Absorbent articles

Abstract

To provide an absorbent article which has preferable appearance and is excellent in a feeling and a cushion property.SOLUTION: A rear surface sheet 10 in an absorbent article 1 comprises, in an order from a skin facing surface side to a non-skin facing surface: a first sheet 11; a second sheet 12; and a third sheet 13. The third sheet 13 forms a non-skin facing surface of the absorbent article 1. The absorbent article has a first junction region 41 where the first sheet 11 and the second sheet 12 are adhered through an adhesive agent, and a second junction region 45 where the second sheet 12 and the third sheet 13 are adhered through the adhesive agent, and has an overlapping region where the first junction region and the second junction region are overlapped in plan view. The first junction region 41 and the second junction region 45 respectively have adhesive agent arrangement parts 42, 46 where the adhesive agent is arranged, and adhesive agent non-arrangement parts 43, 47 where no adhesive agent is arranged. The first junction region 41 has an area ratio of the adhesive agent arrangement part which is greater than that of the second junction region 45.SELECTED DRAWING: Figure 5

Description

【Technical Field】 【0001】 The present invention relates to absorbent articles. 【Background Art】 【0002】 Absorbent articles such as disposable diapers generally include an absorber having an absorbent core and a plurality of sheets disposed on the non-skin-facing side of the absorber. For example, the present applicant has previously disclosed an absorbent body having a liquid-permeable surface sheet, a liquid-impermeable back sheet, and a liquid-retaining absorber interposed between the two sheets, and an exterior body located on the back sheet side of the absorbent body. In a portion excluding both side edges and front and rear end portions in the longitudinal direction of the absorbent body, the back sheet and the exterior body are adhered by an adhesive intermittently applied in a stripe shape (Patent Document 1). 【0003】 Further, the present applicant has previously disclosed an exterior body disposed on the non-skin-facing side of an absorbent body, the exterior body having an outer layer sheet, an inner layer sheet, a leg elastic member between the two sheets, and an adhesive for legs for fixing the leg elastic member. Each adhesive for legs is disposed along the transverse direction in a region where the leg elastic member is disposed in the longitudinal direction in the unfolded state of the diaper, and the intervals between the adhesives for legs adjacent to each other in the longitudinal direction are arranged at two or more different intervals (Patent Document 2). 【0004】 Further, Patent Document 3 discloses an absorbent article having a first joining region where an exterior sheet and the back sheet are joined to each other, and a first non-joining region where the exterior sheet and the back sheet are not joined to each other. The first joining region includes a plurality of first width-direction extending joining regions that extend in the article width direction while being spaced apart from each other in the article length direction. The first non-joining region is located between the first width-direction extending joining regions with respect to the article length direction, and in the first non-joining region, the exterior sheet is slidable with respect to the back sheet at least in the article width direction. 【Prior Art Documents】 【Patent Documents】 【0005】 [Patent Document 1] Japanese Patent Publication No. 2005-095261 [Patent Document 2] Japanese Patent Publication No. 2016-022236 [Patent Document 3] Japanese Patent Publication No. 2021-000218 [Overview of the Initiative] [Problems that the invention aims to solve] 【0006】 The outer surface of absorbent articles is often visible to the wearer or their guardian, and is frequently touched by the wearer's hands when wearing the article. Furthermore, if absorbent articles have poor breathability, they tend to become stuffy, which can easily cause rashes and itching. From these perspectives, absorbent articles are required to have an outer surface with a good texture and good cushioning. The absorbent articles described in Patent Documents 1 to 3 take into consideration the softness and texture of the outer surface of the absorbent article, but no special consideration has been given to improving the appearance of the absorbent article, and there was room for improvement in terms of texture and cushioning. 【0007】 Therefore, the object of the present invention is to provide an absorbent article that has a good appearance as well as excellent texture and cushioning properties. [Means for solving the problem] 【0008】 The present invention relates to an absorbent article having a surface sheet, a back sheet, and an absorbent core disposed between the surface sheet and the back sheet, and having a longitudinal direction corresponding to the front-to-back direction of the wearer and a transverse direction perpendicular to the longitudinal direction. Preferably, the back sheet has a first sheet, a second sheet, and a third sheet arranged in order from the skin-facing side toward the non-skin-facing side. Preferably, the third sheet forms the non-skin-facing surface of the absorbent article. Preferably, the back sheet has a first bonding region in which the first sheet and the second sheet are partially joined via an adhesive, and a second bonding region in which the second sheet and the third sheet are partially joined via an adhesive. Preferably, the back sheet has, in each of the first and second bonding regions, an adhesive-placed portion where the adhesive is provided and an adhesive-free portion where the adhesive is not provided. Preferably, the back surface sheet has an overlapping region where the first bonding region and the second bonding region overlap in a plan view. In the superimposed region of the back sheet, it is preferable that the area ratio of the adhesive placement portion in the first bonding region is higher than that of the second bonding region. Preferably, the adhesive-free portion of the second bonding region of the back sheet overlaps with the adhesive-free portion of the first bonding region. [Effects of the Invention] 【0009】 The absorbent article of the present invention has a good appearance and excellent texture and cushioning properties. [Brief explanation of the drawing] 【0010】 [Figure 1] Figure 1 is a plan view showing the unfolded and extended state of a disposable diaper, which is one embodiment of the present invention. [Figure 2] Figure 2 is a cross-sectional view taken along line II-II in Figure 1. [Figure 3] Figure 3(a) is a plan view illustrating the location of the first joint region, and Figure 3(b) is a plan view illustrating the location of the second joint region. [Figure 4] Figure 4 is a cross-sectional view along the vertical direction of the overlapping region shown in Figure 3. [Figure 5] Figure 5 is a cross-sectional view taken along the vertical direction, showing the non-extended state of the overlapping region shown in Figure 4. [Figure 6] Figures 6(a) to 6(c) are equivalent to Figure 5 and show another embodiment of the superimposed region according to the present invention. [Figure 7] Figures 7(a) to 7(c) are longitudinal cross-sectional views illustrating the coating patterns of the adhesive forming the first and second bonding regions according to the present invention. [Modes for carrying out the invention] 【0011】 The present invention will now be described below with reference to the drawings, based on preferred embodiments thereof. Figures 1 and 2 show a pant-type disposable diaper 1 (hereinafter simply referred to as "diaper 1"), which is one embodiment of the absorbent article of the present invention. Diaper 1 has an abdominal portion A that is positioned on the wearer's abdominal side when worn, a dorsal portion B that is positioned on the wearer's dorsal side, and a crotch portion C located between the abdominal portion A and the dorsal portion B. Diaper 1 has a longitudinal direction X that corresponds to the wearer's front-to-back direction, i.e., the direction extending from the abdominal portion A through the crotch portion C to the dorsal portion B, and a transverse direction Y that is perpendicular to the longitudinal direction X. 【0012】 Diaper 1 includes an absorbent core 22 located in the center of the lateral direction Y, and a backing sheet 10 positioned on the non-skin-facing side of the absorbent core 22, that is, on the side further away from the wearer's body than the absorbent core 22 (see Figure 2). 【0013】 In this specification, "skin-facing surface" refers to the surface of an absorbent article or its component (e.g., surface sheet 21) that faces the wearer's skin when the absorbent article is worn, i.e., the side that is relatively closer to the wearer's skin, and "non-skin-facing surface" refers to the surface of an absorbent article or its component that faces away from the skin when the absorbent article is worn, i.e., the side that is relatively further away from the wearer's skin. Here, "when worn" means the normal and proper wearing position, i.e., the state in which the correct wearing position of the absorbent article is maintained. 【0014】 As shown in Figure 1, when diaper 1 is unfolded and extended, it is formed symmetrically with respect to a vertical center line CL that extends in the vertical direction X and bisects diaper 1 in the horizontal direction Y. As shown in Figure 1, the absorbent body 22 has a rectangular shape in plan view, and its longitudinal direction coincides with the vertical direction X of diaper 1 when unfolded and extended. In plan view, the absorbent body 22 is positioned in the center of the horizontal direction Y of the outer casing 3 (second sheet 12 and third sheet 13), which will be described later, and is bonded to the back sheet 10 with adhesive. The "unfolded and stretched state" of diaper 1 refers to the state in which diaper 1 is separated at the side seal portion S to be unfolded, and then the elastic members of each part of the unfolded diaper 1 are stretched to the design dimensions (the same dimensions as when spread flat in a planar state with the influence of the elastic members completely eliminated). In this specification, unless otherwise specified, each dimension of each part of diaper 1, such as the length in the vertical direction X or the horizontal direction Y, refers to the dimensions (design dimensions) when each part's elastic member is stretched and each member is extended. 