Absorbent article

Abstract

An absorbent core (24) of an absorbent article (1) has a narrow region (24a) in which the width of the core (24) gradually decreases toward the outside in a longitudinal direction (X) in an outer side end region of a rear-side part (R) in the longitudinal direction (X). A rear-side elastic region (8) capable of expanding and contracting in a lateral direction (Y) is provided in an end region of the rear-side part (R). In a plan view, at least a portion of the narrow region (24a) and at least a portion of the rear-side elastic region (8) overlap. A rear-side elastic member (83) overlapping the narrow region (24a) is provided in a continuous manner. When the absorbent article (1) is viewed along the longitudinal direction (X), at least a portion of the narrow region (24a) and at least a portion of a fastening tape (7) are at the same position.

Description

Absorbent articles

[0001] This invention relates to absorbent articles.

[0002] As an example of an absorbent product, a disposable diaper is known that has fastening tape on the back side, which is positioned on the wearer's back. By securing the disposable diaper around the waist with the fastening tape, the comfort of wearing the diaper can be improved.

[0003] For example, Patent Documents 1 and 2 describe a disposable diaper that includes tape for securing the diaper around the wearer's waist and a waist gather that surrounds the wearer's abdomen. These documents state that the elastic material in the waist gather allows the disposable diaper to adhere closely to the wearer's skin.

[0004] Japanese Patent Publication No. 2022-42475 Japanese Patent Publication No. 2023-126000

[0005] The present invention provides an absorbent article. In one embodiment, the absorbent article preferably has a longitudinal direction extending from the wearer's ventral side through the crotch area to the dorsal side and a transverse direction perpendicular thereto, and preferably has a crotch area that is positioned in the crotch area when worn, an ventral area positioned closer to the wearer's ventral side than the crotch area, and a dorsal area positioned closer to the wearer's dorsal side than the crotch area. In one embodiment, the absorbent article preferably has an absorbent core extending along the longitudinal direction from the ventral area through the crotch area to the dorsal area. In one embodiment, the absorbent article preferably has a pair of fastening tapes extending outward in the transverse direction from the lateral side of the dorsal area. In one embodiment, the absorbent core preferably has a narrowing region in the longitudinal outward end area of ​​the dorsal area where the width of the absorbent core gradually decreases as it moves outward in the longitudinal direction. In one embodiment, the absorbent article preferably has a back elastic region that is expandable and contractible in the lateral direction at the longitudinal end region of the back portion. In one embodiment, the absorbent article preferably has a plurality of elastic members that extend in the lateral direction and are spaced apart along the longitudinal direction and arranged in an extended state in the back elastic region. In one embodiment, in a plan view of the absorbent article, it is preferable that at least a portion of the narrow region and at least a portion of the back elastic region overlap. In one embodiment, in the absorbent article, of the elastic members constituting the back elastic region, the one that overlaps with the narrow region has one end located at one side edge of the back elastic region and the other end located at the other side edge of the back elastic region, and the space between the one end and the other end is continuous. In one embodiment, in the absorbent article, when viewed along the longitudinal direction, it is preferable that at least a portion of the narrow region and at least a portion of the fastening tape are in the same position.

[0006] Figure 1 is a schematic plan view showing the skin-facing side of a disposable diaper, which is one embodiment of the absorbent article of the present invention, in its unfolded and fully extended state. Figure 2 is a schematic cross-sectional view showing a cross-section along the thickness direction of the disposable diaper shown in Figure 1 along the line II-II. Figure 3 is a schematic enlarged plan view showing the main part of the back side of the disposable diaper shown in Figure 1. Figure 4 is an explanatory diagram showing the state of performing the operation of expanding the back side of the disposable diaper shown in Figure 1 in the lateral direction. Figure 5 is a schematic perspective view of the disposable diaper shown in Figure 1 as it is in its state as it has been removed from its packaging, viewed from the back. Figure 6 is a schematic plan view showing a disposable diaper, which is another embodiment of the absorbent article of the present invention, and corresponds to Figure 3. Detailed description of the invention

[0007] Disposable diapers are required to prevent leakage of excrement, and to prevent leakage, it is necessary to properly attach the diaper to the wearer's body. For example, it is necessary to fasten a pair of fastening tapes provided on the back of the diaper to the correct position on the front of the diaper, thereby generating a suitable tightening force to prevent leakage without compromising comfort. To achieve this, it is advantageous to make it easy to pinch the fastening tapes and stretch the back of the diaper. However, the diapers described in the aforementioned Patent Documents 1 and 2 do not incorporate any features to facilitate the operation of pinching the fastening tapes and stretching the back of the diaper. Therefore, the present invention relates to an absorbent article that is easy to spread out in a flat shape and easy to attach to the wearer.

[0008] The present invention will be described below with reference to the drawings, based on preferred embodiments thereof. In the following drawings, identical or similar parts are denoted by the same or similar reference numerals. The drawings are basically schematic, and the proportions of the dimensions may differ from those of reality.

[0009] Figure 1 shows a disposable diaper (hereinafter also simply referred to as "diaper") 1, which is one embodiment of the absorbent article of the present invention.

[0010] Diaper 1 has a vertically elongated shape with a vertical direction X corresponding to the direction extending from the wearer's ventral side through the crotch area to the back, and a horizontal direction Y perpendicular to it. Diaper 1 has a crotch area M that is positioned at the wearer's crotch when worn, a ventral area F positioned on the wearer's ventral side of the crotch area M, and a dorsal area R positioned on the wearer's back side of the wearer's back than the ventral area F. The crotch area M extends in the vertical direction X perpendicular to the vertical center line CLx of diaper 1. The vertical center line CLx is a hypothetical straight line that bisects the diaper 1 in its unfolded and fully extended state shown in Figure 1 in the vertical direction X and extends in the horizontal direction Y. The crotch area M has an excretory area facing section (not shown) that is positioned opposite the wearer's excretory area when wearing diaper 1, and typically includes the part of diaper 1 with the shortest length in the horizontal direction Y. The ventral region F, the crotch region M, and the dorsal region R are the regions obtained by dividing the unfolded and fully extended diaper 1 into three equal parts in the longitudinal direction X. The diaper 1 is formed symmetrically on one side and the other side with respect to the transverse center line Cly. The transverse center line Cly is a hypothetical straight line that bisects the unfolded and fully extended diaper 1 shown in Figure 1 in the transverse direction Y and extends in the longitudinal direction X.

[0011] In this specification, "unfolded and fully extended state" refers to the state in which the diaper 1 is unfolded and the elastic member provided on the diaper 1 is extended so that the dimensions of the other members in a plan view become the design dimensions, that is, until the influence of the elastic member is completely eliminated, and the diaper 1 is spread out in a planar shape. In this specification, "skin-facing surface" refers to the surface of an absorbent article or its component (e.g., surface sheet) that faces the wearer's skin when the absorbent article is worn, that is, the side that is relatively closer to the wearer's skin. "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, that is, the side that is relatively farther from the wearer's skin.

