Absorbent article and absorbent pad

Abstract

This absorbent article (1) has a longitudinal direction, a width direction, and a thickness direction that are orthogonal to each other in an unfolded state, and comprises a liquid-absorbing absorbent core (10). The absorbent article (1) has, on the skin-side surface thereof, a bonding agent (31) that can be bonded to a portion of the absorbent article (1) when the absorbent article (1) is discarded, and has, on the surface of the bonding agent (31), a plurality of protruding portions (301) that protrude in the thickness direction and a plurality of recessed portions (302) that is recessed in the thickness direction.

Description

Absorbent articles and absorbent pads

[0001] The present invention relates to absorbent articles and absorbent pads.

[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, when an absorbent article is used (worn, etc.), foreign matter such as sebum or fiber debris may adhere to the surface of the adhesive, self-adhesive, or other bonding agent used in the closing mechanism, which may reduce the bonding strength of the self-adhesive, making it difficult to maintain the absorbent article closed.

[0006] The present invention has been made in consideration of the above-mentioned problems, and its purpose is to provide an absorbent article equipped with a closing mechanism that prevents a decrease in the bonding strength of the closing mechanism and can maintain a state in which 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 which are perpendicular to one another when unfolded, and comprising a liquid-absorbent core, the absorbent article having an adhesive on the skin side which can be bonded to a part of the absorbent article when discarded, the adhesive having a surface which has a plurality of convex portions which are convex in the thickness direction and a plurality of concave portions which are concave in the thickness direction. Other features of the present invention will become clear 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 suppress a decrease in the bonding strength of the closing mechanism and maintain a state in which excrement on the skin side is covered by the absorbent article.

[0009] 12A to 12C are schematic plan views of a urine absorption pad 1 according to an embodiment of the present invention, viewed from the skin side in an unfolded and stretched state.

[0034] FIG. 12A is a schematic cross-sectional view of the urine absorption pad 1.

[0035] FIG. 12B is an explanatory diagram of the pad 1 when folded in half.

[0036] FIG. 12C is a partial enlarged view for explaining the detailed configuration of the pad 1.

[0037] FIG. 12B is an explanatory diagram of the self-adhesive joining means 30, 30'.

[0038] FIG. 12C is an explanatory diagram of a case where the joining means 30 on one side and the joining means 30' on the other side each have a convex portion 301 and a concave portion 302.

[0039] FIG. 12C is an explanatory diagram of a case where the joining means 30 (30') and the leakage preventing wall elastic member 7 overlap in the thickness direction.

[0039] FIG. 12B is an explanatory diagram of a case where the joining means 30 (30') and the absorbent polymer 101 overlap in the thickness direction.

[0039] FIG. 12C is an explanatory diagram of a case where the joining means 30 (30') and the groove portion overlap in the thickness direction.

[0039] FIG. 12A to 12C are explanatory diagrams of the relationship between the core wrap sheet 11 and the joining means 30. 13A and 13B are diagrams for explaining a case where a part of the overlap portion 11or of the core wrap sheet 11 is turned up. A plan view of the pad 1 in an unfolded and stretched state, seen from the non-skin side. An explanatory diagram of an example of use when attached to a pants-type diaper 50. An explanatory diagram of the joining means 30, 30'. A diagram for explaining the action and effect of the pad 1 to which the joining means 30, 30' is applied. An explanatory diagram of modified examples of the joining means 30, 30'.

[0010] The present specification and the accompanying drawings make clear at least the following: (Aspect 1) An absorbent article having a liquid-absorbing absorbent core with a longitudinal direction, a width direction, and a thickness direction that are perpendicular to one another when in an unfolded state, wherein an adhesive agent is provided on the skin side that can be bonded to a part of the absorbent article when discarded, and the surface of the adhesive agent has a plurality of convex portions that are convex in the thickness direction and a plurality of concave portions that are concave in the thickness direction.

[0011] According to Aspect 1, when the surface of the adhesive comes into contact with the wearer's skin or clothing while the absorbent article is being worn, the recesses on the surface of the adhesive are less likely to attract sebum, fiber debris, and the like compared to the protrusions. Therefore, by providing multiple recesses on the surface of the adhesive, the adhesive strength is less likely to decrease compared to when no recesses are provided. This makes it easier for the absorbent article to maintain a closed state.

[0012] (Aspect 2) An absorbent article according to aspect 1, having an elastic member that stretches in at least one of the longitudinal direction and the width direction, and when viewed in the thickness direction, at least a portion of the adhesive overlaps with the elastic portion of the elastic member.

[0013] According to Aspect 2, since at least a portion of the bonding agent overlaps with the elastic member, recesses and protrusions are likely to be formed on the surface of the bonding agent at the overlapping portion. In addition, wrinkles formed by the expansion and contraction of the elastic member tend to form recesses and protrusions on the surface of the bonding agent.

[0014] (Aspect 3) An absorbent article according to Aspect 1 or Aspect 2, wherein the elastic member has a non-elastic portion that does not have elasticity, and when viewed in the thickness direction, at least a portion of the adhesive overlaps with the non-elastic portion.

[0015] According to aspect 3, at least a portion of the bonding agent overlaps with the non-stretchable portion of the elastic member, and since the thickness of the elastic member in the non-stretchable portion tends to be larger than that in the elastic portion, larger recesses and protrusions tend to be formed on the surface of the bonding agent in the overlapping portion.

[0016] (Aspect 4) An absorbent article according to any one of Aspects 1 to 3, comprising a superabsorbent polymer, wherein when viewed in the thickness direction, at least a portion of the binder does not overlap with the absorbent core and overlaps with the absorbent polymer.

[0017] According to aspect 4, at least a portion of the binder does not overlap with the absorbent core but overlaps with the absorbent polymer (SAP), which makes it easier to form recesses and protrusions on the surface of the binder in the overlapping areas.

[0018] (Aspect 5) The absorbent article according to any one of Aspects 1 to 4, wherein the binder is disposed across the longitudinal ends of the absorbent core.

[0019] According to aspect 5, since a step occurs in the thickness direction at the edge of the absorbent core (the outline of the absorbent core), a step is likely to be formed in the adhesive placed across the edge, and in addition to the multiple convex and concave portions provided on the surface of the adhesive, the step can also further reduce the probability of sebum, fiber debris, etc. adhering.