【0015】 As shown in Figure 2, diaper 1 comprises an absorbent body 2 having a liquid-permeable surface sheet 21, a leak-proof sheet 28, a liquid-retaining absorbent body 22 interposed between these two sheets 21 and 28, and a pair of leak-proof cuffs 26, 26. In the absorbent body 2, the surface sheet 21, the absorbent body 22, the pair of leak-proof cuffs 26, and the leak-proof sheet 28 are integrated together by known joining means such as adhesive. In a plan view, the absorbent body 2 has a rectangular shape that is long in the vertical direction X, extending in the vertical direction X from the ventral side A to the dorsal side B. In this embodiment, the positions of both ends of the absorbent body 2 in the vertical direction X are substantially the same as the positions of both ends of the absorbent body 22 in the vertical direction X. The leak-proof sheet 28 in this embodiment corresponds to the first sheet 11, which will be described later. 【0016】 The absorbent body 22 extends in the longitudinal direction X between the ventral portion A and the dorsal portion B, and is composed of a liquid-retaining absorbent core 24 and a core wrap sheet 25 that contacts its outer surface and encloses it. As shown in Figure 2, the absorbent core 24 of this embodiment has a pair of side absorbent cores 24S, 24S and a pair of central absorbent cores 24C located between the pair of side absorbent cores 24S, 24S. Each of these pairs of side absorbent cores 24S, 24S and the central absorbent core 24C extends in the vertical direction X in the crotch area C. The central absorbent core 24C has a two-layer structure, while the side absorbent cores 24S have a single-layer structure. The absorbent core 24 of this embodiment has a side bending guide portion 23S between the side absorbent cores 24S and the central absorbent core 24C, and further has a central bending guide portion 23C between the pair of central absorbent cores 24C. The absorbent body 22 can be deformed so that the side absorbent cores 24S lift towards the wearer's skin, starting from the side bending guide portions 23S, 23S (see Figure 2). Furthermore, the absorbent body 22 can be deformed so that a pair of central absorbent cores 24C bend into a mountain fold, starting from the central bending guide portion 23C (not shown). 【0017】 In this embodiment, the side bending guide portions 23S, 23S and the central bending guide portion 23C in the absorber 22 consist of through holes that extend in the vertical direction X and penetrate the absorbent core 24. Alternatively, the side bending guide portions 23S, 23S and the central bending guide portion 23C may be recesses formed on the skin-facing or non-skin-facing surface of the absorbent core 24. 【0018】 The absorbent body 22 of this embodiment is equipped with core elastic members 31 on each side along the longitudinal direction X, which are arranged in an extended state in the longitudinal direction X. The core elastic members 31 are arranged between the absorbent core 24 and the core wrap sheet 25 on both sides along the longitudinal direction X of the absorbent body 22. When the core elastic members 31 contract in the longitudinal direction X, they can assist in the deformation of the side absorbent core 24S starting from the side bending guide portion 23S. In other words, the side absorbent core 24S becomes easier to deform so that it lifts towards the wearer's skin. 【0019】 As shown in Figure 1, the absorbent body 2 is equipped with a pair of leak-proof cuffs 26, 26 on both sides of its skin-facing surface along the longitudinal direction X. As shown in Figure 2, the leak-proof cuff 26 of this embodiment is formed by folding a liquid-resistant or water-repellent and breathable leak-proof cuff-forming sheet 27 in half and joining two opposing leak-proof cuff-forming sheets 27 together. The leak-proof cuff 26 of this embodiment is equipped with a cuff elastic member 35 and an outer cuff elastic member 32 between the two opposing leak-proof cuff-forming sheets 27. The cuff elastic member 35 is positioned at the inner end of the leak-proof cuff 26 in the transverse direction Y, and the outer cuff elastic member 32 is positioned at the outer end of the leak-proof cuff 26 in the transverse direction Y (see Figures 1 and 2). These cuff elastic member 35 and outer cuff elastic member 32 are positioned in an extended state in the longitudinal direction X. Each leak-proof cuff 26 has a base end fixed between the absorbent body 22 and the leak-proof sheet 28 in the absorbent body 2, and a free end to which the cuff elastic member 35 is fixed. The leak-proof cuff 26 is designed so that the free end of the leak-proof cuff 26 stands up at least in the crotch area C when the cuff elastic member 35, which is positioned in an extended state in the longitudinal direction X, contracts. In addition, the outer cuff elastic member 32 assists in the upright position of the leak-proof cuff 26 by contracting in the longitudinal direction X. 【0020】 As shown in Figure 2, the back sheet 10 has a first sheet 11, a second sheet 12, and a third sheet 13 in order from the skin-facing side toward the non-skin-facing side. In other words, the back sheet 10 has a third sheet 13, a second sheet 12, and a first sheet 11 in order from the non-skin-facing side toward the skin-facing side of the diaper 1. The non-skin-facing side of the diaper 1 is formed by the third sheet 13 of the back sheet 10. Thus, the back sheet 10 is positioned on the non-skin-facing side of the absorbent core 24, and the third sheet 13 forms the non-skin-facing side of the diaper 1. The first sheet 11 and the second sheet 12 are directly joined, and the second sheet 12 and the third sheet 13 are directly joined. In this embodiment, the back sheet 10 is positioned on the non-skin-facing side of the absorbent body 22 (core wrap sheet 25). The back sheet 10 in this embodiment includes a leak-proof sheet 28 as the first sheet 11, which forms the non-skin-facing side of the absorbent body 2. The back sheet 10 also includes a second sheet 12 and a third sheet 13, which are positioned on the non-skin-facing side of the absorbent body 2. The components (second sheet 12 and third sheet) positioned on the non-skin-facing side of the absorbent body 2 are also referred to as the outer casing 3. In the outer casing 3, the second sheet 12 and the third sheet 13 are identical in shape and size in plan view. In this embodiment, the first sheet 11 (leak-proof sheet 28) is a moisture-permeable film, and the second sheet 12 and the third sheet 13 are fiber sheets made of fibrous material, respectively. In Figure 2, the first adhesive placement section 42 and the second adhesive placement section 46, which will be described later, are not shown. 【0021】 In the outer casing 3, the side edges of the outer casing 3 along the longitudinal direction X in the ventral portion A and the dorsal portion B are joined to each other by known joining means such as hot melt adhesive, heat seal, or ultrasonic seal, thereby forming a pair of side seal portions S, S, as well as a waist opening through which the wearer's torso passes and a pair of leg openings through which the wearer's lower limbs pass (not shown). 【0022】 The outer casing 3 forms the outline of the diaper 1 in its unfolded and extended state as shown in Figure 1, and the periphery of the outer casing 3 forms the contour lines of the diaper 1 in its unfolded and extended state, namely the contour lines of the ventral part A, the crotch area C, and the dorsal part B, respectively. As shown in Figure 1, at the crotch area C, both side edges of the outer casing 3 along the longitudinal direction X are curved in a convex arc towards the center in the transverse direction Y, and the central area in the longitudinal direction X is narrowed inward in the transverse direction Y. The outer casing 3 and the absorbent body 2 are joined by known joining means such as adhesive. In addition, at least one of the second sheet 12 and the third sheet 13 of the outer casing 3 is folded back towards the skin-facing side along the peripheral edge WE of the waist opening. 【0023】 In the outer casing 3, the third sheet 13 forms the outer surface of the diaper 1, i.e., the non-skin-facing surface, and the second sheet 12 is positioned on the skin-facing side of the third sheet 13. The outer casing 3 has a plurality of thread-like or strip-like elastic members 36, 37 arranged between the second sheet 12 and the third sheet 13. Specifically, the outer casing 3 has a waist elastic member 36 arranged along the transverse direction Y in the ventral portion A and the dorsal portion B, and a leg elastic member 37 arranged along the leg opening (see Figure 1). In this embodiment, the waist elastic member 36 positioned in a position overlapping with the absorbent body 2 in the longitudinal direction X is arranged so as not to exhibit elastic stretchability in the region overlapping with the absorbent body 2 in the thickness direction Z by processing such as fine division, but the waist elastic member 36 may exhibit elastic stretchability in the aforementioned region. In the ventral portion A and the dorsal portion B, the waist elastic member 36 is arranged intermittently at predetermined intervals in the longitudinal direction X, in an extended state in the transverse direction Y. In this way, because the waist elastic member 36 is positioned in a state in which its elastic stretchability is exhibited, a substantially continuous annular waist gather (pleat) is formed around the entire circumference of the opening edge of the waist opening. 【0024】 The leg edge LS that forms the opening edge of the leg opening in the outer casing 3 has one or more thread-like or strip-like leg elastic members 37 arranged in an expandable and expandable state for forming leg gathers. The leg elastic members 37 extend in the longitudinal direction X from a part of the dorsal part B on the crotch side C, i.e., the central side of the longitudinal direction X, through the crotch C, to a part of the ventral part A on the central side of the longitudinal direction X (see Figure 1). Because these leg elastic members 37 are arranged in an extended state, a substantially continuous annular leg gather is formed around the entire circumference of the opening edge of the leg opening (leg edge LS). These leg elastic members 37 are also clamped and fixed between the third sheet 13 and the second sheet 12 that constitute the outer casing 3 by bonding means such as adhesive. 