Absorbent article

Abstract

Provided is an absorbent article (1) that has a longitudinal direction, a width direction, and a thickness direction orthogonal to each other in an unfolded state and that is provided with a liquid-absorbing absorbent core (10), wherein: the absorbent article (1) has, on a skin-facing surface, a bonding agent (30) that can be bonded to a part of the absorbent article (1) at the time of disposal; and a state in which at least a part of the bonding agent (30) is bonded to a part (30') of the absorbent article is maintained when a drop test is performed in which the absorbent article (1) is dropped from a prescribed height (h) to a floor surface (FL) in a state in which the bonding agent (30) is bonded to the part (30') of the absorbent article with the absorbent article (1) folded in half in the longitudinal direction such that the skin-facing surface is on the inner side.

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 become difficult to roll it up by rolling it from the end because the swelling increases in the thickness direction. In such cases, an absorbent article equipped with a closing mechanism that allows the absorbent article to be folded with the skin-facing side inward is desired. The closing mechanism is, for example, such that when the absorbent article is folded in half with the skin-facing side inward, joining means made of an adhesive, a self-adhesive, or the like are provided at both ends of the absorbent article so that they face each other. 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 excrement and its odor to be contained and disposed of hygienically.

[0005] When such absorbent articles are disposed of after use, they are likely to be thrown into a trash can (such as a sanitary box) from a predetermined height with the skin side of the absorbent article closed. If the closing mechanism opens due to the impact of the fall, the skin side will be exposed, causing the smell of excrement and other fluids to spread, making disposal unhygienic.

[0006] The present invention has been made in consideration of the above-mentioned problems, and its purpose is to provide an absorbent article that has a closing mechanism using an adhesive and that is less likely to open on the skin side when disposed of with the skin side closed.

[0007] The main invention for achieving the above object is an absorbent article having a liquid-absorbing absorbent core with a longitudinal direction, a width direction, and a thickness direction that are perpendicular to each other when unfolded, and having an adhesive on the skin-side surface that can be bonded to a part of the absorbent article when discarded, characterized in that when the absorbent article is folded in half in the longitudinal direction with the skin-side surface on the inside, and dropped from a predetermined height onto the floor with the adhesive bonded to a part of the absorbent article, at least a part of the adhesive remains bonded to a part of the absorbent article.

[0008] Other features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[0009] According to the present invention, it is possible to provide an absorbent article that has a closing mechanism using an adhesive and that is unlikely to open on the skin side when disposed of with the skin side closed.

[0010] 1 is a schematic plan view of the pad 1 in an unfolded and stretched state, as seen from the skin side. FIG. 3A is a schematic cross-sectional view of the pad 1. FIG. 3B is a diagram illustrating the pad 1 folded in half in the longitudinal direction. FIG. 4 is a partially enlarged view illustrating the detailed configuration of the pad 1. FIG. 5A and FIG. 5B are explanatory diagrams of one-side joining means 30 and the other-side joining means 30'. FIG. 5B is an explanatory diagram of the joining means 30, 30'. FIG. 5B is an explanatory diagram of the function and effect of the pad 1 to which the joining means 30, 30' are applied. FIG. 8A and FIG. 8B are explanatory diagrams illustrating the operation when the pad 1 is disposed of. FIG. 8B is an explanatory diagram illustrating a drop test method. FIG. 8A is a diagram illustrating a case in which the one-side joining means 30 and the other-side joining means 30' are joined while being misaligned in the longitudinal direction. FIG. 8B is an explanatory diagram illustrating the positional relationship between the absorbent core 10 and the joining means 30, 30'. FIG. 12A and FIG. 12B are explanatory diagrams illustrating the operation of opening the skin side when starting to use the pad 1. FIG. 12B is an explanatory diagram illustrating the case in which the pad 1 is attached to a disposable diaper 100 for use. 14A and 14B are diagrams illustrating a state in which the pad 1 is attached to the inside of the diaper 100. FIG. 14B is an explanatory diagram showing modified examples of the joining means 30, 30' of the pad 1. FIG. 14C is a diagram illustrating an adjacent layer 40. FIG. 14D is a schematic plan view of the pad 1 in an unfolded and stretched state, viewed from the non-skin side.

[0011] The present specification and the accompanying drawings make at least the following clear: (Aspect 1) An absorbent article having a liquid-absorbent absorbent core with a longitudinal direction, a width direction, and a thickness direction that are orthogonal to one another in an unfolded state, wherein an adhesive agent that can be bonded to a part of the absorbent article when disposed of is applied to the skin-facing side, and wherein when the absorbent article is folded in half in the longitudinal direction so that the skin-facing side is on the inside, and dropped from a predetermined height onto a floor in a state where the adhesive agent is bonded to a part of the absorbent article, at least a part of the adhesive agent remains bonded to a part of the absorbent article.

[0012] According to the absorbent article of aspect 1, when the absorbent article is closed with the skin side facing down after use and discarded (dropped) in a trash can, the adhesive tends to maintain its bonded state even when subjected to the impact of the drop, and the skin side is unlikely to open. Therefore, the absorbent article can be disposed of hygienically and is less likely to cause discomfort to the user.

[0013] (Aspect 2) The absorbent article according to Aspect 1, wherein when the drop test is performed with the absorbent core soaked in 300 ml of artificial urine, at least a portion of the adhesive remains bonded to a portion of the absorbent article.

[0014] According to the absorbent article of aspect 2, if the adhesive can be maintained in a drop test on an absorbent article whose weight has increased due to absorbing artificial urine, the absorbent article is likely to maintain the skin-side closed state when the absorbent article that has actually absorbed bodily waste is discarded in a trash can. Therefore, the absorbent article can be disposed of hygienically and is less likely to cause discomfort to the user.

[0015] (Aspect 3) The absorbent article according to Aspect 1 or 2, which has a top sheet provided closer to the skin than the absorbent core, and the adhesive has adhesive properties, and when the absorbent article is folded in half in the longitudinal direction so that the skin side is on the inside and the top sheet facing the adhesive is bonded to the adhesive, at least a portion of the adhesive remains bonded to a portion of the absorbent article when the drop test is performed in this state.

