Absorbent article

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 an absorbent article. [Background technology]

[0002] Absorbent articles such as disposable diapers generally include an absorbent core and a plurality of sheets arranged on the non-skin-facing side of the absorbent core. For example, the present applicant previously disclosed an absorbent article (Patent Document 1) that includes an absorbent body including a liquid-permeable top sheet, a liquid-leakproof back sheet, and a liquid-retentive absorbent body interposed between them, and an exterior body located on the back sheet side of the absorbent body, and in a portion of the absorbent body excluding both side edges and front and rear ends in the longitudinal direction, the back sheet and the exterior body are bonded together by an adhesive intermittently applied in stripes.

[0003] The present applicant has also previously disclosed an absorbent article (Patent Document 2) which is provided with an outer body arranged on the non-skin-facing side of an absorbent main body and which has an outer sheet, an inner sheet, and leg elastic members between these two sheets and leg adhesives for fixing the same, and in the unfolded state of the diaper, each leg adhesive is arranged horizontally in the area in which the leg elastic members are arranged in the vertical direction, and adjacent leg adhesives in the vertical direction are arranged at two or more different intervals.

[0004] Furthermore, Patent Document 3 discloses an absorbent article having a first bonded region where an outer sheet and the back sheet are bonded to each other, and a first non-bonded region where the outer sheet and the back sheet are not bonded to each other, the first bonded region includes a plurality of first widthwise extending bonded regions that are spaced apart from each other in the length direction of the article and each extend in the width direction of the article, the first non-bonded regions are located between the first widthwise extending bonded regions in the length direction of the article, and within the first non-bonded region, the outer sheet is able to slip relative to the back sheet at least in the width direction of the article. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2005-095261 A [Patent Document 2] JP 2016-022236 A [Patent Document 3] Patent Publication No. 2021-000218 Summary of the Invention [Problem to be solved by the invention]

[0006] The outer surface of an absorbent article is often viewed by users such as the wearer or the guardian of the wearer, and is often touched by the user's fingers when wearing the absorbent article. In addition, if the absorbent article has poor breathability, it is likely to become stuffy and cause rashes, itching, and the like. From these perspectives, the absorbent article is required to have an outer surface with excellent 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 particular consideration has been given to improving the appearance of the absorbent article, and there is room for improvement in the texture and cushioning.

[0007] Therefore, an object of the present invention is to provide an absorbent article which 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 top sheet, a back sheet, and an absorbent core arranged between the top sheet and the back sheet, and having a longitudinal direction corresponding to the front-to-back direction of a wearer and a transverse direction perpendicular to the longitudinal direction. The back sheet preferably has, in this order from the skin-facing surface side to the non-skin-facing surface, a first sheet, a second sheet, and a third sheet. The third sheet preferably forms a non-skin facing surface of the absorbent article. It is preferable that the back sheet has a first bonding region where the first sheet and the second sheet are partially bonded via an adhesive, and a second bonding region where the second sheet and the third sheet are partially bonded via an adhesive. It is preferable that the first bonding area and the second bonding area of ​​the back sheet each have an adhesive placement portion where the adhesive is placed and an adhesive non-placement portion where the adhesive is not placed. The back sheet preferably has an overlapping region in which the first joining region and the second joining region overlap in a plan view. In the overlapping region of the backsheet, it is preferable that the first bonding region has a higher area ratio of the adhesive placement portion than the second bonding region. It is preferable that the back sheet has the non-adhesive portion of the second bonding region overlapping the non-adhesive portion of the first bonding region. Effect of the Invention

[0009] The absorbent article of the present invention has a good appearance, and is excellent in texture and cushioning properties. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a plan view showing a disposable diaper according to one embodiment of the present invention in an unfolded and extended state. [Diagram 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Diagram 3] FIG. 3(a) is a plan view for explaining the position of the first bonding region, and FIG. 3(b) is a plan view for explaining the position of the second bonding region. [Figure 4] FIG. 4 is a cross-sectional view of the overlapping region shown in FIG. 3 taken along the vertical direction. [Diagram 5] FIG. 5 is a vertical cross-sectional view showing the overlapping region shown in FIG. 4 in a non-stretched state. [Figure 6] 6(a) to 6(c) are views corresponding to FIG. 5, showing another embodiment of the overlapping region according to the present invention. [Figure 7] 7(a) to 7(c) are cross-sectional views taken along the vertical direction for explaining the application pattern of the adhesive that forms the first and second bonding regions according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The present invention will be described below based on preferred embodiments with reference to the drawings. Figures 1 and 2 show a pants-type disposable diaper 1 (hereinafter simply referred to as "diaper 1"), which is one embodiment of the absorbent article of the present invention. The diaper 1 has a ventral portion A arranged on the ventral side of a wearer when worn, a dorsal portion B arranged on the dorsal side of the wearer, and a crotch portion C located between the ventral portion A and the dorsal portion B. The diaper 1 has a longitudinal direction X corresponding to the direction corresponding to the front-rear direction of the wearer, i.e., the direction extending from the ventral portion A through the crotch portion C to the dorsal portion B, and a lateral direction Y perpendicular to the longitudinal direction X.

[0012] The diaper 1 has an absorbent body 22 in the center in the lateral direction Y, and also has a back sheet 10 arranged on the non-skin-facing side of the absorbent body 22, i.e., on the side farther from the wearer's body than the absorbent body 22 (see Figure 2).

[0013] In this specification, the "skin-facing side" refers to the side of the absorbent article or its constituent members (e.g., topsheet 21) that faces the wearer's skin when the absorbent article is worn, i.e., the side relatively closer to the wearer's skin, and the "non-skin-facing side" refers to the side of the absorbent article or its constituent members that faces the opposite side to the skin when the absorbent article is worn, i.e., the side relatively farther from the wearer's skin. Note that "when worn" here refers to the normal, proper wearing position, i.e., the state in which the absorbent article is maintained in the correct wearing position.

[0014] As shown in Fig. 1, the diaper 1 is formed symmetrically with respect to a longitudinal centerline CL that extends in the longitudinal direction X and divides the diaper 1 in half in the transverse direction Y when in an unfolded and stretched state. As shown in Fig. 1, the absorbent body 22 has a rectangular shape in a plan view, and its longitudinal direction coincides with the longitudinal direction X of the diaper 1 when in an unfolded and stretched state. The absorbent body 22 is located in the center of the transverse direction Y of the exterior body 3 (second sheet 12 and third sheet 13) described below when viewed in a plan view, and is joined to the backsheet 10 with an adhesive. The "unfolded and stretched state" of the diaper 1 refers to a state in which the diaper 1 is separated at the side seal portions S to be unfolded, and the elastic members of the diaper 1 in the unfolded state are stretched to the design dimensions (the same dimensions as when the diaper 1 is unfolded flat with all the influence of the elastic members eliminated). In this specification, each dimension of each part of the diaper 1, such as the length in the vertical direction X or the horizontal direction Y, refers to the dimension (design dimension) when the elastic members of each part are stretched and each member is stretched, unless otherwise specified.

[0015] As shown in FIG. 2, the diaper 1 includes an absorbent body 2 including a liquid-permeable top sheet 21, a leak-proof sheet 28, a liquid-retentive absorbent body 22 interposed between the sheets 21, 28, and a pair of leak-proof cuffs 26, 26. In the absorbent body 2, the top sheet 21, the absorbent body 22, the pair of leak-proof cuffs 26, and the leak-proof sheet 28 are integrated together by a known joining means such as an adhesive. The absorbent body 2 has a rectangular shape elongated in the vertical direction X in a plan view, and extends in the vertical direction X from the ventral side part A to the dorsal side part B. In the absorbent body 2 in this embodiment, the positions of both ends in the vertical direction X are substantially the same as the positions of both ends in the vertical direction X of the absorbent body 22. The leak-proof sheet 28 in this embodiment corresponds to a first sheet 11 described later.

