Absorbent article

Abstract

The present invention provides an absorbent article (1) having a longitudinal direction, a width direction, and a thickness direction that are mutually orthogonal in an unfolded state and comprising an absorbent core (10) that is liquid-absorbent, a top sheet (2) layered farther on the skin side than the absorbent core (10), and a leakproof sheet (3) layered farther on the non-skin side than the absorbent core (10), wherein said article has: a bonding agent (31) farther on the skin side than the top sheet (2) that can be bonded to a portion of the absorbent article (1) when discarding the article; adjacent layers (40, 40') adjacent to the top sheet (2) from the thickness direction, farther on the skin side than the leakproof sheet (3), and farther on the non-skin side than the bonding agent (31); and a portion where the bonding agent (31) and the adjacent layers (40, 40') overlap when viewed in the thickness direction in an unfolded and stretched state.

Description

absorbent articles

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

[0002] Patent Literature 1 describes an absorbent article that is easy to remove after use and can be kept in a compact state after removal. Specifically, when a used absorbent article is rolled up by rolling it from one end in the longitudinal direction for disposal, the rolled state can be maintained by a band-shaped region near the outer periphery of the absorbent article.

[0003] JP 2024-77999 A

[0004] On the other hand, when an absorbent article absorbs a large amount of excrement, it may swell in the thickness direction, making it difficult to roll up from the end. In such cases, an absorbent article equipped with a closing mechanism that allows the absorbent article to be folded with the skin-facing side facing inward is desired. The closing mechanism is, for example, such that adhesives such as pressure-sensitive adhesives or self-adhesives are provided at both ends of the absorbent article when the absorbent article is folded in half with the skin-facing side facing inward. In an absorbent article equipped with such a closing mechanism, after use, the skin-facing side that has been adhering to the excrement can be closed, allowing the absorbent article to be disposed of hygienically while containing the excrement and its odor.

[0005] However, if moisture from excretory fluid adheres to the closing mechanism (adhesive agent) and it becomes wet, the function of the closing mechanism will be reduced (adhesive strength will be reduced), and there is a risk that the skin side will open when the diaper is disposed of.

[0006] The present invention has been made in consideration of the above-mentioned problems, and its purpose is to provide an absorbent article that prevents the adhesive from becoming wet with excrement and can maintain a state in which the excrement on the skin side is covered by the absorbent article.

[0007] The main invention for achieving the above object is an absorbent article having a longitudinal direction, a width direction, and a thickness direction that are perpendicular to one another in an unfolded state, comprising: a liquid-absorbent core, a top sheet layered on the skin side of the absorbent core, and a leak-barrier sheet layered on the away-from-skin side of the absorbent core, wherein the absorbent article has an adhesive agent on the skin side of the top sheet that can be bonded to a part of the absorbent article when discarded, and an adjacent layer adjacent to the top sheet in the thickness direction and on the skin side of the leak-barrier sheet and away from the skin side of the adhesive agent, and wherein the adhesive agent and the adjacent layer have an overlapping portion when viewed in the thickness direction in an unfolded and stretched state. Other features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[0008] According to the present invention, it is possible to provide an absorbent article that can prevent the adhesive from becoming wet with excrement and can maintain a state in which excrement on the skin side is covered by the absorbent article.

[0009] 1 is a schematic plan view of a urine absorption pad 1 in an unfolded and stretched state according to an embodiment of the present invention, as seen from the skin side. FIG. 1 is a schematic cross-sectional view of the urine absorption pad 1. FIG. 2 is an explanatory diagram of the pad 1 when folded in half. FIG. 3 is a partially enlarged view for explaining the details of the configuration of the pad 1. FIG. 4 is an explanatory diagram of self-adhesive joining means 30, 30'. FIG. 5 is an explanatory diagram of the joining means 30, 30' and adjacent layers 40, 40'. FIG. 6 is an explanatory diagram of the size relationship between the adjacent layers 40, 40' and the joining means 30, 30'. FIG. 7 is a diagram for explaining the action and effect of a pad 1 to which the adjacent layers 40, 40' and the joining means 30, 30' are applied. FIG. 8 is an explanatory diagram of a modified example of this embodiment. FIG. 9 is an explanatory diagram of a modified example of the joining means 30, 30'.

[0010] The present specification and the accompanying drawings make at least the following clear: (Aspect 1) An absorbent article having a longitudinal direction, a width direction, and a thickness direction that are orthogonal to one another in an unfolded state, and comprising: a liquid-absorbent absorbent core, a top sheet laminated closer to the skin than the absorbent core, and a leak-barrier sheet laminated closer to the skin than the absorbent core, wherein an adhesive agent is disposed closer to the skin than the top sheet and capable of bonding to a part of the absorbent article when discarded, and an adjacent layer is disposed adjacent to the top sheet in the thickness direction and closer to the skin than the leak-barrier sheet and closer to the skin than the adhesive agent, and wherein there is an overlapping portion between the adhesive agent and the adjacent layer when viewed in the thickness direction in an unfolded and stretched state.

[0011] According to Aspect 1, even if moisture such as excrement absorbed by the absorbent core permeates from the non-skin side to the skin side of the top sheet (so-called rewet), the adjacent layer provided on the non-skin side of the adhesive agent helps to prevent moisture from reaching the adhesive agent. This prevents the mechanism (adhesive agent) that closes the absorbent core from becoming wet. Therefore, the adhesive strength is less likely to decrease, making it easier to maintain the absorbent article in a closed state.

[0012] (Aspect 2) The absorbent article according to aspect 1, wherein the adjacent layer is made of a nonwoven fabric.

[0013] According to the second aspect, the presence of a thick nonwoven fabric (adjacent layer) between the absorbent core and the binder makes it easier to prevent excreted liquid from reaching the binder.

[0014] (Aspect 3) The absorbent article according to aspect 1 or 2, wherein the adjacent layer has a concave portion that is concave in the thickness direction and a convex portion that is convex in the thickness direction.

[0015] According to aspect 3, the unevenness of the adjacent layer makes it easier to inhibit the movement of moisture from the adjacent layer (nonwoven fabric) to the bonding agent, compared to when the adjacent layer is smooth and comes into surface contact with the bonding agent.