[0016] According to the absorbent article of aspect 3, by using an adhesive as the adhesive, the adhesive and the opposing top sheet are more easily maintained in a bonded state when pressed together, and the skin side is less likely to open up even when the absorbent article is disposed of in a trash can.

[0017] (Aspect 4) The absorbent article according to Aspect 1 or 2, wherein the adhesive agent has a one-side adhesive agent provided on one side in the longitudinal direction and a other-side adhesive agent provided on the other side in the longitudinal direction, the one-side adhesive agent and the other-side adhesive agent each have self-adhesive properties, and when the absorbent article is folded in half in the longitudinal direction so that the skin-side surface is on the inside and the one-side adhesive agent and the other-side adhesive agent are bonded to each other, and the drop test is performed in this state, at least a portion of the one-side adhesive agent remains bonded to a portion of the other-side adhesive agent.

[0018] According to the absorbent article of Aspect 4, even if the self-adhesive adhesive comes into contact with the wearer's skin when worn, it is unlikely to adhere to the skin and is unlikely to cause discomfort to the wearer. Furthermore, when the adhesive on one side and the adhesive on the other side are pressure-bonded together, the adhesive state between the adhesives is likely to be maintained, making it difficult for the skin-facing side to open when the absorbent article is disposed of in a trash can.

[0019] (Aspect 5) The absorbent article according to any one of Aspects 1 to 4, wherein, in a state in which the one-side bonding agent and the other-side bonding agent are bonded to each other, a center position in the longitudinal direction of the one-side bonding agent is misaligned with a center position in the longitudinal direction of the other-side bonding agent.

[0020] According to the absorbent article of Aspect 5, even when the adhesive agent on one side and the adhesive agent on the other side are joined in a misaligned state, the adhesive agents tend to maintain their joined state, which makes it difficult for the skin side to open when the absorbent article is disposed of in a trash can.

[0021] (Aspect 6) The absorbent article of any one of Aspects 1 to 5, further comprising a top sheet provided closer to the skin than the absorbent core, the one-side adhesive agent and the other-side adhesive agent being applied to the skin-side surface of the top sheet, and the magnitude of the force required to peel off the one-side adhesive agent from a state in which the one-side adhesive agent is bonded to the other-side adhesive agent is smaller than the force required to peel off the one-side adhesive agent from a state in which the one-side adhesive agent is applied to the skin-side surface of the top sheet.

[0022] According to the absorbent article of aspect 6, when the skin-side surface of the absorbent article folded in half is opened, the bonded state between the one-side adhesive agent and the other-side adhesive agent can be released while maintaining the bonded state between the one-side adhesive agent and the top sheet. Therefore, the operation of opening the skin-side surface when starting to use the absorbent article and the operation of closing the skin-side surface when discarding it can be performed smoothly.

[0023] (Aspect 7) The absorbent article according to any one of Aspects 1 to 6, further comprising a top sheet disposed closer to the skin than the absorbent core, and further comprising a fastening means on the non-skin side capable of fastening to the skin side of a disposable diaper, wherein the magnitude of the force required to peel off the one adhesive from a state in which the one adhesive is bonded to the other adhesive is smaller than the force required to peel off the fastening means from a state in which the fastening means is fastened to the top sheet.

[0024] According to the absorbent article of aspect 7, when the absorbent article is attached to the skin side of a disposable diaper for use, the adhesive state between the one side adhesive agent and the other side adhesive agent can be released while the skin side of the diaper remains engaged with the fastening means, thereby facilitating the operation of opening the waist opening of the disposable diaper with the absorbent article attached.

[0025] (Aspect 8) The absorbent article according to any one of Aspects 1 to 7, wherein the adhesive is provided across an end of the absorbent core in the longitudinal direction, and when the absorbent article is folded in half in the longitudinal direction with the skin side facing inward and a portion of the adhesive that overlaps with the absorbent core in the longitudinal direction is joined to a portion of the absorbent article, at least a portion of the overlapping portion remains joined to the portion of the absorbent article.

[0026] According to the absorbent article of Aspect 8, when the portion of the one-side adhesive that overlaps with the absorbent core is pressed from the non-skin side, the thickness of the absorbent core allows the pressing force to act efficiently, making it easier to firmly bond the one-side adhesive to the opposing surface. This makes it more difficult for the skin-facing side to open when the absorbent article is disposed of after use.

[0027] (Aspect 9) The absorbent article according to any one of Aspects 1 to 8, wherein the adhesive is provided across an end of the absorbent core in the longitudinal direction, and when the absorbent article is folded in half in the longitudinal direction with the skin side facing inward and a portion of the adhesive that does not overlap with the absorbent core in the longitudinal direction is joined to a portion of the absorbent article, at least a portion of the non-overlapping portion remains joined to the portion of the absorbent article.

[0028] According to the absorbent article of Aspect 9, by pressing the portion of the one-side adhesive that does not overlap with the absorbent core from the non-skin side, excreted fluid absorbed in the absorbent core is less likely to seep out (rewetting is less likely to occur). This prevents the bonding means from becoming wet with excreted fluid, which would otherwise reduce the bonding strength, and makes it easier to firmly bond the one-side adhesive to the opposing surface. This makes it less likely that the skin-side surface will open when the absorbent article is disposed of after use.

[0029] (Aspect 10) The absorbent article according to any one of Aspects 1 to 9, wherein when the adhesive is divided into three equal parts into a first adjacent region, a central region, and a second adjacent region in either the longitudinal direction or the width direction, the adhesive strength of the first adjacent region or the second adjacent region is weaker than the adhesive strength of the central region.

[0030] According to the absorbent article of aspect 10, when the absorbent article is folded in half lengthwise, one end of the absorbent article abuts against the other, making it easier to maintain a state in which the absorbent article covers excrement on the skin side, which makes it more difficult for the skin side to open when the absorbent article is disposed of after use.

[0031] (Aspect 11) The absorbent article according to any one of aspects 1 to 10, comprising a top sheet provided closer to the skin than the absorbent core and a back sheet provided closer to the skin than the absorbent core, and an adjacent layer adjacent to the top sheet in the thickness direction and closer to the skin than the back sheet and closer to the skin than the adhesive, wherein the adhesive and the adjacent layer have an overlapping portion when viewed in the thickness direction in an unfolded and stretched state.