【0025】 On the back sheet 10, the first sheet 11 and the second sheet 12, and the second sheet 12 and the third sheet 13, which are adjacent in the thickness direction Z of the diaper 1, are partially joined via adhesive. The diaper 1 has a first joining region 41 where the first sheet 11 and the second sheet 12 are partially joined via adhesive, and a second joining region 45 where the second sheet 12 and the third sheet 13 are partially joined via adhesive [see Figures 3(a) and (b)]. In diaper 1, the absorbent body 2 and the outer casing 3 are joined in the first joining region 41, and the sheets 12 and 13 constituting the outer casing 3 and the leg elastic member 37 are joined in the second joining region 45. 【0026】 The first bonding region 41 and the second bonding region 45 each have adhesive-placed portions 42 and 46 where adhesive is placed, and adhesive-free portions 43 and 47 where adhesive is not placed [see Figures 3(a) and (b)]. Hereinafter, the adhesive-placed portion 42 in the first bonding region 41 will be referred to as the "first adhesive-placed portion 42," and the adhesive-free portion 43 in the first bonding region 41 will be referred to as the "first adhesive-free portion 43." Similarly, the adhesive-placed portion 46 in the second bonding region 45 will be referred to as the "second adhesive-placed portion 46," and the adhesive-free portion 47 in the second bonding region 45 will be referred to as the "second adhesive-free portion 47." In the first bonding region 41, the first adhesive-placed portion 42 and the first adhesive-free portion 43 are arranged alternately in the vertical direction X, and each extends along the horizontal direction Y. Similarly, in the second bonding region 45, the second adhesive-placed portion 46 and the second adhesive-free portion 47 are arranged alternately in the vertical direction X, and each extends along the horizontal direction Y. In other words, in both the first bonding region 41 and the second bonding region 45, the adhesive is intermittently coated in a stripe pattern extending along the horizontal direction Y. 【0027】 The first bonding region 41 is located in the region overlapping with the absorber 22 and, like the absorber 22, has a rectangular shape in plan view (see Figure 3(a)). The positions of both ends of the first bonding region 41 in the lateral direction Y are approximately the same as the positions of both ends of the absorbent body 2 in the lateral direction Y. The positions of both ends of the first bonding region 41 in the vertical direction X are approximately the same as the positions of both ends of the absorber 22 in the vertical direction X. 【0028】 The second bonding region 45 is located in the outer casing 3 (third sheet 13) in a region consisting of a portion where the central area in the longitudinal direction X is constricted inward in the transverse direction Y, and portions of the ventral portion A and dorsal portion B that are on the inward side in the longitudinal direction X and adjacent to the constricted portion in the longitudinal direction X [see Figure 3(b)]. In the second bonding region 45, the second adhesive placement portion 46 is arranged continuously along the entire length of the region in the transverse direction Y. In the second bonding region 45, the positions of both ends in the longitudinal direction X are located further inward in the longitudinal direction X than the positions of both ends of the absorber 22 in the longitudinal direction X. 【0029】 In a plan view, diaper 1 has an overlapping region 48 where the first joining region 41 and the second joining region 45 overlap (see Figure 3(b)). In this embodiment, the overlapping region 48 is the region where the first joining region 41 overlaps with the second joining region 45 on the inward side in the vertical direction X of region 41. In this embodiment, the overlapping region 48 extends in the vertical direction X in a plan view and is positioned to partially overlap the absorbent material 22 (see Figures 3(a) and (b)). 【0030】 Figure 4 shows a cross-sectional view of the back sheet 10 along the longitudinal direction X in the overlapping region 48. In Figure 4, the back sheet 10 is shown stretched in the longitudinal direction X. The first bonding region 41 has a higher area ratio of adhesive-containing areas than the second bonding region 45. In other words, the first bonding region 41 has a lower area ratio of areas without adhesive than the second bonding region 45. 【0031】 The first bonding region 41 is the region enclosed by a virtual line connecting the edges of adjacent first adhesive-placed portions 42 in the vertical direction X, with the first adhesive-free portion 43 in between, and the outer edges of the first adhesive-placed portions 42 located furthest out in the direction perpendicular to the extension direction of the first adhesive-placed portions 42. The second bonding region 45 is the region enclosed by a virtual line connecting the edges of adjacent second adhesive-placed portions 46 in the vertical direction X, with the second adhesive-free portion 47 in between, and the outer edges of the second adhesive-placed portions 46 located furthest out in the direction perpendicular to the extension direction of the second adhesive-placed portions 46. 【0032】 The area ratio of the first adhesive placement area 42 is determined by dividing the total area of ​​the first adhesive placement area 42 in the first bonding region 41 by the area of ​​the first bonding region 41 (total area of ​​the first adhesive placement area 42 / area of ​​the first bonding region 41). The area ratio of the second adhesive placement area 46 is determined by dividing the total area of ​​the second adhesive placement area 46 in the second bonding region 45 by the area of ​​the second bonding region 45 (total area of ​​the second adhesive placement area 46 / area of ​​the second bonding region 45). 【0033】 The area ratio of the first adhesive placement area 42 and the area ratio of the second adhesive placement area 46 can be measured, for example, by the following method. First, a sample piece is cut from the superimposed region 48, specifically from the portion joined in the first joining region 41 or the second joining region 45. Specifically, the first sheet 11 and the second sheet 12, joined in the first joining region 41, are cut out as sample pieces, or the second sheet 12 and the third sheet 13, joined in the second joining region 45, are cut out as sample pieces. From the sample piece, components not involved in the joining of the adhesive placement area to be measured are removed. For example, when measuring the area ratio of the first adhesive placement area 42, the third sheet 13 is peeled off the sample piece using a cold spray or the like. At this time, other components are peeled off the sample piece in a way that does not affect the bonding state of the adhesive placement area to be measured. The size of the sample piece is 50 mm x 50 mm. Next, the sample sheets are separated using a cold spray or the like to expose the surface where the adhesive is applied, i.e., the surface coated with adhesive. Printing toner is uniformly sprayed onto this adhesive-coated surface, and after the toner is adsorbed onto the adhesive, the printing toner that was not adsorbed by the adhesive is removed. The removal of the printing toner is done by blowing air or by suction. Next, an image of the surface on which the printing toner has been absorbed is acquired using a scanner (Seiko Epson Corporation ES-10000G). This image is then binarized to black and white, making it possible to distinguish between the areas where the printing toner has been absorbed and the areas where it has not, in black and white. Next, the area ratio of the portion in the image where the printing toner has been adsorbed is measured using image analysis software (for example, Image-Pro Plus, manufactured by Nippon Roper Co., Ltd.). This measured area ratio is converted to the area ratio of the adhesive-placed portion in the sample piece based on a previously measured reference value. The reference value is the value measured for the area ratio of the adhesive-placed portion of a reference sample piece using the same method as described above. The reference sample piece is a sample piece (50 mm x 50 mm) in which adhesive is coated on a nonwoven fabric in a stripe pattern so that the area ratio of the adhesive-placed portion is 50%. More specifically, in the reference sample piece, the coated portion with adhesive and the uncoated portion without adhesive each extend in one direction, and these coated and uncoated portions are arranged alternately in a direction perpendicular to this one direction. In the reference sample piece, the width of each coated and uncoated portion is 1 mm, and the amount of adhesive applied to the coated portion is 3 g / m². 2 Let's assume that. 【0034】 The area ratio of the first adhesive placement area 42 is determined by dividing the total area of ​​the first adhesive placement area 42 in the first bonding region 41 by the area of ​​the first bonding region 41 (total area of ​​the first adhesive placement area 42 / area of ​​the first bonding region 41). The area ratio of the second adhesive placement area 46 is determined by dividing the total area of ​​the second adhesive placement area 46 in the second bonding region 45 by the area of ​​the second bonding region 45 (total area of ​​the second adhesive placement area 46 / area of ​​the second bonding region 45). Unless otherwise specified, the areas of the first bonding region 41 and the second bonding region 45, as well as the widths of the adhesive-placed portions 42, 46 and the non-adhesive-placed portions 43, 47, are measured with the back sheet 10 stretched in a direction perpendicular to the extension direction of the adhesive-placed portions 42, 46 (in this embodiment, the vertical direction X) (see Figure 3). That is, the measurements are taken with the folds in the first non-adhesive-placed portion 43 and the second non-adhesive-placed portion 47 removed. 