Absorbent article

Abstract

To provide an absorbent article suppressing decline in wearing comfort.SOLUTION: An absorbent article comprises: an absorber including an SAP layer formed of a group of particles of SAP being the superabsorbent polymer, core wrap sheets sandwiching the SAP layer from above and below, and adhesive parts interposed between the upper / lower core wrap sheets with a predetermined width at both ends in a longitudinal direction and bonding the upper / lower core wrap sheets by entangling the SAP particles with respective fibrous materials of the upper / lower core wrap sheets by pressure due to cutting; a skin surface-side sheet disposed on a skin surface side of the absorber and fixed to the absorber at least on an end side in the longitudinal direction; a non-skin surface-side sheet disposed on a non-skin surface side of the absorber and fixed to the absorber at least on the end side in the longitudinal direction; and a concavo-convex part provided at least on the skin surface side sheet so as to span the end in the longitudinal direction of the absorber in the longitudinal direction and where concave portions and convex portions are alternately arranged along a with direction.SELECTED DRAWING: Figure 10

Description

[Technical field]

[0001] The present invention relates to an absorbent article. [Background technology]

[0002] 2. Description of the Related Art Absorbent articles such as diapers are known (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-19728 Summary of the Invention [Problem to be solved by the invention]

[0004] The absorbent article has an absorbent body. The absorbent body is sealed inside the absorbent article, and is generally shorter in length than the absorbent article. For this reason, a step is generated at the end of the absorbent body in the absorbent article. If this step comes into contact with the skin of a wearer, the wearer feels the hardness of the step, which reduces the comfort of wearing the absorbent article.

[0005] An object of the present invention is to provide an absorbent article that suppresses deterioration in wearing comfort. [Means for solving the problem]

[0006] An absorbent article according to one aspect of the present invention comprises: A length along a longitudinal direction corresponding to the front-to-back direction of the wearer; A length along a width direction perpendicular to the longitudinal direction; an absorbent body having an SAP layer formed of particles of SAP, which is a highly absorbent polymer; core wrap sheets sandwiching the SAP layer from above and below; and adhesive parts interposed between the upper and lower core wrap sheets at both ends in the longitudinal direction with a predetermined width, and bonding the upper and lower core wrap sheets together by pressing the SAP particles to become entangled with the fibrous material of each of the upper and lower core wrap sheets when pressed by cutting; a skin-facing sheet disposed on the skin-facing side of the absorbent body and fixed to the absorbent body at least at the end side in the longitudinal direction; a non-skin-facing sheet disposed on the non-skin-facing side of the absorbent body and fixed to the absorbent body at least at the end side in the longitudinal direction; a concave-convex portion provided on at least the skin-facing sheet so as to span the longitudinal end of the absorbent body in the longitudinal direction, the concave portion and the convex portion being arranged alternately along the width direction; Equipped with. Effect of the Invention

[0007] According to the present invention, it is possible to suppress deterioration in wearing comfort. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view of a diaper according to an embodiment. [Diagram 2] FIG. 2 is an exploded perspective view of the diaper according to the embodiment. [Diagram 3] FIG. 3 is a cross-sectional view of the diaper according to the embodiment taken along the width direction at the center in the longitudinal direction. [Figure 4] FIG. 4 is a plan view of the diaper according to the embodiment in a stretched state. [Diagram 5] FIG. 5 is a cross-sectional view of the absorbent core of the diaper according to the embodiment cut in the width direction. [Figure 6] FIG. 6 is a cross-sectional view of the absorbent core of the diaper according to the embodiment cut along the longitudinal direction. [Figure 7] FIG. 7 is a first enlarged view of the vicinity of the boundary between the SAP sheet and the SAP particles when pressure is applied. [Figure 8] FIG. 8 is a second enlarged view of the vicinity of the boundary between the SAP sheet and the SAP particles when pressure is applied. [Figure 9] FIG. 9 is a cross-sectional view of the diaper according to the embodiment, taken along the longitudinal direction at the center in the width direction. [Figure 10] FIG. 10 is a plan view of the diaper according to the embodiment in a stretched state. [Figure 11] FIG. 11 is a plan view of a diaper according to a modified example in an expanded state. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, absorbent articles according to embodiments of the present invention will be described with reference to the drawings. Note that the configurations of the following embodiments are merely examples, and the present invention is not limited to the configurations of these embodiments.

[0010] <Embodiment> In this embodiment, the longitudinal direction of a tape-type disposable diaper (an example of an "absorbent article" in the present application, hereinafter simply referred to as a "diaper") is the direction connecting the front body arranged opposite the wearer's abdomen and the rear body arranged opposite the wearer's back. Between the front body (one side in the longitudinal direction) and the rear body (the other side in the longitudinal direction) (the center in the longitudinal direction), a crotch portion arranged under the wearer's crotch (opposed to the crotch). In addition, when the diaper is worn by a wearer (hereinafter abbreviated as "worn state"), the side facing the wearer's skin (the inner side when worn) is the skin-facing side, and the opposite side to the skin-facing side (the outer side when worn) is the non-skin-facing side. Furthermore, the direction connecting the skin-facing side and the non-skin-facing side is the thickness direction, and the direction perpendicular to both the longitudinal direction and the thickness direction is the width direction. In addition, the view from the thickness direction is the planar view. Additionally, the front, back, left and right of the diaper 1 refer to the directions that correspond to the front, back, left and right of the wearer when the diaper 1 is worn by the wearer. For example, the left and right direction in this application refers to the directions that correspond to the left and right of the wearer when the diaper 1 is worn by the wearer, and the front and back direction in this application refers to the directions that correspond to the front and back of the wearer when the diaper 1 is worn by the wearer.