[0032] According to the absorbent article of Aspect 11, 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 (rewetting), the provision of an adjacent layer on the non-skin side of the joining means makes it easier to prevent moisture from reaching the joining means. This prevents the joining means from getting wet and reducing its joining strength, making it easier to maintain the absorbent article in a closed state (a state in which the joining means are joined). This makes it more difficult for the skin side to open when the absorbent article is disposed of after use.

[0033] (Aspect 12) The 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.

[0034] According to the absorbent article of aspect 12, when the absorbent article is folded with the skin side facing inward for disposal, the mark visible from the non-skin side is pressed, and the joining means is pressed at the portion overlapping with the mark, making it easier to crimp the joining means. This makes it more difficult for the skin side to open when the absorbent article is disposed of after use.

[0035] First Embodiment A urine absorption pad (hereinafter, sometimes simply referred to as a "pad") will be described as an example of an absorbent article according to the first embodiment. However, the absorbent article according to this embodiment is not limited to urine absorption pads, and can also be applied to, for example, sanitary napkins, pants-type disposable diapers, shorts-type napkins, tape-type disposable diapers, pet diapers, absorbent sheets for nursing care or for pets, etc.

[0036] <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 by being placed directly inside the wearer's underwear (pants or shorts).

[0037] 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.

[0038] 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.

[0039] The pad 1 comprises a liquid-absorbent core 10, a liquid-permeable surface 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 top sheet 2 so as to encase the absorbent core 10.

[0040] 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.

[0041] 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.

[0042] The pad 1 also has a pair of leg elastic members 5 provided 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 wearer's legs.

[0043] 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.

[0044] The pad 1 also has joining means 30, 30' at both ends in the longitudinal direction, respectively. The details of the configuration of these will be described below.

[0045] <Joining means 30, 30'> As shown in Fig. 1, one-side joining means 30 is provided as joining means on the skin side (topsheet 2) of the pad 1. In addition, other-side joining means 30' is provided on the skin side (topsheet 2) of the pad 1 at the other longitudinal end. When the pad 1 is disposed of, the one-side joining means 30 can be joined to the other-side joining means 30' as part of the pad 1 as a closing mechanism. Note that 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).

[0046] FIG. 3 shows the state of 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 in half along the center line (central position) 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 is, 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.

[0047] 4 is a partially enlarged view for explaining the details of the configuration of the pad 1, and shows a portion of the pad 1 in an unfolded and extended state. 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, at a position spaced a predetermined distance d 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.

[0048] 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.

[0049] 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) by itself, but has the property of developing adhesive strength (hereinafter referred to as "bonding strength") when the adhesives 31 are pressed together with a 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 (developing bonding strength). On the other hand, as shown in FIG. 5B, when the adhesive 31 contacts 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 contacting member.

[0050] 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.

[0051] 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.

[0052] Next, the specific configuration of the one-side joining means 30 and the other-side joining means 30' will be described in detail with reference to FIG. 6. FIG. 6 is a diagram for explaining the joining means 30, 30'. As shown in FIG. 6, the one-side joining means 30 and the other-side joining means 30' are quadrilateral regions circumscribing the portion to which the self-adhesive bonding agent 31 is applied as the joining portion. Note that in FIG. 6, the region to which the self-adhesive bonding agent 31 is applied is shown lightly shaded.

[0053] 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.

[0054] 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.

[0055] <Regarding the bonding strength of bonding means 30, 30'> Figure 7 is a diagram for explaining the action and effect of the pad 1 to which bonding means 30, 30' are applied. Figure 7A is a diagram viewed from the thickness direction showing the pad folded in half along fold line FL so that one-side bonding means 30 and the other-side bonding means 30' face each other and then bonded together. Figure 7B is a diagram showing the state when one-side bonding means 30 and the other-side bonding means 30' are peeled apart when unfolding the pad 1.

[0056] In this embodiment, when the pad 1 is folded in half along the center line CL (fold line FL), at least a portion of the central region Lc of the one-side joining means 30 and a central region Lc' of the other-side joining means 30' overlap in the thickness direction, as shown in Fig. 7A. Also, although not shown, at least a portion of the central region We of the one-side joining means 30 and a central region We' of the other-side joining means 30' overlap in the width direction, as in the longitudinal direction.

[0057] 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.

[0058] 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.

[0059] The strength of the bonding strength in each region may also be evaluated using a measuring device.

[0060] 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.

[0061] 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.

[0062] Next, the sample pieces are held by the holders in the chucks of a tensile tester (e.g., a universal testing machine manufactured by Instron), 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.

[0063] The bonding strength can be measured in the same manner for the first width adjacent region W1, the width central region Wc, and the second width adjacent region W2.

[0064] 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. 7A. 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. 7B.

[0065] 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.

[0066] In this embodiment, since the second adjacent region L2, which has a weaker bonding strength, is located on the longitudinal centerline CL side, the pad 1 can be peeled away from the leg-around elastic member 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.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 3B, the pad 1 after use is folded in half at the longitudinal center CL so that the skin side (the side on which the top sheet 2 is provided) is on the inside, and the one-side joining means 30 and the other-side joining means 30' are joined together facing each other, and the pad 1 is discarded with the skin side closed. In this way, the pad 1 can be discarded hygienically without exposing the skin side on which excrement adheres.

[0077] 8A and 8B are diagrams illustrating the disposal of the pad 1. When disposing of a used pad 1, a user (wearer) of the pad 1 typically folds the used pad 1 in half lengthwise with the skin-side closed, then grasps the upper end and discards it from a predetermined height into a trash can (sanitary box, etc.) as shown in FIG. 8A . However, at this time, the skin-side of the pad 1 may open due to the impact of the drop. For example, if the bonding between the one-side joining means 30 and the other-side joining means 30′ separates, the folded pad 1 may unfold, exposing the top sheet 2, etc., as shown in FIG. 8B . In this case, the odor of excrement adhering to the skin-side surface may easily diffuse into the trash can or outside, potentially causing discomfort to the user.