【0035】 Figure 5 shows a cross-sectional view of the back sheet 10 in its non-stretched state along the longitudinal direction X. Reference numeral 20 in Figure 5 indicates a component of the diaper 1 located on the skin-facing side of the back sheet 10. As shown in Figure 5, in the back sheet 10 of diaper 1, the first sheet 11 and the second sheet 12 are not joined in the first adhesive-free area 43, and the second sheet 12 and the third sheet 13 are not joined in the second adhesive-free area 47. As a result, folds that bulge out on the non-skin-facing side are formed in both the first adhesive-free area 43 and the second adhesive-free area 47. As shown in Figure 5, in diaper 1, the second adhesive-free area 47 overlaps with the first adhesive-free area 43. That is, the fold formed by the first adhesive-free area 43 and the fold formed by the second adhesive-free area 47 overlap. 【0036】 In the diaper 1 of this embodiment, because the area ratio of the adhesive-placed portion in the first bonding region 41 is higher than that of the second bonding region 45, finer folds are formed in the first non-adhesive portion 43 than in the folds in the second non-adhesive portion 47. Also, as shown in Figure 5, in the overlapping region 48, a fold structure is formed in which the folds in the first non-adhesive portion 43 and the folds in the second non-adhesive portion 47 overlap in the thickness direction Z, so when the back sheet 10 is touched with fingers, it gives the feeling that the overlapping folds are gradually crushed from the non-skin-facing side. In addition, because the large and small folds overlap, it is easier for them to return to their original shape when the pressure from the fingers is released, so a good cushioning feeling is obtained. Furthermore, because larger folds are formed in the second adhesive-free area 47 than in the first bonding area 41, the occurrence of wrinkles on the outer surface (third sheet 13) of the overlapping area 48 is suppressed, resulting in a smooth texture and a soft, fluffy appearance. This improves the appearance of the outer surface (non-skin-facing surface) of the diaper 1. Therefore, the diaper 1 has a good appearance as well as excellent texture and cushioning. Furthermore, since the folds formed in the second adhesive-free section 47 and the first adhesive-free section 43 function as air passages, the breathability of the back sheet 10 can be maintained well. 【0037】 From the viewpoint of further improving the effects described above, the area ratio of the first adhesive placement portion 42 in the first bonding region 41 is preferably 1.1 or more, more preferably 1.5 or more, preferably 10.0 or less, more preferably 5.0 or less, preferably 1.1 or more and 10.0 or less, more preferably 1.5 or more and 5.0 or less, relative to the area ratio of the second adhesive placement portion 46 in the second bonding region 45. The area ratio of the first adhesive placement portion 42 in the first bonding region 41 is preferably 12% or more, more preferably 15% or more, also preferably 70% or less, more preferably 50% or less, also preferably 12% to 70%, and more preferably 15% to 50%. The area ratio of the second adhesive placement portion 46 in the second bonding region 45 is preferably 5% or more, more preferably 10% or more, also preferably 50% or less, more preferably 35% or less, also preferably 5% to 50% or less, more preferably 10% to 35% or less. 【0038】 From the viewpoint of further improving the effects described above, it is preferable that the areas of the first bonding region 41 and the second bonding region 45 are within the following ranges. The ratio of the area of ​​the superimposed region 48 to the area of ​​the first joining region 41 is preferably 30% or more, more preferably 40% or more, also preferably 100% or less, more preferably 80% or less, also preferably 30% or more and 100% or less, more preferably 40% or more and 80% or less. The ratio of the area of ​​the superimposed region 48 to the area of ​​the second joining region 45 is preferably 20% or more, more preferably 30% or more, also preferably 80% or less, more preferably 70% or less, also preferably 20% to 80%, and more preferably 30% to 70%. 【0039】 In the superimposed region 48, at least a portion of the second adhesive-free portion 47 may partially overlap with the first adhesive-free portion 43, may overlap with one first adhesive-free portion 43, or may overlap with two or more first adhesive-free portions 43. In this embodiment, the second adhesive-free area 47 overlaps with more than one first adhesive-free area 43. More specifically, the second adhesive-free area 47 overlaps with 1.5 adhesive-free areas 43. In this case, since there is more than one fold inside one adhesive-free area 47, the cushioning of the diaper 1 is improved, and the appearance becomes softer. 【0040】 From the viewpoint of improving the cushioning feel of the outer surface of the diaper 1, it is preferable that the adhesive placement area 42 in the first joining area 41 is narrower than the adhesive non-placement area 43. With this configuration, the number of folds formed by joining the first sheet 11 and the second sheet 12 increases, and these folds tend to overlap with the folds formed by joining the second sheet 12 and the third sheet 13. From the viewpoint of making it easier for the folds to overlap, the width W2 of the first adhesive-placed portion 42 (see Figure 4) is preferably 10% or more, more preferably 20% or more, and also preferably 90% or less, more preferably 70% or less, and also preferably 10% to 90% or less, and more preferably 20% to 70% or less, relative to the width W3 of the first adhesive-free portion 43 (see Figure 4). 【0041】 From the viewpoint of improving the soft impression of diaper 1, it is preferable that the width of the adhesive-free portion of the second bonding region 45 is wider than that of the first bonding region 41. That is, it is preferable that the width of the adhesive-free portion of the second bonding region 47 is wider than that of the adhesive-free portion of the first bonding region 43. With such a configuration, the folds formed on the outer surface of diaper 1 tend to be larger. From the same viewpoint as described above, the width W7 (see Figure 4) of the second adhesive-free portion 47 is preferably 120% or more, more preferably 150% or more, and also preferably 1000% or less, more preferably 500% or less, and also preferably 120% or more and 1000% or less, and more preferably 150% or more and 500% or less, relative to the width W3 (see Figure 4) of the first adhesive-free portion 43. 【0042】 The first adhesive placement section 42 and the second adhesive placement section 46 may have the same width, or they may have different widths. From the viewpoint of further improving the soft impression of diaper 1, it is preferable that the width W6 (see Figure 4) of the second adhesive placement area 46 is less than or equal to the width W2 of the first adhesive placement area 42. With this configuration, even if the adhesive placement areas overlap, the folds tend to rise towards the non-skin-facing side. From the same viewpoint as described above, the width W6 of the second adhesive placement portion 46 (see Figure 4) is preferably 20% or more, more preferably 30% or more, and also preferably 100% or less, more preferably 90% or less, and also preferably 20% or more and 100% or less, and more preferably 30% or more and 90% or less, relative to the width W2 of the first adhesive placement portion 42 (see Figure 4). 【0043】 From the viewpoint of further improving the appearance of the outer surface of diaper 1, it is preferable that the second adhesive placement area 46 is narrower than the second adhesive non-placement area 47. In this case, the width W6 of the second adhesive placement area 46 (see Figure 4) is preferably 10% or more, more preferably 20% or more, and also preferably 90% or less, more preferably 70% or less, and also preferably 10% to 90%, and more preferably 20% to 70%. 【0044】 From the viewpoint of more reliably achieving one or more of the above-mentioned effects, it is preferable that the widths of the adhesive-placed portions 42, 46 and the adhesive-free portions 43, 47 in the first bonding region 41 and the second bonding region 45, respectively, be within the following ranges. The width W2 of the first adhesive placement section 42 (see Figure 4) is preferably 0.5 mm or more, more preferably 0.8 mm or more, and also preferably 10.0 mm or less, more preferably 5.0 mm or less, and also preferably 0.5 mm or more and 10.0 mm or less, and more preferably 0.8 mm or more and 5.0 mm or less. The width W3 (see Figure 4) of the first adhesive-free portion 43 is preferably 0.5 mm or more, more preferably 1.0 mm or more, also preferably 10.0 mm or less, more preferably 7.0 mm or less, also preferably 0.5 mm or more and 10.0 mm or less, more preferably 1.0 mm or more and 7.0 mm or less. The width W6 (see Figure 4) of the second adhesive placement portion 46 is preferably 0.5 mm or more, more preferably 0.8 mm or more, and also preferably 10.0 mm or less, more preferably 7.0 mm or less, and also preferably 0.5 mm or more and 10.0 mm or less, and more preferably 0.8 mm or more and 7.0 mm or less. The width W7 (see Figure 4) of the second adhesive-free portion 47 is preferably 1.0 mm or more, more preferably 1.5 mm or more, also preferably 10.0 mm or less, more preferably 7.0 mm or less, also preferably 1.0 mm or more and 10.0 mm or less, more preferably 1.5 mm or more and 7.0 mm or less. 【0045】 In this specification, the width of the adhesive-placed portions 42, 46 or the non-adhesive-placed portions 43, 47 is the length of the adhesive-placed portions 42, 46 or the non-adhesive-placed portions 43, 47 in a direction perpendicular to the extending direction of the adhesive-placed portions 42, 46 or the non-adhesive-placed portions 43, 47. In this embodiment, the perpendicular direction coincides with the longitudinal direction X. 【0046】 In the diaper 1 of this embodiment, the core elastic member 31 of the absorbent body 22, the cuff elastic member 35 of the leak-proof cuff 26, and the outer cuff elastic member 32 are each arranged so as to overlap with the overlapping region 48 in a plan view (not shown). In addition, in the diaper 1, the leg elastic members 37 of the outer body 3 are located on both sides of the overlapping region 48 in the lateral direction Y (not shown). In this way, in the diaper 1 in which adhesive placement portions 42 and 46 extending in the lateral direction Y are intermittently arranged, it is preferable that the elastic members having elasticity in the vertical direction X are arranged so as to overlap with the overlapping region 48 in a plan view, or are arranged on both sides of the overlapping region 48 in the lateral direction Y. When the diaper 1 has such a configuration, the formation of the pleat structure becomes easier due to the contraction of the elastic members 31, 32, 35, and 37, so that the cushioning and texture of the back sheet 10 can be further improved. The diaper 1 having the above configuration only needs to have either the elastic members 31, 32, and 35 arranged to overlap the superimposed region 48 in a plan view, or the elastic members 37 arranged on each of the lateral Y sides of the superimposed region 48, and it is preferable to have both. 