[0011] FIG. 1 is a perspective view of a diaper according to an embodiment. The diaper 1 has a length along the longitudinal direction and a length along the width direction perpendicular to the longitudinal direction. The diaper 1 has a crotch region 1B, which is a region corresponding to the crotch of the wearer covering the pubic area when worn, a front body region 1F, which is located in front of the crotch region 1B and corresponds to the front body of the wearer, and a back body region 1R, which is located behind the crotch region 1B and corresponds to the back body of the wearer. Tapes 2L and 2R that can be attached to a front patch 2F provided on the non-wearer side surface of the front body region 1F are provided on both left and right edges of the back body region 1R. When the tapes 2L and 2R are attached to the front patch 2F with the front body region 1F arranged on the wearer's abdomen and the back body region 1R arranged on the wearer's back, the diaper 1 is fixed to the wearer's body in a state of surrounding the wearer's waist circumference and thighs. Since the diaper 1 is fixed to the wearer's body in this manner, the wearer can stand and walk around while wearing the diaper 1.

[0012] In the diaper 1, an absorbent capable of absorbing and retaining liquid is disposed mainly in the crotch region 1B. In addition, in order to prevent the formation of gaps between the diaper 1 and the wearer's skin that could serve as a liquid outflow path, the diaper 1 is provided with leg gathers 3AL, 3AR in areas surrounding the wearer's legs (thighs), and three-dimensional gathers 3BL, 3BR are provided on the inner side of the leg gathers 3AL, 3AR in the width direction of the diaper 1, and a waist gather 3R is provided in an area surrounding the wearer's abdominal circumference. The BL, 3BR and waist gathers 3R are brought into close contact with the wearer's skin by the contraction force (elastic force) of the stretchable members. Therefore, liquid discharged from the wearer's private parts is absorbed into the absorbent body of the diaper 1 without leaking out of the diaper 1. Note that the stretchable members can be appropriately selected from rubber threads (rubber threads) or rubber strips.

[0013] FIG. 2 is an exploded perspective view of the diaper 1. FIG. 3 is a cross-sectional view of the diaper 1 when not worn, cut in the width direction at the center in the longitudinal direction. FIG. 4 is a plan view of the diaper 1 when stretched, as viewed from the skin-facing side. Note that the elastic members 4C, 4SL, and 4SR are omitted in FIG. 4. The diaper 1 has a cover sheet 4 that forms an outer surface when worn. The cover sheet 4 is a sheet-like member having a substantially rectangular appearance with constrictions 4KL and 4KR at the portions corresponding to the long sides, and forms the exterior surface of the diaper 1. The constrictions 4KL and 4KR are provided at the portions where the wearer's thighs are located (the leg-surrounding regions 10L and 10R shown in FIG. 4). The cover sheet 4 is provided to reinforce the back sheet 5 described later and to improve the feel, and may be made of a nonwoven fabric made of a liquid-impermeable thermoplastic resin to suppress leakage of excrement, for example. Examples of liquid-impermeable thermoplastic resins include polyethylene (PE) and polypropylene (PP). The cover sheet 4 is not limited to a single-layer structure, and may be a multi-layer (two-layer) structure having an inner cover sheet and an outer cover sheet. The cover sheet 4 forms the outer peripheral shape (outer shape) of the absorbent pad 1. The cover sheet 4 forms an exterior surface where the front body region 1F, the crotch region 1B, and the back body region 1R are connected.

[0014] The diaper 1 has a back sheet 5 (an example of the "non-skin-facing sheet" of the present disclosure), an absorbent 6, and a top sheet 7 (an example of the "skin-facing sheet" of the present disclosure) which are laminated in this order on the skin-facing side of the cover sheet 4. The back sheet 5, the absorbent 6, and the top sheet 7 are all sheet-like members having a substantially rectangular appearance, and are laminated in this order on the cover sheet 4 with their longitudinal directions coinciding with the longitudinal direction of the cover sheet 4. The back sheet 5, like the cover sheet 4, is a sheet formed from a water-impermeable thermoplastic resin material to suppress leakage of excrement. The back sheet 5 is preferably made of a material that also has moisture permeability to suppress stuffiness when worn. The top sheet 7 is a sheet-like member disposed on the skin-facing side of the wearer. The top sheet 7 is liquid-permeable in part or in its entirety. Therefore, when the diaper 1 is worn, liquid excreted from the wearer passes through the top sheet 7, which may come into contact with the wearer's skin, into the absorbent 6, and is absorbed therein. For example, a woven fabric, a nonwoven fabric, or a porous film can be used as the material for the top sheet 7. The top sheet 7 may be hydrophilic. The basis weight of the top sheet 7 is, for example, 16 to 35 g / m 2 It is.

[0015] The back sheet 5, the absorbent 6, and the top sheet 7 all extend from the front body region 1F to the rear body region 1R. Therefore, when the cover sheet 4, in which the back sheet 5, the absorbent 6, and the top sheet 7 are laminated, covers the wearer's private parts, the longitudinal ends of the back sheet 5, the absorbent 6, and the top sheet 7 are located on the wearer's ventral side and back side. In other words, the wearer's private parts are covered by the absorbent 6 from the ventral side to the back side. Therefore, whether the wearer is in a ventral or back-down position when excreting liquid, the excreted liquid comes into contact with the absorbent 6 via the top sheet 7. The top sheet 7 and the back sheet 5 are longer in the longitudinal direction than the absorbent 6, and extend to the ends of the front body region 1F and the rear body region 1R of the diaper 1.