[0016] The absorbent body 22 extends between the ventral portion A and the dorsal portion B in the longitudinal direction X, and is composed of a liquid-retentive absorbent core 24 and a core wrap sheet 25 that contacts the outer surface of the absorbent core 24 and wraps it. As shown in FIG. 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 the pair of side absorbent cores 24S, 24S and the central absorbent core 24C extends in the vertical direction X in the crotch portion C. The central absorbent core 24C has a two-layer structure, while the side absorbent core 24S has a single-layer structure. The absorbent core 24 of this embodiment has a side fold guide portion 23S between the side absorbent cores 24S and the central absorbent core 24C, and further has a central fold guide portion 23C between the pair of central absorbent cores 24C. The absorbent body 22 can deform from the side fold guide portions 23S, 23S as starting points so that the side absorbent cores 24S are raised toward the wearer's skin (see FIG. 2). Furthermore, the absorbent body 22 can be deformed such that the pair of central absorbent cores 24C are folded in a mountain fold starting from the central fold guide portion 23C (not shown).

[0017] The side fold guide portions 23S, 23S and the central fold guide portion 23C in the absorbent body 22 of this embodiment are formed of through holes extending in the longitudinal direction X and penetrating the absorbent core 24. Alternatively, the side fold guide portions 23S, 23S and the central fold guide portion 23C may be recesses formed on the skin-facing surface or non-skin-facing surface of the absorbent core 24.

[0018] The absorbent body 22 of this embodiment includes a core elastic member 31 arranged in a stretched state in the longitudinal direction X on both sides along the longitudinal direction X. The core elastic member 31 is 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. The core elastic member 31 contracts in the longitudinal direction X to assist the deformation of the side absorbent core 24S starting from the side fold guide portion 23S. In other words, the side absorbent core 24S becomes more likely to deform so as to be lifted toward the wearer's skin.

[0019] As shown in Fig. 1, the absorbent body 2 is provided with a pair of leakage-preventing cuffs 26, 26 on both sides along the longitudinal direction X of the skin-facing surface. As shown in Fig. 2, the leakage-preventing cuff 26 of this embodiment is formed by folding a liquid-resistant or water-repellent and breathable leakage-preventing cuff-forming sheet 27 in half and joining the two opposing leakage-preventing cuff-forming sheets 27 together. The leakage-preventing cuff 26 of this embodiment is provided with a cuff elastic member 35 and an outer cuff elastic member 32 between the two opposing leakage-preventing cuff-forming sheets 27. The cuff elastic member 35 is disposed at the inner end of the leakage-preventing cuff 26 in the transverse direction Y, and the outer cuff elastic member 32 is disposed at the outer end of the leakage-preventing cuff 26 in the transverse direction Y (see Figs. 1 and 2). The cuff elastic member 35 and the outer cuff elastic member 32 are disposed in a stretched state in the longitudinal direction X. Each leakproof cuff 26 has a base end fixed between the absorber 22 and the leakproof sheet 28 in the absorbent main body 2, and a free end to which a cuff elastic member 35 is fixed. The leakproof cuffs 26 are configured so that the free ends of the leakproof cuffs 26 stand up at least in the crotch region C when the cuff elastic members 35, which are arranged in a stretched state in the longitudinal direction X, contract. The outer cuff elastic members 32 also assist the leakproof cuffs 26 in standing up by contracting in the longitudinal direction X.

[0020] As shown in Fig. 2, the back sheet 10 has a first sheet 11, a second sheet 12, and a third sheet 13 in this order from the skin-facing side to 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 this order from the non-skin-facing side to 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. In this way, the back sheet 10 is disposed closer to the non-skin-facing side than 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. The back sheet 10 of this embodiment is disposed on the non-skin facing side of the absorbent body 22 (core wrap sheet 25). The back sheet 10 of this embodiment includes a leakproof sheet 28 forming the non-skin facing side of the absorbent main body 2 as a first sheet 11. The back sheet 10 also includes a second sheet 12 and a third sheet 13 disposed on the non-skin facing side of the absorbent main body 2. The components (second sheet 12 and third sheet) disposed on the non-skin facing side of the absorbent main body 2 are also referred to as an exterior body 3. In the exterior body 3, the second sheet 12 and the third sheet 13 have the same shape and size in a 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 each a fiber sheet made of a fiber material. In FIG. 2, a first adhesive disposing section 42 and a second adhesive disposing section 46, which will be described later, are omitted from the illustration.

[0021] In the outer casing 3, both side edges along the longitudinal direction X of the outer casing 3 in each of the ventral portion A and the dorsal portion B are joined to each other by a known joining means such as an adhesive such as a hot melt adhesive, heat sealing, ultrasonic sealing, etc., to form 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 legs pass (not shown).

[0022] The exterior body 3 forms the outer shape of the diaper 1 in an unfolded and stretched state as shown in Fig. 1, and the periphery of the exterior body 3 forms the contour line of the diaper 1 in an unfolded and stretched state, i.e., the contour lines of the abdominal portion A, the crotch portion C, and the back portion B. As shown in Fig. 1, in the crotch portion C of the exterior body 3, both side edges along the longitudinal direction X of the exterior body 3 are curved in a convex arc shape toward the center in the lateral direction Y, and the central region in the longitudinal direction X is narrowed toward the inside in the lateral direction Y. The exterior body 3 and the absorbent main body 2 are joined by a known joining means such as an adhesive. At least one of the second sheet 12 and the third sheet 13 of the exterior body 3 is folded back toward the skin-facing side along the peripheral edge WE of the waist opening.

[0023] In the exterior body 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 disposed on the skin facing surface side of the third sheet 13. The exterior body 3 has a plurality of thread-like or band-like elastic members 36, 37 disposed between the second sheet 12 and the third sheet 13. Specifically, the exterior body 3 has waist elastic members 36 disposed along the lateral direction Y in the ventral side portion A and the back side portion B, and leg elastic members 37 disposed along the leg openings (see FIG. 1). In this embodiment, the waist elastic members 36 disposed at positions overlapping the absorbent main body 2 in the longitudinal direction X are disposed so as not to exhibit elastic stretchability in the regions overlapping the absorbent main body 2 in the thickness direction Z by processing such as finely dividing the waist elastic members 36, but the waist elastic members 36 may exhibit elastic stretchability in the aforementioned regions. In each of the ventral side portion A and the back side portion B, the waist elastic members 36 are disposed intermittently at a predetermined interval in the longitudinal direction X in a stretched state in the lateral direction Y. In this manner, the waist elastic member 36 is arranged in a state in which its elastic stretchability is expressed, so that a substantially continuous circular waist gather (pleats) is formed around the entire circumference of the opening edge of the waist opening.

[0024] At the leg edge LS forming the opening edge of the leg opening in the exterior body 3, one or more thread-like or band-like leg elastic members 37 for forming leg gathers are arranged in a stretchable state. The leg elastic members 37 extend from the crotch C side in the longitudinal direction X, i.e., from a part of the back side B at the center of the longitudinal direction X, through the crotch C, to a part of the ventral side A at the center of the longitudinal direction X (see FIG. 1). Since the leg elastic members 37 are arranged in a stretched state, a substantially continuous annular leg gather is formed around the entire periphery of the opening edge (leg edge LS) of the leg opening. The leg elastic members 37 are also sandwiched and fixed between the third sheet 13 and the second sheet 12 constituting the exterior body 3 by a joining means such as an adhesive.

[0025] In the backsheet 10, the first sheet 11 and the second sheet 12, and the second sheet 12 and the third sheet 13 adjacent to each other in the thickness direction Z of the diaper 1, are partially joined together via an adhesive. The diaper 1 has a first joining region 41 where the first sheet 11 and the second sheet 12 are partially joined together via an adhesive, and a second joining region 45 where the second sheet 12 and the third sheet 13 are partially joined together via an adhesive (see Figures 3(a) and (b)). In the diaper 1, the absorbent body 2 and the exterior body 3 are joined in a first joining region 41, and the sheets 12, 13 constituting the exterior body 3 and the leg elastic members 37 are joined in a second joining region 45.