【0047】 In a plan view, when one or both of the elastic members 31, 32, 35, which are arranged to overlap the superimposed region 48, and the elastic members 37, which are arranged on each of the lateral Y sides of the superimposed region 48, are stretched, the folds in the first adhesive-free area 43 and the second adhesive-free area 47 disappear (see Figure 4), or the height of the folds decreases. On the other hand, when one or both of the elastic members 31, 32, 35, which are arranged to overlap the superimposed region 48, and the elastic members 37, which are arranged on each of the lateral Y sides of the superimposed region 48, are contracted, the height of the folds in the first adhesive-free area 43 and the second adhesive-free area 47 increases (see Figure 5). From the viewpoint of making it easier to form the pleat structure by contracting the elastic member and further improving the fluffy impression of the diaper 1, it is preferable that at least one of the first joining region 41 and the second joining region 45 includes wider adhesive-free portions 43 and 47 when the elastic member is extended (see Figure 4) than when the elastic member is contracted (see Figure 5). In this case, the natural state of the elastic members 31, 32, 35, and 37 that expand and contract in the vertical direction (a state in which no external force is applied) is defined as "when the elastic member is contracted," and the state when the diaper 1 is stretched to its maximum length in the vertical direction X is defined as "when the elastic member is extended." 【0048】 From the same viewpoint as above, it is preferable that the width of the adhesive-free portions 43, 47 when the elastic member is stretched or contracted is within the following range. When the elastic member is stretched, the width of the adhesive-free portions 43 and 47 is W, and when the elastic member is contracted, the width of the adhesive-free portions 43 and 47 is W'. The ratio of W' to W (W' / W) is preferably 20% or more, more preferably 30% or more, preferably 90% or less, more preferably 80% or less, and preferably 20% to 90%, more preferably 30% to 80%. Specifically, such a ratio is the ratio of the width W3' of the first adhesive-free portion 43 when the elastic member is contracted to the width W3 of the first adhesive-free portion 43 when the elastic member is stretched (W3' / W3), or the ratio of the width W7' of the second adhesive-free portion 47 when the elastic member is contracted to the width W7 of the second adhesive-free portion 47 when the elastic member is contracted (W7' / W7). When the elastic member is contracted, the width W3' of the first adhesive-free portion 43 [see Figure 5] is preferably 0.2 mm or more, more preferably 0.4 mm or more, also preferably 7.0 mm or less, more preferably 5.0 mm or less, also preferably 0.2 mm or more and 7.0 mm or less, more preferably 0.4 mm or more and 5.0 mm or less. When the elastic member is contracted, the width W7' of the second adhesive-free portion 47 [see Figure 5(a)] is preferably 0.5 mm or more, more preferably 1.0 mm or more, also preferably 8.0 mm or less, more preferably 6.0 mm or less, also preferably 0.5 mm or more and 8.0 mm or less, more preferably 1.0 mm or more and 6.0 mm or less. 【0049】 As described above, the first sheet 11 is a moisture-permeable film, and the second sheet 12 and the third sheet 13 are fiber sheets made of fibrous material, respectively. From the viewpoint of more easily forming the pleated structure, in the diaper 1 of this embodiment, it is preferable that the constituent fibers of at least one of the second sheet 12 and the third sheet 13 are oriented in the transverse direction Y. That is, it is preferable that the constituent fibers of at least one of the second sheet 12 and the third sheet 13 are oriented in the direction of extension of the adhesive placement portions 42 and 46. 【0050】 The orientation of fibers in a sheet can be confirmed by the following method. First, the sheet to be measured is removed from the absorbent material by peeling it off using a cold spray or the like. The removed sheet is cut using a cutter or the like into a rectangular shape in plan view with a length of 2 cm along the longitudinal direction X and a length of 2 cm along the transverse direction Y, and this is used as the measurement piece. The measurement piece is cut from the overlapping region 48 of the second sheet 12 or the third sheet 13. Next, the measurement piece is observed at a magnification of 60 to 200 times using a microscope (for example, Keyence Corporation's digital microscope VHX-1000). For each arbitrary fiber observed within a certain observation area (for example, 1 mm square), two points are determined such that the fiber length is maximum within that area. Next, the angle between the line connecting these two ends and the transverse direction Y is measured. This measurement is performed in at least three observation areas, and the arithmetic mean (average angle) of the angles measured for a total of 30 or more fibers is calculated. If the average angle is within 45 degrees, the constituent fibers are determined to be oriented in the transverse direction (Y), and if the average angle exceeds 45 degrees, the constituent fibers are determined to be oriented in the longitudinal direction (X). In the above measurement, it is preferable to observe at a magnification that allows for the identification of 10 or more fibers within the observation area. 【0051】 From the viewpoint of making the folds in the back sheet 10 more mobile, thereby improving the softness of the back sheet 10, and further improving the ability to form the folds, at least one of the second sheet 12 and the third sheet 13 has a ring crush compressive strength (hereinafter also simply referred to as "ring crush compressive strength") when compressed in a direction perpendicular to the orientation direction of the constituent fibers, preferably 1.0 cN or more, more preferably 1.5 cN or more, also preferably 7.0 cN or less, more preferably 5.0 cN or less, also preferably 1.0 cN or more and 7.0 cN or less, more preferably 1.5 cN or more and 5.0 cN or less. 【0052】 The ring crush compressive strength can be measured as follows. First, the sheet to be measured is removed from the absorbent material by peeling it off using a cold spray or the like. From the removed sheet, five rectangular pieces are cut out, each with a length of 80 mm along the orientation direction of the constituent fibers of the sheet and a length of 30 mm along the direction perpendicular to the orientation direction. These will be used as test specimens. Each test specimen is rolled into a cylindrical shape along its longitudinal direction, and one end of the specimen is overlapped by 10 mm along its longitudinal direction to create a cylinder with an outer circumference of 70 mm. The upper end (upper end in the direction of the cylinder axis) and lower end of the overlapped portion at both ends are fastened with staples (for example, Max Co., Ltd. No. 10-1M staples) to obtain five cylindrical measurement samples. The orientation of the staples is parallel to the circumferential direction of the measurement sample. Each obtained measurement sample (initial sample width: 30 mm) is set in a Tensilon compression tester (Orientec Co., Ltd. "RTA-100"), and the maximum load (cN) is measured when compressed at a compression rate of 10 mm / min in the axial direction of the cylinder (the width direction of the test piece) using a circular compression plate with a diameter of 70 mm or more. The same measurement is performed for five measurement samples, and the arithmetic mean of these measurements is taken as the ring crush compression strength of the sheet. The measurement environment is room temperature 23 ± 2°C and relative humidity 50% RH ± 5%. 【0053】 From the viewpoint of making the pleats in the back sheet 10 more flexible and improving the feel against the skin, it is preferable that the second sheet 12 has a greater ring crush compression strength than the third sheet 13 when compressed in a direction perpendicular to the orientation direction of the constituent fibers. From the same viewpoint as above, it is preferable that the ring crush compression strengths of the first sheet 11, the second sheet 12, and the third sheet are within the following ranges. The ring crush compressive strength of the first sheet 11 is preferably 1.0 cN or more, more preferably 1.5 cN or more, also preferably 7.0 cN or less, more preferably 5.0 cN or less, also preferably 1.0 cN or more and 7.0 cN or less, more preferably 1.5 cN or more and 5.0 cN or less. The ring crush compression strength of the second sheet 12 is preferably 1.0 cN or more, more preferably 1.5 cN or more, and is preferably 7.0 cN or less, more preferably 5.0 cN or less, and is preferably 1.0 cN or more and 7.0 cN or less, more preferably 1.5 cN or more and 5.0 cN or less. The ring crush compression strength of the third sheet 13 is preferably 0.5 cN or more, more preferably 1.0 cN or more, and is preferably 6.0 cN or less, more preferably 4.0 cN or less, and is preferably 0.5 cN or more and 6.0 cN or less, more preferably 1.0 cN or more and 4.0 cN or less. 