[0012] As shown in Figure 1, the diaper 1 comprises an absorbent body 2. The absorbent body 2 has a surface sheet 21 that is positioned closer to the wearer's skin when worn, and a back sheet 22 that is positioned further away from the wearer's skin when worn. The absorbent body 2 further comprises an absorbent material 23 that extends along the longitudinal direction X. The absorbent material 23 is positioned between the surface sheet 21 and the back sheet 22. The absorbent body 2 has a long shape in the longitudinal direction X, and its longitudinal direction is aligned with the longitudinal direction X, and it is positioned in the abdominal area F, the crotch area M, and the back area R. The diaper 1 further comprises an outer covering 3 located on the non-skin-facing surface of the back sheet 22 of the absorbent body 2 (i.e., the surface opposite to the surface facing the surface sheet 21).

[0013] As shown in Figure 1, the surface sheet 21 is located on the skin-facing side of the absorbent body 23. The surface sheet 21 consists of a single sheet and is positioned on the ventral side F, the crotch area M, and the dorsal side R of the absorbent body 2. The periphery of the surface sheet 21 forms the contour of the absorbent body 2 in a plan view. As the surface sheet 21, a liquid-permeable sheet can be used, such as a nonwoven fabric like an air-through nonwoven fabric, a perforated nonwoven fabric, or a perforated film. The surface sheet 21 may have an uneven shape on its skin-facing side. For example, multiple protrusions can be formed in a scattered pattern on the skin-facing side of the surface sheet 21. Alternatively, alternating ridges and grooves extending in one direction can be formed on the skin-facing side of the surface sheet 21. For such purposes, the surface sheet 21 can also be formed using two or more nonwoven fabrics.

[0014] The back sheet 22 is located on the non-skin-facing side of the absorbent body 23 and on the skin-facing side of the outer casing 3. The back sheet 22 consists of a single sheet and is positioned on the ventral side F, crotch area M, and dorsal side R of the absorbent body 2. The back sheet 22 is approximately the same size as the front sheet 21. The positions of both ends of the back sheet 22 in the longitudinal direction X coincide with the positions of both ends of the front sheet 21 in the longitudinal direction X. These positions are also the positions of both ends of the diaper 1 in the longitudinal direction X. The positions of both sides of the back sheet 22 coincide with the positions of both sides of the front sheet 21. The periphery of the back sheet 22, like the front sheet 21, forms the contour of the absorbent body 2. Therefore, the positions of both ends of the front sheet 21 and the back sheet 22 are also the positions of both ends of the absorbent body 2, and the positions of both sides of the front sheet 21 and the back sheet 22 are also the positions of both sides of the absorbent body 2. For the backing sheet 22, for example, a liquid-impermeable film or a spunbond, meltblown, or spunbond laminated nonwoven fabric can be used. A liquid-impermeable film may be provided with multiple micropores to give it water vapor permeability. To further improve the feel of the absorbent article, a sheet with a good texture, such as a nonwoven fabric, may be laminated to the outer surface of the backing sheet 22.

[0015] The absorbent core 23 has the function of absorbing and retaining excretions such as urine. The absorbent core 23 is located in the ventral part F, the crotch area M, and the dorsal part R of the absorbent body 2. The entire surface of the absorbent core 23 facing the skin is covered with a surface sheet 21, and the entire surface that does not face the skin is covered with a back sheet 22. The absorbent core 23 comprises an hourglass-shaped absorbent core 24 with a constricted central area in the longitudinal direction X, and a core wrap sheet 25 covering the absorbent core 24. The hourglass shape of the absorbent core 24 improves the fit of the diaper 1 in the crotch area M. The absorbent core 24 has its longitudinal direction aligned with the longitudinal direction X and extends from the ventral part F through the crotch area M to the dorsal part R. The absorbent core 24 may have at least its skin-facing surface covered with a liquid-permeable core wrap sheet 25, or the entire surface including the skin-facing and non-skin-facing surfaces may be covered with the core wrap sheet 25. The front and rear edges of the core wrap sheet 25 in the longitudinal direction X are both sealed by joining opposing sheets 25, 25 together.

[0016] The absorbent core 24 is composed of, for example, a stack of hydrophilic fibers such as cellulose including pulp, a mixed stack of hydrophilic fibers and an absorbent polymer, a deposit of an absorbent polymer, or a laminated structure in which an absorbent polymer is supported between two absorbent sheets. As the core wrap sheet 25, for example, a thin paper made of hydrophilic fibers or a liquid-permeable nonwoven fabric can be used.

[0017] The absorbent core 24 has a constant width in the ventral portion F. In the ventral portion F, the absorbent core 24 has a pair of corners located in the outer end region in the longitudinal direction X of the ventral portion F that are approximately right angles. On the other hand, the absorbent core 24 in the dorsal portion R has a constant width in the portion near the crotch M, whereas in the outer end region in the longitudinal direction X of the dorsal portion R, the width of the absorbent core 24 gradually decreases as it moves outward in the longitudinal direction X. As a result, in the outer end region in the longitudinal direction X of the dorsal portion R, the absorbent core 24 has a narrow region 24a. As shown in Figure 3, the narrow region 24a is located in the center of the width direction of the absorbent core 24.

[0018] More specifically, the absorbent core 24 has a shape in which a pair of corners in the end region of the dorsal portion R are curved in an arc shape. More specifically, the pair of corners in the end region of the absorbent core 24 have a shape in which the arc is convex toward the centroid in the plan view of the absorbent core 24. As a result, the width of the absorbent core 24 decreases continuously toward the edge 24b in the vertical direction X. Consequently, the absorbent core 24 has a narrow region 24a including its edge 24b in the end region of the dorsal portion R. The narrow region 24a is narrowest at the position of the edge 24b of the absorbent core 24 and widest at the position on the crotch area M. Note that although the narrow region 24a shown in Figure 3 decreases in width continuously toward the edge 24b, the width may instead decrease in stages.

[0019] The outer casing 3 is located on the non-skin-facing side of the backing sheet 22. The outer casing 3 is continuously arranged over the entire area of ​​the ventral F, crotch M, and dorsal R of the diaper 1. The periphery of the outer casing 3 forms the outline of the diaper 1. As the outer casing 3, nonwoven fabrics made by various manufacturing methods, resin films, etc., can be used. Examples of nonwoven fabrics include spunbond nonwoven fabric, air-through nonwoven fabric, needle-punched nonwoven fabric, etc. The outer casing 3 may be a single-layer structure or a laminated structure in which two or more sheets are stacked. The outer casing 3 may also be an elastic sheet that is stretchable in the lateral direction Y, or a non-elastic sheet that is not stretchable.