[0020] (Aspect 6) An absorbent article according to any one of Aspects 1 to 5, wherein the absorbent core has a groove portion that is concave in the thickness direction, and when viewed in the thickness direction, at least a portion of the adhesive overlaps the groove portion.

[0021] According to aspect 6, at least a portion of the binder overlaps with the grooves in the absorbent core, which makes it easier to form recesses and protrusions on the surface of the binder at the overlapping portions.

[0022] (Aspect 7) An absorbent article according to any one of Aspects 1 to 6, comprising a top sheet laminated on the skin side of the absorbent core, wherein the top sheet has a plurality of sheet convex portions that are convex in the thickness direction and a plurality of sheet concave portions that are concave in the thickness direction, and when viewed in the thickness direction, at least a portion of the adhesive overlaps with the sheet convex portions and the sheet concave portions.

[0023] According to aspect 7, by overlapping with the irregularities of the top sheet, depressions and projections are likely to be formed on the surface of the bonding agent in the overlapping areas.

[0024] (Aspect 8) An absorbent article according to any one of Aspects 1 to 7, wherein the adhesive comprises a one-side adhesive provided at one end of the absorbent article in the longitudinal direction and a other-side adhesive provided at the other end of the absorbent article in the longitudinal direction, and when the absorbent article is folded in half at a predetermined position in the longitudinal direction and the one-side adhesive and the other-side adhesive are bonded facing each other, a certain convex portion of the plurality of convex portions provided on the surface of the one-side adhesive and a certain convex portion of the plurality of convex portions provided on the surface of the other-side adhesive have a portion where they are misaligned.

[0025] According to Aspect 8, the probability that the protrusions with the bonding agent on one side and the protrusions with the bonding agent on the other side, which have reduced bonding strength, face each other is reduced, making it easier to maintain the bonded state between the two.

[0026] (Aspect 9) An absorbent article according to any one of Aspects 1 to 8, comprising a core wrap sheet covering the absorbent core, wherein the core wrap sheet, in a planar state before covering the absorbent core, has one side end located on one side in the width direction and another side end located on the other side in the width direction, and when the absorbent core is covered by the core wrap sheet, the one side end and the other side end have an overlapping portion where they are overlapped in the thickness direction, and when viewed in the thickness direction in an unfolded and stretched state, the adhesive and the overlapping portion have an overlapping portion.

[0027] According to Aspect 9, the bonding agent has a convex portion that is convex in the thickness direction in accordance with the convex shape of the overlapping portion in the portion that overlaps the overlapping portion. That is, a step is formed on the surface of the bonding agent, and the probability that sebum, fiber debris, etc. will adhere to the portion other than the convex portion is reduced. This makes it less likely that the bonding strength of the bonding agent will decrease.

[0028] (Aspect 10) An absorbent article according to Aspect 9, wherein in the overlap portion, at least a portion of the one side end or the other side end has a rolled-up portion rolled up in the thickness direction, and when viewed in the thickness direction in an unfolded and stretched state, there is a portion where the adhesive and the rolled-up portion overlap.

[0029] According to Aspect 10, in the portion of the bonding agent that overlaps with the turned-up portion, a convex portion that is further convex in the thickness direction is formed in accordance with the convex shape of the turned-up portion 11. In other words, a large step is likely to be formed on the surface of the bonding agent, and the probability that sebum, fiber debris, etc. will adhere to portions other than the convex portion is reduced. This makes it less likely that the bonding strength of the bonding agent will decrease.

[0030] (Aspect 11) An absorbent article according to any one of Aspects 1 to 10, having a fastening means on the non-skin side that can be fastened to the skin side of a pants-type absorbent article, and having a portion where the adhesive and the fastening means overlap when viewed in the thickness direction in an unfolded and stretched state.

[0031] According to Aspect 11, the portion where the fixing portion is provided has higher rigidity than the other portions, so that by pressing the portion overlapping with the fixing portion from the non-skin side, a force can be efficiently applied to the adhesive, which makes it easier to bond the adhesives together more strongly.

[0032] (Aspect 12) An absorbent article according to any one of Aspects 1 to 11, having a mark visible from the non-skin side, and having a portion where the adhesive and the mark overlap when viewed in the thickness direction in an unfolded and stretched state.

[0033] According to Aspect 11, since the mark is easily visible from the non-skin side, by pressing the portion overlapping with the mark from the non-skin side, a force can be efficiently applied to the bonding agent, which makes it easier to bond the bonding means together more strongly.

[0034] (Mode 13) An absorbent pad that has a longitudinal direction, a width direction, and a thickness direction that are perpendicular to each other when unfolded, has a liquid-absorbing absorbent core, and can be attached to the skin-side surface of a pants-type absorbent article for use, wherein the pants-type absorbent article has pants-side stretch members that stretch along at least one of the longitudinal direction and the width direction, and the skin-side surface of the absorbent pad has an adhesive that can be bonded to a part of the absorbent article when discarded, and when viewed in the thickness direction with the absorbent pad attached to the pants-type absorbent article, at least a part of the adhesive overlaps with the pants-side stretch member, and the adhesive has a plurality of convex portions and concave portions on its surface.

[0035] According to Aspect 13, when the pad is attached to pants, the pad overlaps with the stretchable member of the pants, which makes it easier to form multiple recesses and protrusions on the adhesive surface of the pad. Furthermore, since the adhesive surface has multiple recesses that are less likely to attract sebum, fiber debris, etc., the adhesive strength is less likely to decrease compared to when no recesses are provided. This makes it easier for the absorbent pad to maintain a closed state.

[0036] 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.

[0037] <<<<Basic Structure of the 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 placed inside a pants-type diaper 50 (sometimes simply referred to as the diaper 50), which will be described later. Furthermore, the urine absorption pad 1 is not limited to pants-type diapers, and can also be placed directly inside, for example, a tape-type disposable diaper or the wearer's underwear (pants or shorts).

[0038] 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.

[0039] 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.

[0040] 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; hereinafter sometimes referred to as leak-proof sheet 3) 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.