[0078] Therefore, in the pad 1 of this embodiment, the one-side joining means 30 and the other-side joining means 30' are configured so that the skin-facing side is unlikely to open even when the pad 1 is thrown into a trash can for disposal. Specifically, when a drop test is performed in which the pad 1 is folded in half with the one-side joining means 30 and the other-side joining means 30' joined to each other and then dropped from a predetermined height onto the floor, the one-side joining means 30 and the other-side joining means 30' are configured so that the one-side joining means 30 and the other-side joining means 30' remain at least partially joined.

[0079] Here, the "drop test" will be described. FIG. 9 is a diagram illustrating the method of the drop test. First, a pad 1 is prepared as a test subject, with the skin-facing side closed and the one-side joining means 30 and the other-side joining means 30' joined to each other. Specifically, as shown in FIG. 3B , the pad 1 is folded in half at the center position CL in the longitudinal direction, so that the one-side joining means 30 and the other-side joining means 30' face each other. Then, the folded pad 1 is pressed in the thickness direction to press the one-side joining means 30 and the one-side joining means 30' together. The pressing is performed by moving a roller having a mass of 2 kg back and forth once along the width direction of the pad 1 at a speed of 5 mm / sec from the one-side joining means 30 or the non-skin side of the one-side joining means 30.

[0080] Next, the pad 1 is held at its upper end (the outer end in the longitudinal direction in FIG. 1 ) for about one minute after being pressed, and is stopped at a position where the height from the floor (FL) to the lower end of the pad 1 (the center position CL in the longitudinal direction) is h. The floor is generally made of concrete, tile, stone, or other material with low shock absorption. The height h is set to 500 mm, assuming the average height at which the pad 1 is thrown into a trash can (see FIG. 8A ).

[0081] Next, the hand holding the upper end of the pad 1 is released, and the pad 1 is allowed to fall freely from a height h. The pad 1 that has fallen to the floor is then checked, and it is recorded whether the one-side joining means 30 and the other-side joining means 30' are entirely separated from each other, or whether at least a portion of the one-side joining means 30 and the other-side joining means 30' are joined. This test is repeated multiple times (e.g., N = 20 times), and if the number of times that at least a portion of the one-side joining means 30 and the other-side joining means 30' are joined is 90% or more of the time, it is determined that the joined state between the one-side joining means 30 and the other-side joining means 30' has been maintained in the drop test.

[0082] In the pad 1 of this embodiment, the joining means 30 and 30' are configured so that the joined state between the one-side joining means 30 and the other-side joining means 30' is maintained even after the drop test is performed with the skin-side side closed. Therefore, even when the pad 1 is closed with the skin-side side closed after use and discarded (dropped) in a trash can, the skin-side side is unlikely to open, allowing the pad 1 to be discarded hygienically and less likely to cause discomfort to the user.

[0083] It is highly likely that the weight of the pad 1 after actual use has increased compared to before use due to the absorbent core 10 absorbing urine and other excrement. If the weight of the pad 1 has increased, the momentum of the pad 1 when it is dropped onto a trash can (floor) increases, which increases the impact of the drop and may make the skin-facing side more likely to open. Therefore, it is more preferable to perform the drop test by allowing the absorbent core 10 to absorb a predetermined amount of liquid, so that the pad 1 is in a state similar to when it is actually used.

[0084] Specifically, 300 ml of artificial urine is poured into (absorbed into) the absorbent core 10 using a cylinder or the like, and then the drop test is performed according to the above procedure. It is more preferable that the joining means 30 and the joining means 30' are configured so that the joining state between the one-side joining means 30 and the other-side joining means 30' is maintained even after the drop test. For example, the artificial urine can be prepared by dissolving 200 g of urea, 80 g of sodium chloride, 8 g of magnesium sulfate, 3 g of calcium chloride, and approximately 1 g of Blue No. 1 dye in 10 L of ion-exchanged water. The amount of artificial urine poured into the absorbent core 10 can be determined based on the intended use of the pad 1. In this embodiment, the drop test was performed assuming that the average amount of urine voided in one use was 150 ml, and that the absorbent core 10 after use had absorbed two voids (150 ml x 2 voids). If the pad 1 is to be used (worn) for a long period of time and absorbs repeated urination, the drop test may be performed by appropriately increasing the amount of artificial urine injected into the absorbent core 10. For example, if the pad 1 is expected to be used in a manner that absorbs up to eight urinations, the drop test may be performed after the absorbent core 10 has absorbed approximately 150 ml x 8 = 1200 ml of artificial urine.

[0085] A drop test was conducted on the pad 1 whose weight had increased by absorbing artificial urine, and the results showed that if the joining state between the one-side joining means 30 and the other-side joining means 30' was maintained, there was a high possibility that the skin-side surface would remain closed when the pad 1 that had actually absorbed excrement was discarded in a trash can. This means that the pad 1 can be disposed of hygienically and is less likely to cause discomfort to the user.

[0086] Furthermore, a tacky adhesive (adhesive) may be used as the adhesive 31 constituting the joining means 30, 30' of the pad 1. Generally, adhesives are semi-solid and viscous, and exhibit a strong bonding force when pressed against the surfaces to be joined. Therefore, by using an adhesive as the adhesive 31, the bonded state between the one-side joining means 30 and the other-side joining means 30' is more easily maintained when pressed against each other, and the skin-side surface is less likely to open when the pad 1 is disposed of in a trash can (see FIG. 8A ).

[0087] Furthermore, when the one-side joining means 30 is formed using an adhesive, the other-side joining means 30' does not necessarily need to be formed using an adhesive. In other words, because the one-side joining means 30 (adhesive) alone can join opposing surfaces, the one-side joining means 30 and the other-side joining means 30' can be joined even if the other-side joining means 30' does not have adhesive properties. For example, even if the other-side joining means 30' is formed using a top sheet 2 (nonwoven fabric) rather than an adhesive 31, the one-side joining means 30 (adhesive) can be pressed against the top sheet 2. Even in this case, the skin-side surface can be made less likely to open when the pad 1 is discarded in a trash can (see FIG. 8A ). Furthermore, because the adhesive 31 is not required as the other-side joining means 30', the manufacturing cost of the pad 1 can be reduced.