[0016] The diaper 1 further includes elastic members 4SL, 4SR for forming the leg gathers 3AL, 3AR described above, which are provided between the cover sheet 4 and the back sheet 5 so as to stretch in the longitudinal direction of the diaper 1. An appropriate number of the elastic members 4SL, 4SR (three in this embodiment) are provided depending on the elastic force (contractile force) required for the design of the diaper 1. As shown in Fig. 4, the leg gathers 3AL, 3AR are arranged to include the leg surrounding regions at both widthwise ends of the crotch region 1B where the wearer's thighs are located. The leg surrounding regions 10L, 10R are arranged at both widthwise ends of the crotch region 1B. The leg gathers 3AL, 3AR are formed in the areas where the stretchable members 4SL, 4SR are arranged.

[0017] The diaper 1 also has long, narrow, strip-shaped side sheets 8L, 8R (a pair of leak-proof sheets). The side sheets 8L, 8R are non-permeable (liquid-impermeable) sheets provided on the long sides of the top sheet 7. Like the cover sheet 4, the side sheets 8L, 8R have constrictions 8KL, 8KR at the locations where the wearer's thighs are located (leg-surrounding regions 10L, 10R shown in FIG. 4). The side sheets 8L, 8R have elastic members 8EL, 8ER arranged along the longitudinal direction of the diaper 1 to form three-dimensional gathers 3BL, 3BR. When the diaper 1 is worn, i.e., when the diaper 1 is U-shaped in side view, the side sheets 8L, 8R are pulled in the longitudinal direction by the contractile force of the elastic members 8EL, 8ER and rise from the top sheet 7 to form three-dimensional gathers 3BL, 3BR that prevent liquid from leaking out.

[0018] The cover sheet 4 is provided with elastic members 4C, which prevent a gap from being formed between the diaper 1 and the wearer's abdominal circumference, on the inner side in the width direction of the diaper 1 than the elastic members 4SL, 4SR and along the longitudinal direction of the diaper 1. The elastic members 4C are provided according to the elastic force (contractile force) and other factors required for the design of the diaper 1.

[0019] The elastic member 9ER (an example of the "contractile member" of the present disclosure) for forming the waist gather 3R is disposed on the waist sheet 9R provided between the back sheet 5 and the top sheet 7 at a position further back than the end of the absorbent body 6. The waist sheet 9R is disposed between the top sheet 7 and the back sheet 5 at a position farther from the absorbent body 6 than the end of the rear body region 1R side of the absorbent body 6 on the tip side (the rear end side of the diaper 1), and is a sheet-like member extending wider in the width direction than the absorbent body 6. The waist sheet 9R is formed by laminating two nonwoven fabric sheets, and the elastic member 9ER is bonded between the two nonwoven fabric sheets in a stretched state in the width direction of the diaper 1. The elastic member 9ER is disposed on the waist sheet 9R with its longitudinal direction, which is the stretch direction, oriented in the left-right direction of the diaper 1. For this reason, the waist sheet 9R has contractibility in the width direction of the diaper 1, and functions as a strip-shaped elastic member together with the elastic member 9ER. When the tapes 2L, 2R provided on both the left and right sides of the waist sheet 9R are attached to the front patch 2F on the abdominal side of the wearer, the elastic member 9ER exerts a contractile force to fit the diaper 1 to the wearer and prevent the formation of a gap between the diaper 1 and the wearer's abdominal circumference.

[0020] A waist sheet 9F is provided between the back sheet 5 and the top sheet 7 at a position further to the ventral side than the end of the absorbent body 6. The waist sheet 9F is disposed between the top sheet 7 and the back sheet 5 at a position further away from the absorbent body 6 than the end of the front body region 1F side of the absorbent body 6 on the tip side (the front end side of the diaper 1), and is a sheet-like member that extends wider in the width direction than the absorbent body 6. The waist sheet 9F is formed by laminating two nonwoven fabric sheets, similar to the waist sheet 9R. Note that no elastic member is disposed in the waist sheet 9F, and therefore the waist sheet 9F does not have contractibility. Note that the basis weight of the waist sheets 9F and 9R is 7 to 10 g / m 2 It is.

[0021] In the present application, the state in which sheets are overlapped is not limited to a state in which the overlapping sheets are in full contact with each other, but includes a concept including a state in which the sheets are partially overlapping each other. In addition, the state in which sheets are bonded to each other includes a concept including a state in which another sheet is interposed between the sheets and the sheets are bonded to each other via the other sheet.

[0022] Next, the absorbent body 6 will be described. The absorbent body 6 according to this embodiment has a substantially rectangular shape. In the diaper 1 according to this embodiment, the absorbent core 6C is not made of pulp. That is, the absorbent body 6 does not contain pulp. The absorbent body 6 has a configuration in which the proportion of SAP is relatively high.

[0023] FIG. 5 is a cross-sectional view showing the absorbent body 6 extracted from the cross-sectional view of FIG. 3. The absorbent body 6 has an absorbent core 6C and a core wrap sheet 6W that wraps the absorbent core 6C. The core wrap sheet 6W is made of a sheet that has water permeability at least on the skin-facing side, and allows liquid that has passed through the top sheet 7 to flow into the absorbent core 6C. In this embodiment, the core wrap sheet 6W is made of two tissues. One of the two tissues is placed on the non-skin-facing side, folded into the widthwise end of the skin-facing side, and bonded to the other tissue placed on the skin-facing side, including the widthwise end of the skin-facing side. As a result, the core wrap sheet 6W covers the skin-facing side and non-skin-facing side of the absorbent core 6C to wrap the absorbent core 6C and prevent the absorbent core 6C from losing its shape. The core wrap sheet 6W may be made of a single sheet.