【0054】 From the viewpoint of facilitating the movement of the folds in the back sheet 10 and further improving the texture, it is preferable that the basis weight of the third sheet is lower than that of the second sheet. From the same viewpoint as above, it is preferable that the basis weights of the first sheet 11, the second sheet 12, and the third sheet are within the following ranges respectively. The basis weight of the first sheet 11 is preferably 5 g / m 2 or more, more preferably 8 g / m 2 or more, and is preferably 40 g / m 2 or less, more preferably 30 g / m2 or less, and is preferably 5 g / m 2 or more and 40 g / m 2 or less, more preferably 8 g / m 2 or more and 30 g / m 2 or less. The basis weight of the second sheet 12 is preferably 5 g / m 2 or more, more preferably 8 g / m 2 or more, and is preferably 30 g / m<00000'11>or less, more preferably 20 g / m 2 or less, and is preferably 5 g / m 2 or more and 30 g / m 2 or less, more preferably 8 g / m 2 or more and 20 g / m 2 or less. The basis weight of the third sheet 13 is preferably 5 g / m 2 or more, more preferably 8 g / m 2The above is preferable, and also preferably 25 g / m 2 More preferably 20 g / m 2 The following is also preferred: 5 g / m 2 More than 25g / m 2 More preferably 8 g / m 2 More than 20g / m 2 The following applies: 【0055】 From the viewpoint of making the pleats in the back sheet 10 more flexible and improving the feel against the skin, it is preferable that the third sheet has a lower density than the second sheet. The density of each sheet is calculated by dividing the basis weight by the thickness of the sheet. The thickness of the sheet is the thickness of the sheet under a load of 0.05 kPa. For measuring the thickness, for example, a non-contact laser displacement meter can be used. From the same viewpoint as above, it is preferable that the basis weight of each of the first sheet 11, the second sheet 12, and the third sheet be within the following ranges. The density of the first sheet 11 is preferably 30 × 10 -6 g / mm 3 The above is comfortable50×10 -6 g / mm 3 The above, and preferably 300 × 10 -6 g / mm 3 Below, 200 x 10 -6 g / mm 3 The following are also preferred: 30 × 10 -6 g / mm 3 300 x 10 -6 g / mm 3 The following is more preferable: 50 x 10 -6 g / mm 3 The above 200 x 10 -6 g / mm 3 The following applies: The density of the second sheet 12 is preferably 30 × 10 -6 g / mm 3 The above is comfortable50×10 -6 g / mm 3 The above, and preferably 200 × 10 -6 g / mm 3 More preferably, 150 g / mm³3 The following, and preferably 30 g / mm³ or more, 200 × 10 -6 g / mm 3 The following is more preferable: 50 x 10 -6 g / mm 3 The above 150 x 10 -6 g / mm 3 The following applies: The density of the third sheet 13 is preferably 30 × 10 -6 g / mm 3 The above is comfortable50×10 -6 g / mm 3 The above, and preferably 180 × 10 -6 g / mm 3 The following is more preferable: 150 x 10 -6 g / mm 3 The following are also preferred: 30 × 10 -6 g / mm³ or more, 180 x 10 -6 g / mm 3 The following is more preferable: 50 x 10 -6 g / mm 3 The above 150 x 10 -6 g / mm 3 The following applies: 【0056】 In the diaper 1 of this embodiment, from the viewpoint of making the back sheet 10 feel smooth against the skin, it is preferable that at least one of the second sheet 12 and the third sheet 13 has a dynamic friction coefficient of 0.6 or less in the direction perpendicular to the fiber orientation direction, and it is more preferable that the dynamic friction coefficient of the third sheet 13 in the said perpendicular direction is 0.6 or less. In this case, the dynamic friction coefficients of the second sheet 12 and the third sheet 13 in the said perpendicular direction may be the same or different. 【0057】 The coefficient of kinetic friction of a sheet can be measured, for example, by the following method. First, each sheet to be measured is removed from the diaper. If the sheet is fixed to other components by adhesive, fusion, etc., a cold spray is applied to the fixing part to detach the sheet to be measured from the other components. The adhesive adhering to the sheet to be measured is removed by dissolving it with an organic solvent. Next, a 50 x 80 mm measurement piece is cut from the sheet to be measured. At this time, the measurement piece is cut so that the longitudinal direction of the measurement piece coincides with the direction perpendicular to the fiber orientation direction of the measurement piece. Next, the coefficient of dynamic friction (MIU) between the artificial leather Supplere PBZ13001 (Idemitsu Technofine Co., Ltd., black, product name) and the evaluation sample is measured using a KES-SE friction tester (manufactured by Kato Tech Co., Ltd., product name). The friction sensor of the KES-SE friction tester uses a pseudo-fingerprint sensor made of ordinary stainless steel wire, but instead of this pseudo-fingerprint sensor, a sensor with artificial leather Supplere PBZ13001 attached is used. The sensor consists of an acrylic plate with the corners of the base rounded off, to which artificial leather Sapurare PBZ13001 is attached with double-sided tape (Nitto Denko No. 5000NS) (base 30 x 30 mm). The dynamic friction coefficient is measured in an environment of room temperature 23°C and humidity 60%. Specifically, with a 25g load, the sensor is pressed against the measurement piece and moved back and forth 30 mm along the longitudinal direction of the measurement piece. The back and forth movement is repeated once, and the dynamic friction coefficient of the first measurement is recorded. The dynamic friction coefficient is taken as the value measured in the middle distance range of 20 mm, excluding the range of 5 mm from the starting point and the range of 5 mm from the turning point within the 30 mm range of the back and forth movement. The above measurement is repeated 5 times, and the average value is taken as the dynamic friction coefficient. In addition, the artificial leather Sapurare PBZ13001 attached to the sensor is replaced after each measurement. 【0058】 Furthermore, from the viewpoint of making the back sheet 10 of diaper 1 even smoother, it is preferable that the third sheet 13 has a smaller coefficient of dynamic friction in the direction perpendicular to the fiber orientation direction than the second sheet 12. In this case, it is preferable that the coefficients of dynamic friction of the second sheet 12 and the third sheet 13 in the aforementioned perpendicular direction are within the following ranges. The difference in the coefficient of dynamic friction between the second sheet 12 and the third sheet 13 in the orthogonal direction is preferably 0.01 or more, more preferably 0.03 or more, also preferably 0.50 or less, more preferably 0.20 or less, also preferably 0.01 or more and 0.50 or less, more preferably 0.03 or more and 0.20 or less. The coefficient of dynamic friction of the second sheet 12 in the orthogonal direction is preferably 0.05 or more, more preferably 0.10 or more, also preferably 0.60 or less, more preferably 0.50 or less, also preferably 0.05 or more and 0.60 or less, more preferably 0.10 or more and 0.50 or less. The coefficient of dynamic friction of the third sheet 13 in the orthogonal direction is preferably 0.05 or more, more preferably 0.10 or more, also preferably 0.60 or less, more preferably 0.50 or less, also preferably 0.05 or more and 0.60 or less, more preferably 0.10 or more and 0.50 or less. 【0059】 Next, another embodiment of the present invention will be described. In the following description, components that differ from those of the embodiments shown in Figures 1 to 5 will be mainly described, and similar components will be denoted by the same reference numerals and their descriptions will be omitted. For components that are not specifically described, the descriptions of the embodiments described above will be applied as appropriate. 【0060】 Figures 6(a) and 6(b) show another embodiment of the back sheet 10 according to the present invention. In the overlapping region 481 shown in Figure 6(a), the second adhesive-free portion 47 overlaps with three first adhesive-free portions 43. This makes it easier for more folds to form inside the second adhesive-free portion 47, further improving the cushiony feel and fluffy impression of the diaper 1. Thus, it is preferable that at least a portion of the second adhesive-free portion 47 overlaps with multiple first adhesive-free portions 43. From the same viewpoint as described above, the number of first adhesive-free portions 43 that overlap the second adhesive-free portion 47 in the second bonding region 45 is preferably more than 1, more preferably more than 2, and preferably less than 5, more preferably less than 4, and preferably more than 1 and less than 5, and more preferably more than 2 and less than 4. 【0061】 In the superimposed region 482 shown in Figure 6(b), the width W2 of the first adhesive placement area 42 is shorter than the width W6 of the second adhesive placement area 46. In this configuration, a wider width W6 of the second adhesive placement area 46 can be secured, resulting in a smooth texture in the second non-adhesive area 47, which has gentle undulations (folds). In this case, the width W2 of the first adhesive placement area 42 is preferably 20% or more, more preferably 40% or more, and also preferably less than 100%, more preferably 90% or less, and also preferably 20% or more and less than 100%, more preferably 40% or more and 90% or less, relative to the width W6 of the second adhesive placement area 46. Note that the width of such adhesive placement area is the width when the back sheet 10 is in an extended state. Furthermore, if the width W2 of the first adhesive placement area 42 is narrower than the width W6 of the second adhesive placement area 46, it is preferable that the first adhesive placement area 42 and the second adhesive placement area 46 overlap. With this configuration, the overlapping area between the first non-adhesive area 43 and the second non-adhesive area 47 becomes larger, and the cushioning feel and soft impression can be easily improved. 【0062】 The first bonding region 41 and the second bonding region 45 in the above-described embodiment can be formed using an adhesive. To form the first bonding region 41, the adhesive can be applied to the non-skin-facing surface of the first sheet 11 or the skin-facing surface of the second sheet 12. To form the second bonding region 45, the adhesive can be applied to the non-skin-facing surface of the second sheet 12 or the skin-facing surface of the third sheet 13. Non-water-soluble adhesives can be used. Examples of non-water-soluble adhesives include those made of hydrophobic thermoplastic resins, such as styrene-ethylene-butylene-styrene (SEBS), styrene-isoprene-styrene (SIS), styrene-butylene-styrene (SBS), styrene-ethylene-propylene-styrene (SEPS), ethylene vinyl acetate (EVA), and polyvinyl alcohol (PVA), among other hot-melt adhesives. The adhesive can be made using one of the above-mentioned components alone or in combination of two or more. 