[0041] The absorbent core 10 can be, for example, a liquid-absorbent fiber such as pulp fiber containing SAP (super absorbent polymer) molded into a predetermined shape, and in this embodiment, it is molded to include an absorbent polymer 101 (described later) and pulp fiber 102. The absorbent core 10 is also covered with a liquid-permeable core wrap sheet 11 (e.g., tissue).

[0042] However, the absorbent core 10 is not limited to the above, and may be an SAP sheet in which an SAP layer is attached to a hydrophilic sheet, an airlaid sheet in which liquid-absorbent fibers are formed into a sheet by an airlaid method, or the like, or may have a laminated structure of two or more layers. Also, the absorbent core 10 does not have to be covered with the core wrap sheet 11.

[0043] 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.

[0044] 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.

[0045] 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 (leg-surrounding elastic members) 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 elasticity 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.

[0046] The pad 1 also has joining means 30, 30' at both ends in the longitudinal direction. The configuration of the joining means 30, 30' will be described in detail below.

[0047] <<<<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).

[0048] 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.

[0049] 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.

[0050] 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.

[0051] FIG. 5 (FIGS. 5A and 5B) is an explanatory diagram of the one-side joining means 30 and the other-side joining means 30'. The adhesive 31 provided as a 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.

[0052] 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.

[0053] 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.

[0054] Next, we will explain the specific configurations of the joining means 30, 30' and the top sheet 2. Figure 6 is a diagram for explaining the convex portions 301 and concave portions 302 in the joining means 30. As shown in Figure 6A, the one-side joining means 30 has, on the surface of the self-adhesive adhesive 31, a plurality of convex portions 301 that are convex in the thickness direction of the pad 1 and a plurality of concave portions 302 that are concave in the thickness direction.

[0055] Furthermore, in this embodiment, the top sheet 2 has a plurality of sheet convex portions 201 that are convex toward the skin side in the thickness direction of the pad 1, and a plurality of sheet concave portions 202 that are concave. When viewed in the thickness direction, at least a portion of the one-side joining means 30 overlaps with the sheet convex portions 201 and the sheet concave portions 202. As a result, of the self-adhesive adhesive 31 of the one-side joining means 30, convex portions 301 are formed in the portions that overlap with the skin side of the sheet convex portions 201, and concave portions 302 are formed in the portions that overlap with the skin side of the sheet concave portions 202. In other words, by applying the self-adhesive adhesive 31 to the skin side of the top sheet 2 that has the sheet convex portions 201 and the sheet concave portions 202, convex portions 301 corresponding to the sheet convex portions 201 and concave portions 302 corresponding to the sheet concave portions 202 are formed on the surface of the one-side joining means 30 (self-adhesive adhesive 31).

[0056] In the example of Figure 6, the sheet protrusions 201 and sheet recesses 202 of the top sheet 2 are formed along the longitudinal direction or width direction, thereby forming wavy projections and depressions on the skin-facing side of the top sheet 2, but the configuration of the top sheet 2 is not limited to this example. For example, the sheet protrusions 201 and sheet recesses 202 may be formed by a sheet that is wavy when viewed in the width and longitudinal directions and is embossed to form a checkered pattern when viewed in the thickness direction.

[0057] Furthermore, the top sheet 2 is not limited to being a corrugated sheet, and may be, for example, a smooth, flat surface with no irregularities on the skin side of the top sheet 2. In this case, the convex portions 301 and concave portions 302 of the joining means 30, 30′ may be formed by other members as described below, rather than by the sheet convex portions 201 and sheet concave portions 202 of the top sheet 2.

[0058] Next, the operation and effects of the pad 1 of this embodiment will be described. When wearing the pad 1, since the bonding means 30 (30') is provided on the skin-facing side of the pad 1, foreign matter such as sebum and fiber debris may adhere to the surface of the self-adhesive adhesive 31 used in the bonding means 30 (30'). On the other hand, when discarding a used pad 1, the pad 1 is first folded along the center line CL (fold line FL) of the pad 1 shown in FIG. 1 with the skin-facing side facing inward. Then, the bonding means 30 (30') are placed on top of each other and pressed from the non-skin side (see FIG. 3B). If foreign matter such as sebum and fiber debris adheres to the surface of the self-adhesive adhesive 31 used in the bonding means 30 (30'), the bonding strength of the self-adhesive adhesive 31 may be reduced, making it difficult to maintain the pad 1 in a closed state.

[0059] In contrast, in this embodiment, when the surface of the self-adhesive adhesive 31 comes into contact with the wearer's skin or clothing while the pad 1 is being worn, the recesses 302 on the surface of the self-adhesive adhesive 31 are less likely to have sebum, fiber debris, and the like adhere to them than the protrusions 301. Therefore, by providing multiple recesses 302 on the surface of the self-adhesive adhesive 31, the bonding strength is less likely to decrease compared to when the recesses 302 are not provided. This makes it easier to maintain the pad 1 in a closed state.

[0060] Furthermore, the sheet convex portions 201 and sheet concave portions 202 are formed on the top sheet 2 of this embodiment, and the concave portions and the joining means 30, 30' overlap in the thickness direction, which makes it easier for the convex portions 301 and the concave portions 302 to be formed on the surface of the self-adhesive bonding agent 31 at the overlapping portions. Therefore, compared to when the concave portions 302 are not provided, the joining strength is less likely to decrease, making it easier for the pad 1 to maintain a closed state.

[0061] In the pad 1 of this embodiment, it is sufficient that the convex portion 301 and the concave portion 302 are formed in at least one of the one-side joining means 30 and the other-side joining means 30'. For example, as shown in FIG. 6B , the one-side joining means 30 has the convex portion 301 and the concave portion 302, but the other-side joining means 30' may be substantially flat without any unevenness. In this case, when the other-side joining means 30' faces the one-side joining means 30, it joins with at least a part of the concave portion 302 of the one-side joining means 30, which is less likely to lose its joining strength, making it easier to maintain the joined state between the two than when the concave portion 302 is not provided.