[0026] The first bonding region 41 and the second bonding region 45 each have adhesive placement sections 42, 46 where adhesive is placed, and non-adhesive placement sections 43, 47 where no adhesive is placed (see Figs. 3(a) and (b)). Hereinafter, the adhesive placement section 42 in the first bonding region 41 will be referred to as the "first adhesive placement section 42," and the non-adhesive placement section 43 in the first bonding region 41 will be referred to as the "first non-adhesive placement section 43." Additionally, the adhesive placement section 46 in the second bonding region 45 will be referred to as the "second adhesive placement section 46," and the non-adhesive placement section 47 in the second bonding region 45 will be referred to as the "second non-adhesive placement section 47." In the first bonding region 41, first adhesive placement sections 42 and first non-adhesive placement sections 43 are alternately arranged in the vertical direction X, and each extends along the horizontal direction Y. In the second bonding region 45, second adhesive placement sections 46 and second non-adhesive placement sections 47 are alternately arranged in the vertical direction X, and each extends along the horizontal direction Y. That is, in each of the first bonding region 41 and the second bonding region 45, the adhesive is intermittently applied in stripes extending in the horizontal direction Y.

[0027] The first bonding region 41 is located in a region overlapping with the absorbent body 22, and has a rectangular shape in a plan view, similar to the absorbent body 22 (see FIG. 3(a)). The positions of both ends of the first bonding region 41 in the horizontal direction Y substantially coincide with the positions of both ends of the absorbent body 2 in the horizontal direction Y. The positions of both ends of the first bonding region 41 in the vertical direction X substantially coincide with the positions of both ends of the absorbent body 22 in the vertical direction X.

[0028] The second bonding region 45 is disposed in a region of the exterior body 3 (third sheet 13) consisting of a central region in the longitudinal direction X that is narrowed inward in the transverse direction Y and a portion of the ventral portion A and the dorsal portion B that is adjacent to the narrowed portion in the longitudinal direction X on the inner side in the longitudinal direction X (see FIG. 3(b)). In the second bonding region 45, the second adhesive disposing portion 46 is disposed continuously over the entire length of the region in the transverse direction Y. The positions of both ends of the second bonding region 45 in the longitudinal direction X are located inward in the longitudinal direction X from both ends of the absorbent body 22 in the longitudinal direction X.

[0029] The diaper 1 has an overlapping region 48 in which the first and second bonding regions 41 and 45 overlap in a plan view (see FIG. 3(b)). In this embodiment, the overlapping region 48 is a region in which the first bonding region 41 overlaps with the second bonding region 45 on the inner side of the first bonding region 41 in the longitudinal direction X. The overlapping region 48 in this embodiment extends in the longitudinal direction X in a plan view and is positioned so as to partially overlap with the absorbent body 22 (see FIGS. 3(a) and 3(b)).

[0030] Fig. 4 shows a cross-sectional view of the back sheet 10 in the longitudinal direction X in the overlapping region 48. Fig. 4 shows the back sheet 10 in a state stretched in the longitudinal direction X. The first bonding region 41 has a higher area ratio of the adhesive placement portion than the second bonding region 45. In other words, the first bonding region 41 has a lower area ratio of the adhesive non-placement portion than the second bonding region 45.

[0031] The first bonding region 41 is a region surrounded by an imaginary line connecting the edges of adjacent first adhesive placement portions 42 in the vertical direction X, sandwiching the first non-adhesive placement portion 43 therebetween, and the outer edge in the perpendicular direction of the first adhesive placement portion 42 that is located outermost on both sides of the direction perpendicular to the extension direction of the first adhesive placement portion 42. The second bonding region 45 is a region surrounded by an imaginary line connecting the edges of adjacent second adhesive placement portions 46 in the vertical direction X, sandwiching the second non-adhesive placement portion 47 therebetween, and the outer edge in the perpendicular direction of the second adhesive placement portion 46 that is located outermost on both sides in the direction perpendicular to the extension direction of the second adhesive placement portion 46.

[0032] The area ratio of the first adhesive placement portion 42 is calculated by dividing the total area of ​​the first adhesive placement portion 42 in the first bonding region 41 by the area of ​​the first bonding region 41 (total area of ​​the first adhesive placement portion 42 / area of ​​the first bonding region 41). The area ratio of the second adhesive placement portion 46 is calculated by dividing the total area of ​​the second adhesive placement portion 46 in the second bonding region 45 by the area of ​​the second bonding region 45 (total area of ​​the second adhesive placement portion 46 / area of ​​the second bonding region 45).

[0033] The area ratio of the first adhesive placement portion 42 and the area ratio of the second adhesive placement portion 46 can be measured, for example, by the following method. First, a portion joined at the first joining region 41 or the second joining region 45 is cut out as a sample piece from the overlapping region 48. Specifically, the first sheet 11 and the second sheet 12 joined at the first joining region 41 are cut out as a sample piece, or the second sheet 12 and the third sheet 13 joined at the second joining region 45 are cut out as a sample piece. From the sample piece, components that are not involved in the joining of the adhesive placement portion to be measured are removed. For example, when measuring the area ratio of the first adhesive placement portion 42, the third sheet 13 is peeled off from the sample piece using a cold spray or the like. At this time, other components are peeled off from the sample piece so as not to affect the adhesive state of the adhesive placement portion to be measured. The size of the sample piece is 50 mm x 50 mm. Next, the sheets of the sample piece are peeled away from each other using a cold spray or the like to expose the surface on which the adhesive placement portion is formed, i.e., the surface on which the adhesive is applied. Printed toner is evenly sprayed onto the surface on which the adhesive is applied, and the printed toner is then allowed to adhere to the adhesive, after which the printed toner that is not adhered to the adhesive is removed. The printed toner is removed by blowing air or by suction. Next, a scanner (Seiko Epson Corporation ES-10000G) is used to obtain an image of the surface to which the printed toner is attached. The image is binarized to black and white, and is an image in which the areas to which the printed toner is attached and the areas to which it is not attached can be distinguished in black and white. Next, the area ratio of the portion of the image where the printed toner is adsorbed is measured using image analysis software (e.g., Image-Pro Plus, manufactured by Nippon Roper Co., Ltd.). The measured value of the area ratio is converted into the area ratio of the adhesive placement portion of the sample piece based on a reference value measured in advance. The reference value is a value obtained by measuring the area ratio of the adhesive placement portion of the reference sample piece using the same method as above. The reference sample piece is a sample piece (50 mm x 50 mm) in which the adhesive is applied to a nonwoven fabric in a stripe pattern so that the area ratio of the adhesive placement portion is 50%. More specifically, in the reference sample piece, the coated portion where the adhesive is applied and the uncoated portion where the adhesive is not applied each extend in one direction, and these coated portions and uncoated portions are alternately arranged in a direction perpendicular to the one direction. In the reference sample piece, the width of each of the coated portion and the uncoated portion is 1 mm, and the amount of adhesive applied in the coated portion is 3 g / m. 2 Let us assume that.

[0034] The area ratio of the first adhesive placement portion 42 is calculated by dividing the total area of ​​the first adhesive placement portion 42 in the first bonding region 41 by the area of ​​the first bonding region 41 (total area of ​​the first adhesive placement portion 42 / area of ​​the first bonding region 41). The area ratio of the second adhesive placement portion 46 is calculated by dividing the total area of ​​the second adhesive placement portion 46 in the second bonding region 45 by the area of ​​the second bonding region 45 (total area of ​​the second adhesive placement portion 46 / area of ​​the second bonding region 45). Unless otherwise specified, each dimension such as the area of ​​the first bonding region 41 and the second bonding region 45 and the width of the adhesive placement portions 42, 46 and the non-adhesive placement portions 43, 47 is measured in a state where the backsheet 10 is stretched in a direction perpendicular to the extending direction of the adhesive placement portions 42, 46 (longitudinal direction X in this embodiment) (see FIG. 3). In other words, the measurements are made in a state where the pleats in the first non-adhesive portions 43 and the pleats in the second non-adhesive portions 47 have disappeared.