[0020] As shown in Figures 1 and 2, a pair of leak-proof cuffs 4, 4 are provided on both sides of the absorbent body 2 along the longitudinal direction X, which stand upright on the side facing the wearer's skin when worn. The leak-proof cuff 4 includes a liquid-impermeable leak-proof sheet 41 that forms the main body of the leak-proof cuff 4, and a thread-like first elastic member 42 fixed to the leak-proof sheet 41. In a plan view of the diaper 1, the leak-proof sheet 41 is in the shape of a strip extending in the longitudinal direction X. The leak-proof sheet 41 is fixed to other members such that the inner edge portion extending in the longitudinal direction X near the horizontal center line Cly becomes a free end portion 43. Other members are, for example, the surface sheet 21 and the outer casing 3. The first elastic member 42 is fixed to the free end portion 43 of the leak-proof sheet 41 in an extended state in the longitudinal direction X. When worn, the contraction of the first elastic member 42 causes the leak-proof cuff 4 to stand upright at least in the crotch area M, with the fixing portion between the leak-proof sheet 41 and other members serving as the base end and the free end 43 being close to the wearer's body. This prevents urine and other excretions from flowing outward in the lateral direction Y.

[0021] A pair of leg gathers 5, 5 are provided on both sides of the leak-proof cuff 4 along the longitudinal direction X, which form multiple folds when worn. More specifically, a thread-like second elastic member 51 is fixed in an extended state in the longitudinal direction X, extending outward in the lateral direction Y from both side edges of the leak-proof cuff 4 in the lateral direction Y. The second elastic member 51 is held and fixed between the leak-proof sheet 41 and the outer casing 3. When the diaper 1 is worn, the contraction of the second elastic member 51 forms leg gathers 5, at least in the crotch area M. This prevents urine and other excretions from flowing outward in the lateral direction Y.

[0022] As shown in Figures 1 to 3, the diaper 1 has a pair of side flap portions 6, 6 extending outward in the lateral direction Y from both side edges of the absorbent body 2 along the vertical direction X on its back side R. In this embodiment, the outer casing 3 and the leak-proof sheet 41 extend outward in the lateral direction Y from both side edges of the absorbent body 2 along the vertical direction X, and the side flap portion 6 is formed by both sheets. In other words, the side flap portion 6 is located outward in the lateral direction Y of the absorbent body 23 on the back side R of the diaper 1 and is composed of at least the outer casing 3 and the leak-proof sheet 41. Alternatively, the surface sheet 21 and the back sheet 22 may also extend outward in the lateral direction Y from both side edges of the absorbent body 23 along the vertical direction X and become components of the side flap portion 6.

[0023] The diaper 1 has a pair of fastening tapes 7, 7 on its dorsal side R. Each fastening tape 7 is positioned to extend outward in the lateral direction Y from the side of the dorsal side R, i.e., from the side of the side flap portion 6. One end of each fastening tape 7 is fixed between the first sheet 81 and the leak-proof sheet 41 in the dorsal elastic region 8. Details of the dorsal elastic region 8 will be described later. The fastening tape 7 has a shape that extends along the lateral direction Y and has a fastening portion 71 in the central area along the lateral direction Y. The fastening portion 71 is made of a material that can be fastened to a landing tape, which will be described later.

[0024] A landing tape 72 (see Fig. 5) is provided as a fastening region on the non-skin-facing surface of the abdominal portion F of the diaper 1, to which the fastening portion 71 of the fastening tape 7 can be detachably fastened. In the diaper 1 of the present embodiment, when the fastening portion 71 is fastened to the landing tape 72, a waist opening WO through which the wearer's torso passes and a pair of leg openings LO, LO through which the wearer's lower limbs pass are formed, and the diaper is worn on the wearer (see Fig. 5 described later). Examples of the combination of the fastening portion 71 and the landing tape 72 include a combination of a hook member and a loop member of a mechanical hook-and-loop fastener, and a combination of an adhesive and a film material to which the adhesive can adhere. In the present embodiment, the fastening portion 71 is formed from a hook member of a mechanical hook-and-loop fastener, and the landing tape 72 is formed from a loop member of the mechanical hook-and-loop fastener.

[0025] As shown in Figs. 1 to 3, the dorsal portion R of the diaper 1 has a dorsal elastic region 8 expandable and contractible in the lateral direction Y in an end region in the longitudinal direction X. Note that no elastic region is present at the position corresponding to the dorsal elastic region 8 in the abdominal portion F of the diaper 1. In the dorsal elastic region 8, two first sheet 81 and second sheet 82 that are long in the lateral direction Y, and a dorsal elastic member 83 fixed in a stretched state between these sheets 81 and 82 are disposed. The dorsal elastic region 8 has the dorsal elastic member 83 which extends in the lateral direction Y, is spaced along the longitudinal direction X, and is formed of a plurality of thread-like elastic members disposed in a stretched state.

[0026] The first sheet 81 is disposed adjacent to the non-skin-facing surface side of the topsheet 21. The second sheet 82 is disposed adjacent to the skin-facing surface side of the backsheet 22. The positions of the outer edges in the longitudinal direction X of each of the sheets 81 and 82 substantially match the positions of the outer edges in the longitudinal direction X of the topsheet 21 and the backsheet 22. Both side edges of each of the sheets 81 and 82 are located outward in the lateral direction Y from both side edges of the topsheet 21 and the backsheet 22. The sizes of each of the sheets 81 and 82 are substantially the same. Both ends of the dorsal elastic member 83 are located outward in the lateral direction Y from both side edges of the topsheet 21 and the backsheet 22, and located inward in the lateral direction Y from both side edges of each of the sheets 81 and 82.

[0027] The dorsal elastic region 8 is a region in the dorsal portion R that exhibits elastic stretchability along the transverse direction Y, and refers to a region overlapping with the region where the dorsal elastic member 83 is disposed in a plan view. In the present embodiment, since a plurality of dorsal elastic members 83 are disposed on the dorsal portion R, the dorsal elastic region 8 of the present embodiment is a region from the outermost dorsal elastic member 83 to the innermost dorsal elastic member 83 in the longitudinal direction X, and is a region between both end portions of each dorsal elastic member 83 in the transverse direction Y.

[0028] Each of the dorsal elastic members 83 disposed in the dorsal elastic region 8 has the same length, has one end portion 83a and the other end portion 83b, and is continuous between the one end portion 83a and the other end portion 83b. In other words, each dorsal elastic member 83 does not have an interrupted portion between the one end portion 83a and the other end portion 83b. By disposing the dorsal elastic members 83 continuously, the dorsal portion R is more likely to come into contact with the wearer without a gap, for example, compared to a case where the dorsal elastic members 83 are disposed intermittently. As a result, for example, excrement that has not been completely absorbed by the absorbent body 23 can be effectively suppressed from leaking out from the ventral side or the dorsal side.

