Disposable diaper

Abstract

In planar view, this disposable diaper (10) has a central line (O) which, running in the longitudinal direction (L) of a pair of pieces of fastening tape (90), overlaps with an elastic waist part (85) and does not overlap with an absorbent body (40). The length (W1) of the elastic waist part (85) in the width direction (W) is longer than the length (W2) of the absorbent body (40) in the width direction (W). The elongation rate of a region (A) of the elastic waist part (85) positioned to the outside of the absorbent body (40) in the width direction (W) is different from the elongation rate of a region (B) of the elastic waist part (85) positioned to the inside of the absorbent body (70) in the width direction (W).

Description

Disposable diapers This invention relates to disposable diapers. