers,

PR: the superabsorbent polymer placement area(s),

BR: the connection region is provided with a connecting region,

l411: low basis weight area (slit), L412: low weight area per unit area (slit)

Claims

1. An absorbent article having a longitudinal direction, a width direction, and a thickness direction that are orthogonal to each other, the absorbent article comprising:

an absorbent body comprising an absorbent core and a core wrap sheet, the core wrap sheet covering the absorbent core,

the absorbent core comprising a superabsorbent polymer in an amount of 70% or more of the mass of the absorbent core,

the absorbent body has superabsorbent polymer placement areas in which superabsorbent polymers are disposed,

the absorbent body has a connection region at a central portion in the longitudinal direction and outside the superabsorbent polymer arrangement region in the width direction, the connection region being a region in which inner surfaces in the thickness direction of the core wrap sheet are connected to each other in a state in which additional sheet-like members are interposed between the inner surfaces or in a state in which no additional sheet-like members are present,

wherein the absorbent core comprises: a skin-side core layer provided on the skin side in the thickness direction, and a non-skin-side core layer provided on the non-skin side with respect to the skin-side core layer, and each of the skin-side core layer and the non-skin-side core layer is sandwiched between the sheet-like members from both sides in the thickness direction,

Wherein the absorbent article further comprises: an intermediate layer sheet located between the skin-side core layer and the non-skin-side core layer in the thickness direction; and a portion in which the intermediate layer sheet and the core wrap sheet are connected to each other, the portion being located outside in the width direction with respect to the skin-side core layer and the non-skin-side core layer,

wherein the fiber density of the core wrap sheet is greater than the fiber density of the intermediate ply.

2. The absorbent article according to claim 1, wherein a width of the connection region at the central portion in the longitudinal direction is larger than a width of the connection region at both end portions in the longitudinal direction.

3. The absorbent article according to claim 1 or 2, wherein a boundary between the superabsorbent polymer arrangement area and the connection area has a curved shape that narrows inwardly in the width direction from an outer position in the longitudinal direction to a center position in the longitudinal direction.

4. The absorbent article according to claim 1, wherein at least one of the skin-side core layer and the non-skin-side core layer has a slit in which a weight per unit area of the superabsorbent polymer is zero, the slit extends in the longitudinal direction, and

The absorbent article further includes a portion that is located in the slit and in which the core wrap sheet and the intermediate layer sheet are connected to each other in the thickness direction.

5. The absorbent article according to claim 4, wherein the width of the slit is smaller than the maximum value of the width of the connecting region at the central portion in the longitudinal direction.

6. The absorbent article according to claim 1, wherein at the central portion in the longitudinal direction, the thickness of the absorbent body when the superabsorbent polymer absorbs moisture and swells to a saturated state is smaller than the maximum value of the width of the connection region.

7. The absorbent article according to claim 1, wherein at least a part of the connecting region is peeled off at both end portions in the longitudinal direction when the superabsorbent polymer absorbs moisture to reach a saturated state.

8. The absorbent article according to claim 1, wherein the core wrap sheet comprises a first core wrap sheet and a second core wrap sheet, the first core wrap sheet being a sheet covered with a superabsorbent polymer from one side in a thickness direction, the second core wrap sheet being a sheet covered with a superabsorbent polymer from the other side in the thickness direction,

The first core wrap sheet has a folded-back portion in which an outer end of the first core wrap sheet in the width direction of the absorbent main body is folded back inward,

the folded-back portion and the second core wrap sheet have an overlapping portion in which the folded-back portion and the second core wrap sheet overlap when viewed in the thickness direction, and

in at least a part of the overlapped portion, the folded-back portion and the second core wrap sheet are connected to each other.

9. The absorbent article of claim 8, wherein,

at least one of the skin-side core layer and the non-skin-side core layer has a slit in which the weight per unit area of the superabsorbent polymer is zero, the slit extending in the longitudinal direction,

in the slit, the intermediate sheet and the core wrap sheet are connected to each other, and

wherein the width of the portion where the folded-back portion and the second core wrap sheet are connected to each other is larger than the width of the slit.

10. The absorbent article of claim 1, wherein the absorbent core does not include wood pulp fibers.