[0062] However, in the pad 1 of this embodiment, it is desirable that the one-side joining means 30 and the other-side joining means 30' each have a convex portion 301 and a concave portion 302 on their surfaces. FIG. 7 is an explanatory diagram of a case where the one-side joining means 30 and the other-side joining means 30' each have a convex portion 301 and a concave portion 302. In the pad 1 of this embodiment, as shown in FIG. 7A , when the pad 1 is folded in half along the fold line FL and the one-side joining means 30 and the other-side joining means 30' are opposed to each other and joined, it is desirable that a convex portion 301 among the multiple convex portions provided on the surface of the one-side joining means 30 and a convex portion 301 among the multiple convex portions provided on the surface of the other-side joining means 30' are misaligned. This reduces the probability that the convex portions 301 with reduced bonding strength will face each other between the convex portions 301 of the one-side joining means 30 and the convex portions 301 of the other-side joining agent. Furthermore, one of the convex portions 301 of the joining means 30 (30') joins with at least a part of the concave portion 302, the joining strength of which is unlikely to decrease, so that the joined state between the two is easily maintained.

[0063] On the other hand, as shown in Figure 7B, when the convex portion 301 of the one-side joining means 30 and the convex portion 301 of the other-side joining means 30' abut in the thickness direction, the convex portions 301 with reduced joining strength face each other, and further, the concave portions 302 with less reduced joining strength are farther apart in the thickness direction than the convex portions 301, so it may be difficult to maintain the joined state between the two.

[0064] In this embodiment, it is desirable that the self-adhesive adhesive 31 of the joining means 30 (30') be disposed across the longitudinal ends of the absorbent core 10. FIG. 8 is a diagram illustrating the convex regions 303 and concave regions 304 of the joining means 30, and is a partially enlarged cross-sectional view of region A in FIG. 3. As shown in FIG. 8, a step occurs in the thickness direction at the end of the absorbent core 10 (the outline of the absorbent core 10). In this case, the convex region 303 refers to a portion of the pad 1 that is thick in the thickness direction due to the absorbent core 10 and where the absorbent core 10 and the joining means 30 (30') overlap when viewed in the thickness direction. On the other hand, the concave region 304 refers to a portion of the pad 1 that is thin in the thickness direction due to the absence of the absorbent core 10 and where the absorbent core 10 and the joining means 30 (30') do not overlap when viewed in the thickness direction. In the pad 1 of this embodiment, it is desirable that the joining means 30 have the convex region 303 and the concave region 304.

[0065] The presence of the convex regions 303 and the concave regions 304 also facilitates the formation of a step in the joining means 30 (30') disposed across the end of the absorbent core 10. That is, when the surface of the self-adhesive adhesive 31 comes into contact with the wearer's skin or clothing during wear, etc., the formation of a step in the joining means 30 (30') reduces the likelihood of adhesion of sebum, fiber debris, etc. to the concave regions 304 of the joining means 30 (30') compared to the convex regions 303. Therefore, the presence of the concave regions 304 in the joining means 30 (30') makes it less likely for the joining strength to decrease compared to when the concave regions 304 are not provided, making it easier for the pad 1 to maintain a closed state. Furthermore, in addition to the multiple convex portions 301 and concave portions 302 provided on the surface of the self-adhesive adhesive 31, the step between the convex regions 303 and the concave regions 304 in the thickness direction also further reduces the likelihood of adhesion of sebum, fiber debris, etc., to the joining means 30 (30'). This makes it easier for the pad 1 to maintain a closed state.

[0066] Furthermore, in the pad 1 of this embodiment, when viewed in the thickness direction, at least a portion of the one-side joining means 30 may overlap a stretchable portion of the leakage preventing wall elastic member 7. FIG. 9 is a diagram showing the joining means 30 (30') and the leakage preventing wall elastic member 7 overlapping in the thickness direction. Herein, the stretchable portion of the leakage preventing wall elastic member 7 as a stretchable member of this embodiment is the portion represented by the section from 7A to 7B in the longitudinal direction in FIG. 1. In this section, the leakage preventing wall elastic member 7 is attached to the side sheet 4 in a stretched state, thereby exhibiting stretchability of the leakage preventing wall elastic member 7. Hereinafter, the length of the stretchable portion of the leakage preventing wall elastic member 7 (stretchable portion) will also be referred to as the "effective length" of the leakage preventing wall elastic member 7.

[0067] 9 illustrates a case where the leak-preventing wall elastic member 7 has a stretchable portion, i.e., a case where the joining means 30 and the leak-preventing wall elastic member 7 overlap when viewed from one stretch region end 7A toward the center line CL of the pad 1 in FIG. 1 or 4 . In this case, at least a portion of the joining means 30 overlaps with the leak-preventing wall elastic member 7, which makes it easier for convex portions 301 and concave portions 302 to form on the surface of the joining means 30 at the overlapping portion. Furthermore, the stretchable portion of the leak-preventing wall elastic member 7 may stretch, forming wrinkles on the surface of the pad 1 (at both longitudinal ends, the leak-preventing wall portion 6, or the side sheet 4, etc.). In this case, the unevenness of the wrinkles makes it easier for convex portions 301 and concave portions 302 to form on the surface of the self-adhesive adhesive 31. Therefore, compared to a case where the concave portions 302 are not provided, the bonding strength of the joining means 30 (30') is less likely to decrease, making it easier for the pad 1 to maintain a closed state.

[0068] Although the above description has been given of the case where there is an overlapping portion between the joining means 30 and the leakage-preventing wall elastic member 7 when viewed from the end 7A of the stretched region on one side toward the center line CL of the pad 1, the same action and effect can be achieved when there is an overlapping portion between the joining means 30' and the leakage-preventing wall elastic member 7 when viewed from the end 7B of the stretched region on the other side toward the center line CL of the pad 1.

[0069] Furthermore, when viewed in the thickness direction, at least a part of the one-side joining means 30 may overlap with a non-stretchable portion (non-stretchable portion) of the leak preventing wall elastic member 7. Here, the non-stretchable portion of the leak preventing wall elastic member 7 as a stretchable member in this embodiment is a non-stretchable region excluding the stretchable region (effective length) of the entire length of the leak preventing wall elastic member 7, and in Figure 1 is both end portions in the longitudinal direction of the leak preventing wall elastic member 7.