[0029] The positions of one end portions 83a of the respective dorsal elastic members 83 coincide with each other in the transverse direction Y. Similarly, the positions of the other end portions 83b of the respective dorsal elastic members 83 also coincide with each other in the transverse direction Y. Therefore, the one end portions 83a of the respective dorsal elastic members 83 are aligned on a straight line so as to extend along the longitudinal direction X. Similarly, the other end portions 83b of the respective dorsal elastic members 83 are also aligned on a straight line so as to extend along the longitudinal direction X. As described above, the dorsal elastic region 8 of the present embodiment is a region from one end portion 83a to the other end portion 83b of the dorsal elastic member 83 in the transverse direction Y. However, the position of one end portion 83a and the position of the other end portion 83b of each dorsal elastic member 83 do not need to coincide with each other in the transverse direction Y. That is, the one end portion 83a and the other end portion 83b of each dorsal elastic member 83 do not independently need to be aligned on a straight line so as to extend along the longitudinal direction X. Advantages of employing such a configuration will be described later.

[0030] As shown in Figure 3, the dorsal elastic region 8 of this embodiment has a first elastic region 8A and a second elastic region 8B along the longitudinal direction X. The first elastic region 8A is located on the outward side of the longitudinal direction X. The second elastic region 8B is located inward in the longitudinal direction X than the first elastic region 8A. The first elastic region 8A and the second elastic region 8B are adjacent, and there are no other elastic regions between the two regions 8A and 8B. Note that although Figure 3 shows the dorsal elastic region 8 consisting of the first elastic region 8A and the second elastic region 8B, this does not mean that the dorsal elastic region 8 does not have any other elastic regions. For example, it is not prevented that the dorsal elastic region 8 has another elastic region located inward in the longitudinal direction X than the second elastic region 8B.

[0031] The first elastic region 8A and the second elastic region 8B are distinguished by their respective positions. In detail, as shown in Figure 3, the first elastic region 8A is the region of the dorsal elastic region 8 that does not overlap with the absorbent core 24 in a plan view of the diaper 1. On the other hand, the second elastic region 8B is the region of the dorsal elastic region 8 that overlaps with the absorbent core 24 in a plan view of the diaper 1.

[0032] In a plan view, diaper 1 has at least a portion of the narrow region 24a of the absorbent core 24 and at least a portion of the dorsal elastic region 8 overlapping. More specifically, as shown in Figure 3, in a plan view of diaper 1, the entire narrow region 24a overlaps with at least a portion of the dorsal elastic region 8, specifically the second elastic region 8B. Of the dorsal elastic members 83 constituting the dorsal elastic region 8, those overlapping with the narrow region 24a have one end 83a located on one side edge of the dorsal elastic region 8 and the other end 83b located on the other side edge of the dorsal elastic region 8. Furthermore, as described above, the dorsal elastic members 83 constituting the second elastic region 8B are continuous from one end 83a to the other end 83b. The one end 83a and the other end 83b of the second elastic region 8B are located outward in the lateral direction Y from the side edge of the narrow region 24a. In other words, in a plan view of diaper 1, the dorsal elastic member 83 that overlaps with the narrow region 24a straddles the narrow region 24a along the lateral direction Y.

[0033] The narrow region 24a also has a specific positional relationship with the fastening tape 7 described above. In detail, as shown in Figure 3, when the diaper 1 is viewed along the vertical direction X, at least a part of the narrow region 24a and at least a part of the fastening tape 7 are in the same position.

[0034] Before putting the diaper 1, which has the above configuration, onto the wearer, as shown in Figure 4, the thumb of one hand A1 (right hand in Figure 4) is placed on the corner of the narrow region 24a, and the fastening tape 7 is grasped with the other hand A2 (left hand in Figure 4), and the fastening tape 7 is pulled outward in the lateral direction Y. This makes it easier to expand the diaper 1 in the lateral direction Y. In particular, since the corners of the narrow region 24a (both edges in the lateral direction Y) are arc-shaped, the position of the corners is easy to understand and easy to place the fingers on. This makes it even easier to pull the fastening tape 7 outward in the lateral direction Y. In this case, as shown in Figure 3, when the entire narrow region 24a overlaps with the second elastic region 8B, the contraction force of the second elastic region 8B is more easily applied to the entire narrow region 24a, and a step with a smooth, arc-shaped contour is more likely to form at the corner of the narrow region 24a, making it easier to place your fingers on the corner. It also makes it easier to firmly grasp the corner.

[0035] Furthermore, in the diaper 1 of this embodiment, a thread-like dorsal elastic member 83 is arranged so as to straddle the narrow region 24a along the lateral direction Y. As a result, the contraction force of the dorsal elastic member 83 makes the corners of the narrow region 24a more prone to indentation, creating a step. This has the advantage of making the position of the corners easier to see and making it easier to place a finger on them.

[0036] Furthermore, in the diaper 1 of this embodiment, at least a portion of the narrow region 24a and at least a portion of the fastening tape 7 are in the same position when the diaper 1 is viewed along the vertical direction X. Therefore, the force generated by placing a finger on the corner of the narrow region 24a and pinching the fastening tape 7 and pulling it outward in the lateral direction Y is effectively transmitted to the thread-like dorsal elastic member 83 that straddles the narrow region 24a. This also makes it easier to pull the fastening tape 7 outward in the lateral direction Y.

[0037] It is preferable that the first elastic region 8A and the second elastic region 8B in the dorsal elastic region 8 satisfy the relationship of the following formula (1). σ １ ≧σ ２ (1) In formula (1), σ １ represents the elongation stress in the lateral direction Y of the first elastic region 8A per unit width. σ ２ represents the elongation stress in the lateral direction Y of the second elastic region 8B per unit width. The "unit width" refers to a unit length in the longitudinal direction X in each of the first elastic region 8A and the second elastic region 8B. When the first elastic region 8A and the second elastic region 8B have the relationship represented by formula (1), that is, when the elongation stress σ ２ of the second elastic region 8B is equal to or less than the elongation stress σ １ of the first elastic region 8A, irregular wrinkles and / or twists are less likely to occur at each corner of the narrow width region 24a of the absorbent core 24, which is a portion overlapping the second elastic region 8B in a plan view of the diaper 1. This is because the contraction force of the second elastic region 8B is less likely to be excessively applied to each corner of the narrow width region 24a. In addition, since portions adjacent to each corner of the narrow width region 24a have low rigidity, the corners are likely to be depressed and form a level difference even without excessive contraction force applied thereto. Since the occurrence of wrinkles and / or twists contributes to the occurrence of liquid leakage, making these less likely to occur is important from the viewpoint of providing a diaper in which liquid leakage is less likely to occur.

[0038] From the viewpoint of more effectively exerting the above advantages, σ １ and σ ２ are such that σ １ / σ ２ preferably has a value of 1.1 or more, and more preferably 1.5 or more. In addition, σ １ / σ ２ preferably has a value of 3.0 or less, and more preferably 2.0 or less.