[0016] (Aspect 4) The absorbent article according to any one of Aspects 1 to 3, wherein the adjacent layer is formed of a nonwoven fabric and ink applied to the nonwoven fabric.

[0017] According to Aspect 4, the ink penetrates into the voids in the fibers that make up the nonwoven fabric, thereby preventing excreted liquid from migrating (impregnating) through the voids in the nonwoven fabric in the thickness direction, and more easily preventing the excreted liquid from reaching the binder. Furthermore, the use of colored ink makes it easier to visually identify the position of the binder using adjacent layers as markers, making it easier to close the absorbent article.

[0018] (Aspect 5) The absorbent article according to any one of Aspects 1 to 4, wherein the adjacent layer is a hydrophobic layer.

[0019] According to aspect 5, the adjacent layer is hydrophobic, so that excreted liquid is less likely to permeate the adjacent layer, and it is easier to prevent excreted liquid from reaching the bonding agent.

[0020] (Aspect 6) The absorbent article according to aspect 5, wherein the hydrophobic layer is formed by a hot melt adhesive applied to the top sheet.

[0021] According to Aspect 6, by applying a hot melt adhesive to the top sheet, it is possible to increase the strength of the top sheet while suppressing the permeation of excreted liquid.

[0022] (Aspect 7) The absorbent article according to either aspect 5 or aspect 6, wherein the hydrophobic layer is formed by a colored ink applied to the top sheet.

[0023] According to aspect 7, by applying colored ink to the top sheet, the position of the adhesive (adjacent layer) can be easily seen, making it easier to close the absorbent article, while also suppressing the permeation of excretory fluid.

[0024] (Aspect 8) An absorbent article according to any one of Aspects 1 to 7, further comprising a second sheet between the absorbent core and the top sheet in the thickness direction, and the adjacent layer is positioned closer to the skin than the second sheet.

[0025] According to the eighth aspect, the second sheet and the adjacent layer are present between the absorbent core and the binder, which further inhibits the transfer of excreted fluid from the absorbent core to the binder.

[0026] (Aspect 9) The absorbent article according to any one of Aspects 1 to 8, wherein the adjacent layer is located between the adhesive and the top sheet in the thickness direction.

[0027] According to aspect 9, even if moisture moves from the absorbent core through the top sheet, the provision of an adjacent layer between the top sheet and the adhesive can prevent moisture from reaching the adhesive.

[0028] (Aspect 10) The absorbent article according to any one of Aspects 1 to 9, wherein when viewed in the thickness direction in an unfolded and stretched state, the area where the adhesive is provided and the adjacent layer are different in size.

[0029] According to Aspect 10, if the adjacent layer is larger than the adhesive area, it is easier to prevent excreted liquid from crossing the adjacent layer and reaching the adhesive. If the adhesive area is larger than the adjacent layer, it is easier to perform the operation of pressing the adhesive when closing the absorbent article (the operation of folding with the skin side facing inward), and the cost of forming the adjacent layer can be reduced.

[0030] (Aspect 11) An absorbent article according to any one of Aspects 1 to 10, wherein when viewed in the thickness direction in an unfolded and stretched state, the adjacent layer is provided over the entire area where the adhesive is provided and in an area outside the area where the adhesive is provided.

[0031] According to aspect 11, the adjacent layer is formed so as to cover the entire area where the adhesive is provided from the non-skin side, so that moisture is less likely to reach the adhesive.

[0032] (Aspect 12) An absorbent article according to any one of Aspects 1 to 11, wherein when the area in which the adhesive is provided is divided into three equal parts in the longitudinal direction into a first adjacent area, a central area, and a second adjacent area, the adhesive strength of the central area is stronger than the adhesive strength of the first adjacent area or the second adjacent area.

[0033] According to aspect 12, the adhesive strength is strong in the central region where moisture is less likely to reach (when moisture moves from the inside to the outside in the longitudinal / width direction of the absorbent article), making it easier to maintain the folded state with the skin side facing inward.

[0034] (Aspect 13) The absorbent article according to any one of Aspects 1 to 12, wherein the adjacent layer is provided across an end of the absorbent core in the longitudinal direction or the width direction.

[0035] According to Aspect 13, excreted fluid that seeps outward from the end of the absorbent core can be prevented from penetrating into the skin and reaching the adhesive layer.

[0036] (Aspect 14) The absorbent article according to any one of Aspects 1 to 13, wherein the adhesive is provided in a non-uniform pattern on the skin side of the top sheet.

[0037] According to Aspect 14, the adhesive itself appears as a pattern and is easy to see, making the closing operation easy. Furthermore, compared to when the adhesive is applied solidly to the top sheet (a uniform pattern), the overall basis weight of the adhesive can be reduced.

[0038] Embodiments The absorbent article according to this embodiment will be described using a urine absorption pad (hereinafter, sometimes simply referred to as a "pad") as an example. However, the absorbent article according to this embodiment is not limited to urine absorption pads, and can also be used, for example, as sanitary napkins, pants-type disposable diapers, shorts-type napkins, tape-type disposable diapers, pet diapers, and absorbent sheets for nursing care or for pets.

[0039] <<<<Basic Structure of Urine Absorption Pad 1>>> First, the basic structure of the urine absorption pad 1 will be described. Fig. 1 is a schematic plan view of the pad 1 in an unfolded and stretched state, as seen from the skin side. Fig. 2 is a schematic cross-sectional view of the pad 1. The urine absorption pad 1 can be used by being placed inside a pants-type or tape-type disposable diaper, or it can be used as a standalone pad 1 by being placed directly inside the wearer's underwear (pants or shorts).

[0040] In its unfolded state, the pad 1 has a substantially rectangular planar shape, with a longitudinal direction, a width direction, and a thickness direction that are perpendicular to one another. The longitudinal direction corresponds to the front-to-rear direction from the wearer's abdominal side to the dorsal side when the pad 1 is worn. In addition, in the thickness direction, the side that contacts the wearer's skin is referred to as the skin side, and the opposite side is referred to as the non-skin side. Since the pad 1 of this embodiment is symmetrical in the longitudinal direction, either side of the pad 1 in the longitudinal direction may correspond to the wearer's abdominal side. Furthermore, unlike tape-type or pants-type diapers, the pad 1 is worn without one longitudinal end and the other longitudinal end being connected along the wearer's waist.