[0035] 5 shows a cross-sectional view of the backsheet 10 in an unstretched state taken along the longitudinal direction X. In FIG. 5, in the backsheet 10 of the diaper 1, the first sheet 11 and the second sheet 12 are not joined at the first non-adhesive section 43, and the second sheet 12 and the third sheet 13 are not joined at the second non-adhesive section 47. As a result, in each of the first non-adhesive section 43 and the second non-adhesive section 47, pleats are formed that bulge towards the non-skin facing surface. 5, in the diaper 1, the second adhesive-free sections 47 overlap the first adhesive-free sections 43. That is, the pleats formed by the first adhesive-free sections 43 and the pleats formed by the second adhesive-free sections 47 overlap.

[0036] In the diaper 1 of this embodiment, the area ratio of the adhesive portion in the first bonding region 41 is higher than that in the second bonding region 45, and therefore, in the first non-adhesive portion 43, finer pleats are formed than in the second non-adhesive portion 47. As shown in Fig. 5, in the overlapping region 48, the pleats in the first non-adhesive portion 43 and the pleats in the second non-adhesive portion 47 overlap in the thickness direction Z to form a pleated structure, so that when the backsheet 10 is touched with the fingers, the overlapped pleats give a feeling that they are gradually being crushed from the non-skin-facing surface side. Furthermore, the overlapping of the large pleats and the small pleats facilitates restoration when pressure from the fingers is released, providing a good cushioning feel. Furthermore, by forming folds in the second non-adhesive portions 47 that are larger than those in the first bonding regions 41, the occurrence of wrinkles on the outer surface (third sheet 13) of the overlapping regions 48 is suppressed, and the outer surface has a smooth texture and a shape that gives a soft impression. 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 properties. Furthermore, the insides of the pleats formed in the second non-adhesive areas 47 and the first non-adhesive areas 43 function as air passages, so that the breathability of the backsheet 10 can be well maintained.

[0037] From the standpoint of further enhancing the above-mentioned effects, the area ratio of the first adhesive placement section 42 in the first bonding region 41 relative to the area ratio of the second adhesive placement section 46 in the second bonding region 45 (area ratio of first adhesive placement section 42 / area ratio of second adhesive placement section 46) is preferably 1.1 or more, more preferably 1.5 or more, and is also preferably 10.0 or less, more preferably 5.0 or less, and is also preferably 1.1 or more and 10.0 or less, more preferably 1.5 or more and 5.0 or less. 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, and preferably 70% or less, more preferably 50% or less, and preferably 12% or more and 70% or less, more preferably 15% or more and 50% or less. 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, and preferably 50% or less, more preferably 35% or less, and preferably 5% or more and 50% or less, more preferably 10% or more and 35% or less.

[0038] In order to further improve the above-mentioned effects, 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 overlap region 48 to the area of ​​the first junction region 41 is preferably 30% or more, more preferably 40% or more, and is preferably 100% or less, more preferably 80% or less, and is preferably 30% or more and 100% or less, more preferably 40% or more and 80% or less. The ratio of the area of ​​the overlap region 48 to the area of ​​the second junction region 45 is preferably 20% or more, more preferably 30% or more, and is preferably 80% or less, more preferably 70% or less, and is preferably 20% or more and 80% or less, more preferably 30% or more and 70% or less.

[0039] In the overlap region 48, at least a portion of the second non-adhesive portion 47 may partially overlap with the first non-adhesive portion 43, may overlap with one first non-adhesive portion 43, or may overlap with two or more first non-adhesive portions 43. The second non-adhesive portion 47 of this embodiment overlaps with more than one first non-adhesive portion 43. More specifically, the second non-adhesive portion 47 overlaps with 1.5 non-adhesive portions 43. In this case, since more than one fold exists inside one non-adhesive portion 47, the cushioning feel of the diaper 1 is improved and the appearance appears fluffier.

[0040] From the viewpoint of improving the cushioning of the outer surface of the diaper 1, it is preferable that the adhesive-placed portion 42 in the first bonding region 41 is narrower than the adhesive-free portion 43. With this configuration, the number of pleats formed by bonding the first sheet 11 and the second sheet 12 increases, and these pleats tend to overlap with the pleats formed by bonding the second sheet 12 and the third sheet 13. From the standpoint of making it easier for the pleats to overlap, the width W2 (see Figure 4) of the first adhesive placement portion 42 is preferably 10% or more, more preferably 20% or more, and preferably 90% or less, more preferably 70% or less, of the width W3 (see Figure 4) of the first non-adhesive placement portion 43, and is preferably 10% or more and 90% or less, more preferably 20% or more and 70% or less.

[0041] In order to improve the fluffy impression of the diaper 1, it is preferable that the second bonding region 45 has a wider non-adhesive portion than the first bonding region 41. In other words, it is preferable that the second non-adhesive portion 47 has a wider portion than the first non-adhesive portion 43. With this configuration, the pleats formed on the outer surface of the diaper 1 are likely to be large. From the same viewpoint as above, the width W7 (see FIG. 4) of the second non-adhesive portion 47 is preferably 120% or more, more preferably 150% or more, and preferably 1000% or less, more preferably 500% or less, relative to the width W3 (see FIG. 4) of the first non-adhesive portion 43, and is preferably 120% or more and 1000% or less, more preferably 150% or more and 500% or less.

[0042] The first adhesive placement portion 42 and the second adhesive placement portion 46 may have the same width, or the widths of these adhesive placement portions may be different. In order to further improve the soft impression of the diaper 1, it is preferable that the width W6 (see FIG. 4) of the second adhesive placement portion 46 is equal to or smaller than the width W2 of the first adhesive placement portion 42. With this configuration, even if the adhesive placement portions overlap each other, the pleats tend to rise up toward the non-skin facing surface. From the same viewpoint as above, the width W6 (see FIG. 4) of the second adhesive placement portion 46 is preferably 20% or more, more preferably 30% or more, and preferably 100% or less, more preferably 90% or less, relative to the width W2 (see FIG. 4) of the first adhesive placement portion 42, and is preferably 20% or more and 100% or less, more preferably 30% or more and 90% or less.

[0043] From the viewpoint of further improving the appearance of the outer surface of the diaper 1, it is preferable that the second adhesive placement section 46 is narrower than the second adhesive non-placement section 47. In this case, the width W6 (see FIG. 4) of the second adhesive placement section 46 is preferably 10% or more, more preferably 20% or more, and preferably 90% or less, more preferably 70% or less, and preferably 10% or more and 90% or less, more preferably 20% or more and 70% or less, of the width W7 (see FIG. 4) of the second adhesive non-placement section 47.

[0044] In order to more reliably achieve one or more of the above-mentioned effects, it is preferable that the widths of the adhesive placement sections 42, 46 and the adhesive non-placement sections 43, 47 in the first bonding area 41 and the second bonding area 45, respectively, are within the following ranges. The width W2 (see FIG. 4) of the first adhesive placement portion 42 is preferably 0.5 mm or more, more preferably 0.8 mm or more, and is preferably 10.0 mm or less, more preferably 5.0 mm or less, and is preferably 0.5 mm or more and 10.0 mm or less, more preferably 0.8 mm or more and 5.0 mm or less. The width W3 (see FIG. 4) of the first non-adhesive portion 43 is preferably 0.5 mm or more, more preferably 1.0 mm or more, and preferably 10.0 mm or less, more preferably 7.0 mm or less, and 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 FIG. 4) of the second adhesive placement portion 46 is preferably 0.5 mm or more, more preferably 0.8 mm or more, and is preferably 10.0 mm or less, more preferably 7.0 mm or less, and is preferably 0.5 mm or more and 10.0 mm or less, more preferably 0.8 mm or more and 7.0 mm or less. The width W7 (see FIG. 4) of the second non-adhesive portion 47 is preferably 1.0 mm or more, more preferably 1.5 mm or more, and is preferably 10.0 mm or less, more preferably 7.0 mm or less, and is 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 placement portion 42, 46 or the non-adhesive placement portion 43, 47 is the length of the adhesive placement portion 42, 46 or the non-adhesive placement portion 43, 47 in a direction perpendicular to the extension direction of the adhesive placement portion 42, 46 and the non-adhesive placement portion 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 absorber 22, the cuff elastic members 35 of the leakproof cuffs 26, and the outer cuff elastic members 32 are arranged so as to overlap the overlapping regions 48 in a plan view (not shown). In the diaper 1, the leg elastic members 37 of the exterior body 3 are located on both sides of the overlapping regions 48 in the lateral direction Y (not shown). In the diaper 1 in which the adhesive placement sections 42, 46 extending in the lateral direction Y are thus intermittently arranged, it is preferable that the elastic members having stretchability in the longitudinal direction X are arranged so as to overlap the overlapping regions 48 in a plan view or are arranged on both sides of the overlapping regions 48 in the lateral direction Y. When the diaper 1 has such a configuration, the contraction of the elastic members 31, 32, 35, 37 makes it easier to form the pleated structure, thereby further improving the cushioning and texture of the backsheet 10. A diaper 1 having the above-described configuration may have either elastic members 31, 32, 35 arranged to overlap the overlap region 48 in a plan view or elastic members 37 arranged on both sides of the overlap region 48 in the lateral direction Y, and it is preferable that the diaper 1 have both.