【0063】 The adhesive coating pattern can be an intermittent pattern without particular limitations, such as one that leaves areas without adhesive coating. For example, the adhesive coating pattern may be a stripe pattern extending in one direction (see Figure 7(a)) or a spiral pattern (see Figure 7(b)). Also, the adhesive placement areas 42 and 46 may be wavy lines (see Figure 7(c)) or a collection of multiple dots extending in one direction (not shown). From the viewpoint of more easily satisfying the aforementioned relationship between the area ratios of the first bonding region 41 and the second bonding region 45 (first bonding region 41 < second bonding region 45), it is preferable that the coating width of the adhesive forming the adhesive bonding region is the same for the first adhesive bonding region 42 and the second adhesive bonding region 46 [see Figures 7(a) to (c)]. In this configuration, the arrangement pitch of the adhesive bonding region in a direction perpendicular to the extension direction of the adhesive bonding region is made different for the first bonding region 41 and the second bonding region 45. 【0064】 The basis weight (amount applied per unit area) of the adhesive in the first adhesive placement section 42 and the second adhesive placement section 46 may be the same or different. From the viewpoint of more reliably ensuring the bonding strength between the absorbent body 2 and the outer casing 3, the basis weight of the adhesive in the first adhesive placement section 42 is preferably 1.0 g / m². 2 More preferably 2.0 g / m 2 The above is true, and more preferably 15.0 g / m² 2 More preferably, 10.0 g / m 2 The following, and more preferably 1.0 g / m² 2 More than 15.0g / m 2 More preferably, 2.0 g / m 2 More than 10.0g / m 2 The following applies: From the viewpoint of more reliably ensuring the bonding strength between the second sheet 12 and the third sheet 13, and between these two sheets and the leg elastic member 37, the basis weight of the adhesive in the second adhesive placement area 46 is preferably 1.0 g / m². 2 More preferably 2.0 g / m 2 The above is true, and more preferably 15.0 g / m² 2More preferably, 10.0 g / m 2 The following, and more preferably 1.0 g / m² 2 More than 15.0g / m 2 More preferably, 2.0 g / m 2 More than 10.0g / m 2 The following applies: 【0065】 Furthermore, the basis weight of the adhesives used to form the individual adhesive placement portions 42 and 46 in the first bonding region 41 or the second bonding region 45 may be the same or different. 【0066】 The forming materials for each part of the diaper 1 in the above-described embodiment will now be explained in detail. The surface sheet 21 and the absorbent material 22 can be any material conventionally used in absorbent articles, without any particular limitations. For example, the surface sheet 21 can be a liquid-permeable nonwoven fabric or a perforated film. The absorbent body 22 can be made of an absorbent core 24, which can be an aggregate of hydrophilic fibers such as wood pulp or hydrophilically treated synthetic fibers, or an aggregate in which a water-absorbing polymer is held. The core wrap sheet 25 can be the same as that used for the surface sheet 21. 【0067】 If the first sheet 11 in the back sheet 10 is a leak-proof sheet 28, the first sheet 11 can be a sheet that is poorly permeable to liquids or water-repellent. Such a sheet can be a resin film or a laminate of a resin film and a nonwoven fabric, etc. Examples of resin films include films made of polymer materials such as polyethylene terephthalate, polyester, polyethylene, polypropylene, cellophane, nylon, polyvinyl alcohol, polyvinyl chloride, and polycarbonate, as well as moisture-permeable films. If the second sheet 12 and third sheet 13 of the back sheet 10 are the outer casing 3, the second sheet 12 and third sheet 13 can be made of nonwoven fabrics produced by various methods, such as spunbond nonwoven fabric, air-through nonwoven fabric, spunlace nonwoven fabric, heat-rolled nonwoven fabric, melt-blown nonwoven fabric, or laminated nonwoven fabrics thereof. 【0068】 From the viewpoint of further improving the cushioning and smoothness of the back sheet 10, it is preferable that at least one of the second sheet 12 and the third sheet 13 has a fiber layer containing crimped fibers. For example, one example is a laminated nonwoven fabric in which at least one of the second sheet 12 and the third sheet 13 has a fiber layer containing crimped fibers. From the same viewpoint as above, it is preferable that the non-skin-facing surface of the third sheet 13 is formed by a fiber layer containing crimped fibers. As crimped fibers, mechanically crimped fibers that are two-dimensionally crimped in a zigzag pattern by mechanical crimping, three-dimensionally crimped fibers that are spirally crimped, and latently crimped fibers that are three-dimensionally crimped in a coil shape by the application of heat can be used. Examples of crimped fibers include those made of eccentric core-sheath type or side-by-side type composite fibers composed of two types of thermoplastic polymer materials with different shrinkage rates. More specifically, examples are given in Japanese Patent Publication No. 9-296325, Japanese Patent No. 2759331, and Japanese Patent No. 5404967. 【0069】 From the viewpoint of making the fibers more mobile when touched by fingers, etc., thereby improving smoothness and cushioning, and from the viewpoint of more reliably ensuring bonding strength in the second bonding region 45, it is preferable that the third sheet 13 has a fiber layer forming the non-skin-facing surface that contains crimped fibers, and a fiber layer forming the skin-facing surface that does not contain the crimped fibers. An example of such a form is a laminated nonwoven fabric in which a fiber layer containing crimped fibers and a fiber layer not containing crimped fibers are laminated in the third sheet 13. 【0070】 If at least one of the second sheet 12 and the third sheet 13 has a fiber layer containing crimped fibers, from the same viewpoint as above, the content ratio of crimped fibers in the fiber layer containing crimped fibers is preferably 10% by mass or more, more preferably 20% by mass or more, preferably 100% by mass or less, more preferably 80% by mass or less, preferably 10% by mass or more and 100% by mass or less, more preferably 20% by mass or more and 80% by mass or less, based on the total mass of the fibers in the fiber layer. 【0071】 The elastic members in the absorber 22, such as the core elastic member 31, the cuff elastic member 35 and outer cuff elastic member 32, and the leg elastic member 37 in the leak-proof cuff 16, can be any known elastic material commonly used in this type of absorbent article without particular limitation. Examples of elastic materials include synthetic rubbers such as styrene-butadiene, butadiene, isoprene, and neoprene, natural rubber, EVA, stretchable polyolefin, and polyurethane. Preferably, the elastic members can be in the form of threads (such as elastic threads) or strings (such as flat rubber) with a rectangular, square, circular, or polygonal cross-section, or multifilament type threads. 【0072】 Although the present invention has been described above based on its preferred embodiments, the present invention is not limited to the embodiments described above. For example, the absorbent item mentioned above was a pant-type disposable diaper, but it could also be a pull-up type disposable diaper, and it could be for infants or adults. In the embodiment described above, the extension directions of the first adhesive placement section 42 and the second adhesive placement section 46 coincided with the lateral direction Y, but these extension directions may also coincide with the vertical direction X. In the above-described embodiment, the absorbent core 24 had bending guide portions 23C and 23S, but it does not have to have bending guide portions 23C and 23S. Also, the entire absorbent core 24 may have a two-layer structure or a single-layer structure. Furthermore, the absorbent core 24 does not have to have a core elastic member 31. In the embodiment described above, the leak-proof cuff 26 had an outer cuff elastic member 32, but it is not necessary to have the outer cuff elastic member 32. 【0073】 Furthermore, although the outer casing 3 shown in Figure 1 is continuous from the ventral part A through the crotch area C to the dorsal part B, the outer casing 3 may instead be divided into a dorsal sheet member positioned on the wearer's back and a ventral sheet member positioned on the ventral side, with the dorsal sheet member and the ventral sheet member joined by a pair of side seals to form a cylindrical shape, and the absorbent body fixed across the dorsal sheet member and the ventral sheet member. Furthermore, although the above-described embodiment had an outer covering 3 having a two-layer structure of a second sheet 12 and a third sheet 13, the outer covering 3 may have a single-layer structure. In that case, the sheet constituting the outer covering 3 becomes the third sheet 13, and the two sheets located between the third sheet 13 and the absorbent core 24 in the thickness direction of the diaper 1 become the first sheet 11 and the second sheet 12. As an example of such a form, the absorbent body 22 comprises an absorbent core 24, a skin-side core wrap sheet covering the skin-facing surface of the absorbent core 24, and a non-skin-side core wrap sheet covering the non-skin-facing surface of the absorbent core 24, wherein the non-skin-facing side of the absorbent core 24 is provided with a non-skin-side core wrap sheet, a moisture-permeable film sheet, and a nonwoven fabric in that order. In this case, the non-skin-side core wrap sheet becomes the first sheet 11, the moisture-permeable film sheet becomes the second sheet 12, and the nonwoven fabric becomes the third sheet 13. 【0074】 Furthermore, in the above-described embodiment, the first adhesive placement section 42 and the second adhesive placement section 46 each extended in the lateral direction Y, but this is not limited to this. For example, the first adhesive placement section 42 and the second adhesive placement section 46 each may extend in the vertical direction X, or one of the first adhesive placement section 42 and the second adhesive placement section 46 may extend in the lateral direction Y and the other may extend in the vertical direction X. 