[0088] On the other hand, a self-adhesive adhesive (self-adhesive) may be used as the adhesive 31 constituting the joining means 30, 30' of the pad 1. When a self-adhesive is used, as described above, a strong adhesive strength is exhibited when the self-adhesive is joined to itself, whereas the adhesive strength is weak when the self-adhesive is joined to a member other than the self-adhesive. Therefore, even if the one-side joining means 30 (one-side adhesive) or the other-side joining means 30' (other-side adhesive) formed of the self-adhesive comes into contact with the wearer's skin when the pad 1 is worn, the joining means 30, 30' (one-side adhesive, other-side adhesive) are unlikely to adhere to the skin and cause discomfort to the wearer. Conversely, the bonded state between the one-side joining means 30 (one-side adhesive) and the other-side joining means 30' (other-side adhesive) is easily maintained when pressed together, which makes it difficult for the skin-side surface to open when the pad 1 is disposed of in a trash can (see FIG. 8A ).

[0089] Furthermore, when the pad 1 is folded in half and the skin-side surface is closed, the one-side joining means 30 (one-side adhesive) and the other-side joining means 30' (other-side adhesive) may be joined in a state where they are misaligned from each other in the longitudinal direction. Even in such a case, it is preferable that the skin-side surface does not easily open when the pad 1 is disposed of. FIG. 10 is a diagram showing a case where the one-side joining means 30 and the other-side joining means 30' are joined in a state where they are misaligned from each other in the longitudinal direction. In FIG. 10, the joining means 30, 30' are partially joined to each other in a state where the center position C30 of the one-side joining means 30 (one-side adhesive) of the pad 1 folded in half is misaligned from the center position C30 of the other-side joining means 30' (other-side adhesive) in the longitudinal direction.

[0090] The act of discarding a used pad 1 may be performed in a restroom or the like while away from home. In such an environment, it is difficult to accurately align and bond the one-side bonding means 30 (one-side bonding agent) and the other-side bonding means 30' (other-side bonding agent), and there is a risk of misalignment as shown in Figure 10. With the pad 1 of this embodiment, even in such a case, the results of the drop test described above show that the bonded state between the one-side bonding means 30 and the other-side bonding means 30' is maintained. Therefore, even if the bonding means 30, 30' are joined with some misalignment when discarding the pad 1, it is possible to prevent the skin-side surface from opening. This allows the pad 1 to be disposed of safely, even when in a restroom or the like while away from home.

[0091] 11 is a diagram illustrating the positional relationship between the absorbent core 10 and the joining means 30, 30'. Fig. 11 shows the cross-sectional state of the pad 1 when the pad 1 is folded in half at the center position CL in the longitudinal direction.

[0092] As shown in FIG. 11 , in the pad 1 of this embodiment, the one-side joining means 30 (one-side adhesive) and the other-side joining means 30′ (other-side adhesive) are arranged so as to straddle the end of the absorbent core 10 in the longitudinal direction. That is, the one-side joining means 30 (one-side adhesive) has an overlapping portion 30r that overlaps with the absorbent core 10 in the longitudinal direction and a non-overlapping portion 30n that does not overlap with the absorbent core 10 in the longitudinal direction. When the joining means 30, 30′ are opposed to each other and pressed in the thickness direction in this state, the overlapping portion 30r is likely to exert a strong pressure in the thickness direction on the joining means 30 due to the thickness of the absorbent core 10. Therefore, in the pad 1 of this embodiment, when the above-mentioned drop test (see FIG. 9 ) is performed with the overlapping portion 30r of the one-side joining means 30 (one-side adhesive) bonded to the opposing surface (other-side joining means 30′), the bonded state of the one-side joining means 30 (one-side adhesive) is likely to be maintained.

[0093] In other words, when the overlapping portion 30r of the one-side joining means 30 (one-side adhesive) that overlaps with the absorbent core 10 is pressed from the non-skin side, the pressing force acts efficiently due to the thickness of the absorbent core, making it easier to firmly join the one-side joining means 30 (one-side adhesive) to the opposing surface. As a result, when the skin-facing side of the pad 1 is closed and disposed of after use, the skin-facing side is less likely to open, allowing the pad 1 to be disposed of hygienically.

[0094] Furthermore, even when the above-mentioned drop test (see Figure 9) is performed with the non-overlapping portion 30n of the one-side joining means 30 (one-side joining agent) joined to the opposing surface (the other-side joining means 30'), it is preferable that the joined state of the one-side joining means 30 (one-side joining agent) is maintained.

[0095] 11, when the joining means 30, 30' are opposed to each other and pressed in the thickness direction, the absorbent core 10 is not pressed at the non-overlapping portion 30n, so excreted liquid such as urine absorbed in the absorbent core 10 is less likely to seep out. In other words, rewetting by urine or the like and wetting of the one-side joining means 30 (one-side adhesive) is suppressed, so the joining means 30, 30' can be easily joined with a weak force.

[0096] In other words, by pressing the non-overlapping portion 30n of the one-side joining means 30 (one-side adhesive) that does not overlap with the absorbent core 10 from the non-skin side, exudation of excrement absorbed in the absorbent core 10 is suppressed, and the one-side joining means 30 (one-side adhesive) can be more easily firmly joined to the opposing surface. As a result, when the skin-facing side of the pad 1 is closed and disposed of after use, the skin-facing side is less likely to open, allowing the pad 1 to be disposed of hygienically.

[0097] Furthermore, the bonding strength between the one-side joining means 30 (one-side adhesive) and the other-side joining means 30' (other-side adhesive) is preferably smaller than the bonding strength between the one-side joining means 30 (one-side adhesive) and the top sheet 2 (surfacesheet 2). In other words, the magnitude of the force required to peel off the one-side joining means 30 (one-side adhesive) from a state in which the one-side joining means 30 (one-side adhesive) is joined to the other-side joining means 30' (other-side adhesive) is preferably smaller than the force required to peel off the one-side joining means 30 (one-side adhesive) provided on the skin-side surface (top sheet 2) of the pad 1 from the skin-side surface (top sheet 2).

[0098] 12A and 12B are diagrams illustrating the operation of opening the skin-side surface of the pad 1 when starting to use it. When shipped from a manufacturing factory, the pad 1 is packaged with the bonding means 30, 30′ bonded together and the skin-side surface closed, as shown in FIG. 3B , and distributed to the market. When a user who purchases the pad 1 starts using the pad 1, they must peel the bonding means 30, 30′ from each other and open the skin-side surface. FIG. 12A shows the pad 1 in a normally opened state with the skin-side surface. When opening the skin-side surface of the pad 1 folded in half, the user grasps one end 1ef and the other end 1eb in the longitudinal direction and pulls them in opposite directions in the thickness direction to separate the one-side bonding means 30 (one-side bonding agent) from the other-side bonding means 30′ (other-side bonding agent).