[0070] 9 illustrates a case where the leak-preventing wall elastic member 7 does not have stretchability, i.e., where the joining means 30 and the leak-preventing wall elastic member 7 overlap when viewed from the end 7A of the stretched region on one side of FIG. 1 or 4 toward the edge of the pad 1. In this case, at least a portion of the joining means 30 overlaps with the non-stretchable portion of the stretchable member. Because the thickness of the stretchable member in the non-stretchable portion tends to be greater than in the stretchable portion, larger convex portions 301 and concave portions 302 are likely to form on the surface of the self-adhesive adhesive 31 in the portion where the one-side joining means 30 overlaps with the non-stretchable portion of the stretchable member. Therefore, compared to a case where the concave portions 302 are not provided, the bonding strength of the joining means 30 (30') is less likely to decrease, making it easier for the pad 1 to maintain a closed state. Although the case has been described where there is an overlapping portion between the joining means 30 and the leakage preventing wall elastic member 7 when viewed from one end 7A of the stretched region toward the end of the pad 1, the same action and effect can be achieved when there is an overlapping portion between the joining means 30' and the leakage preventing wall elastic member 7 when viewed from the other end 7B of the stretched region toward the end of the pad 1. The leakage preventing wall elastic member 7, exemplified as an elastic member, is arranged along the longitudinal direction of the pad 1, but the elastic member is not limited to this and may be an elastic member arranged along the width direction.

[0071] Furthermore, in this embodiment, when viewed in the thickness direction, at least a portion of the joining means 30 does not overlap with the absorbent core 10, and may overlap with the absorbent polymer 101. Fig. 10 is a diagram showing the joining means 30 (30') and the absorbent polymer 101 overlapping in the thickness direction. Fig. 10A is a plan view of one longitudinal end of the pad 1 as viewed from the thickness direction, and Fig. 10B is a cross-sectional view taken along the X1-X1 arrows in Fig. 10A.

[0072] The absorbent core 10 of this embodiment is molded to include absorbent polymer 101 and pulp fibers 102 and is covered with a core wrap sheet 11. As shown in the schematic cross-sectional view of FIG. 2, the core wrap sheet 11 covers the pad 1 across its width, so that a portion of the absorbent polymer 101 in the absorbent core 10 may move outward in the longitudinal direction from the absorbent core 10 (see FIG. 10A). In this case, as shown in FIG. 10B, at least a portion of the bonding means 30 does not overlap the absorbent core 10, and in the portion that overlaps with the absorbent polymer 101, convex portions 301 and concave portions 302 are likely to be formed on the surface of the self-adhesive adhesive 31. Therefore, compared to when the concave portions 302 are not provided, the bonding strength is less likely to decrease, making it easier for the pad 1 to maintain a closed state.

[0073] In this embodiment, the absorbent core 10 has a groove portion recessed in the thickness direction, and at least a portion of the joining means 30 may overlap the groove portion when viewed in the thickness direction. FIG. 11 shows the joining means 30 (30') and the groove portion overlapping in the thickness direction. FIG. 11A is a plan view of one longitudinal end of the pad 1 as viewed from the thickness direction, and FIG. 11B is a cross-sectional view taken along the X2-X2 arrow in FIG. 11A. Here, the groove portion refers to a groove portion in the thickness direction formed by at least one of the compressed portion 10A and the slit portion 10B in the absorbent core 10. As shown in FIGS. 1, 4, and 11A, the absorbent core 10 of this embodiment has a compressed portion 10A and a slit portion 10B as groove portions recessed in the thickness direction. The compressed portion 10A is a portion formed by compressing the absorbent core 10 and the core wrap sheet 11 in the thickness direction. The slit portions 10B are portions where the basis weight is set to zero by making cuts of a predetermined width in the absorbent core 10. By providing these compressed portions 10A and slit portions 10B, the absorbent core 10 can easily deform in accordance with the shape of the wearer's body when the pad 1 is worn, which facilitates improving the fit.

[0074] When viewed in the thickness direction, in the area where at least a part of the joining means 30 overlaps with the compressed portion 10A and the slit portion 10B, a recess 302 is likely to be formed on the surface of the self-adhesive adhesive 31, as shown in Fig. 11B. Therefore, compared to when the recess 302 is not provided, the bonding strength of the joining means 30 (30') is less likely to decrease, and the pad 1 can more easily maintain a closed state.

[0075] Furthermore, the core wrap sheet 11 covering the absorbent core 10 may form convex portions 301 and concave portions 302 on the surface of the joining means 30 (adhesive 31). Figures 12A to 12C are diagrams illustrating the relationship between the core wrap sheet 11 and the joining means 30. Figure 12A is a plan view of one longitudinal end of the pad 1 in an expanded and stretched state, as viewed from the thickness direction. Figure 12B is a cross-sectional view showing the core wrap sheet 11 before covering the absorbent core 10. Figure 12C is a cross-sectional view taken along the X3-X3 arrows in Figure 12A.

[0076] First, a method for covering the absorbent core 10 with the core wrap sheet 11 will be briefly described. Before covering the absorbent core 10, the core wrap sheet 11 is a planar sheet member. In FIG. 12B , the portion of the planar core wrap sheet 11 including one edge in the width direction is designated as one end 11ea, and the portion including the other edge in the width direction is designated as the other end 11eb. Then, with the absorbent cores 10 stacked in the thickness direction, the one end 11ea is folded back from one side to the other in the width direction, and the other end 11eb is folded back from the other side to one side in the width direction to encase the absorbent core 10. The folded one end 11ea and the other end 11eb are folded back on the skin side of the absorbent core 10 and joined to each other. This results in the absorbent core 10 being covered by the core wrap sheet 11. Hereinafter, the portion where the one side end 11ea and the other side end 11eb overlap in the thickness direction will be referred to as an overlap portion 11or.

[0077] When viewed in the thickness direction, the pad 1 of this embodiment has an overlapping portion between the bonding means 30 and the overlapping portion 11or, as shown in FIG. 12A . The overlapping portion 11or is thicker than other portions because one end 11ea and the other end 11eb are stacked in the thickness direction, as shown in FIG. 12C . That is, the overlapping portion 11or is convex in the thickness direction. Therefore, in the portion of the bonding means 30 (bonding agent 31) that overlaps with the overlapping portion 11or, a convex portion 301 that is convex in the thickness direction according to the convex shape of the overlapping portion 11or is formed. On the other hand, in the portion of the bonding means 30 that does not overlap with the overlapping portion 11or, a concave portion 302 is formed, as it is less likely to be convex in the thickness direction. As a result, a step (unevenness) is formed in the bonding means 30 (bonding agent 31).