[0041] The expanded state of the pad 1 refers to the state in which the entire pad 1 is expanded in a plane. The stretched state of the pad 1 refers to the state in which the pad 1 is stretched to the extent that wrinkles that have occurred in the pad 1 are substantially invisible, and the pad 1 is stretched to the extent that the dimensions of each member constituting the pad 1 (for example, the side sheet 4 described below) match or are close to the dimensions of the member alone.

[0042] The pad 1 comprises a liquid-absorbent core 10, a liquid-permeable top sheet 2 (hereinafter sometimes referred to as top sheet 2) (e.g., nonwoven fabric) provided closer to the skin than the absorbent core 10, a liquid-impermeable back sheet 3 (e.g., a resin film such as polyethylene or polypropylene) provided closer to the skin than the absorbent core 10, and a pair of side sheets 4 provided on both widthwise sides of the pad 1. As shown in Figure 2, the pair of side sheets 4 are folded inward in the widthwise direction from the widthwise sides of the back sheet 3 on the non-skin-side surface toward the skin-side surface of the skin-side sheet 2 so as to encase the absorbent core 10.

[0043] An example of the absorbent core 10 is a liquid-absorbent fiber such as pulp fiber containing SAP (super absorbent polymer) molded into a predetermined shape. The absorbent core 10 is covered with a liquid-permeable core wrap sheet 11 (e.g., tissue). However, without being limited to the above, the absorbent core 10 may be an SAP sheet in which an SAP layer is attached to a hydrophilic sheet, an airlaid sheet in which liquid-absorbent fiber is molded into a sheet by an airlaid method, or the like, or may be configured with two or more layers laminated together. Furthermore, the absorbent core 10 does not have to be covered with the core wrap sheet 11.

[0044] Furthermore, a fixing member 20 is provided on the non-skin side of the pad 1, which joins the pad 1 to the inner surface of a pants-type diaper or underwear (outerwear). The fixing member 20 is provided at each of both longitudinal ends of the pad 1. The fixing member 20 is, for example, a rectangular member, and is provided so that its long side is aligned with the width direction of the pad 1. The fixing member 20 is preferably a member that can be peeled off from the inner surface of the outerwear without damaging the outerwear and can be reattached. The fixing member 20 in this embodiment is a tape having a hook material (for example, a male member of a hook-and-loop fastener). Other examples of the fixing member 20 include tape coated with adhesive. The fixing member 20 does not necessarily have to be provided.

[0045] The pad 1 also has a pair of leg elastic members 5 arranged along the longitudinal direction on both widthwise sides. In Fig. 2, the leg elastic members 5 are fixed in a stretched state in the longitudinal direction between the backsheet 3 and the sidesheets 4. This makes it easier for both widthwise sides of the pad 1 to fit closely around the legs of the wearer.

[0046] The pad 1 also has a pair of leakage preventing walls 6 that can stand up toward the skin on both widthwise sides. The leakage preventing walls 6 include side sheets 4 and leakage preventing wall elastic members 7. Both longitudinal ends are fixed to the topsheet 2 by adhesive regions 8. The leakage preventing wall elastic members 7 are fixed to the inner widthwise ends of the side sheets 4 in a stretched state along the longitudinal direction of the pad 1. When the pad 1 is worn, the stretchability of the leakage preventing wall elastic members 7 causes the tips of the leakage preventing walls 6 to stand up toward the skin, and the standing leakage preventing walls 6 suppress lateral leakage of excrement and the like.

[0047] The pad 1 also has joining means 30, 30' and adjacent layers 40, 40' at both ends in the longitudinal direction, respectively. The details of their configuration will be described below.

[0048] <<<<Joining Means 30, 30'>>> As shown in Fig. 1 , one-side joining means 30 serving as a closing mechanism is provided on the skin side (topsheet 2) of the pad 1 at one longitudinal end. Furthermore, other-side joining means 30' is provided on the skin side (topsheet 2) of the pad 1 at the other longitudinal end. The other-side joining means 30' is part of the pad 1. When the pad 1 is disposed of, the one-side joining means 30 serving as joining means can be joined to the other-side joining means 30' serving as part of the pad 1. The joining means 30, 30' in this embodiment are regions at least partially provided with an adhesive (such as a self-adhesive adhesive described below).

[0049] FIG. 3 shows the pad 1 folded in half in the longitudinal direction. Specifically, the folded state refers to a state in which the pad 1 is folded along the center line CL of the pad 1 in the longitudinal direction, i.e., the pad 1 is divided into two equal parts in the longitudinal direction and folded along the center line CL (hereinafter, sometimes referred to as the fold line FL) along the width direction. This state represents, for example, the state of the pad 1 before use or when discarded after use. FIG. 3A is a plan view of the pad 1 folded in half in the longitudinal direction, and FIG. 3B is a schematic cross-sectional view of the pad 1 folded in half with the ends of the pad 1 closed, as viewed from the width direction. As shown in FIGS. 3A and 3B, when the pad 1 is folded in half in the longitudinal direction, the one-side joining means 30 and the other-side joining means 30′ overlap and face each other in the thickness direction, and are arranged to be joinable.

[0050] 4 is a partially enlarged view illustrating the detailed configuration of the pad 1. The position of the one-side joining means 30 in the longitudinal direction will be described. However, since the pad 1 is symmetrical in the longitudinal direction, the other-side joining means 30' has the same configuration as the one-side joining means 30. The one-side joining means 30 is provided at an end of the pad 1 in the longitudinal direction, a predetermined distance d away from the end of the pad 1 in the longitudinal direction. The region extending in the width direction from the end of the pad 1 in the longitudinal direction to the one-side joining means 30 over the predetermined distance d is also referred to as the dry edge D. The dry edge D is a non-adhesive region from the end of the pad 1 to the one-side joining means 30 where no adhesive is provided.

[0051] The one-side joining means 30 and the other-side joining means 30' have a self-adhesive bonding agent 31 (hereinafter, may be referred to as a self-adhesive bonding agent or a self-adhesive bonding agent) as a bonding portion. Note that the bonding agent in this embodiment is not limited to a self-adhesive bonding agent, and may be an adhesive.