[0024] The absorbent core 6C has a layered structure in which, from the non-skin facing side, a flow guide layer 60A, a lower SAP layer 60B, a base layer 60C, an upper SAP layer 60D, and a diffusion layer 60E are laminated. The flow guide layer 60A and the diffusion layer 60E are formed of nonwoven fabric. The flow guide layer 60A has the function of diffusing urine throughout the entire absorbent core 6C on the non-skin facing side. The diffusion layer 60E has the function of diffusing urine throughout the entire absorbent core 6C on the skin facing side. In this embodiment, the flow guide layer 60A and the diffusion layer 60E have a basis weight of 45 g / m 2The flow guide layer 60A is formed of an air-laid nonwoven fabric. The thickness of the flow guide layer 60A is 300 to 700 μm.

[0025] The lower SAP layer 60B is formed by bonding a large number of SAP (Super Absorbent Polymer) particles to the skin-facing side of the flow guidance layer 60A with a hot melt adhesive. In this way, the lower SAP layer 60B, which is formed by containing SAP particles, which is a super absorbent polymer, is disposed on the skin-facing side of the flow guidance layer 60A. The upper SAP layer 60D is formed by bonding a large number of SAP particles to the non-skin-facing side of the diffusion layer 60E with a hot melt adhesive. In this way, the upper SAP layer 60D, which is formed by containing SAP particles, which is a super absorbent polymer, is disposed on the non-skin-facing side of the diffusion layer 60E. In this way, in this embodiment, two SAP layers are formed in the absorbent core.

[0026] In this embodiment, the SAP particles refer to a resin composition containing SAP in a granular form. The term "SAP-containing resin composition" as used herein includes both a composition consisting of SAP alone and a composition containing SAP as the main component and containing other substances to the extent that they do not adversely affect the water absorption. Examples of "other substances" include additives (such as surface modifiers added to make the particle surface hydrophobic) and unreacted monomers remaining during the synthesis of SAP.

[0027] The base layer 60C is disposed between the two SAP layers and is made of a bulky air-through nonwoven fabric. The base layer 60C diffuses liquids such as urine to the lower SAP layer 60B and the upper SAP layer 60D. The absorbent body 6 can absorb and retain liquids such as urine by the entire lower SAP layer 60B and upper SAP layer 60D.

[0028] When the absorbent core is made of pulp, the SAP particles become entangled with the pulp fibers and are less likely to fall off from the absorbent core. However, in this embodiment, the absorbent core 6C contains pulp in the flow guide layer 60A and diffusion layer 60E made of airlaid nonwoven fabric, but contains less pulp than in a typical absorbent core. In this embodiment, the SAP particles are in contact with the flow guide layer 60A, which is made of airlaid nonwoven fabric and contains pulp, and the diffusion layer 60E, which is also made of airlaid nonwoven fabric. In an absorbent body 6 having such a configuration, the SAP particles are less likely to become entangled with fibers and the like, and the SAP particles are more likely to fall off at the end sides of the absorbent body 6 in the width direction and length direction.

[0029] 6 is a cross-sectional view of the absorbent body 6 taken out of the diaper 1 and cut longitudinally at the center in the width direction. The absorbent core 6C is sandwiched between two core wrap sheets 6W at the upper side facing the skin and the lower side facing away from the skin, and has adhesive portions 61 at both ends in the longitudinal direction where the two core wrap sheets 6W are bonded together. The adhesive portions 61 bond the upper and lower core wrap sheets 6W together by entangling SAP particles with the fibrous material of each of the upper and lower core wrap sheets 6W.

[0030] The SAP particles in the SAP layers 60B, 60D are also bonded to the flow guide layer 60A and the diffusion layer 60E, but a number of SAP particles 62 have fallen off from the flow guide layer 60A and the diffusion layer 60E. When the continuous absorbent body is cut into single diapers with the fallen SAP particles 62 still interposed between the upper and lower core wrap sheets 6W before the formation of the adhesive portion 61, the pressure caused by the cutting causes the SAP particles 62 to become entangled with the fibrous material of the upper and lower core wrap sheets 6W. The principle of this adhesion will now be described.

[0031] When a predetermined pressure is applied to the upper and lower core wrap sheets 6W with a plurality of SAP particles 62 sandwiched between them, the SAP particles 62 corresponding to the pressurized portion to which the predetermined pressure is applied are pressurized and entangled with the fibrous members of each sheet, and as a result, the SAP particles 62 exert a binding force on the upper and lower core wrap sheets 6W, and the two sheets can be bonded together. Here, Figs. 7 and 8 show enlarged views of the vicinity of the boundary between each sheet and the SAP particles when the two sheets are bonded together in this manner. Figs. 7 and 8 are micrographs taken with a scanning electron microscope (SEM), with a magnification of 200 times in Fig. 7 and 500 times in Fig. 8. In both figures, a portion of the SAP particles entangled with the fibrous members of the sheets is circled and exemplarily extracted. In particular, in Fig. 8, it can be seen that the voids between the fibrous members of the sheets are also closed by the pressure applied to the fibrous members of the sheets on the roughly left side of the figure, and the SAP particles have entered therein. It is also considered that, depending on the predetermined pressure, the SAP particles are compressed and crushed or deformed, and become entangled with the fibrous members of both sheets, thereby realizing adhesion between the two sheets. Note that it is considered that the predetermined pressure varies depending on the type and particle size of SAP, the thickness of the SAP particles interposed between the upper and lower core wrap sheets 6W, the material of the core wrap sheet 6W, etc. In this embodiment, the adhesive part 61 is formed by utilizing adhesion by the SAP particles through pressure application at this predetermined pressure.