[0078] By forming a step in the joining means 30 (bonding agent 31), the recessed portion 302 of the joining means 30 (30') is less likely to have sebum, fiber debris, etc. attached to it than the protruding portion 301. Therefore, the joining strength of the joining means 30 (bonding agent 31) is less likely to decrease, and the pad 1 can more easily maintain a closed state.

[0079] 13A and 13B are diagrams illustrating a case where a part of the overlap portion 11or of the core wrap sheet 11 is turned up. 13A is a plan view of one end portion in the longitudinal direction of the pad 1 in an expanded and stretched state, as viewed from the thickness direction, and corresponds to FIG. 12A. 13B is a cross-sectional view taken along the X4-X4 arrows in FIG. 13A.

[0080] In the overlap portion 11or of the core wrap sheet 11, a portion of one side end portion 11ea or the other side end portion 11eb may be turned up in the thickness direction. In Figures 13A and 13B, a turned-up portion 11t is formed in which a portion of the other side end portion 11eb is turned up toward the skin side in the thickness direction. In the portion of the overlap portion 11or where the turned-up portion 11t is formed, the turned-up portion 11t is stacked in the thickness direction, making the portion thicker than the portion where the turned-up portion 11t is not formed.

[0081] When viewed in the thickness direction, the pad 1 of this embodiment has an overlapping portion between the bonding means 30 and the turned-up portion 11t, as shown in FIG. 13A. In the portion of the bonding means 30 (bonding agent 31) that overlaps the turned-up portion 11t, a convex portion 301t is formed, which is larger in the thickness direction in accordance with the convex shape of the turned-up portion 11t, as shown in FIG. 13B. Meanwhile, in the portion of the bonding means 30 that does not overlap with the overlapping portion 11or, a concave portion 302 is formed. In other words, a step (unevenness) is formed in the bonding means 30 (bonding agent 31). Therefore, the concave portion 302 of the bonding means 30 (30') is less likely to attract sebum, fiber debris, and the like compared to the convex portion 301t. This reduces the bonding strength of the bonding means 30 (bonding agent 31) and makes it easier to maintain the pad 1 in a closed state.

[0082] Furthermore, by efficiently applying a force when pressing in the thickness direction to the joining means 30, 30' having the convex portions 301 and the concave portions 302, the joining means 30, 30' can be strongly pressed together. Figure 14 is a plan view of the pad 1 in an expanded and stretched state, as seen from the non-skin side.

[0083] In Figure 14, the pad 1 has a fixing member 20 on its non-skin side as a fastening means for fastening the pad 1 to the inner surface of the pants-type diaper. When viewed in the thickness direction, the fixing member 20 (fastening means) and the joining means 30 (30') overlap in some areas. As described above, the fixing member 20 (fastening means) is made of a material different from the leakproof sheet 3 (backsheet 3), such as a hook-and-loop tape. Therefore, the portion of the leakproof sheet 3 of the pad 1 where the fixing member 20 (fastening means) is provided has higher rigidity than the other portions. Therefore, when the pad 1 is folded in half longitudinally and the one-side joining means 30 and the other-side joining means 30' are pressed against each other, pressing the overlapping portion with the fixing member 20 (fastening means) (i.e., the portion with higher rigidity) from the non-skin side allows for efficient application of force to the joining means 30, 30'. This facilitates stronger joining of the joining means 30, 30' and makes it easier to maintain the pad 1 in a closed state.

[0084] 14, the pad 1 is provided with a mark 40 that is visible from the non-skin side. The mark 40 is, for example, an image printed on the non-skin side of the leakbarrier sheet 3, and in Fig. 14, the word "press" (image) is printed to encourage pressing the pad 1. However, the mark 40 is not limited to an image printed on the non-skin side of the leakbarrier sheet 3 (backsheet 3), and an image printed on the skin side of the leakbarrier sheet 3 that is visible through the pad 1 from the non-skin side. Alternatively, a sheet member (such as a nonwoven fabric or film) with a printed image may be bonded to the leakbarrier sheet 3.

[0085] In the pad 1 of this embodiment, as shown in FIG. 14 , when viewed in the thickness direction, the mark 40 and the joining means 30 have an overlapping portion. The mark 40 makes it easy to confirm the position of the joining means 30 provided on the skin side of the pad 1, even from the non-skin side. Therefore, when the pad 1 is folded in half longitudinally and the one-side joining means 30 and the other-side joining means 30' are brought face to face and pressed together, pressing the overlapping portion with the mark 40 from the non-skin side makes it possible to efficiently apply force to the joining means 30, 30'. This makes it easier to join the joining means 30, 30' more firmly together, making it easier to maintain the pad 1 in a closed state.

[0086] <<<When Attached to a Pants-Type Diaper 50 for Use>>> Figure 12 is an explanatory diagram showing an example of when the pad 1 is attached to a pants-type diaper 50 for use. As shown in Figure 12A, the pad 1 can be used by being placed inside the diaper 50. However, this is not limitative, and the pad 1 can also be used by being placed inside the wearer's underwear.

[0087] The diaper 50 has at least an elastic member 51 as a pants-side elastic member. In this embodiment, the elastic member 51 is, for example, a waist elastic member, which is a plurality of thread-like elastic members (thread rubber) arranged along the width direction, but is not limited thereto and may be a leg elastic member or other elastic member. Furthermore, although the elastic member 51 in this embodiment stretches along the width direction of the diaper 50, it is not limited thereto and may stretch along the longitudinal direction.

[0088] 12A, the plurality of waist elastic members 51 are attached in a state stretched in the width direction at intervals in the up-down direction of the diaper 50. When the waist elastic members 51 and leg elastic members are stretched, they contract, allowing the diaper 50 to fit more closely around the waist and rear legs of the wearer when worn.