[0052] 5A and 5B are explanatory diagrams of the one-side joining means 30 and the other-side joining means 30'. The adhesive 31 provided as the joining portion in the one-side joining means 30 and the other-side joining means 30' has low tackiness (adhesion) itself, but has the property of exhibiting adhesive strength (hereinafter referred to as "bonding strength") when the adhesives 31 are brought into contact with each other with relatively weak pressure. As shown in FIG. 5A, when the one-side joining means 30 and the other-side joining means 30' are pressed together, the one-side joining means 30 and the other-side joining means 30' are bonded together by the respective adhesives 31 (bonding strength is exhibited). On the other hand, as shown in FIG. 5B, when the adhesive 31 comes into contact with a member other than the adhesive 31, such as the nonwoven fabric provided on the pad 1 or the skin, the one-side joining means 30 does not easily adhere to the abutting member.

[0053] The bonding strength between the bonding agent 31 and other members is preferably ¼ or less of the bonding strength between the bonding agents 31 themselves. More preferably, the bonding strength between the bonding agent 31 and other members is 1 / 10 or less of the bonding strength between the bonding agents 31 themselves. Furthermore, when the bonding agents 31 are brought into contact with each other, they can be peeled off without damaging the bonding agents 31, and can be re-bonded by bringing them into contact with each other after peeling.

[0054] The adhesive 31 is not particularly limited as long as it is safe to come into contact with the wearer's skin, and examples thereof include emulsion-based self-adhesives (emulsion inks) and hot-melt-based self-adhesives (HMAs). The main component of an emulsion-based self-adhesive may be a mixture of natural rubber, synthetic rubber, or the like with an emulsifier, and examples of such emulsion-based self-adhesives include those disclosed in Japanese Patent No. 2589307 and Japanese Patent Publication No. 2005-095381. Furthermore, the main component of a hot-melt-based self-adhesive may be a thermoplastic resin, such as a polyolefin or polyamide resin, which is heated and melted and used, and examples of such hot-melt-based self-adhesives include those disclosed in Japanese Patent Nos. 7476348 and 7543716. In this embodiment, an emulsion-based self-adhesive is used.

[0055] Next, the specific configuration of the one-side joining means 30 and the other-side joining means 30' will be described in detail using FIG. 6 . FIG. 6 is a diagram illustrating the joining means 30, 30' and the adjacent layers 40, 40'. For simplicity's sake, only the one-side adjacent layer 40 and the one-side joining means 30 will be described, but the other-side adjacent layer 40' and the other-side joining means 30' have similar configurations. Furthermore, in the cross-sectional view of FIG. 6 , the topsheet 2 and the adjacent layers 40, 40' are shown flat for ease of explanation. However, in an actual pad 1, the topsheet 2 and the adjacent layers 40, 40' may deform in the thickness direction due to the influence of the thickness of the absorbent core 10. In other words, the topsheet 2 and the adjacent layers 40, 40' are not necessarily flat as shown in FIG. 6 , and the joining means 30, 30' may also deform in the thickness direction in response to deformation of the topsheet 2 and the adjacent layers 40, 40'. This also applies to FIGS. 7 and 9 , which will be described later.

[0056] As shown in Fig. 6, the one-side joining means 30 and the other-side joining means 30' are quadrilateral areas circumscribing the portion where the self-adhesive bonding agent 31 is applied as the joining portion. In Fig. 6, the area where the self-adhesive bonding agent 31 is applied is shown lightly shaded.

[0057] As described above, in this embodiment, an emulsion-based self-adhesive or the like is used as the bonding agent 31. Furthermore, a single application of the bonding agent 31 is defined as a uniform application (a so-called solid application) in a generally rectangular shape that is elongated in the width direction, and in the example shown in FIG. 6 , the bonding agent 31 is repeatedly applied three times. Applying the bonding agent 31 multiple times in a layered manner in the thickness direction can increase the bonding strength when the bonding agent 31 is bonded together compared to a single application. Although the bonding agent 31 is applied three times in this embodiment, the present invention is not limited to this.

[0058] In this embodiment, as shown in Fig. 6 , the application positions of the bonding agent 31 are shifted in the longitudinal direction and the width direction. Therefore, as shown in the diagrams (bottom side view and right side view) showing the thickness direction in Fig. 6 , the application amount (basis weight or basis weight) of the bonding agent 31 per unit area in the first adjacent regions L1, W1 adjacent to one of the central regions Lc, Wc and the second adjacent regions L2, W2 adjacent to the other of the central regions Lc, Wc is smaller than the application amount of the bonding agent 31 per unit area in the central regions Lc, Wc. In other words, since the application amount of the bonding agent 31 per unit area is smaller than that in the central regions Lc, Wc, the bonding strength is also smaller than that in the central regions Lc, Wc.

[0059] The skin-side surface of the one-side joining means 30 has convex portions 32 and concave portions 33 formed due to differences in the amount of adhesive 31 applied per unit area. The convex portions 32 are first portions 34 where the amount of adhesive 31 applied per unit area is greater than the surrounding areas, and are portions where the adhesive 31 is applied three times out of three times. On the other hand, the concave portions 33 are second portions 35 where the amount of adhesive 31 applied per unit area is less than the surrounding areas. As described above, the first portions 34 are thicker in the thickness direction due to the greater amount of adhesive 31 applied per unit area, while the second portions 35 are thinner due to the less amount applied than the first portions 34. Note that other methods may be used to form the convex portions 32 and concave portions 33 on the skin-side surface of the one-side joining means 30. For example, the surface of the topsheet 2 may be unevenly formed to form the convex portions and concave portions on the skin-side surface of the adhesive 31 applied to the topsheet 2, or the convex portions and concave portions may be formed by squeezing a portion of the applied adhesive 31.

[0060] <<<<Adjacent Layers 40, 40'>>> Next, the specific configuration of the adjacent layer 40 will be described. As shown in Fig. 6, the pad 1 of this embodiment has adjacent layers 40, 40' adjacent to the topsheet 2 in the thickness direction, closer to the skin than the leak-barrier sheet 3, and closer to the skin than the joining means 30, 30'. An adjacent layer 40 corresponding to the joining means 30 on one side and an adjacent layer 40' corresponding to the joining means 30' on the other side are provided. Furthermore, when the pad 1 is in an expanded and stretched state, there are portions where the joining means 30, 30' and the adjacent layers 40, 40' overlap when viewed in the thickness direction. Note that in Fig. 6, the adjacent layers 40, 40' are located between the joining means 30, 30' and the topsheet 2 in the thickness direction.