[0032] In the absorbent body 6, adhesive parts 61 are formed in the cut portions at both ends in the longitudinal direction along the width direction. The SAP that adheres the upper and lower core wrap sheets 6W to each other in the adhesive parts 61 is interposed between the core wrap sheets 6W at a predetermined width from the cut surface of the edge of the absorbent body 6, sealing the gap between the two sheets. This predetermined width is a width necessary for the SAP of the adhesive parts 61 to exert adhesive strength to such an extent that the core wrap sheet 6W can maintain the shape of a bag containing the absorbent core 6C including the SAP layers 60B and 60D, and is a width that is appropriately determined depending on the magnitude of the expected external force and the adhesive strength of the SAP.

[0033] 9 is a cross-sectional view of the diaper 1 when not being worn, taken along the longitudinal direction at the widthwise center. The waist sheets 9F, 9R are bonded at their skin-facing sides to the top sheet 7, and at their non-skin-facing sides to the back sheet 5. For example, a hot melt adhesive is used for this bonding.

[0034] The top sheet 7 is fixed to the absorbent body 6 by a hot melt adhesive (not shown) applied in a strap-like shape along the longitudinal direction of the absorbent body 6 and the diaper 1. The back sheet 5 is fixed to the absorbent body 6 by a hot melt adhesive (not shown) applied in a strap-like shape along the longitudinal direction of the absorbent body 6 and the diaper 1. The top sheet 7 and the back sheet 5 are fixed to the absorbent body 6 by a bolster adhesive (not shown). The top sheet 7 and the back sheet 5 are also bonded to the absorbent body 6 at both longitudinal end sides of the absorbent body 6. This fixes the absorbent body 6 to the top sheet 7 and the back sheet 5 at the longitudinal end sides, and prevents the absorbent body 6 from shifting out of position within the diaper 1.

[0035] The SAP particles in the lower SAP layer 60B are adhered to the flow guide layer 60A with a hot melt adhesive, but some SAP particles may peel off and fall off from the flow guide layer 60A. For this reason, the diaper 1 according to this embodiment may contain unfixed SAP particles. If the adhesion of the core wrap sheet 6W at the adhesive part 61 peels off, the SAP particles may leak out to the outside of the diaper 1. For example, if a gap is formed between the top sheet and the back sheet, the SAP particles that have fallen off from the absorbent body may spread to the longitudinal end side of the diaper and leak out from between the top sheet and the back sheet.

[0036] Therefore, the diaper 1 according to this embodiment includes waist sheets 9F, 9R arranged at the end side of the absorbent body 6 in the longitudinal direction. The top sheet 7 and the back sheet 5 are weakly bonded or non-bonded to each other at the end side of the absorbent body 6, i.e., between the absorbent body 6 and the waist sheets 9F, 9R. More specifically, the top sheet 7 and the back sheet 5 are weakly bonded or non-bonded in the areas D1 and D2 shown in FIG. 9. D1 is the distance between the absorbent body 6 and the waist sheet 9R on the side of the rear body region 1R. D2 is the distance between the absorbent body 6 and the waist sheet 9F on the side of the front body region 1F. The specific lengths of D1 and D2 are omitted. Here, the term "weakly bonded" refers to an adhesive strength that allows the sheets bonded to each other to be peeled off without tearing, and is an adhesive strength that is expected to cause the sheets to naturally peel off due to the action (for example, the contraction force of an elastic member) that occurs when the diaper 1 is worn. By making the top sheet 7 and the back sheet 5 non-bonded or weakly bonded in the regions D1 and D2, the SAP particles fall off the lower SAP layer 60B and the upper SAP layer 60D, enter between the top sheet 7 and the back sheet 5, and peel them off, forming a space (hereinafter sometimes referred to as the "SAP storage space") between the top sheet 7 and the back sheet 5, and the SAP particles can be stored in the SAP storage space. In addition, since the waist sheets 9F and 9R are arranged on the longitudinal end side of the SAP storage space, the SAP particles are prevented from moving toward the end side of the waist sheets 9F and 9R. Since the waist sheets 9F and 9R are bonded relatively strongly to the top sheet 7 and the back sheet 5, the SAP storage space is prevented from communicating with the outside of the diaper 1, and the leakage of the SAP particles to the outside can be prevented. Furthermore, since the waist sheets 9F, 9R are wider than the absorbent body 6, even if SAP particles that have leaked into the SAP storage space move in the width direction, the waist sheets 9F, 9R can suppress the leakage of the SAP particles.

[0037] In addition, in the region D2, when the top sheet 7 and the back sheet 5 are not bonded, no hot melt adhesive is applied between the top sheet 7 and the back sheet 5, and when the top sheet 7 and the back sheet 5 are weakly bonded, a small amount of hot melt adhesive is applied between the top sheet 7 and the back sheet 5, so that the region D2 has a relatively low rigidity and is easily folded. Here, when the hook portions of the tapes 2L and 2R in the worn state of the diaper 1 are attached to the loop portions of the front patch 2F and the front (abdominal) ends of the tapes 2L and 2R overlap with the region D2 in the thickness direction, the diaper 1 is easily folded toward the non-skin side in front of the front ends. In this way, when the top sheet 7 and the back sheet 5 in the worn state of the diaper 1 are folded toward the non-skin side in the region D2, the SAP particles can be blocked at the folded portion.