[0039] In order for the first elastic region 8A and the second elastic region 8B to satisfy the relationship in equation (1), for example, the spacing D2 of the dorsal elastic members 83 located in the second elastic region 8B should be wider than the spacing D1 of the dorsal elastic members 83 located in the first elastic region 8A located in the longitudinal direction X. By adjusting the spacing of the dorsal elastic members 83 in this way, a large step is more likely to occur at the corners of the narrow region 24a of the absorbent core 24, which has the advantage of making it easier to place a finger on the corner. １ and D ２ That is, D １ / D ２ The value of is preferably 0.3 or higher, and more preferably 0.5 or higher. Also, D １ / D ２ The value of is preferably 0.9 or less, and more preferably 0.6 or less. １ / D ２ When the above is set, it is preferable that the filamentous back elastic member 83 constituting the first elastic region 8A and the filamentous back elastic member 83 constituting the second elastic region 8B are made of the same material, have the same diameter, and are fixed at the same elongation ratio.

[0040] The width of the first elastic region 8A, that is, the length of the first elastic region 8A along the longitudinal direction X, is L. １ Let L be the width of the second elastic region 8B, that is, the length of the second elastic region 8B along the longitudinal direction X. ２ When that happens, L １ / L ２ The value of is preferably 2.0 or higher, and more preferably 3.0 or higher, from the viewpoint of effectively preventing liquid leakage from the dorsal side R. １ / L ２ The value of is preferably 5.0 or less, and more preferably 4.0 or less, from the viewpoint of making it easier to create steps at the corners of the narrow region 24a.

[0041] Furthermore, by making the dorsal elastic member 83 constituting the first elastic region 8A longer in the lateral direction Y than the dorsal elastic member 83 constituting the second elastic region 8B, the first elastic region 8A and the second elastic region 8B can be made to satisfy equation (1). In this case, one end 83a and the other end 83b of the dorsal elastic member 83 constituting the first elastic region 8A are each positioned outward in the lateral direction Y than one end 83a and the other end 83b of the dorsal elastic member 83 constituting the second elastic region 8B.

[0042] Extension stress σ in the dorsal elastic region 8 １ and σ ２The elasticity is measured by the following method. First, the diaper 1 is unfolded and extended to its maximum length. In this state, a sample piece is cut out of the dorsal elastic region 8 of the diaper 1 so as to include the entire elastic region to be measured (first elastic region 8A or second elastic region 8B) and not include the elastic region not to be measured. The sample piece is cut out together with the surface sheet 21, the first sheet 81, the second sheet 82, the dorsal elastic member 83, the back sheet 22, and the outer casing 3. Next, the sample piece is returned to its natural state (relaxed state), and the vicinity of both side edges of the outer casing 3 of the sample piece (near the base 72a, described later) is clamped in a pair of chucks on a Tensilon tensile testing machine (ORIENTEC "RTC-1210A"). Next, the sample piece is stretched in the lateral direction Y at a speed of 300 mm / min until the distance between the pair of chucks is 10 mm shorter than the design dimension of the outer casing 3 (length along the lateral direction Y in the maximum stretched state) (hereinafter, this length is referred to as "L"). The tensile stress (stress / width of the elastic region) is measured when the distance between the chucks is stretched to 0.8 times the length L. This measurement is performed for five sample pieces, and the arithmetic mean of these measurements is taken as the tensile stress. The "width of the elastic region" used in calculating the tensile stress refers to the width of the first elastic region 8A or the width of the second elastic region 8B. The width of the first elastic region 8A is the distance between the two outermost back elastic members 83 in the longitudinal direction X among the back elastic members 83 that constitute the first elastic region 8A. The width of the second elastic region 8B is the distance between the two outermost back elastic members 83 in the longitudinal direction X among the back elastic members 83 that constitute the second elastic region 8B. For example, if the first elastic region 8A includes three dorsal elastic members 83 extending in the lateral direction Y, and the distance between each elastic member 83 is 5 mm, then the width of the first elastic region is 10 mm.

[0043] As shown in Figure 2, the fastening tape 7 in the diaper 1 consists of a fixed area 7A fixed between the first sheet 81 and the leak-proof sheet 41 in the dorsal elastic region 8, and a free area 7B that is not fixed to any other member. As shown in Figure 1, the free area 7B has a tapered portion 74 in part of it, in which the width gradually decreases from the base 72a to the tip 73. The width of the free area 7B is the length along the vertical direction X in Figure 1.

[0044] As shown in Figure 1, when the diaper 1 is viewed along the vertical direction X, at least a portion of the tapered portion 74 and at least a portion of the narrow region 24a of the absorbent core 24 are in the same position. The phrase "at least a portion of the tapered portion 74 and at least a portion of the narrow region 24a of the absorbent core 24 are in the same position" includes embodiments in which only a portion of the narrow region 24a is in the same position as at least a portion of the tapered portion 74, and embodiments in which the entire narrow region 24a is in the same position as at least a portion of the tapered portion 74. As shown in Figure 4, the tapered portion 74 is a suitable part to pinch with your fingers when pulling the fastening tape 7. Therefore, because the tapered portion 74 and the narrow region 24a are in the position described above, the force generated by pinching the fastening tape 7 and pulling it outward in the lateral direction Y is effectively transmitted to the thread-like dorsal elastic member 83 that straddles the narrow region 24a. As a result, the operation of expanding the diaper 1 can be made even easier. In this specification, the "tapered portion 74" is defined as the region extending 25 mm inward in the lateral direction Y from the tip portion 73 in the free region 7B.

[0045] Let W1 be the length of the narrow region 24a along the vertical direction X, and let W2 be the length of the portion of the narrow region 24a that overlaps with the tapered portion 74 when the diaper 1 is viewed along the vertical direction X. At this time, from the viewpoint of making the operation of unfolding the diaper 1 easier, the percentage of W2 to W1, W2 / W1 × 100 (%), is preferably 50% or more, and more preferably 70% or more.

[0046] In this embodiment, as shown in Figure 5, multiple diapers 1, each folded in half in the vertical direction X so that a fold line is formed along the horizontal direction Y, may be contained within a single package. For example, each side of the diaper 1 may be folded back towards the surface sheet 21, and then the diaper 1 may be folded in half along the vertical center line CLx so that the surface sheets 21 face each other, and then contained within a single package. In this state, the diaper 1 has a dorsal elastic region 8 on the dorsal side R, and there is no elastic region corresponding to the dorsal elastic region 8 on the ventral side F. As a result, the dorsal side R contracts more in the horizontal direction Y than the ventral side F. Consequently, the diaper 1 in its state as it is removed from the package (as shown in Figure 5) has a width W of the ventral side F. Ｆ The width W of the dorsal side Ｒ It is larger than the width W of the ventral part F. Ｆ and the width W of the dorsal side Ｒ This refers to the width at the narrowest point of the ventral part F and the width at the narrowest point of the dorsal part R in the diaper 1 in the state shown in Figure 5. Ｆ >W Ｒ As a result, in the state shown in the figure, that is, immediately after being removed from the package, the area near the narrow region 24a of the absorbent core 24 is the most constricted. Therefore, when placing your fingers on the diaper 1 to open it, you can use this most constricted area as a guide. This allows you to open the diaper 1 smoothly.