[0061] The adjacent layers 40, 40' in this embodiment are hydrophobic layers that have a low affinity for (easily repel) moisture, and the hydrophobic layers are formed, for example, by colored ink applied to the topsheet 2. However, the configuration is not limited to the above, and the adjacent layers 40, 40' may be formed by nonwoven fabric, or by nonwoven fabric and ink applied to the nonwoven fabric. Furthermore, the hydrophobic layers may be formed by a material other than those described above, or may be formed by a hot melt adhesive applied to the topsheet 2.

[0062] Next, the function and effect of the pad 1 of this embodiment will be described with reference to Figure 6. When a large amount of excrement (excrement, etc.) is stored in the pad 1, the pad 1 expands in the thickness direction, and moisture such as excrement absorbed by the absorbent core 10 may permeate from the non-skin side to the skin side of the topsheet 2, a phenomenon known as rewetting. If the moisture that has permeated the skin side of the topsheet 2 due to rewetting reaches the one-side joining means 30 or the other-side joining means 30', the adhesive 31 may become wet, thereby reducing the bonding strength.

[0063] In contrast, in this embodiment, the adjacent layers 40, 40' are provided on the non-skin side of the joining means 30, 30' (adhesive 31), which helps to prevent moisture from reaching the joining means 30, 30'. This prevents the mechanism that closes the absorbent core 10 (i.e., the self-adhesive adhesive 31 in the joining means 30, 30') from becoming wet. This makes it difficult for the adhesive strength of the self-adhesive adhesive 31 to decrease, making it easier to maintain the pad 1 in a closed state.

[0064] 6, the adjacent layers 40, 40' are located in the thickness direction between the joining means 30, 30' and the topsheet 2. Therefore, even if moisture moves along the topsheet 2 on the skin side of the absorbent core 10, the provision of the adjacent layers 40, 40' between the topsheet 2 and the joining means 30, 30' can prevent moisture from reaching the joining means 30, 30'.

[0065] Furthermore, since the adjacent layers 40, 40' are hydrophobic, excretory liquid is less likely to pass through the adjacent layers 40, 40' than when the adjacent layers 40, 40' are hydrophilic, making it easier to prevent excretory liquid from reaching the joining means 30, 30'.

[0066] The hydrophobic adjacent layers 40, 40' are formed of colored ink applied to the topsheet 2. Here, colored ink refers to ink of a different color from the topsheet 2. The "different color" refers to any ink that can be visually recognized as a different color by a user. For example, if the topsheet 2 is white, blue or green ink can be recognized as a different color. The application of colored ink to the topsheet 2 not only prevents excretory fluid from penetrating the adjacent layers 40, 40', but also makes it easier for the user to recognize the position of the self-adhesive adhesive 31 (bonding means 30, 30') that overlaps the adjacent layers 40, 40' in the thickness direction. This facilitates the operation of closing the pad 1 while suppressing the penetration of excretory fluid.

[0067] In addition, the hydrophobic adjacent layers 40, 40' may be formed of a hot melt adhesive applied to the top sheet 2. In this case, by applying the hot melt adhesive to the top sheet 2, the strength of the top sheet 2 can be increased while suppressing the permeation of excretory fluids.

[0068] The adjacent layers 40, 40' may be made of nonwoven fabric. The presence of a thick nonwoven fabric between the absorbent core 10 and the joining means 30, 30' can make it easier to prevent excreted liquid from reaching the joining means 30, 30'.

[0069] Alternatively, the adjacent layers 40, 40' may be formed of a nonwoven fabric and ink applied to the nonwoven fabric. With this configuration, the ink penetrates into the voids in the fibers that make up the nonwoven fabric, thereby preventing excreted liquid from moving through the voids in the nonwoven fabric in the thickness direction (impregnation), and more effectively preventing excreted liquid from reaching the joining means 30, 30'. Furthermore, using colored ink makes it easier to visually identify the position of the self-adhesive adhesive 31 (joining means 30, 30') using the adjacent layers 40, 40' as markers, facilitating the operation of closing the pad 1.

[0070] In this embodiment, it is desirable that the adjacent layers 40, 40' are provided in the longitudinal direction or width direction so as to straddle the ends of the absorbent core 10. For example, in the case of Figure 6, the adjacent layers 40, 40' are provided in the longitudinal direction so as to straddle the ends of the absorbent core 10. By doing so, it is possible to prevent excreted liquid that seeps outward from the ends of the absorbent core 10 from penetrating the skin side and reaching the joining means 30, 30'.

[0071] In this embodiment, when viewed from the thickness direction of the pad 1, the bonding means 30, 30', which are the areas where the self-adhesive adhesive 31 is provided, and the adjacent layers 40, 40' may be different in size. Figures 7 (7A and 7B) are explanatory diagrams showing the size relationship between the adjacent layers 40, 40' and the bonding means 30, 30'. Figure 7A shows a case where the adjacent layers 40, 40' are larger than the bonding means 30, 30', while Figure 7B shows a case where the adjacent layers 40, 40' are smaller than the bonding means 30, 30'. In Figures 7A and 7B, the left side shows the skin-side surface as viewed from the thickness direction, and the right side shows a cross-sectional view taken along the center line C in the width direction shown in Figure 4.

[0072] As shown in Figure 7A, if the adjacent layers 40, 40' are larger than the joining means 30, 30', even if the excretory liquid flows in the direction of the arrow, it can be more easily prevented from passing over the adjacent layers 40, 40' and reaching the joining means 30, 30'.

[0073] On the other hand, as shown in Figure 7B, if the adjacent layers 40, 40' are smaller than the joining means 30, 30', the joining force of the overlapping adjacent layers 40, 40' can be maintained even if excretory fluid flows in the direction of the arrow, and therefore, the joining means 30, 30' can be pressed together (i.e., folded with the skin side facing inward) when closing the pad 1. Furthermore, by making the adjacent layers 40, 40' smaller, the material costs of the adjacent layers 40, 40' can be reduced. Furthermore, when at least a portion of the adjacent layers 40, 40' is made of colored ink, the joining means 30, 30' are formed so as to cover the entire area where the adjacent layers 40, 40' are provided from the skin side, thereby preventing the colored ink contained in the adjacent layers 40, 40' from bleeding or transferring to the skin.