[0038] The waist sheets 9F, 9R have a thickness larger than the average particle size of the SAP particles. For example, the average particle size of the SAP particles is 350 μm, and the particle size is set to be 150 to 650 μm. The waist sheets 9F, 9R are thicker than the particle size of the SAP particles, for example. For example, the thickness is 0.8 mm or more. Even if SAP particles migrate into the SAP storage space, the SAP storage space is located between the absorbent body 6 and the waist sheets 9F, 9R, and therefore the thickness of the absorbent body 6 and the waist sheets 9F, 9R can prevent the SAP in the SAP storage space from coming into contact with the wearer's skin surface via the top sheet 7. This makes it possible for the diaper 1 to prevent the SAP particles that have migrated into the SAP storage space from imparting thickness or a foreign body sensation to the wearer.

[0039] Furthermore, when the distances D1, D2 between the absorbent body 6 and the waist sheets 9F, 9R are set to 10 mm or less, the skin of the wearer's abdomen and back is curved, so that the skin is unlikely to come into contact with the top sheet 7 above the SAP storage space, and the SAP does not give a foreign body sensation to the skin even when body pressure is applied to the diaper 1. By setting the absorbent body 6 and the waist sheets 9F, 9R to a thickness of 1 mm or more, the wearer's skin comes into contact with the absorbent body 6 and the waist sheets 9F, 9R, and the wearer's skin is prevented from coming into contact with the SAP in the SAP storage space. Therefore, the diaper 1 can prevent the wearer from feeling uncomfortable due to contact with SAP particles.

[0040] Moreover, each distance D1, D2 between the absorbent body 6 and the waist sheets 9F, 9R in the longitudinal direction of the diaper 1 is preferably at least twice the average particle size of the SAP particles. More preferably, each distance D1, D2 is at least 10 times the average particle size of the SAP particles. When the SAP particles fall off the lower SAP layer 60B and the upper SAP layer 60D and a space for storing SAP is formed between the top sheet 7 and the back sheet 5, by setting each distance between the absorbent body 6 and the waist sheets 9F, 9R as described above, it is possible to prevent the force of the SAP particles peeling the top sheet 7 and the back sheet 5 from acting on the adhesion between the waist sheets 9F, 9R and the top sheet 7 and the back sheet 5. Therefore, the diaper 1 can prevent the waist sheets 9F, 9R from peeling off the top sheet 7 and the back sheet 5, and suppress leakage of the SAP particles.

[0041] In addition, the waist sheet 9F on the front body region 1F side does not have contractility. Therefore, in the front body region 1F side, the core wrap sheet 6W is not subjected to a contraction force in the width direction, and the core wrap sheet 6W is prevented from opening in the thickness direction. In addition, when a contraction force is applied to the absorbent 6, the SAP particles are likely to fall off from the lower SAP layer 60B and the upper SAP layer 60D, but in the front body region 1F side, the absorbent 6 is not subjected to a contraction force, and the SAP particles are less likely to fall off.

[0042] The crotch region side of the waist sheet 9F and the back sheet 5 may be weakly bonded or not bonded at all. This forms a space for storing SAP between the crotch region side of the waist sheet 9F and the back sheet 5, and when SAP particles are stored in the space, the waist sheet 9F is disposed closer to the skin than the space, thereby reducing the contact with the skin (foreign body sensation) of the SAP particles in the space. As described above, the top sheet 7 and the back sheet 5 bend away from the skin in the region within D2 when worn, thereby further reducing the contact with the skin of the SAP particles in the space.

[0043] Next, the three-dimensional gathers 3BL and 3BR will be described with reference to FIG. As shown in Fig. 4, the three-dimensional gathers 3BL, 3BR formed by the side sheets 8L, 8R and the elastic members 8EL, 8ER are disposed along the widthwise ends of the top sheet 7 and extend in the longitudinal direction of the diaper 1. The side sheets 8L, 8R are joined to the widthwise ends of the top sheet 7 using a hot melt adhesive. The side sheets 8L, 8R are joined to the top sheet 7 with a hot melt adhesive HM (see Fig. 3) on the widthwise outer side of the fold-back lines 30L, 30R extending in the longitudinal direction. Outside the hot melt adhesive HM, the side sheets 8L, 8R are adhered to the cover sheet 4 with a hot melt adhesive. Inside the fold lines 30L, 30R, the side sheets 8L, 8R are not adhered to the top sheet 7. Therefore, when the diaper 1 is worn, the inside of the fold lines 30L, 30R of the side sheets 8L, 8R rise up against the skin due to the contractile force of the elastic members 8EL, 8ER provided on the side sheets 8L, 8R in a state in which the diaper 1 is stretched in the longitudinal direction, thereby forming three-dimensional gathers 3BL, 3BR.

[0044] When the three-dimensional gathers 3BL, 3BR are raised, the fixed parts 31L, 31R are formed as the longitudinal starting points of the raised gathers. In FIG. 4, the fixed parts 31L, 31R are illustrated as being filled in. The fixed parts 31L, 31R are formed on the inner side of the fold lines 30L, 30R in the width direction of the diaper 1, and on the longitudinal end side of the absorbent body 6. The fixed parts 31L, 31R are formed on both sides of the front body region 1F and the rear body region 1R, and each fixed part 31L, 31R is disposed across the absorbent body 6 and the waist sheet 9F, 9R when viewed in the thickness direction. The fixed parts 31L, 31R are formed by applying a hot melt adhesive between the non-skin facing side of the side sheets 8L, 8R and the top sheet 7. The side sheets 8L, 8R are also fixed to the top sheet 7 by the fixed parts 31L, 31R.