[0047] In a plan view, when either or both of the elastic members 31, 32, 35 arranged to overlap the overlapping region 48 and the elastic members 37 arranged on both sides of the overlapping region 48 in the lateral direction Y are stretched, the pleats in the first adhesive non-placed portion 43 and the second adhesive non-placed portion 47 disappear (see FIG. 4) or the height of each pleat decreases. On the other hand, when either or both of the elastic members 31, 32, 35 arranged to overlap the overlapping region 48 and the elastic members 37 arranged on both sides of the overlapping region 48 in the lateral direction Y are contracted, the height of each pleat in the first adhesive non-placed portion 43 and the second adhesive non-placed portion 47 increases (see FIG. 5). From the viewpoint of facilitating the formation of the pleated structure by contraction of the elastic members and further improving the soft impression of the diaper 1, it is preferable that at least one of the first and second bonding regions 41 and 45 includes non-adhesive portions 43, 47 which are wider when the elastic members are stretched (see Fig. 4) than when the elastic members are contracted (see Fig. 5). In this case, the natural state (state where no external force is applied) of the elastic members 31, 32, 35, 37 which stretch in the vertical direction is defined as "when the elastic members are contracted", and the state when the diaper 1 is maximum stretched in the vertical direction X is defined as "when the elastic members are stretched".

[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. If the width of the adhesive non-placed portions 43, 47 when the elastic member is stretched is W and the width of the adhesive non-placed portions 43, 47 when the elastic member is contracted is W', the ratio of W' to W (W' / W) is preferably 20% or more, more preferably 30% or more, and also preferably 90% or less, more preferably 80% or less, and also preferably 20% to 90%, more preferably 30% to 80%. Specifically, such a ratio is the ratio (W3' / W3) of the width W3' of the first adhesive non-placed portion 43 when the elastic member is contracted to the width W3 of the first adhesive non-placed portion 43 when the elastic member is stretched, or the ratio (W7' / W7) of the width W7' of the second adhesive non-placed portion 47 when the elastic member is contracted to the width W7 of the second adhesive non-placed portion 47 when the elastic member is stretched. The width W3' [see Figure 5] of the first non-adhesive portion 43 when the elastic member is contracted is preferably 0.2 mm or more, more preferably 0.4 mm or more, and preferably 7.0 mm or less, more preferably 5.0 mm or less, and preferably 0.2 mm or more and 7.0 mm or less, and more preferably 0.4 mm or more and 5.0 mm or less. The width W7' [see Figure 5 (a)] of the second non-adhesive portion 47 when the elastic member is contracted is preferably 0.5 mm or more, more preferably 1.0 mm or more, and preferably 8.0 mm or less, more preferably 6.0 mm or less, and preferably 0.5 mm or more and 8.0 mm or less, and 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 each a fiber sheet made of a fiber material. From the viewpoint of more easily forming the pleated structure, in the diaper 1 of this embodiment, it is preferable that at least one of the second sheet 12 and the third sheet 13 has constituent fibers oriented in the lateral direction Y. In other words, it is preferable that at least one of the second sheet 12 and the third sheet 13 has constituent fibers oriented in the extension direction of the adhesive placement sections 42, 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 article by peeling it off using a cold spray or the like. The removed sheet is cut 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 using a cutter or the like, and this is used as a measurement piece. The measurement piece is cut out 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 of any fibers observed in a certain observation area (for example, 1 mm square), two points are determined at which the length of the fiber is maximum in the 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 average value (average angle) of the angles measured for a total of 30 or more fibers is calculated. When the average angle is within 45 degrees, the constituent fibers are judged to be oriented in the transverse direction Y, and when the average angle is more than 45 degrees, the constituent fibers are judged to be oriented in the longitudinal direction X. In the above measurement, it is preferable to observe at a magnification at which 10 or more fibers can be confirmed in the observation area.

[0051] In order to facilitate the movement of the pleats in the back sheet 10, thereby improving the softness of the back sheet 10 and improving the formability of the pleats, at least one of the second sheet 12 and the third sheet 13 has a ring crush compression strength (hereinafter simply referred to as "ring crush compression strength") when compressed in a direction perpendicular to the orientation direction of the constituent fibers of preferably 1.0 cN or more, more preferably 1.5 cN or more, and preferably 7.0 cN or less, more preferably 5.0 cN or less, and 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 article by peeling it off using a cold spray or the like. Five rectangular pieces 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 are cut out from the removed sheet, and these are used as test pieces. Each test piece is rolled into a cylindrical shape in the longitudinal direction of the test piece, and one end and the other end in the longitudinal direction of the test piece are overlapped by 10 mm to form a cylinder with an outer circumferential length of 70 mm, and the upper end (upper end in the axial direction of the cylinder) and the lower end of the overlapped parts at both ends are fixed using staples (e.g., No. 10-1M needles manufactured by Max Co., Ltd.) to obtain five cylindrical measurement samples. The direction of the staples is parallel to the circumferential direction of the measurement sample. Each measurement sample (initial sample width: 30 mm) obtained is set in a Tensilon compression tester ("RTA-100" manufactured by Orientec Co., Ltd.), and the maximum load (cN) is measured when compressed in the axial direction of the cylinder (width direction of the test piece) at a compression speed of 10 mm / min 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 average value is the ring crush compression strength of the sheet. The measurement environment is room temperature of 23±2°C and relative humidity of 50%RH±5%.

[0053] From the viewpoint of facilitating the movement of the pleats in the back sheet 10 and further improving the feel against the skin, it is preferable that the second sheet 12 has a greater ring crush compression strength when compressed in a direction perpendicular to the orientation direction of the constituent fibers than the third sheet 13. From the same viewpoint as above, it is preferable that the ring crush compressive strength of each of the first sheet 11, the second sheet 12 and the third sheet is within the following range. The ring crush compressive strength of the first sheet 11 is preferably 1.0 cN or more, more preferably 1.5 cN or more, and preferably 7.0 cN or less, more preferably 5.0 cN or less, and 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 compressive strength of the second sheet 12 is preferably 1.0 cN or more, more preferably 1.5 cN or more, and preferably 7.0 cN or less, more preferably 5.0 cN or less, and 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 compressive strength of the third sheet 13 is preferably 0.5 cN or more, more preferably 1.0 cN or more, and preferably 6.0 cN or less, more preferably 4.0 cN or less, and 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 pleats in the backsheet 10 and improving the feel against the skin, it is preferable that the third sheet has a lower basis weight than the second sheet. 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 is within the following range. The basis weight of the first sheet 11 is preferably 5 g / m 2 More preferably, 8 g / m 2 More preferably, it is 40 g / m 2 or less, more preferably 30 g / m2 or less, and preferably 5 g / m 2 More than 40g / m 2 Less than 8g / m, more preferably 2 More than 30g / m 2 The following is the result. The basis weight of the second sheet 12 is preferably 5 g / m 2 More preferably, 8 g / m 2 More preferably, it is 30 g / m 2 Less than 20 g / m, more preferably 20 g / m 2 and preferably 5 g / m 2 More than 30g / m 2 Less than 8g / m, more preferably 2 More than 20g / m 2 The following is the result. The basis weight of the third sheet 13 is preferably 5 g / m 2 More preferably, 8 g / m 2More preferably, it is 25 g / m 2 Less than 20 g / m, more preferably 20 g / m 2 and preferably 5 g / m 2 More than 25g / m 2 Less than 8g / m, more preferably 2 More than 20g / m 2 The following is the result.