[0074] In this embodiment, a configuration in which the adjacent layers 40, 40' are larger than the joining means 30, 30' shown in Figure 7A is preferred. That is, it is desirable that the adjacent layers 40, 40' be provided over the entire area of ​​the joining means 30, 30' and even in the area outside the joining means 30, 30'. By doing so, the adjacent layers 40, 40' are formed so as to cover the entire area where the joining means 30, 30' are provided from the non-skin side, which makes it easier to prevent moisture from reaching the joining means 30, 30'.

[0075] In this embodiment, as shown in FIG. 6 and FIGS. 8 and 10 (described later), when the region in which the bonding means 30, 30' are provided is divided into three equal parts in the longitudinal direction: first adjacent regions L1, L1', central regions Lc, Lc', and second adjacent regions L2, L2', the bonding strength of the central regions Lc, Lc' is preferably stronger than the bonding strength of the first adjacent regions L1, L1' or the second adjacent regions L2, L2'. This configuration ensures that the bonding strength is stronger in the central regions Lc, Lc', where moisture is less likely to reach when moisture moves from the inside to the outside in the longitudinal or width direction of the pad 1. This makes it easier to maintain the folded state with the skin-side facing inward. Furthermore, this configuration allows the pad 1 to be peeled off and unfolded with a relatively weak force. The peeling operation of the bonding means 30 is described in detail below.

[0076] <<<<Regarding the bonding strength of the bonding means 30, 30' as bonding means>>> Figure 8 is a diagram for explaining the action and effect of the pad 1 to which the adjacent layer 40 and the bonding means 30, 30' are applied. Figure 8A is a diagram viewed from the thickness direction showing the pad folded in half along the fold line FL so that the one-side bonding means 30 and the other-side bonding means 30' face each other and then bonded together. Figure 8B is a diagram showing the one-side bonding means 30 and the other-side bonding means 30' being peeled apart when the pad 1 is unfolded.

[0077] 8A, in this embodiment, when the pad 1 is folded in half along the center line CL (fold line FL), the central region Lc of the one-side joining means 30 and the central region Lc' of the other-side joining means 30' overlap in the thickness direction. Also, although not shown, the central region We of the one-side joining means 30 and the central region We' of the other-side joining means 30' overlap in the width direction as well, similar to the longitudinal direction.

[0078] The one-side joining means 30 is divided into three equal parts in both the longitudinal and width directions. From one side, the longitudinally separated regions are a first longitudinal adjacent region L1, a longitudinal central region Lc, and a second longitudinal adjacent region L2. The widthwise separated regions are a first widthwise adjacent region W1, a widthwise central region Wc, and a second widthwise adjacent region W2 (see FIG. 6). These regions have different joining strengths. In this embodiment, the joining strength of the first adjacent regions L1 and W1 adjacent to one of the central regions Lc and Wc is weaker than the joining strength of the central regions Lc and Wc in both the longitudinal and width directions. Furthermore, the joining strength of the second adjacent regions L2 and W2 adjacent to the other of the central regions Lc and Wc is weaker than the joining strength of the central regions Lc and Wc.

[0079] The strength of the bonding in each region, such as the first longitudinal adjacent region L1 and the longitudinal central region Lc, can be evaluated based on the amount per unit area (basis weight) of the bonding agent 31 provided in each region as a bonding portion. In each region, the greater the amount per unit area (basis weight) of the bonding agent 31, the greater the bonding strength.

[0080] The strength of the bonding strength in each region may also be evaluated using a measuring device.

[0081] When measuring the bonding strength of each of the first longitudinal adjacent region L1, the longitudinal central region Lc, and the second longitudinal adjacent region L2, two sample pieces are prepared. The first sample piece is a cutout of the region to be measured from each of the first longitudinal adjacent region L1, the longitudinal central region Lc, etc. The second sample piece is a nonwoven fabric coated with a uniform amount of bonding agent 31.

[0082] A holding portion (grip portion) is formed at the end of each sample piece by attaching gum tape to the end of the sample piece. Next, two sample pieces are overlapped and joined by rolling a 2 kg roller at 5 mm / s from the opposite side of the holding portion.

[0083] Next, the sample piece is held by the holders in the chucks of a tensile testing machine (e.g., an Instron universal testing machine), and the two holders are pulled apart in the direction corresponding to the longitudinal direction to separate the two sample pieces, and the tensile load at the time of separation is measured. The average value of the tensile load is the magnitude of the bonding strength in the region to be measured. The bonding strength can also be measured in the same manner for the first width-adjacent region W1, the width-center region Wc, and the second width-adjacent region W2.

[0084] Before use (when packaged), the pad 1 is closed, and the one-side joining means 30 and the other-side joining means 30' are in contact with each other, as shown in Fig. 8A. When using the pad 1, the user grasps the dry edge D areas provided at both longitudinal ends of the pad 1 and pulls it away toward the center in the longitudinal direction, as shown in Fig. 8B.

[0085] If the adhesive strength at the beginning of the peeling is too strong, it may be difficult to open when unfolding, especially for elderly users with reduced dexterity. However, in the pad 1 of this embodiment, the adhesive strength of the first longitudinal adjacent regions L1, L1' in the one-side adhesive means 30 is weaker than the adhesive strength of the longitudinal central regions Lc, Lc'. Therefore, compared to when the adhesive strength of the first longitudinal adjacent regions L1, L1' in the one-side adhesive means 30 is stronger than or the same as the adhesive strength of the longitudinal central regions Lc, Lc', it can be peeled and unfolded with a relatively weak force. Furthermore, the provision of the dry edge D makes it easier for the user to grasp and peel.

[0086] In this embodiment, since the second adjacent region L2, which has a weaker adhesive strength, is located on the longitudinal centerline CL side, the pad 1 can be peeled away from the leg elastic members 5 toward the edge. In this case, the same effect as above can be achieved. Furthermore, since the dry edge D is provided over a predetermined distance d from the edge in the width direction of the pad 1, the ease of peeling can be improved even when peeling away in this manner.