[0045] Here, there is no non-adhesive region between the fixing parts 31L, 31R and between the top sheet 7 and absorbent body 6, and between the top sheet 7 and waist sheet 9F, 9R. The interlayers refer to the interlayers between the sheets, and the top sheet 7 and absorbent body 6, and the top sheet 7 and waist sheet 9F, 9R are adhered on the non-skin-facing side of the fixing parts 31L, 31R. The fixing parts 31L, 31R increase the rigidity of the longitudinal end side of the absorbent body 6. In addition, since the fixing parts 31L, 31R are arranged across the waist sheet 9F, which has no contractile force, contraction of the absorbent body 6 is also suppressed on the front body region 1F side, and therefore, the SAP particles can be prevented from falling off the lower SAP layer 60B and the upper SAP layer 60D on the front side of the absorbent body 6. Furthermore, even if the fixing parts 31L, 31R are disposed across the waist sheet 9R having a contractile force, the rigidity of the absorbent body 6 on the rear body region 1R side can be increased, thereby preventing the rear end of the absorbent body 6 from twisting. Note that, in order to prevent the absorbent body 6 from twisting, the fixing parts 31L, 31R are preferably formed so as to overlap the absorbent body 6 on the end side in the width direction of the absorbent body 6.

[0046] Furthermore, even if the SAP particles leak outside the fold lines 30L, 30R and penetrate between the side sheets 8L, 8R and the top sheet 7 or the back sheet 5, the SAP can be contained in the SAP containing space and the waist sheets 9F, 9R can prevent the SAP particles from leaking to the outside.

[0047] Next, the unevenness 40 provided on the top sheet 7 of the diaper 1 according to this embodiment will be described with reference to Fig. 3 and Fig. 10. Fig. 10 is a plan view of the diaper 1 according to this embodiment as viewed from the skin-facing side. Note that Fig. 10 omits illustration of the side sheets 8L, 8R, elastic members 8EL, 8ER, and elastic members 4C, 4SL, 4SR.

[0048] As shown in FIG. 10, the uneven portion 40 consisting of the recessed portions 40A and the protruding portions 40B is formed on the entire top sheet 7. Although FIG. 4 shows only a part of the uneven portion 40, in this embodiment, the uneven portion 40 is provided on the entire surface of the top sheet 7. The recessed portions 40A and the protruding portions 40B are arranged so that the recessed portions and the protruding portions are alternately arranged when viewed along the width direction of the diaper 1. More specifically, the protruding portions 40B adjacent to each other in the width direction are arranged with a shift in the longitudinal position, and the protruding portions 40B are arranged in a staggered arrangement pattern as a whole. The uneven portion 40 is not shown in FIG. 9.

[0049] As shown in FIG. 3, the top sheet 7 has an upper core arranged on the non-skin side. The top sheet 7 is joined to the wrap sheet 6W at a plurality of joining regions 42. The joining regions 42 are formed by a hot melt adhesive, and the top sheet 7 and the upper core wrap sheet 6W are joined to each other at the joining regions 42. The top sheet 7 has a higher fiber density and a relatively smaller thickness at the joining regions 42 with the core wrap sheet 6W, so that a recess 40A is formed in the top sheet 7. A plurality of convex portions 40B of the top sheet 7 are formed between the plurality of concave portions 40A. The convex portions 40B are formed by being provided between the respective joining regions 42, so that the thickness of the top sheet 7 becomes relatively thick and protrudes toward the skin side. By partially joining the top sheet 7 and the core wrap sheet 6W, the top sheet 7 is depressed at the joining regions 14 to form the recess 40A, and a bulky convex portion 40B is formed around the recess 40A, so that an uneven portion 40 can be provided.

[0050] In this embodiment, a plurality of bonding regions 42 are formed in the arrangement pattern of the recesses 40A shown in FIG. 10, thereby forming a plurality of recesses 40A and a plurality of protrusions 40B formed around the recesses 40A.

[0051] Here, as shown in FIG. 10, the uneven portion 40 is provided so as to straddle the end of the longitudinal direction of the absorbent 6 in the longitudinal direction (front and back) of the diaper 1. A step corresponding to the thickness of the absorbent 6 occurs before and after the end of the longitudinal direction of the absorbent 6. Also, as shown in FIG. 6, since the adhesive portion 60 is provided at the end of the longitudinal direction of the absorbent 6, the end is relatively harder than other regions of the absorbent 6. Therefore, when the end of the absorbent abuts against the skin of the wearer through the top sheet, the wearer feels the step and hardness, and the wearing comfort is deteriorated. However, in this embodiment, the uneven portion 40 is provided so as to straddle the end of the longitudinal direction of the absorbent 6. The uneven portion 40 changes the thickness of the top sheet 7, so that the top sheet 7 bulges at the convex portion 40B, and the convex portion 40B abuts against the skin of the wearer. The convex portion 40B is a portion where the top sheet 7 is relatively thick, and this thickness provides high cushioning. As a result, the protrusions 40B of the diaper 1 make it difficult for the wearer to feel any unevenness or hardness at the longitudinal ends of the absorbent body 6, thereby preventing deterioration in wearing comfort.

[0052] In this embodiment, the centers of the multiple protrusions 40B are offset when viewed in the width direction of the diaper 1, and the protrusions 40B are arranged in a staggered pattern. This allows the protrusions 40B to be reliably arranged at positions that overlap with the longitudinal ends of the absorbent body 6, and therefore the protrusions 40B of the diaper 1 can prevent the wearer from feeling any unevenness or hardness at the longitudinal ends of the absorbent body 6.