【0075】 With regard to the embodiments of the present invention described above, the following absorbent articles are further disclosed. <1> An absorbent article having a surface sheet, a back sheet, and an absorbent core disposed between the surface sheet and the back sheet, having a longitudinal direction corresponding to the front-to-back direction of the wearer and a transverse direction perpendicular to the longitudinal direction, The aforementioned back sheet has a first sheet, a second sheet, and a third sheet in order from the skin-facing side toward the non-skin-facing side. The third sheet forms the non-skin-facing surface of the absorbent article, The first sheet and the second sheet are partially joined together via an adhesive to form a first joining region, and the second sheet and the third sheet are partially joined together via an adhesive to form a second joining region. Each of the first and second bonding regions has an adhesive-placed portion where the adhesive is provided and an adhesive-free portion where the adhesive is not provided. In a plan view, the first joining region and the second joining region have an overlapping region. In the aforementioned superimposed region, The first bonding region has a higher area ratio of the adhesive placement area than the second bonding region. An absorbent article in which the portion of the second bonding region where no adhesive is placed overlaps with the portion of the first bonding region where no adhesive is placed. 【0076】 <2> The ratio of the area ratio of the adhesive placement area in the first bonding region to the area ratio of the adhesive placement area in the second bonding region is 1.1 or more and 10.0 or less, preferably 1.5 or more and 5.0 or less. <1> Absorbent articles as described above. <3> The area ratio of the adhesive placement portion in the first bonding region is 12% or more and 70% or less, more preferably 15% or more and 50% or less. <1> or <2> Absorbent articles as described above. <4> The area ratio of the adhesive placement portion in the second bonding region is 5% or more and 50% or less, more preferably 10% or more and 35% or less. <1> ~ <3> The absorbent article described in any one of the following (1). <5> In the first and second bonding regions, the adhesive placement portion and the adhesive non-placement portion are arranged alternately in the vertical direction and each extends in the horizontal direction, <1> ~ <4> The absorbent article described in any one of the following (1). <6> In the first bonding region, the adhesive placement portion is narrower in width than the adhesive non-placement portion. <1> ~ <5> The absorbent article described in any one of the following (1). <7> The first bonding region has a ratio of the width of the adhesive-placed portion to the width of the adhesive-free portion, which is 10% or more and 90% or less, preferably 20% or more and 70% or less. <6> Absorbent articles as described above. <8> The width of the adhesive placement portion in the second bonding region is less than or equal to the width of the adhesive placement portion in the first bonding region. <1> ~ <7> The absorbent article described in any one of the following (1). <9> The ratio of the width of the adhesive placement portion in the second joining region to the width of the adhesive placement portion in the first joining region is 20% or more and 100% or less, preferably 30% or more and 90% or less. <8> Absorbent articles as described above. <10> The second bonding region has a wider width of the adhesive-free portion than the first bonding region. <1> ~ <9> The absorbent article described in any one of the following (1). 【0077】 <11> The ratio of the width of the adhesive-free portion of the second bonding region to the width of the adhesive-free portion of the first bonding region is 120% or more and 1000% or less, preferably 150% or more and 500% or less. <10> Absorbent articles as described above. <12> At least a portion of the adhesive-free portion of the second bonding region overlaps with a plurality of adhesive-free portions of the first bonding region, <1> ~ <11> The absorbent article described in any one of the following (1). <13> The aforementioned elastic member having stretchability in the vertical direction is arranged so as to overlap with the superimposed region in a plan view, or is arranged on both sides of the superimposed region in the horizontal direction. At least one of the first bonding region and the second bonding region includes an adhesive-free portion that is wider when the elastic member is extended than when the elastic member is contracted. <5> ~ <12> Absorbent articles as described in any one of the following: <14> At least one of the second sheet and the third sheet has a coefficient of dynamic friction of 0.6 or less in a direction perpendicular to the fiber orientation direction. <1> ~ <13> The absorbent article described in any one of the following (1). <15> The third sheet has a smaller coefficient of kinetic friction in the orthogonal direction than the second sheet, <14> Absorbent articles as described above. <16> At least one of the second sheet and the third sheet has constituent fibers oriented in the transverse direction, and when compressed in a direction perpendicular to the orientation direction, the ring crush compression strength is 7.0 cN or less, preferably 1.0 cN or more and 7.0 cN or less, more preferably 1.5 cN or more and 5.0 cN or less. <1> ~ <15> The absorbent article described in any one of the following (1). <17> The second sheet has a greater ring crush compression strength than the third sheet, <16> Absorbent articles as described above. <18> At least one of the second sheet and the third sheet has a fiber layer containing crimped fibers, <1> ~ <17> The absorbent article described in any one of the following (1). [Explanation of Symbols] 【0078】 1. Disposable diapers 2 Absorbent body 3. Exterior 10 Back sheet 11. Sheet 1 12. Second seat 13. Third seat 22 absorbent 24 Absorbent core 25 Core Wrap Sheets 26 Leak proof cuff 31 Core elastic member 32 Outer cuff elastic member 35 Cuff elastic member 36 Waist elastic member 41 1st junction area 42 First adhesive placement section 43. First Adhesive-Free Area 45 Second joint area 46 Second adhesive placement section 47 Second Adhesive-Free Area 48, 481, 482 Overlapping regions A. Ventral part B Dorsal part C Inseam X vertical direction Y (horizontal direction)

Claims

[Claim 1] An absorbent article having a surface sheet, a back sheet, and an absorbent core disposed between the surface sheet and the back sheet, having a longitudinal direction corresponding to the front-to-back direction of the wearer and a transverse direction perpendicular to the longitudinal direction, The aforementioned back sheet has a first sheet, a second sheet, and a third sheet in order from the skin-facing side toward the non-skin-facing side. The third sheet forms the non-skin-facing surface of the absorbent article, The first sheet and the second sheet are partially joined together via an adhesive to form a first joining region, and the second sheet and the third sheet are partially joined together via an adhesive to form a second joining region. Each of the first and second bonding regions has an adhesive-placed portion where the adhesive is provided and an adhesive-free portion where the adhesive is not provided. In the first and second bonding regions, the adhesive-placed portions and the non-adhesive-placed portions are arranged alternately in the vertical direction and are formed continuously in the horizontal direction. The second bonding region has a wider width in the adhesive-free portion than the first bonding region. In a plan view, it has an overlapping region where the first joining region and the second joining region overlap. The aforementioned elastic member having stretchability in the vertical direction is arranged so as to overlap with the superimposed region in a plan view, or is arranged on both sides of the superimposed region in the horizontal direction. In the aforementioned superimposed region, The first bonding region has a higher area ratio of the adhesive placement area than the second bonding region. The portion of the second bonding region where adhesive is not applied overlaps with the portion of the first bonding region where adhesive is not applied. The adhesive-placed portion in the first bonding region and the adhesive-free portion in the second bonding region have an overlapping portion. An absorbent article in which a fold formed in the adhesive-free portion of the first bonding region and a fold formed in the adhesive-free portion of the second bonding region overlap. [Claim 2] The absorbent article according to claim 1, wherein in the first bonding region, the adhesive-placed portion is narrower in width than the adhesive-free portion. [Claim 3] The absorbent article according to claim 1, wherein the width of the adhesive placement portion in the second bonding region is less than or equal to the width of the adhesive placement portion in the first bonding region. [Claim 4] The absorbent article according to claim 1, wherein at least a portion of the adhesive-free portion of the second bonding region overlaps with a plurality of adhesive-free portions of the first bonding region. [Claim 5] The absorbent article according to claim 1, wherein at least one of the first bonding region and the second bonding region includes an adhesive-free portion that is wider when the elastic member is extended than when the elastic member is contracted. [Claim 6] The absorbent article according to claim 1, wherein at least one of the second sheet and the third sheet has a coefficient of dynamic friction of 0.6 or less in a direction perpendicular to the fiber orientation direction. [Claim 7] The absorbent article according to claim 6, wherein the third sheet has a smaller coefficient of dynamic friction in the orthogonal direction than the second sheet. [Claim 8] The absorbent article according to claim 1, wherein at least one of the second sheet and the third sheet has constituent fibers oriented in the transverse direction, and the ring crush compression strength when compressed in a direction perpendicular to the orientation direction is 7.0 cN or less. [Claim 9] The absorbent article according to claim 8, wherein the second sheet has a greater ring crush compression strength than the third sheet. [Claim 10] The absorbent article according to claim 1, wherein at least one of the second sheet and the third sheet has a fiber layer containing crimped fibers.

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