[0099] At this time, if the bonding strength between the one-side joining means 30 (one-side bonding agent) applied to the top sheet 2 and the top sheet 2 is greater than the bonding strength between the one-side joining means 30 (one-side bonding agent) and the other-side joining means 30' (other-side bonding agent), the bond between the one-side joining means 30 (one-side bonding agent) and the other-side joining means 30' (other-side bonding agent) will tend to peel off first. In other words, the bond between the one-side joining means 30 (one-side bonding agent) and the top sheet 2 is maintained, while the bond between the one-side joining means 30 (one-side bonding agent) and the other-side joining means 30' (other-side bonding agent) is released. Therefore, as shown in FIG. 12A , it is possible to open the skin-side surface of the pad 1, and when the pad 1 is disposed of, the one-side joining means 30 (one-side bonding agent) and the other-side joining means 30' (other-side bonding agent) can be re-bonded to close the skin-side surface.

[0100] In contrast, Figure 12B shows a state in which the skin-side surface of the pad 1 is not opened normally. In Figure 12B, the bonding strength between the one-side joining means 30 (one-side adhesive) and the top sheet 2 is smaller than the bonding strength between the one-side joining means 30 (one-side adhesive) and the other-side joining means 30' (other-side adhesive), and the bonding between the one-side joining means 30 (one-side adhesive) and the top sheet 2 peels off first. In other words, the one-side joining means 30 (one-side adhesive) peels off from the top sheet 2 while the bonding state between the one-side joining means 30 (one-side adhesive) and the other-side joining means 30' (other-side adhesive) remains. In this case, it is possible to open the skin-side surface of the pad 1, but the skin-side surface cannot be kept closed when the pad 1 is disposed of. Furthermore, there is a risk that the top sheet 2 may tear when the one-side joining means 30 (one-side adhesive) peels off from the top sheet 2.

[0101] In the pad 1 of this embodiment, the bonding strength between the one-side bonding means 30 (one-side bonding agent) and the other-side bonding means 30′ (other-side bonding agent) is smaller than the bonding strength between the one-side bonding means 30 (one-side bonding agent) and the top sheet 2 (surface sheet 2), which allows for smooth opening of the skin-side surface at the start of use and smooth closing of the skin-side surface at disposal. Furthermore, tearing of the top sheet 2 is suppressed.

[0102] Next, the case where the pad 1 is attached to a disposable diaper and used will be described. FIG. 13 is a diagram illustrating the case where the pad 1 is attached to a disposable diaper 100 and used. As described above, the pad 1 of this embodiment can be attached to the inside (skin-side) of a pants-type or tape-type disposable diaper. For example, in FIG. 13 , the pad 1 is inserted from above the waist opening of a pants-type disposable diaper 100 (hereinafter also referred to as "diaper 100"), and a fastening member 20 (such as a hook-and-loop fastener) provided on the non-skin-side surface of the pad 1 is fastened to the skin-side surface of the diaper 100. Generally, the skin-side surface of a disposable diaper is made of a nonwoven fabric (such as the top sheet 2) similar to the skin-side surface of the pad 1. Therefore, by fastening the fastening member 20 (such as a hook-and-loop fastener) of the pad 1 to the nonwoven fabric constituting the skin-side surface of the disposable diaper, the pad 1 can be firmly fixed to the inside (skin-side) of the diaper 100.

[0103] At this time, the bonding strength between the one-side joining means 30 (one-side bonding agent) and the other-side joining means 30' (other-side bonding agent) is preferably smaller than the bonding strength (engagement force) between the fixing member 20 and the top sheet 2 (nonwoven fabric). In other words, the magnitude of the force required to peel off the one-side joining means 30 (one-side bonding agent) from a state in which the one-side joining means 30 (one-side bonding agent) is bonded to the other-side joining means 30' (other-side bonding agent) is preferably smaller than the force required to peel off the fixing member 20 (locking means) from a state in which the fixing member 20 (locking means) is locked to the top sheet 2 (nonwoven fabric).

[0104] 14A and 14B are diagrams illustrating a state in which the pad 1 is attached to the inside of the diaper 100. Fig. 14A shows a state in which the pad 1 is normally attached to the inside of the diaper 100. That is, it shows a state in which the fixing member 20 of the pad 1 is engaged with the nonwoven fabric on the skin side of the diaper 100. In Fig. 14A, if the one-side joining means 30 (one-side adhesive) and the other-side joining means 30' (other-side adhesive) are joined together, the waist opening of the diaper 100 will close, so it is necessary to peel the one-side joining means 30 (one-side adhesive) from the other-side joining means 30' (other-side adhesive). At this time, if the bonding strength between the fixing member 20 (fastening means) of the pad 1 and the nonwoven fabric (assuming the same nonwoven fabric as the top sheet 2) constituting the skin-side surface of the diaper 100 is greater than the bonding strength between the one-side joining means 30 (one-side bonding agent) and the other-side joining means 30' (other-side bonding agent), the bonding between the one-side joining means 30 (one-side bonding agent) and the other-side joining means 30' (other-side bonding agent) will be more likely to peel off first. In other words, the bonding between the one-side joining means 30 (one-side bonding agent) and the other-side joining means 30' (other-side bonding agent) will be released while the fixing member 20 of the pad 1 remains engaged with the skin-side surface of the diaper 100. Therefore, as shown in FIG. 14A , the diaper 100 can be worn with the waist opening open with the pad 1 attached.