[0055] From the viewpoint of facilitating the movement of the pleats in the back sheet 10 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 example, a non-contact laser displacement meter or the like can be used to measure the thickness. 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 is within the following range. The density of the first sheet 11 is preferably 30×10 -6 g / mm 3 More preferably, 50×10 -6 g / mm 3 More preferably, 300×10 -6 g / mm 3 Less than or equal to 200×10 -6 g / mm 3 or less, and preferably 30×10 -6 g / mm 3 More than 300 x 10 -6 g / mm 3 Less than or equal to 50×10 -6 g / mm 3 More than 200 x 10 -6 g / mm 3 The following is the result. The density of the second sheet 12 is preferably 30×10 -6 g / mm 3 More preferably, 50×10 -6 g / mm 3 More preferably, 200×10 -6 g / mm 3 Less than 150g / mm3 and preferably 30 g / mm3 or more and 200 × 10 -6 g / mm 3 Less than or equal to 50×10 -6 g / mm 3 Over 150 x 10 -6 g / mm 3 The following is the result. The density of the third sheet 13 is preferably 30×10 -6 g / mm 3 More preferably, 50×10 -6 g / mm 3 or more, and preferably 180×10 -6 g / mm 3 Less than or equal to 150×10 -6 g / mm 3 or less, and preferably 30×10 -6 g / mm3 or more 180×10 -6 g / mm 3 Less than or equal to 50×10 -6 g / mm 3 Over 150 x 10 -6 g / mm 3 The following is the result.

[0056] In the diaper 1 of this embodiment, from the viewpoint of making the backsheet 10 smooth to the touch, 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 a direction perpendicular to the fiber orientation direction, and it is more preferable that the dynamic friction coefficient of the third sheet 13 in the 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 perpendicular direction may be the same or different.

[0057] The dynamic friction coefficient of the sheet can be measured, for example, by the following method. First, each sheet to be measured is taken out of the diaper. If the sheet is fixed to other components by adhesive, fusion, etc., cold spray is sprayed on the fixed part to peel off 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 test piece is cut out from the sheet to be measured. At this time, the test piece is cut out so that the longitudinal direction of the test piece coincides with the direction perpendicular to the fiber orientation direction of the test piece. Next, the dynamic friction coefficient (MIU) between the artificial leather Suprale 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 normal pseudo-fingerprint sensor using a stainless steel wire, but instead of the pseudo-fingerprint sensor, a sensor with the artificial leather Suprale PBZ13001 attached is used. The sensor is made by attaching artificial leather Suprale PBZ13001 with double-sided tape (Nitto Denko No. 5000NS) to an acrylic plate with the corners of the bottom rounded off (bottom surface 30 x 30 mm). The measurement of the dynamic friction coefficient is performed in an environment of room temperature 23°C and humidity 60%. In detail, the sensor is pressed against the test piece under a load of 25 g and the sensor is moved back and forth 30 mm along the longitudinal direction of the test piece. The sensor is moved back and forth once, and the dynamic friction coefficient of the first time is recorded. The dynamic friction coefficient is the value measured in a 20 mm distance range in the middle of the 30 mm range of the reciprocating movement, excluding the range of 5 mm from the starting point and the range of 5 mm from the turning point. The above measurement is repeated five times, and the average value is the dynamic friction coefficient. In addition, the artificial leather Suprale PBZ13001 attached to the sensor is replaced for each measurement.

[0058] In order to make the backsheet 10 of the diaper 1 smoother to the touch, it is preferable that the third sheet 13 has a smaller dynamic friction coefficient in a direction perpendicular to the fiber orientation direction than the second sheet 12. In this case, it is preferable that the dynamic friction coefficients of the second sheet 12 and the third sheet 13 in the perpendicular direction are within the following ranges. The difference in the dynamic friction coefficient between the second sheet 12 and the third sheet 13 in the perpendicular direction is preferably 0.01 or more, more preferably 0.03 or more, and is preferably 0.50 or less, more preferably 0.20 or less, and is preferably 0.01 or more and 0.50 or less, more preferably 0.03 or more and 0.20 or less. The dynamic friction coefficient of the second sheet 12 in the perpendicular direction is preferably 0.05 or more, more preferably 0.10 or more, and is preferably 0.60 or less, more preferably 0.50 or less, and is preferably 0.05 or more and 0.60 or less, more preferably 0.10 or more and 0.50 or less. The dynamic friction coefficient of the third sheet 13 in the perpendicular direction is preferably 0.05 or more, more preferably 0.10 or more, and is preferably 0.60 or less, more preferably 0.50 or less, and is 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 different from the embodiment shown in Figures 1 to 5 will be mainly described, and similar components will be given the same reference numerals and will not be described. For components that are not particularly described, the description of the above-mentioned embodiment will be applied as appropriate.

[0060] 6(a) and (b) show another embodiment of the backsheet 10 according to the present invention. In the overlapping region 481 shown in FIG. 6(a), the second non-adhesive portion 47 overlaps with three first non-adhesive portions 43. This makes it easier for a greater number of folds to be formed inside the second non-adhesive portion 47, further improving the cushioned feel and fluffy impression of the diaper 1. In this way, it is preferable that at least a portion of the second non-adhesive portion 47 overlaps with a plurality of the first non-adhesive portions 43. From the same viewpoint as above, the number of first non-adhesive portions 43 overlapped by the second non-adhesive portions 47 in the second bonding region 45 is preferably more than 1, more preferably more than 2, and also preferably less than 5, more preferably less than 4, and also preferably more than 1 but less than 5, more preferably more than 2 but less than 4.

[0061] In the overlapping region 482 shown in FIG. 6(b), the width W2 of the first adhesive placement section 42 is shorter than the width W6 of the second adhesive placement section 46. In this embodiment, the width W6 of the second adhesive placement section 46 can be made wider, so that the second non-adhesive placement section 47 has a gentle undulation (folds) and a smooth texture. In this case, the width W2 of the first adhesive placement section 42 is preferably 20% or more, more preferably 40% or more, and also preferably less than 100%, more preferably 90% or less, of the width W6 of the second adhesive placement section 46, and also preferably 20% or more and less than 100%, more preferably 40% or more and 90% or less. The width of such an adhesive placement section is the width when the backsheet 10 is in an extended state. Furthermore, when the width W2 of the first adhesive placement portion 42 is narrower than the width W6 of the second adhesive placement portion 46, it is preferable that the first adhesive placement portion 42 and the second adhesive placement portion 46 overlap. With this configuration, the area where the first non-adhesive placement portion 43 and the second non-adhesive placement portion 47 overlap becomes larger, which can easily improve the cushioned feel and fluffy impression.

[0062] The first bonding area 41 and the second bonding area 45 in the above-described embodiment can be formed using an adhesive. When forming the first bonding region 41, an adhesive may be applied to the non-skin facing surface of the first sheet 11 or the skin facing surface of the second sheet 12. When forming the second bonding region 45, an adhesive may be applied to the non-skin facing surface of the second sheet 12 or the skin facing surface of the third sheet 13. A water-insoluble adhesive may be used. Examples of water-insoluble adhesives include those made of hydrophobic thermoplastic resins, such as various hot melt adhesives based on styrene-ethylene-butylene-styrene (SEBS), styrene-isoprene-styrene (SIS), styrene-butylene-styrene (SBS), styrene-ethylene-propylene-styrene (SEPS), ethylene vinyl acetate (EVA), polyvinyl alcohol (PVA), etc. The adhesive may be one of the above-mentioned components, or a combination of two or more of them.