[0087] Furthermore, the central region (first portion 34) of both the one-side joining means 30 and the other-side joining means 30' has a stronger joining strength than the adjacent regions. As a result, after use or when discarding the pad 1, by folding the pad 1 in half along the fold line FL and bringing one end of the pad 1 into contact with the other, it becomes easier to keep the pad 1 covering excrement on the skin side.

[0088] The configuration is not limited to the above, and the amount of coating in either the first adjacent region L1, W1 or the second adjacent region L2, W2 may be less than that in the central region Lc, Wc, or the amount of coating may be different only in either the longitudinal direction or the width direction. For example, the amount of coating in only the second adjacent region L2 (second longitudinal adjacent region) in the longitudinal direction may be less than that in the central region Lc. In this case, when the user peels off the pad 1, the pad can be easily unfolded by peeling it off from the second adjacent region L2, which has weaker adhesive strength.

[0089] Furthermore, in the pad 1 of this embodiment, when the pad 1 is folded in half along the center line CL (fold line FL), the central regions Lc, Wc of the one-side joining means 30 and the central regions Lc', Wc' of the other-side joining means 30' overlap in the thickness direction. By overlapping the central regions, when the pad 1 is discarded, it is easy to fold the pad 1 in half and maintain the state in which the pad 1 covers the excrement on the skin side.

[0090] The same action and effect can be achieved even when the pad 1 is folded in half at the center position in the width direction (a fold line along the center line in the width direction). In this case, two joining means may be provided on one side and the other side in the width direction with the center line in the width direction as the reference.

[0091] Alternatively, the joining force may be varied only in the joining means 30 on one side, and the joining force of the joining means 30' on the other side may be uniform. Alternatively, the joining force may be varied only in the joining means 30' on the other side, and the joining force of the joining means 30 on one side may be uniform.

[0092] Furthermore, with regard to the magnitude of the joining strength in the longitudinal direction and width direction of the one-side joining means 30, the value obtained by dividing the difference between the joining strength in the longitudinal central region Lc and the joining strength in the first longitudinal adjacent region L1 by the longitudinal length of the longitudinal central region Lc is greater than the value obtained by dividing the difference between the joining strength in the widthwise central region Wc and the joining strength in the first widthwise adjacent region W1 by the widthwise length of the widthwise central region Wc. In other words, the difference in joining strength per unit length is greater in the longitudinal direction than in the widthwise direction.

[0093] Because the difference in bonding strength per unit length between the central region Lc (Lc') and the adjacent region L1 (L1') is large in the longitudinal direction, even when the pad 1 is folded along the fold line FL along the width direction before use and the one-side bonding means 30 and the other-side bonding means 30' are bonded, the one-side bonding means 30 and the other-side bonding means 30' can be easily peeled apart and unfolded in the longitudinal direction. On the other hand, as shown in the configuration of Figure 6, because the difference in bonding strength per unit length between the central region Wc (Wc') and the adjacent region W1 (W1') is small in the width direction, bonding the one-side bonding means 30 and the other-side bonding means 30' provided on the skin-side surface makes it easier to maintain the pad 1 covering excrement on the skin-side surface when discarding the pad 1.

[0094] Furthermore, the pad 1 of this embodiment can form convex and concave portions by providing the joining means 30, 30' with a first portion 34 and a second portion 35 that is thinner than the first portion 34. As a result, when the joining means 30 on one side and the joining means 30' on the other side of the pad 1 are joined before use, the joining means 30 on one side and the joining means 30' on the other side can be easily peeled apart and expanded in the longitudinal direction. In other words, by forming concave and convex portions with the joining agent 31, the concave portions 33 that are thinner in the thickness direction can be easily peeled apart.

[0095] In addition, in the pad 1 of this embodiment, the joining means 30, 30' are provided at the ends of the pad 1, respectively, making it easier to peel off and less likely to open when disposed of than when the joining means 30, 30' are provided in the center.

[0096] ===Modifications of Adjacent Layers 40, 40'=== Figure 9 is an explanatory diagram showing modifications of the adjacent layers 40, 40' of the pad 1. In the modification shown in Figure 9A, a second sheet 50 is provided between the absorbent core 10 and the topsheet 2 in the thickness direction, and the adjacent layers 40, 40' are provided closer to the skin than the second sheet 50. In this way, the presence of the second sheet 50 and the adjacent layers 40, 40' between the absorbent core 10 and the joining means 30, 30' further facilitates suppressing the movement of excreted liquid from the absorbent core 10 to the joining means 30, 30'.

[0097] 9B , the adjacent layers 40, 40′ have layer recesses 51 that are recessed in the thickness direction and layer protrusions 52 that are protruded in the thickness direction. This reduces the contact area between the adjacent layers 40, 40′ and the joining means 30, 30′ compared to when the adjacent layers 40, 40′ are smooth and in surface contact with the joining means 30, 30′, making it easier to inhibit the movement of moisture from the adjacent layers 40, 40′ to the joining means 30, 30′.

[0098] In the modified example shown in Figure 9C, the adjacent layers 40, 40' are located between the absorbent core 10 and the topsheet 2 in the thickness direction. Even in such a case, the adjacent layers 40, 40' are provided on the non-skin side of the joining means 30, 30', which helps prevent moisture from reaching the joining means 30, 30'. This prevents the mechanism that closes the absorbent core 10 (i.e., the self-adhesive adhesive 31 in the joining means 30, 30') from becoming wet. Therefore, the adhesive strength of the self-adhesive adhesive 31 is less likely to decrease, making it easier to maintain the pad 1 in a closed state.

[0099] ===Modified Examples of Joining Means 30, 30'=== Figure 10 is an explanatory diagram showing modified examples of joining means 30, 30' of the pad 1. It is desirable that the self-adhesive adhesive 31 in the joining means 30, 30' be provided in a non-uniform pattern on the skin side of the topsheet 2. An example of such a configuration is shown in Figures 10A and 10B. Figures 10A and 10B show self-adhesive quadrilateral joining means 30, 30', respectively.

[0100] 10A , the longitudinal central region Lc is a region where the adhesive 31 is uniformly applied (solidly applied) in a substantially rectangular shape that is elongated in the width direction on the skin-facing side of the topsheet 2. Furthermore, the first longitudinal adjacent region L1 and the second longitudinal adjacent region L2 are coated with the self-adhesive adhesive 31 in a wave-like pattern, as shown in FIG.