[0105] In contrast, Figure 14B shows a state in which the pad 1 has become detached from the inside of the diaper 100. In Figure 14B, the bonding strength between the fixing member 20 (fastening means) of the pad 1 and the nonwoven fabric (top sheet 2) constituting the skin-side surface of the diaper 100 is smaller than the bonding strength between the one-side joining means 30 (one-side adhesive) and the other-side joining means 30' (other-side adhesive). In this case, the bonding between the fixing member 20 (fastening means) of the pad 1 and the skin-side surface of the diaper 100 (top sheet 2) occurs first. That is, the bonding state between the one-side joining means 30 (one-side adhesive) and the other-side joining means 30' (other-side adhesive) remains, but the fixing member 20 (fastening means) of the pad 1 has become detached from the skin-side surface of the diaper 100 (top sheet 2). When the fixing member 20 of the pad 1 has become detached as shown in Figure 14B, the diaper 100 cannot be worn normally.

[0106] In the pad 1 of this embodiment, the bonding strength between the one-side joining means 30 (one-side bonding agent) and the other-side joining means 30′ (other-side bonding agent) is made smaller than the bonding strength (engagement force) between the fixing member 20 and the top sheet 2 (nonwoven fabric), which makes it easier to open the waist opening of the diaper 100 with the pad 1 attached. This allows the user to wear the diaper 100 normally.

[0107] <Modifications of Bonding Means 30, 30'> Figure 15 is an explanatory diagram showing modifications of the bonding means 30, 30' of the pad 1. Figures 15A and 15B show quadrilateral bonding means 30, 30', respectively, which have self-adhesive properties. The portion where the bonding agent 31 is applied corresponds to the region where the bonding portion is provided in the modification of this embodiment.

[0108] 15A , 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 adhesive 31 is applied in a wave-like pattern in the first longitudinal adjacent region L1 and the second longitudinal adjacent region L2, as shown in FIG.

[0109] In this case, the adhesive 31 is applied in a wavy pattern to the first longitudinal adjacent region L1 and the second longitudinal adjacent region L2, which have margins, so that the adhesive strength is weaker than that of the solidly applied longitudinal center region Lc. As a result, the pad 1 can be easily peeled off when unfolding, while the adhesive strength in 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.

[0110] 15B, the longitudinal central region Lc is a region that is uniformly coated with the adhesive 31, as in the modification of Fig. 15A. The first longitudinal adjacent region L1 and the second longitudinal adjacent region L2 are partially coated with the adhesive 31 in the width direction, with margins remaining, as shown in Fig. 15B.

[0111] In this case, the adhesive 31 is applied only partially in the width direction to the first longitudinal adjacent region L1 and the second longitudinal adjacent region L2, which have a margin, and the adhesive strength of these regions is weaker than that of the solidly applied longitudinal center region Lc. As a result, the adhesive strength of the longitudinal center region Lc is stronger than that of the adjacent regions, ensuring ease of peeling when unfolding the pad 1, and therefore, when folding the pad 1 for disposal, the pad 1 can maintain a state in which excrement on the skin side is covered by the pad 1.

[0112] In these modified examples, the application amount per unit area of ​​the bonding means 30 in the central regions Lc and Wc and the arrangement pattern using margins are different from the arrangement pattern of the bonding means 30 in the first adjacent regions L1, W1 or the second adjacent regions L2, W2.

[0113] ===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.

[0114] <Regarding the adjacent layer 40> The pad 1 may have an adjacent layer 40 (40') on the non-skin side of the joining means 30 (30') and on the non-skin side of the backsheet 3 and the absorbent core 10. Fig. 16 is a diagram illustrating the adjacent layer 40. Fig. 16A is a schematic cross-sectional view of the pad 1 in a state where it is folded in half in the longitudinal direction and the joining means 30, 30' are pressed against each other. Fig. 16B is an enlarged cross-sectional view of the joining means 30 and adjacent layer 40 in Fig. 16A.

[0115] The adjacent layer 40 is a hydrophobic layer that has a low affinity for moisture (easily repels moisture), and the hydrophobic layer is formed, for example, by a colored ink applied to the top sheet 2. However, the configuration is not limited to the above, and the adjacent layers 40, 40' may be formed by a nonwoven fabric, or by a nonwoven fabric and ink applied to the nonwoven fabric. The hydrophobic layer may also be formed by a material other than those described above, or may be formed by a hot melt adhesive applied to the top sheet 2.

[0116] During use (wearing) of the pad 1, moisture such as excrement absorbed by the absorbent core 10 may permeate from the non-skin side of the top sheet 2 toward the skin side, a phenomenon known as rewetting. In particular, if the joining means 30, 30' are formed using a bonding agent 31 such as a self-adhesive or pressure-sensitive adhesive, moisture that has permeated the skin side of the top sheet 2 due to rewetting and reaches the one-side joining means 30 or the other-side joining means 30' may wet the bonding agent 31, thereby reducing the bonding strength. In contrast, as shown in Figures 16A and 16B, by providing adjacent layers 40, 40' on the non-skin side of the joining means 30, 30' (bonding agent 31), moisture is more likely to be prevented from reaching the joining means 30, 30'. In other words, wetting of the mechanism that closes the absorbent core 10 (i.e., the self-adhesive bonding agent 31 in the joining means 30, 30') is prevented. Therefore, even after a drop test is performed with the skin side closed, the bonding state between the one-side bonding means 30 and the other-side bonding means 30' is likely to be maintained. This makes it less likely for the odor of excrement to leak to the outside (non-skin side) of the pad 1 when the pad 1 is disposed of, making it easier to suppress the odor of excrement.

[0117] 16B, the adjacent layer 40 is disposed adjacent to the top sheet 2 between the joining means 30 (adhesive 31) and the top sheet 2 in the thickness direction, but other configurations are also possible. For example, the adjacent layer 40 may be disposed between the absorbent core 10 and the top sheet 2 in the thickness direction. That is, the adjacent layer 40 may be provided adjacent to the non-skin side of the top sheet 2. Even in such cases, by disposing the adjacent layer 40 on the non-skin side of the joining means 30, moisture is prevented from reaching the absorbent core 10 to the joining means 30, the joining strength of the joining means 30 is less likely to decrease, and the pad 1 can be more easily maintained in a closed state.

[0118] <Regarding the Marking 50> The pad 1 may have a marking 50 that is visible from the non-skin side and that at least partially overlaps with the joining means 30 when viewed in the thickness direction. Fig. 17 is a schematic plan view of the pad 1 in an unfolded and extended state as viewed from the non-skin side. In Fig. 17, the pad 1 has marks 50, 50' that are visible from the non-skin side. Furthermore, when viewed in the thickness direction of the pad 1 in an unfolded and extended state, there is a portion where the joining means 30 (30') and the marking 50 (50') overlap.