[0063] The adhesive application pattern can be any intermittent pattern that leaves some areas uncoated with adhesive. For example, the adhesive application pattern can be stripes extending in one direction (see FIG. 7(a)), or a spiral pattern (see FIG. 7(b)). The adhesive placement portions 42, 46 can also be wavy lines (see FIG. 7(c)), or a collection of multiple dots extending in one direction (not shown). From the viewpoint of more easily satisfying the relationship in area ratio between the first bonding region 41 and the second bonding region 45 (first bonding region 41<second bonding region 45), it is preferable that the first adhesive placement portion 42 and the second adhesive placement portion 46 have the same coating width of the adhesive that forms the adhesive placement portion (see Figs. 7(a) to (c)). In such a configuration, the arrangement pitch of the adhesive placement portion in the direction perpendicular to the extension direction of the adhesive placement portion is made different between the first bonding region 41 and the second bonding region 45.

[0064] The basis weight (amount applied per unit area) of the adhesive in each of 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 securing the bonding strength between the absorbent body 2 and the exterior body 3, the basis weight of the adhesive in the first adhesive placement section 42 is preferably 1.0 g / m 2 More preferably, 2.0 g / m 2 More preferably, it is 15.0 g / m 2 Less than 10.0 g / m 2 and preferably 1.0 g / m 2 More than 15.0g / m 2 Less than 2.0 g / m 2 More than 10.0g / m 2 The following is the result. In order to more reliably ensure the bonding strength between the second sheet 12 and the third sheet 13, and between these two sheets and the leg elastic members 37, the basis weight of the adhesive in the second adhesive placement section 46 is preferably 1.0 g / m 2 More preferably, 2.0 g / m 2 More preferably, it is 15.0 g / m 2Less than 10.0 g / m 2 and preferably 1.0 g / m 2 More than 15.0g / m 2 Less than 2.0 g / m 2 More than 10.0g / m 2 The following is the result.

[0065] Furthermore, the basis weight of the adhesive forming each of the adhesive placement portions 42, 46 in the first bonding region 41 or the second bonding region 45 may be the same or different.

[0066] Materials forming each part of the diaper 1 in the above-mentioned embodiment will be described in detail below. For the topsheet 21 and absorbent body 22, materials conventionally used in absorbent articles can be used without any particular restrictions. The top sheet 21 may be, for example, a liquid-permeable nonwoven fabric or a perforated film. The absorbent body 22 may use an assembly of hydrophilic fibers such as wood pulp or hydrophilically treated synthetic fibers, or such an assembly with a water-absorbent polymer retained therein, as the absorbent core 24. The core wrap sheet 25 may be the same as the top sheet 21.

[0067] When the first sheet 11 in the backsheet 10 is the leakproof sheet 28, a liquid-impermeable or water-repellent sheet can be used as the first sheet 11. Such a sheet can be a resin film or a laminate of a resin film and a nonwoven fabric. Examples of the resin film include films made of polymeric materials such as polyethylene terephthalate, polyester, polyethylene, polypropylene, cellophane, nylon, polyvinyl alcohol, polyvinyl chloride, and polycarbonate, and moisture-permeable films. When the second sheet 12 and the third sheet 13 in the back sheet 10 are the outer casing 3, the second sheet 12 and the third sheet 13 can be made of, for example, nonwoven fabric manufactured 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, at least one of the second sheet 12 and the third sheet 13 may be a laminated nonwoven fabric having 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 of a fiber layer containing crimped fibers. As the crimped fiber, there can be used mechanically crimped fibers that are two-dimensionally crimped into a zigzag shape by mechanical crimping, three-dimensionally crimped fibers that are three-dimensionally crimped into a spiral shape, and latent crimped fibers that are three-dimensionally crimped into a coil shape by applying heat. As the crimped fiber, there can be mentioned eccentric core-sheath type or side-by-side type composite fibers that are composed of two types of thermoplastic polymer materials with different shrinkage rates. More specifically, there can be mentioned those described in JP-A-9-296325, JP-A-2759331, and JP-A-5404967.

[0069] From the viewpoints of making the fibers easier to move when touching the fingers or the like, further improving the smoothness and cushioning feeling, and more reliably ensuring the bonding strength in the second bonding region 45, it is preferable that the fiber layer forming the non-skin-facing surface of the third sheet 13 contains crimped fibers, and the fiber layer forming the skin-facing surface does not contain the crimped fibers. One such embodiment is a laminated nonwoven fabric in which a fiber layer containing crimped fibers and a fiber layer not containing crimped fibers are laminated together in the third sheet 13.

[0070] When 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 of crimped fibers in the fiber layer containing crimped fibers is preferably 10 mass% or more, more preferably 20 mass% or more, and preferably 100 mass% or less, more preferably 80 mass% or less, and also preferably 10 mass% or more and 100 mass% or less, more preferably 20 mass% or more and 80 mass% or less, relative to the total mass of fibers in the fiber layer.

[0071] Elastic members such as the core elastic member 31 in the absorbent body 22, the cuff elastic members 35 and outer cuff elastic members 32 in the leakage preventing cuffs 16, and the leg elastic members 37 can be made of various known elastic materials that are usually used in this type of absorbent article, without any particular restrictions. Examples of elastic materials include synthetic rubbers such as styrene-butadiene, butadiene, isoprene, and neoprene, natural rubber, EVA, elastic polyolefin, and polyurethane. As the form of the elastic member, a thread-like (e.g., rubber thread) or string-like (e.g., flat rubber) member having a rectangular, square, circular, polygonal, or other cross section, or a multifilament type thread-like member can be preferably used.

[0072] Although the present invention has been described based on the preferred embodiments, the present invention is not limited to the above-described embodiments. For example, the absorbent article described above is a pants-type disposable diaper, but it may be an open-type disposable diaper, and may be for either infants or adults. In the above-described embodiment, the extending direction of the first adhesive placement portion 42 and the second adhesive placement portion 46 coincides with the horizontal direction Y. However, the extending direction may coincide with the vertical direction X. In the above-described embodiment, the absorbent core 24 has the folding guide portions 23C and 23S, but it is not necessary to have the folding guide portions 23C and 23S. In addition, the entire absorbent core 24 may have a two-layer structure or a single-layer structure. Furthermore, the absorbent core 24 may not have the core elastic member 31. In the above-described embodiment, the leakage preventing cuff 26 has the outer cuff elastic member 32, but the outer cuff elastic member 32 may not be included.

[0073] Furthermore, for example, the outer casing 3 shown in FIG. 1 is continuous from the ventral portion A through the crotch portion C to the dorsal portion B, but instead, the outer casing 3 may be of a split outer casing type in which the outer casing 3 is divided into a dorsal sheet member arranged on the dorsal side of the wearer and a ventral sheet member arranged on the ventral side, the dorsal sheet member and the ventral sheet member are joined by a pair of side seal portions to form a tubular shape, and the absorbent main body is fixed between the dorsal sheet member and the ventral sheet member. In the above-mentioned embodiment, the exterior body 3 has a two-layer structure of the second sheet 12 and the third sheet 13, but the exterior body 3 may have a single-layer structure. In this case, the sheet constituting the exterior body 3 is 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 are the first sheet 11 and the second sheet 12. As an example of such a configuration, the absorbent body 22 includes the 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, and includes a non-skin-side core wrap sheet, a moisture-permeable film sheet, and a non-woven fabric in this order on the non-skin-facing surface side of the absorbent core 24. In this case, the non-skin-side core wrap sheet is the first sheet 11, the moisture-permeable film sheet is the second sheet 12, and the non-woven fabric is the third sheet 13.

[0074] In the above-described embodiment, the first adhesive placement section 42 and the second adhesive placement section 46 each extend in the horizontal direction Y, but this is not limited to the above. 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 horizontal direction Y and the other may extend in the vertical direction X.