[0053] In addition, in the uneven portion 40, the protrusions 40B have a larger area ratio than the recesses 40A when viewed in the width direction of the diaper 1. Since the protrusions 40B have a larger area ratio in the diaper 1, the cushioning properties of the diaper 1 can be improved by the protrusions 40B.

[0054] Moreover, the contour line of the protrusion 40B is curved and can be formed depending on the shape of the bonding region 42. More specifically, the contour line of the protrusion 40B has an S-shape.

[0055] As shown in Fig. 4, the top sheet 7 is contracted in the width direction by the elastic members 9ER provided outside the longitudinal ends of the absorbent body 6. This allows the diaper 1 to form pleats by contracting the top sheet 7 outside the longitudinal ends of the absorbent body 6. The pleats in the diaper 1 reduce the contact area of ​​the top sheet 7 with the wearer, making it difficult for the wearer to feel the step or hardness of the longitudinal ends of the absorbent body 6. It is preferable that the distance between the elastic members 9ER and the longitudinal ends of the absorbent body 6 is short, and the distance is preferably, for example, 8 mm or less.

[0056] <Modification> Next, a diaper 1 according to a modification of the present embodiment will be described. 11 is a plan view of the skin-facing side of the diaper 1. Note that side sheets 8L, 8R, elastic members 8EL, 8ER, and elastic members 4C, 4SL, 4SR are not shown in Fig. 11.

[0057] In this modification, the convex portions 40B of the concave-convex portion 40 are arranged in a dot-like arrangement pattern. By forming the concave-convex portion 40 in such an arrangement pattern, the concave-convex portion 40 can be provided so as to straddle the front and rear ends of the longitudinal end of the absorbent body 6. Therefore, the convex portions 40B of the diaper 1 make it difficult for the wearer to feel the step or hardness of the longitudinal end of the absorbent body 6, and can suppress a decrease in wearing comfort. Also, in the arrangement pattern of this modification, the centers of the multiple convex portions 40B are offset when viewed in the width direction of the diaper 1, and the convex portions 40B are arranged in a staggered pattern. This allows the convex portions 40B to be reliably arranged at positions overlapping the longitudinal end of the absorbent body 6, so that the convex portions 40B of the diaper 1 make it difficult for the wearer to feel the step or hardness of the longitudinal end of the absorbent body 6.

[0058] <Other embodiments> Although the present embodiment has been described above, the contents of the present invention are not limited to the above embodiment. In the above embodiment, a tape-type disposable diaper has been described as an example, but the present invention is not limited to this, and the present invention can also be applied to absorbent articles such as absorbent pads and pants-type disposable diapers.

[0059] The features included in each of the embodiments and the modified examples thereof disclosed above can be combined with each other. [Explanation of symbols]

[0060] 1. Diapers 1B...Inseam area 1F: Front body area 1R: Back body area 2L, 2R Tape 2F: Front patch 3BL, 3BR...Expansion member 3L, 3R: 3D gathers 4. Cover sheet 5. Back sheet 6. Absorber 6C··Absorbent core 6W··Core wrap sheet 7. Top sheet 8R, 8L··Side seat 8EL, 8ER... Elastic material 9F, 9R: West seat 9ER··Expansion member 20 Embossed groove 30L, 30R ·· Folding line 31L, 31R · Fixed part 40...Uneven part 40A··Concave 40B Recess 42...Joint area 60A･･･Driving layer 60B...Lower SAP layer 60C·Base layer 60D··Upper SAP layer 60E Diffusion layer 61...Adhesive part 62...SAP particles

Claims

1. A length along a longitudinal direction corresponding to the front-to-back direction of the wearer; A length along a width direction perpendicular to the longitudinal direction; an absorbent body having an SAP layer formed of a group of particles of SAP, which is a highly absorbent polymer; core wrap sheets sandwiching the SAP layer from above and below; and adhesive parts interposed between the upper and lower core wrap sheets at both ends in the longitudinal direction with a predetermined width, and bonding the upper and lower core wrap sheets together by pressing the SAP particles to intertwine with the fibrous materials of the upper and lower core wrap sheets when pressed by cutting; a skin-facing sheet disposed on the skin-facing side of the absorbent body and fixed to the absorbent body at least at the end side in the longitudinal direction; a non-skin-facing sheet disposed on the non-skin-facing side of the absorbent body and fixed to the absorbent body at least at the end side in the longitudinal direction; a concave-convex portion provided on at least the skin-facing sheet so as to span the longitudinal end of the absorbent body in the longitudinal direction, the concave portion and the convex portion being arranged alternately along the width direction; An absorbent article comprising:

2. The uneven portion is arranged such that the positions of the convex portions adjacent to each other in the width direction are shifted in the longitudinal direction. The absorbent article of claim 1.

3. When viewed along the width direction, the uneven portion has an area ratio of the protrusions larger than that of the recesses. The absorbent article according to claim 1 or 2.

4. The contour line of the protrusion is a curved line. The absorbent article according to claim 1 or 2.

5. The contour line of the protrusion has an S-shape. The absorbent article according to claim 1 or 2.

6. The convex portions are arranged in a dot pattern. The absorbent article according to claim 1 or 2.

7. a contraction member provided on the outer side of the end portion of the absorbent body in the longitudinal direction and configured to contract the skin-facing sheet in the width direction; The absorbent article according to claim 1 or 2.

8. The distance between the absorbent body and the contraction member is 8 mm or less. The absorbent article of claim 7.

9. a waist sheet disposed between the skin-facing side sheet and the non-skin-facing side sheet at a position farther from the absorbent body than the end of the longitudinal direction of the absorbent body and extending longer in the width direction than the absorbent body; The absorbent article according to claim 1 or 2.

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