[0047] When the folded diaper 1 shown in Figure 5 is viewed from the dorsal side R, as described above, the dorsal side R is more contracted in the lateral direction Y than the ventral side F, so a part of the ventral side F is visible. Specifically, a part of the ventral side F is located on the lateral side Y of the dorsal side R. In this way, a part of the ventral side F is visible through the dorsal side R of the diaper 1. This makes it easier to find the narrow area 24a of the absorbent core 24 when placing your fingers on the diaper 1 to open it, allowing you to open the diaper 1 smoothly. From the viewpoint of making this advantage even more pronounced, it is preferable that the part of the ventral side F that is visible through the dorsal side R and at least a part of the narrow area 24a are in the same position when the diaper 1 is viewed along the vertical direction X.

[0048] Preferably, the outer surface (non-skin-facing surface) of the diaper 1 on the ventral part F has a different design from the outer surface (non-skin-facing surface) of the dorsal part R. For example, as shown in Figure 5, a landing tape 72 having a different design from the outer covering 3 on the ventral part F can be applied to the outer surface of the dorsal part R. This makes it possible to make the outer surface design of the diaper 1 different on the ventral part F and the dorsal part R. As a result, when the diaper 1 is viewed from above from the dorsal part R side after being removed from the package, a part of the design applied to the ventral part F becomes visible, making it easier to distinguish the boundary between the ventral part F and the dorsal part R. This boundary serves as a guide for placing a finger on the diaper 1 when opening it. This makes it possible to open the diaper 1 smoothly. From the viewpoint of making this effect even more pronounced, it is preferable to make the constricted shape of the dorsal elastic region 8 recognizable to the caregiver. To achieve this, when the diaper 1 is viewed from above from the dorsal side R in the removed state, it is preferable that the entire area of ​​the second elastic region 8B, which is relatively contracted, overlaps with the design of the ventral side F. In particular, it is especially preferable that the entire area of ​​the dorsal elastic region 8 overlaps with the design of the ventral side F in order to make the degree of contraction more clearly recognizable.

[0049] The aforementioned "different designs" refer to designs that can be recognized as different visually or tactilely, such as designs that differ in one or more of the following: color, two-dimensional shape, three-dimensional shape, and texture. The method for making the outer surface designs of the diaper 1 different in the ventral part F and the dorsal part R is not particularly limited, and methods well known in the art can be used as appropriate.

[0050] Figure 6 shows a disposable diaper 1, which is an absorbent article of another embodiment of the present invention. The following description will focus on the differences between the diaper 1 of this embodiment and the diaper 1 of the embodiments shown in Figures 1 to 5. For configurations not specifically described, the above-described explanation for the embodiments shown in Figures 1 to 5 applies. Furthermore, the description of the narrow region 24a of the embodiments shown in Figures 1 to 5 applies to the overlapping region 24c of the embodiment shown in Figure 6 (details will be described later), except for the points described below.

[0051] The diaper 1 shown in Figure 6 differs from the diaper 1 shown in Figure 3 in that it does not have a narrow region 24a. In other words, in this embodiment, the width (length in the lateral direction Y) of the absorbent core 24 of the diaper 1 is constant in the outer end region in the longitudinal direction X of the dorsal portion R. In this embodiment, the absorbent core 24 has an overlapping region 24c that overlaps with at least a part of the dorsal elastic region 8, more specifically, the second elastic region 8B. The overlapping region 24c is located in the outer end region in the longitudinal direction X of the dorsal portion R of the absorbent core 24. Of the dorsal elastic members 83 that constitute the dorsal elastic region 8, the one that overlaps with the overlapping region 24c has one end 83a located on one side edge of the dorsal elastic region 8 and the other end 83b located on the other side edge of the dorsal elastic region 8. Furthermore, the dorsal elastic member 83 constituting the second elastic region 8B is continuous from one end 83a to the other end 83b. The one end 83a and the other end 83b of the second elastic region 8B are located outward in the lateral direction Y from the side edge of the overlapping region 24c. In other words, in a plan view of the diaper 1, the dorsal elastic member 83 that overlaps with the overlapping region 24c straddles the overlapping region 24c along the lateral direction Y.

[0052] The overlapping region 24c also has a specific positional relationship with the fastening tape 7. More specifically, as shown in Figure 6, when the diaper 1 is viewed along the vertical direction X, at least a portion of the overlapping region 24c and at least a portion of the fastening tape 7 are in the same position.

[0053] In the diaper 1 having the above configuration, at least a portion of the overlapping region 24c and at least a portion of the fastening tape 7 are in the same position when the diaper 1 is viewed along the vertical direction X. Therefore, the force generated by placing fingers on the corners of the overlapping region 24c (both edges in the horizontal direction Y) and pinching the fastening tape 7 and pulling it outward in the horizontal direction Y is effectively transmitted to the thread-like dorsal elastic member 83 that straddles the overlapping region 24c. This makes it easier to pull the fastening tape 7 outward in the horizontal direction Y.

[0054] Although the present invention has been described above based on its preferred embodiments, the present invention is not limited to the above embodiments. For example, in the above embodiments, the dorsal elastic region 8 was formed by a thread-like dorsal elastic member 83, but a strip-shaped or sheet-shaped elastic member may be used instead of the thread-like elastic member. Also, in the embodiments shown in Figures 1 to 5, the absorbent core 24 had an arc-shaped contour at a pair of corners in the end region of the dorsal portion R, but instead, only one of the pair of corners may have an arc-shaped contour, and the other corner may be at a right angle. Even in this case, the absorbent core 24 will have a narrowing region 24a in the end region of the dorsal portion R, where the width of the absorbent core 24 gradually decreases as it moves outward in the vertical direction X. Furthermore, the contour of the corners of the absorbent core 24 is not limited to an arc shape, but may be a curve other than an arc or a straight line. Furthermore, in the above embodiment, the stretching force between the first elastic region 8A and the second elastic region 8B in the dorsal elastic region 8 was adjusted by the spacing of the dorsal elastic members 83. However, instead, the stretching force between the first elastic region 8A and the second elastic region 8B may be made different by varying the thickness and / or elongation ratio of the dorsal elastic members 83, while keeping the spacing of the dorsal elastic members 83 the same. Also, in the above embodiment, all the dorsal elastic members 83 were the same length, but instead, the dorsal elastic members 83 may each have a different length.