[0119] The mark 50 is formed, for example, by printing a predetermined design on the non-skin side of the backsheet 3. The mark 50 is preferably a display that encourages pressing the pad 1, and in Fig. 17 the word "press" is printed. However, the mark 50 is not limited to the example in Fig. 17 and may be another design (color, shape, text information, etc.).

[0120] As described above, when discarding a used pad 1, the pad 1 is folded in half lengthwise with the skin side facing inward, and the joining means 30 (30') are placed on top of each other and pressed from the non-skin side (see FIG. 3B). At this time, since the joining means 30 (30') is provided on the skin side, it is difficult to recognize the position of the joining means 30 (30') from the outside (non-skin side), and it can be difficult to sufficiently press the joining means 30 (30'). Furthermore, opening the skin side to check the position of the joining means 30 (30') can cause problems in terms of hygiene and odor.

[0121] In contrast, if a mark 50 (50') visible from the non-skin side is provided as shown in Figure 17, when the pad 1 is folded with the skin side facing inward for disposal, the mark 50 (50') is pressed from the non-skin side in the thickness direction, pressing the joining means 30 (30') at the portion overlapping the mark 50, 50', thereby crimping the one-side joining means 30 and the other-side joining means 30' together. Therefore, even after a drop test is performed with the skin side closed, the joining state between the one-side joining means 30 and the other-side joining means 30' is likely to be maintained. This makes it less likely for the odor of excrement to leak outside the pad 1 (non-skin side) when the pad 1 is disposed of, making it easier to suppress the odor of excrement.

[0122] REFERENCE SIGNS LIST 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, 8 adhesive region, 10 absorbent core, 11 core wrap sheet, 20 fixing member (locking means), 30 one-side joining means, 30r overlapping portion, 30n non-overlapping portion, 30' other-side joining means, 31 adhesive, 40 adjacent layer, 50, 50' marks, 100 disposable diaper (diaper), 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, and comprising a liquid-absorbent absorbent core, wherein an adhesive capable of being joined to a part of the absorbent article at the time of disposal is provided on the skin side surface, and when a drop test is performed by folding the absorbent article in half in the longitudinal direction with the skin side surface on the inside and dropping it from a predetermined height in a state where the adhesive is joined to a part of the absorbent article, at least a part of the adhesive maintains a state of being joined to a part of the absorbent article.

2. The absorbent article according to claim 1, wherein when the drop test is performed with 300 ml of artificial urine contained in the absorbent core, at least a part of the adhesive maintains a state of being joined to a part of the absorbent article.

3. The absorbent article according to claim 1 or 2, having a topsheet provided on the skin side of the absorbent core, wherein the adhesive has adhesiveness, and when the drop test is performed in a state where the absorbent article is folded in half in the longitudinal direction with the skin side surface on the inside and the topsheet facing the adhesive is joined, at least a part of the adhesive maintains a state of being joined to a part of the absorbent article.

4. The absorbent article according to claim 1 or 2, wherein the adhesive has a first-side adhesive provided on one side in the longitudinal direction and a second-side adhesive provided on the other side in the longitudinal direction, the first-side adhesive and the second-side adhesive each have self-adhesiveness, and when the drop test is performed in a state where the absorbent article is folded in half in the longitudinal direction with the skin side surface on the inside and the first-side adhesive and the second-side adhesive are joined to each other, at least a part of the first-side adhesive maintains a state of being joined to a part of the second-side adhesive.

5. The absorbent article according to claim 4, wherein in a state where the first-side adhesive and the second-side adhesive are joined to each other, the central position of the first-side adhesive in the longitudinal direction and the central position of the second-side adhesive in the longitudinal direction are displaced.

6. The absorbent article according to claim 4, having a topsheet provided on the skin side of the absorbent core, wherein the one-side adhesive and the other-side adhesive are applied to the skin side surface of the topsheet, and the magnitude of the force required to peel off the one-side adhesive from a state where the one-side adhesive is joined to the other-side adhesive is smaller than the force required to peel off the one-side adhesive from a state where the one-side adhesive is applied to the skin side surface of the topsheet. An absorbent article characterized by this.

7. The absorbent article according to claim 4, having a topsheet provided on the skin side of the absorbent core, having locking means on the non-skin side surface that can be locked to the skin side surface of the disposable diaper, and the magnitude of the force required to peel off the one-side adhesive from a state where the one-side adhesive is joined to the other-side adhesive is smaller than the force required to peel off the locking means from a state where the locking means is locked to the topsheet. An absorbent article characterized by this.

8. The absorbent article according to claim 1 or 2, wherein the adhesive is provided across the end of the absorbent core in the longitudinal direction, and when the absorbent article is folded in half in the longitudinal direction with the skin side surface inside, and the falling test is performed in a state where a portion of the adhesive that overlaps the absorbent core in the longitudinal direction is joined to a part of the absorbent article, at least a part of the overlapping portion maintains a state of being joined to a part of the absorbent article. An absorbent article characterized by this.

9. The absorbent article according to claim 1 or 2, wherein the adhesive is provided across the end of the absorbent core in the longitudinal direction, and when the absorbent article is folded in half in the longitudinal direction with the skin side surface inside, and the falling test is performed in a state where a portion of the adhesive that does not overlap the absorbent core in the longitudinal direction is joined to a part of the absorbent article, at least a part of the non-overlapping portion maintains a state of being joined to a part of the absorbent article. An absorbent article characterized by this.

10. The absorbent article according to claim 1 or 2, wherein when the adhesive is trisected into a first adjacent region, a central region, and a second adjacent region in either the longitudinal direction or the width direction, the bonding strength of the first adjacent region or the second adjacent region is weaker than the bonding strength of the central region.

11. The absorbent article according to claim 1 or 2, comprising a topsheet provided closer to the skin side than the absorbent core and a backsheet provided closer to the non-skin side than the absorbent core, having an adjacent layer adjacent to the topsheet from the thickness direction, closer to the skin side than the backsheet, 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 deployed and stretched state.

12. The absorbent article according to claim 1 or 2, 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 the deployed and stretched state.

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