[0101] In this case, the total application amount (basis weight) of the self-adhesive adhesive 31 can be reduced compared to when the self-adhesive adhesive 31 is applied solidly (in a uniform pattern) to the topsheet 2. Furthermore, the adhesive strength of the first longitudinal adjacent region L1 and the second longitudinal adjacent region L2, where the self-adhesive adhesive 31 is applied in a wavy pattern and has margins, is weaker than that of the solidly applied longitudinal center region Lc. As a result, the pad 1 can be easily peeled off when unfolded, while the adhesive strength of the longitudinal center region Lc is stronger than that of the adjacent regions, so that when the pad 1 is folded for disposal, the pad 1 can maintain a state in which excrement on the skin side is covered by the pad 1.

[0102] 10B, the longitudinal central region Lc is a region that is uniformly coated with the self-adhesive adhesive 31, as in the modification of FIG. 10A. The first longitudinal adjacent region L1 and the second longitudinal adjacent region L2 are partially coated with the self-adhesive adhesive 31 in the width direction, as shown in FIG. 10B, with margins remaining.

[0103] 10A , the total amount (basis weight) of the self-adhesive adhesive 31 applied can be reduced compared to when the self-adhesive adhesive 31 is applied solidly (in a uniform pattern) to the topsheet 2. Furthermore, the adhesive strength of the first longitudinal adjacent region L1 and the second longitudinal adjacent region L2, which are only partially applied with the self-adhesive adhesive 31 in the width direction and have margins, is weaker than that of the solidly applied longitudinal center region Lc. As a result, the pad 1 can be easily peeled off when unfolded, while the adhesive strength of the longitudinal center region Lc is stronger than that of the adjacent regions. Therefore, when the pad 1 is folded for disposal, the pad 1 can maintain a state in which excrement on the skin side is covered by the pad 1.

[0104] In these modified examples, the application amount per unit area of ​​the bonding means 30, 30' and the arrangement pattern using margins in the central regions Lc, Wc are different from the arrangement pattern of the bonding means 30, 30' in the first adjacent regions L1, W1 or the second adjacent regions L2, W2.

[0105] ===Other=== The above embodiments are intended to facilitate understanding of the present invention and are not intended to limit the present invention. The present invention may be modified or improved without departing from the spirit thereof, and it goes without saying that the present invention includes equivalents thereof.

[0106] 1 and 4, both widthwise ends of the joining means 30, 30' overlap with the side sheet 4 in the thickness direction, and the side sheet 4 is interposed between the joining means 30, 30' and the top sheet 2. In other words, at least a part of the side sheet 4 forming the leakage preventing wall portion 6 may function as the adjacent layer 40, 40'.

[0107] 1 urine absorption pad (pad, absorbent article) 2 surface sheet (top sheet), 3 back sheet, 4 side sheet, 5 leg-hole elastic member, 6 leakage-preventing wall portion, 7 leakage-preventing wall elastic member, 10 absorbent core, 11 core wrap sheet, 20 fixing member, 30 one-side joining means, 30' other-side joining means, 31 self-adhesive adhesive, 40 one-side adjacent layer, 40' other-side adjacent layer, 50 second sheet, Lc longitudinal central region, Wc width central region, L1 first longitudinal adjacent region, W1 first width adjacent region, L2 second longitudinal adjacent region, W2 second width adjacent region,

Claims

1. An absorbent article having a longitudinal direction, a width direction, and a thickness direction that are orthogonal to each other in the unfolded state, an absorbent core having liquid absorbency, a topsheet laminated closer to the skin side than the absorbent core, and a leak-proof sheet laminated closer to the non-skin side than the absorbent core, the absorbent article comprising: having an adhesive on the skin side of the topsheet that can be joined to a part of the absorbent article at the time of disposal; having an adjacent layer adjacent to the topsheet from the thickness direction, closer to the skin side than the leak-proof sheet, and closer to the non-skin side than the adhesive; and having a portion where the adhesive and the adjacent layer overlap when viewed in the thickness direction in the unfolded and stretched state. An absorbent article characterized by this.

2. The absorbent article according to claim 1, characterized in that the adjacent layer is composed of a non-woven fabric.

3. The absorbent article according to claim 2, characterized in that the adjacent layer has a concave portion that is concave in the thickness direction and a convex portion that is convex in the thickness direction.

4. The absorbent article according to claim 1, characterized in that the adjacent layer is composed of a non-woven fabric and ink applied to the non-woven fabric.

5. The absorbent article according to claim 1, characterized in that the adjacent layer is a hydrophobic layer.

6. The absorbent article according to claim 5, characterized in that the hydrophobic layer is composed of a hot melt adhesive applied to the topsheet.

7. The absorbent article according to claim 5, characterized in that the hydrophobic layer is composed of colored ink applied to the topsheet.

8. The absorbent article according to any one of claims 1 to 7, having a second sheet between the absorbent core and the topsheet in the thickness direction, and the adjacent layer is provided closer to the skin side than the second sheet. An absorbent article characterized by this.

9. The absorbent article according to any one of claims 1 to 7, characterized in that the adjacent layer is located between the adhesive and the topsheet in the thickness direction.

10. The absorbent article according to any one of claims 1 to 7, wherein in the thickness direction when viewed in the developed and extended state, the size of the region where the adhesive is provided is different from that of the adjacent layer.

11. The absorbent article according to claim 10, wherein in the thickness direction when viewed in the developed and extended state, the adjacent layer is provided in the entire region where the adhesive is provided and in a region outside the region where the adhesive is provided.

12. The absorbent article according to claim 11, wherein when the region where the adhesive is provided is trisected into a first adjacent region, a central region, and a second adjacent region in the longitudinal direction, the bonding strength of the central region is stronger than the bonding strength of the first adjacent region or the second adjacent region.

13. The absorbent article according to any one of claims 1 to 7, wherein the adjacent layer is provided across the end of the absorbent core in the longitudinal direction or the width direction.

14. The absorbent article according to any one of claims 1 to 7, wherein the adhesive is provided in a non-uniform pattern closer to the skin side than the topsheet.

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