[0055] Further relating to the embodiments of the present invention described above, the following absorbent article is disclosed: [1] An absorbent article having a longitudinal direction extending from the ventral side of the wearer through the crotch to the dorsal side and a transverse direction perpendicular thereto, and having a crotch portion that is positioned in the crotch when worn, an ventral portion positioned on the ventral side of the wearer than the crotch portion, and a dorsal portion positioned on the dorsal side of the wearer than the crotch portion, having an absorbent core extending along the longitudinal direction from the ventral portion through the crotch portion to the dorsal portion, and having a pair of fastening tapes extending outward in the transverse direction from the transverse side of the dorsal portion, wherein the absorbent core has a narrowing region in the longitudinal outward end region of the dorsal portion where the width of the absorbent core gradually decreases as it moves outward in the longitudinal direction, the dorsal portion has a dorsal elastic region in the longitudinal end region that is expandable and contractible in the transverse direction, and the dorsal elastic region has a plurality of elastic members that extend in the transverse direction and are spaced apart along the longitudinal direction and arranged in an extended state, [2] An absorbent article in which, in a plan view of the absorbent article, at least a portion of the narrow region and at least a portion of the back elastic region overlap, and of the elastic members constituting the back elastic region, the one end of which overlaps with the narrow region is located on one side edge of the back elastic region and the other end is located on the other side edge of the back elastic region, and the space between the one end and the other end is continuous, and when the absorbent article is viewed along the longitudinal direction, at least a portion of the narrow region and at least a portion of the fastening tape are in the same position. [2] The absorbent article according to [1], wherein the absorbent core has a narrow region in the end area of ​​the back portion in which the width of the absorbent core decreases continuously toward the end edge in the longitudinal direction.

[0056] [3] The absorbent article according to [1] or [2], wherein, in a plan view of the absorbent article, the entire area of ​​the narrow region and at least a portion of the dorsal elastic region overlap. [4] The absorbent article according to any one of [1] to [3], wherein the fastening tape has a tapered portion in which the width gradually decreases from the base to the tip, and when the absorbent article is viewed along the longitudinal direction, at least a portion of the tapered portion and at least a portion of the narrow region are in the same position. [5] The absorbent article according to [4], wherein the length of the narrow region along the longitudinal direction is W1, and when the absorbent article is viewed along the longitudinal direction X, the length of the portion of the narrow region that overlaps with the tapered portion along the longitudinal direction X is W2, and the percentage of W2 to W1, W2 / W1 × 100, is 50% or more. [6] The absorbent article according to any one of [1] to [5], wherein the dorsal elastic region has a first elastic region located on the outward side in the longitudinal direction and not overlapping with the absorbent core in a plan view of the absorbent article, and a second elastic region located on the inward side in the longitudinal direction than the first elastic region and overlapping with the absorbent core in a plan view of the absorbent article, and the first elastic region and the second elastic region satisfy the following relationship (1). １ ≧σ ２ (1) In formula (1), σ １ This represents the lateral tensile stress per unit width of the first elastic region. ２ This represents the lateral tensile stress of the second elastic region per unit width.

[0057] [7] σ １ / σ ２The absorbent article according to [6], wherein the value of is 1.1 or more and 3.0 or less. [8] The absorbent article according to any one of [1] to [7], wherein the dorsal elastic region has a first elastic region located on the outward side in the longitudinal direction and not overlapping with the absorbent core in a plan view of the absorbent article, and a second elastic region located on the inward side in the longitudinal direction than the first elastic region and overlapping with the absorbent core in a plan view of the absorbent article, and the spacing D2 of the elastic members located in the second elastic region along the longitudinal direction is wider than the spacing D1 of the elastic members located in the first elastic region along the longitudinal direction. [9] The absorbent article according to [8], wherein the value of D1 / D2 is 0.3 or more and 0.9 or less.

[10] The absorbent article according to any one of [1] to [9], wherein a plurality of the absorbent articles are folded in half at the longitudinal center and housed in a single package, and in the state as it is removed from the package, the width of the ventral portion is greater than the width of the dorsal portion.

[11] The absorbent article according to any one of [1] to

[10] , wherein the outer surface of the ventral portion has a different design than the outer surface of the dorsal portion, a plurality of the absorbent articles are folded in half at the longitudinal center and housed in a single package, and when viewed from the dorsal side in the state as it is removed from the package, a part of the design applied to the ventral portion is visible.

[12] The absorbent article according to any one of [1] to

[11] , wherein a plurality of the absorbent articles are folded in half at the center in the longitudinal direction and housed in a single package, and when viewed from the dorsal side in the state as it has been removed from the package, a part of the ventral side is visible, and when the absorbent article is viewed along the longitudinal direction, the visible part of the ventral side and at least a part of the narrow region are in the same position.

[0058]

[13] The absorbent article according to any one of [1] to

[12] , wherein the outer surface of the ventral portion has a different design from the outer surface of the dorsal portion, a plurality of the absorbent articles are folded in half at the longitudinal center and housed in a single package, and when viewed from the dorsal side in the state as it has been removed from the package, the entire dorsal elastic region overlaps with the design on the ventral portion.

[14] The absorbent article according to any one of [1] to

[13] , wherein both lateral edges of the narrow region are arc-shaped.

[15] The absorbent article according to any one of [1] to

[14] , wherein the dorsal elastic region has a first elastic region located on the outward side in the longitudinal direction and not overlapping with the absorbent core in a plan view of the absorbent article, and a second elastic region located on the inward side in the longitudinal direction than the first elastic region and overlapping with the absorbent core in a plan view of the absorbent article, and when the width of the first elastic region is L1 and the width of the second elastic region is L2, the value of L1 / L2 is 2.0 or more and 5.0 or less.

[16] An absorbent article having a longitudinal direction extending from the wearer's ventral side through the crotch to the dorsal side and a transverse direction perpendicular thereto, and having a crotch portion that is positioned in the crotch when worn, an ventral portion positioned on the wearer's ventral side of the crotch portion, and a dorsal portion positioned on the wearer's dorsal side of the crotch portion, having an absorbent core extending along the longitudinal direction from the ventral portion through the crotch portion to the dorsal portion, and having a pair of fastening tapes extending outward in the transverse direction from the transverse side of the dorsal portion, wherein the dorsal portion has a dorsal elastic region that is expandable in the transverse direction at the end region in the longitudinal direction, the dorsal elastic region has a plurality of elastic members that extend in the transverse direction and are spaced apart along the longitudinal direction and arranged in an extended state, and in a plan view of the absorbent article, the absorbent core has an overlapping region that overlaps with at least a part of the dorsal elastic region. An absorbent article wherein, among the elastic members constituting the dorsal elastic region, the one overlapping with the overlapping region has one end located on one side edge of the dorsal elastic region and the other end located on the other side edge of the dorsal elastic region, and the space between the one end and the other end is continuous, and when the absorbent article is viewed along the longitudinal direction, at least a part of the overlapping region and at least a part of the fastening tape are in the same position.

[0059] According to the absorbent article of the present invention, the operation of pinching the fastening tape and stretching the back side of the diaper can be easily performed, and a tightening force suitable for preventing leakage can be generated without compromising the feeling of wearing it.