[0089] When the pad 1 of this embodiment is attached to the pants-type diaper 50 having such a configuration, the fixing member 20 provided on the non-skin-side surface of the pad 1 is joined (engaged) to the top sheet (skin-side, inner surface) of the diaper 50, thereby fixing the pants-type diaper 50 and the pad 1 together (see FIG. 12B ). When viewed in the thickness direction with the pad 1 attached to the pants-type diaper 50, it is desirable that at least a portion of the joining means 30 (30′) overlaps with the elastic member 51, and that the surface of the self-adhesive adhesive 31 has a plurality of convex portions 301 and concave portions 302.

[0090] Fig. 12C is a partial cross-sectional view of the pants-type diaper 50 with the pad 1 attached thereto, viewed from the width direction, and is a view taken along the line X5-X5 in Fig. 12B when cut in the thickness direction. As shown in Fig. 12C, in the area where at least a portion of the joining means 30 (30') overlaps with the elastic member 51, the elastic member 51 tends to form convex portions 301 and concave portions 302 on the surface of the self-adhesive adhesive 31. Therefore, compared to when the concave portions 302 are not provided, the joining strength is less likely to decrease, making it easier to maintain the pad 1 in a closed state.

[0091] Fig. 12D is a partial cross-sectional view of the pants-type diaper 50 with the pad 1 attached, as viewed from above and below, and is a view taken along the line X6-X6 in Fig. 12B. As shown in Fig. 12D, in the area where at least a portion of the joining means 30 (30') overlaps with the elastic member 51, wrinkles formed due to the expansion and contraction of the elastic member 51 tend to form convex portions 301 and concave portions 302 on the surface of the self-adhesive adhesive 31. Therefore, compared to when the concave portions 302 are not provided, the joining strength is less likely to decrease, and the pad 1 is more likely to maintain a closed state.

[0092] Next, the specific configurations of the one-side joining means 30 and the other-side joining means 30' will be described in detail using FIG. 15 . FIG. 15 is a diagram for explaining the joining means 30 and 30'. Note that for simplicity's sake, only the one-side joining means 30 will be described, but the other-side joining means 30' has a similar configuration. Furthermore, in the cross-sectional view of FIG. 15 , the topsheet 2 is shown flat for ease of explanation. However, in an actual pad 1, the topsheet 2 may deform in the thickness direction due to the influence of the thickness of the absorbent core 10. In other words, the topsheet 2 is not necessarily flat as shown in FIG. 15 , and the joining means 30 and 30' may also deform in the thickness direction in response to deformation of the topsheet 2, etc. The same applies to FIG. 16 , which will be described later.

[0093] As shown in Fig. 15, 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. 15, the area where the self-adhesive bonding agent 31 is applied is shown lightly shaded.

[0094] As described above, in this embodiment, an emulsion-based self-adhesive or the like is used as the bonding agent 31. A single application of the bonding agent 31 is defined as a uniform application (a so-called solid application) of the bonding agent 31 in a generally rectangular shape that is elongated in the width direction, and in the example shown in FIG. 15 , 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.

[0095] In this embodiment, as shown in Fig. 15 , 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. 15 , 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.

[0096] The skin-side surface of the one-side bonding means 30 is formed with a layer convex portion 32 and a layer concave portion 33 due to differences in the amount of adhesive 31 applied per unit area. The layer convex portion 32 is a first portion 34 where the amount of adhesive 31 applied per unit area is greater than that of the surrounding area, and is the portion where the adhesive 31 is applied three times out of three times. On the other hand, the layer concave portion 33 is a second portion 35 where the amount of adhesive 31 applied per unit area is less than that of the surrounding area. As described above, the first portion 34 is thicker in the thickness direction due to the greater amount of adhesive 31 applied per unit area, while the second portion 35 is thinner due to the less amount applied than the first portion 34. Therefore, the layer convex portion 32 and the layer concave portion 33 provided on the surface of the one-side bonding means 30 make the bonding strength less likely to decrease compared to when the layer concave portion 33 is not provided. This makes it easier to maintain the pad 1 in a closed state.

[0097] 15, however, only one layer protrusion 32 is formed over a wide area in the center in the width and length directions, and layer recesses 33 are formed on both sides of the layer protrusion 32, so there is a risk of a significant decrease in bonding strength if foreign matter such as fiber debris adheres to the layer protrusion 32. In contrast, in the pad 1 of this embodiment, as described in FIG. 6, multiple protrusions 301 and recesses 302 are formed on the surface of the bonding means 30, so foreign matter such as fiber debris is less likely to adhere to the multiple recesses 302, making it easier to prevent a decrease in bonding strength.

[0098] <<<<Regarding the joining strength of joining means 30, 30' as joining means>>> Figure 16 is a diagram for explaining the action and effect of the pad 1 to which the joining means 30, 30' are applied. Figure 16A is a diagram viewed from the thickness direction of the pad 1 folded in half along the fold line FL so that the one-side joining means 30 and the other-side joining means 30' face each other and then bonded together. Figure 16B is a diagram of the one-side joining means 30 and the other-side joining means 30' being peeled away when the pad 1 is unfolded.

[0099] 16A, 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.

[0100] The one-side joining means 30 is divided into three equal parts in both the longitudinal and width directions. From one side, the longitudinal direction is divided into a first longitudinal adjacent region L1, a longitudinal central region Lc, and a second longitudinal adjacent region L2. The width direction is divided into a first width adjacent region W1, a width central region Wc, and a second width adjacent region W2 (see FIG. 15 ). 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.

[0101] 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.

[0102] The strength of the bonding strength in each region may also be evaluated using a measuring device.

[0103] 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.

[0104] 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.

[0105] 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.

[0106] 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. 15A. 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 longitudinal center, as shown in Fig. 15B.

[0107] 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.

[0108] 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.

[0109] 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.

[0110] 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.

[0111] 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.

[0112] 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.

[0113] 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.

[0114] 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.

[0115] 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 15, because the difference in bonding strength per unit length between the central region Wc (Wc') and the adjacent region W1 (W1') in the width direction is small, when the pad 1 is discarded, the one-side bonding means 30 and the other-side bonding means 30' provided on the skin-side surface can be bonded, making it easier to maintain the pad 1 covering excrement on the skin-side surface.