[0075] In relation to the above-mentioned embodiment of the present invention, the following absorbent article is further disclosed. <1> An absorbent article having a top sheet, a back sheet, and an absorbent core disposed between the top sheet and the back sheet, the absorbent article having a longitudinal direction corresponding to the front-to-rear direction of a wearer and a transverse direction perpendicular to the longitudinal direction, The back sheet has, in order from the skin-facing side to the non-skin-facing side, a first sheet, a second sheet, and a third sheet, the third sheet forms a non-skin facing surface of the absorbent article; a first bonding region where the first sheet and the second sheet are partially bonded to each other via an adhesive, and a second bonding region where the second sheet and the third sheet are partially bonded to each other via an adhesive, Each of the first bonding region and the second bonding region has an adhesive placement portion where the adhesive is placed and an adhesive non-placement portion where the adhesive is not placed, The first bonding region and the second bonding region have an overlapping region in a plan view, In the overlapping region, the first bonding region has a higher area ratio of the adhesive placement portion than the second bonding region; An absorbent article, wherein the non-adhesive portion of the second bonded region overlaps the non-adhesive portion of the first bonded region.

[0076] <2> a ratio of an area ratio of the adhesive placement portion of the first bonding region to an area ratio of the adhesive placement portion of 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> An absorbent article 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> An absorbent article as described above. <4> The area ratio of the adhesive application portion in the second bonding region is 5% or more and 50% or less, and more preferably 10% or more and 35% or less. <1> ~ <3> 13. An absorbent article according to any one of the preceding claims. <5> In the first bonding region and the second bonding region, the adhesive placement sections and the adhesive non-placement sections are alternately arranged in the vertical direction and are formed to extend in the horizontal direction, <1> ~ <4> 13. An absorbent article according to any one of the preceding claims. <6> In the first bonding region, the adhesive placement portion has a width narrower than that of the non-adhesive placement portion. <1> ~ <5> 13. An absorbent article according to any one of the preceding claims. <7> In the first bonding region, the ratio of the width of the adhesive placement portion to the width of the non-adhesive placement portion is 10% or more and 90% or less, preferably 20% or more and 70% or less. <6> An absorbent article as described above. <8> a width of the adhesive placement portion in the second bonding region is equal to or less than a width of the adhesive placement portion in the first bonding region; <1> ~ <7> 13. An absorbent article according to any one of the preceding claims. <9> a ratio of a width of the adhesive placement portion of the second bonding region to a width of the adhesive placement portion of the first bonding region is 20% or more and 100% or less, preferably 30% or more and 90% or less; <8> An absorbent article as described above. <10> The second bonding region has a width of the non-adhesive portion wider than that of the first bonding region. <1> ~ <9> 13. An absorbent article according to any one of the preceding claims.

[0077] <11> a ratio of a width of the non-adhesive portion of the second bonding region to a width of the non-adhesive portion of the first bonding region is 120% or more and 1000% or less, preferably 150% or more and 500% or less; <10> An absorbent article as described above. <12> At least a portion of the non-adhesive portion of the second bonding region overlaps with a plurality of the non-adhesive portions of the first bonding region. <1> ~ <11> 13. An absorbent article according to any one of the preceding claims. <13> The elastic members having elasticity in the vertical direction are arranged so as to overlap the overlapping region in a plan view, or are arranged on both sides of the overlapping region in the horizontal direction, At least one of the first bonding region and the second bonding region includes the non-adhesive portion that is wider when the elastic member is stretched than when the elastic member is contracted. <5> ~ <12> The absorbent article according to any one of the above. <14> At least one of the second sheet and the third sheet has a dynamic friction coefficient of 0.6 or less in a direction perpendicular to a fiber orientation direction. <1> ~ <13> 13. An absorbent article according to any one of the preceding claims. <15> The third sheet has a smaller dynamic friction coefficient in the perpendicular direction than the second sheet. <14> An absorbent article as described above. <16> At least one of the second sheet and the third sheet has constituent fibers oriented in the transverse direction, and has a ring crush compressive strength of 7.0 cN or less, preferably 1.0 cN or more and 7.0 cN or less, and more preferably 1.5 cN or more and 5.0 cN or less, when compressed in a direction perpendicular to the orientation direction. <1> ~ <15> 13. An absorbent article according to any one of the preceding claims. <17> The second sheet has a ring crush compressive strength greater than that of the third sheet. <16> An absorbent article as described above. <18> At least one of the second sheet and the third sheet has a fiber layer containing crimped fibers. <1> ~ <17> 13. An absorbent article according to any one of the preceding claims. [Explanation of symbols]

[0078] 1. Disposable diapers 2. Absorbent body 3 Exterior body 10 Back sheet 11 Sheet 1 12 2nd Sheet 13 Third Sheet 22 Absorbent 24 Absorbent Core 25 Core wrap sheet 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 non-placement portion 45 Second joint area 46 Second adhesive placement section 47 Second non-adhesive portion 48, 481, 482 Overlapping Areas A Ventral part B Dorsal part C Inseam X vertical direction Y Horizontal

Claims

1. An absorbent article having a top sheet, a back sheet, and an absorbent core disposed between the top sheet and the back sheet, the absorbent article having a longitudinal direction corresponding to the front-back direction of the wearer and a lateral direction orthogonal to the longitudinal direction, wherein the back sheet has, in order from the skin-facing surface side to the non-skin-facing surface, a first sheet, a second sheet, and a third sheet, the third sheet forms the non-skin-facing surface of the absorbent article, the first sheet and the second sheet have a first joining region partially joined via an adhesive, and the second sheet and the third sheet have a second joining region partially joined via an adhesive, each of the first joining region and the second joining region has an adhesive arrangement portion where the adhesive is disposed and an adhesive non-arrangement portion where the adhesive is not disposed, the absorbent article has an overlapping region where the first joining region and the second joining region overlap in plan view, in the overlapping region, the first joining region has a higher area ratio of the adhesive arrangement portion than the second joining region, the absorbent article, wherein the adhesive non-arrangement portion of the second joining region overlaps with the adhesive non-arrangement portion of the first joining region.

2. The absorbent article according to claim 1, wherein in the first joining region and the second joining region, the adhesive arrangement portions and the adhesive non-arrangement portions are alternately arranged in the longitudinal direction and extend in the lateral direction, respectively.

3. The absorbent article according to claim 1 or 2, wherein in the first joining region, the adhesive arrangement portion has a narrower width than the adhesive non-arrangement portion.

4. The absorbent article according to claim 1 or 2, wherein the width of the adhesive arrangement portion of the second joining region is equal to or less than the width of the adhesive arrangement portion of the first joining region.

5. The absorbent article according to claim 1 or 2, wherein the second joining region has a wider width of the adhesive non-arrangement portion than the first joining region.

6. The absorbent article according to claim 1 or 2, wherein at least a part of the adhesive non-arrangement portion of the second joining region overlaps with a plurality of the adhesive non-arrangement portions of the first joining region.

7. The elastic member having elasticity in the longitudinal direction is disposed so as to overlap with the overlapping region in plan view or is disposed on both lateral sides of the overlapping region in the longitudinal direction, In the absorbent article according to claim 2, at least one of the first joining region and the second joining region includes the adhesive non-arrangement portion that is wider when the elastic member is extended than when the elastic member is contracted.

8. In the absorbent article according to claim 1 or 2, at least one of the second sheet and the third sheet has a coefficient of kinetic friction in a direction orthogonal to the fiber orientation direction of 0.6 or less.

9. In the absorbent article according to claim 8, the third sheet has a smaller coefficient of kinetic friction in the orthogonal direction than the second sheet.

10. In the absorbent article according to claim 1 or 2, at least one of the second sheet and the third sheet has a fiber layer containing crimped fibers, and the ring crush compression strength when compressed in a direction orthogonal to the orientation direction is 7.0 cN or less.

11. In the absorbent article according to claim 10, the second sheet has a larger ring crush compression strength than the third sheet.

12. In the absorbent article according to claim 1 or 2, at least one of the second sheet and the third sheet has a fiber layer containing crimped fibers.

Images