Claims

1. An absorbent article having a longitudinal direction extending from the wearer's ventral side through the crotch area to the back and a transverse direction perpendicular thereto, and comprising an inseam portion positioned in the crotch area when worn, an ventral portion positioned on the wearer's ventral side of the inseam portion, and a dorsal portion positioned on the wearer's back side of the inseam portion, having an absorbent core extending along the longitudinal direction from the ventral portion through the crotch area to the dorsal portion, and having a pair of fastening tapes extending outward in the transverse direction from the transverse side portion of the dorsal portion, wherein the absorbent core has a narrowing region in the longitudinal outward end region of the dorsal portion where the width of the absorbent core gradually decreases as it moves outward in the longitudinal direction, the dorsal portion has a dorsal elastic region in the longitudinal end region that is expandable and contractible in the transverse direction, and the dorsal elastic region has a plurality of elastic members that extend in the transverse direction and are spaced apart along the longitudinal direction and arranged in an extended state, An absorbent article wherein, in a plan view of the absorbent article, at least a portion of the narrow region and at least a portion of the back elastic region overlap, and of the elastic members constituting the back elastic region, the one end of which overlaps with the narrow region is located on one side edge of the back elastic region and the other end is located on the other side edge of the back elastic region, and the space between the one end and the other end is continuous, and when the absorbent article is viewed along the longitudinal direction, at least a portion of the narrow region and at least a portion of the fastening tape are in the same position.

2. The absorbent article according to claim 1, wherein the absorbent core has a narrowing region at the end area of ​​the dorsal side portion in which the width of the absorbent core continuously decreases toward the longitudinal edge.

3. The absorbent article according to claim 1 or 2, wherein, in a plan view of the absorbent article, the entire area of ​​the narrow region and at least a portion of the dorsal elastic region overlap.

4. The fastening tape has a tapered portion in which the width gradually decreases from the base to the tip, and when the absorbent article is viewed along the longitudinal direction, at least a part of the tapered portion and at least a part of the narrow region are in the same position, as described in any one of claims 1 to 3.

5. The absorbent article according to claim 4, wherein the length of the narrow region along the vertical direction is W1, and when the absorbent article is viewed along the vertical direction X, the length of the portion of the narrow region that overlaps with the tapered portion along the vertical direction X is W2, and the percentage of W2 to W1, W2 / W1 × 100, is 50% or more.

6. The absorbent article according to any one of claims 1 to 5, wherein the dorsal elastic region has a first elastic region located on the outward side in the longitudinal direction and not overlapping with the absorbent core in a plan view of the absorbent article, and a second elastic region located on the inward side in the longitudinal direction than the first elastic region and overlapping with the absorbent core in a plan view of the absorbent article, and the first elastic region and the second elastic region satisfy the following relationship (1): σ １ ≧σ ２ (1) In formula (1), σ １ This represents the lateral tensile stress per unit width of the first elastic region. ２ This represents the lateral tensile stress of the second elastic region per unit width.

7. σ １ / σ ２ The absorbent article according to claim 6, wherein the value of is 1.1 or more and 3.0 or less.

8. The absorbent article according to any one of claims 1 to 7, wherein the dorsal elastic region has a first elastic region located on the outward side in the longitudinal direction and not overlapping with the absorbent core in a plan view of the absorbent article, and a second elastic region located on the inward side in the longitudinal direction than the first elastic region and overlapping with the absorbent core in a plan view of the absorbent article, wherein the spacing D2 of the elastic members located in the second elastic region along the longitudinal direction is wider than the spacing D1 of the elastic members located in the first elastic region along the longitudinal direction.

9. The absorbent article according to claim 8, wherein the value of D1 / D2 is 0.3 or more and 0.9 or less.

10. The absorbent article according to any one of claims 1 to 9, wherein a plurality of the absorbent articles are folded in half at the longitudinal center and housed in a single package, and in the state as removed from the package, the width of the ventral portion is greater than the width of the dorsal portion.

11. The absorbent article according to any one of claims 1 to 10, wherein the outer surface of the ventral portion has a different design from the outer surface of the dorsal portion, a plurality of the absorbent articles are folded in half at the longitudinal center and housed in a single package, and when viewed from the dorsal side in the state as it has been removed from the package, a part of the design applied to the ventral portion is visible.

12. The absorbent article according to any one of claims 1 to 11, wherein a plurality of the absorbent articles are folded in half at the longitudinal center and housed in a single package, a portion of the ventral portion is visible when viewed from the dorsal side in the state as removed from the package, and when the absorbent article is viewed along the longitudinal direction, the visible portion of the ventral portion and at least a portion of the narrow region are in the same position.

13. The absorbent article according to any one of claims 1 to 12, wherein the outer surface of the ventral portion has a different design from the outer surface of the dorsal portion, a plurality of the absorbent articles are folded in half at the longitudinal center and housed in a single package, and when viewed from the dorsal side in the state as it has been removed from the package, the entire dorsal elastic region overlaps with the design on the ventral portion.

14. The absorbent article according to any one of claims 1 to 13, wherein both lateral edges of the narrow region are arc-shaped.

15. The absorbent article according to any one of claims 1 to 14, wherein the dorsal elastic region comprises a first elastic region located on the outward side in the longitudinal direction and not overlapping with the absorbent core in a plan view of the absorbent article, and a second elastic region located on the inward side in the longitudinal direction than the first elastic region and overlapping with the absorbent core in a plan view of the absorbent article, and the width of the first elastic region is L1 and the width of the second elastic region is L2, and the value of L1 / L2 is 2.0 or more and 5.0 or less.

16. An absorbent article having a longitudinal direction extending from the wearer's ventral side through the crotch to the dorsal side and a transverse direction perpendicular thereto, and having an inseam portion that is positioned in the crotch when worn, an ventral portion positioned on the wearer's ventral side of the inseam portion, and a dorsal portion positioned on the wearer's dorsal side of the inseam portion, having an absorbent core extending along the longitudinal direction from the ventral portion through the crotch portion to the dorsal portion, and having a pair of fastening tapes extending outward in the transverse direction from the transverse side portion of the dorsal portion, wherein the dorsal portion has a dorsal elastic region that is expandable in the transverse direction at the end region in the longitudinal direction, the dorsal elastic region has a plurality of elastic members that extend in the transverse direction and are spaced apart along the longitudinal direction and arranged in an extended state, and in a plan view of the absorbent article, the absorbent core has an overlapping region that overlaps with at least a part of the dorsal elastic region. An absorbent article wherein, among the elastic members constituting the dorsal elastic region, the one overlapping with the overlapping region has one end located on one side edge of the dorsal elastic region and the other end located on the other side edge of the dorsal elastic region, and the space between the one end and the other end is continuous, and when the absorbent article is viewed along the longitudinal direction, at least a part of the overlapping region and at least a part of the fastening tape are in the same position.

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