[0116] 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.

[0117] 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.

[0118] ===Modified Examples of Joining Means 30, 30'=== Figure 17 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 17A and 17B. Figures 17A and 17B show self-adhesive quadrilateral joining means 30, 30', respectively.

[0119] 17A, the longitudinal central region Lc is a region where the adhesive 31 is uniformly applied (solidly coated) in a substantially rectangular shape that is long in the width direction on the skin-facing side of the topsheet 2. In addition, 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.

[0120] 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 longitudinal center region Lc, where the self-adhesive adhesive 31 is applied solidly. 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.

[0121] 17B, ​​the longitudinal central region Lc is a region that is uniformly coated with the self-adhesive adhesive 31, as in the modification of FIG. 17A. 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. 17B, with margins remaining.

[0122] 17A , 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 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.

[0123] 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.

[0124] ===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.

[0125] In the above-described embodiment, the leak-preventing wall elastic members 7 and leg-around elastic members (leg gathers) are exemplified as stretchable members, but the present invention is not limited to these. For example, waist-around fit gathers or the like may be provided as stretchable members. Furthermore, in addition to stretchable members that stretch in the longitudinal direction, stretchable members that stretch in the width direction may also be provided.

[0126] 1 urine absorption pad (pad, absorbent article) 2 surface sheet (top sheet) 3 back sheet (leak-proof sheet) 4 side sheet 5 leg-hole elastic member 6 leakage-proof wall portion 7 leakage-proof wall elastic member 10 absorbent core 11 core wrap sheet 20 fixing member (locking means) 30 one-side joining means 30' other-side joining means 301 convex portion 302 concave portion 31 self-adhesive adhesive 40 mark 50 diaper (pants-type diaper) 51 pants-side elastic member Lc longitudinal center region, Wc width center 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, and comprising a liquid-absorbent absorbent core, wherein a bonding agent that can be joined to a part of the absorbent article at the time of disposal is provided on the skin side surface, and the surface of the bonding agent has a plurality of convex portions that protrude in the thickness direction and concave portions that are concave in the thickness direction. An absorbent article characterized by this.

2. The absorbent article according to claim 1, having a stretchable member that stretches in at least one of the longitudinal direction and the width direction, and when viewed in the thickness direction, at least a part of the bonding agent overlaps with a stretchable portion of the stretchable member. An absorbent article characterized by this.

3. The absorbent article according to claim 2, wherein the stretchable member has a non-stretchable portion that is not stretchable, and when viewed in the thickness direction, at least a part of the bonding agent overlaps with the non-stretchable portion. An absorbent article characterized by this.

4. The absorbent article according to any one of claims 1 to 3, including a superabsorbent polymer, and when viewed in the thickness direction, at least a part of the bonding agent does not overlap with the absorbent core and overlaps with the superabsorbent polymer. An absorbent article characterized by this.

5. The absorbent article according to any one of claims 1 to 3, wherein the bonding agent is disposed so as to straddle an end of the absorbent core in the longitudinal direction. An absorbent article characterized by this.

6. The absorbent article according to any one of claims 1 to 3, wherein the absorbent core has a groove portion that is concave in the thickness direction, and when viewed in the thickness direction, at least a part of the bonding agent overlaps with the groove portion. An absorbent article characterized by this.

7. The absorbent article according to any one of claims 1 to 3, having a topsheet laminated on the skin side of the absorbent core, the topsheet having a plurality of sheet convex portions that protrude in the thickness direction and sheet concave portions that are concave in the thickness direction, and when viewed in the thickness direction, at least a part of the bonding agent overlaps with the sheet convex portions and the sheet concave portions. An absorbent article characterized by this.

8. The absorbent article according to any one of claims 1 to 3, wherein the adhesive has a first adhesive provided at one end of the absorbent article in the longitudinal direction and a second adhesive provided at the other end of the absorbent article in the longitudinal direction, and when the absorbent article is folded in half at a predetermined position in the longitudinal direction and the first adhesive and the second adhesive are opposed and joined, there is a portion where a certain convex portion among the plurality of convex portions provided on the surface of the first adhesive and a certain convex portion among the plurality of convex portions provided on the surface of the second adhesive are displaced. Absorbent article characterized by that.

9. The absorbent article according to any one of claims 1 to 3, having a core wrap sheet that covers the absorbent core, the core wrap sheet having a first end portion located on one side in the width direction and a second end portion located on the other side in the width direction in a flat state before covering the absorbent core, and in a state where the absorbent core is covered by the core wrap sheet, having an overlap portion where the first end portion and the second end portion are overlapped in the thickness direction, and having a portion where the adhesive and the overlap portion overlap when viewed in the thickness direction in a deployed and extended state. Absorbent article characterized by that.

10. The absorbent article according to claim 9, wherein in the overlap portion, at least a part of the first end portion or the second end portion has a curled portion curled in the thickness direction, and having a portion where the adhesive and the curled portion overlap when viewed in the thickness direction in a deployed and extended state. Absorbent article characterized by that.

11. The absorbent article according to any one of claims 1 to 3, having locking means on the non-skin side that can be locked to the skin side of the pant-type absorbent article, and having a portion where the adhesive and the locking means overlap when viewed in the thickness direction in a deployed and extended state. Absorbent article characterized by that.

12. The absorbent article according to any one of claims 1 to 3, having a mark visible from the non-skin side, and having a portion where the adhesive and the mark overlap when viewed in the thickness direction in a deployed and extended state. Absorbent article characterized by that.

13. An absorbent pad having a longitudinal direction, a width direction, and a thickness direction that are orthogonal to each other in the unfolded state, comprising a liquid-absorbent absorbent core, and being attachable to and usable on the skin side surface of a pant-type absorbent article, wherein the pant-type absorbent article has a pant-side stretchable member that stretches along at least one of the longitudinal direction and the width direction, the skin side surface of the absorbent pad has an adhesive that can be joined to a part of the absorbent article at the time of disposal, and when viewed in the thickness direction with the absorbent pad attached to the pant-type absorbent article, at least a part of the adhesive overlaps with the pant-side stretchable member, and the surface of the adhesive has a plurality of convex portions and concave portions. The absorbent pad is characterized by this.

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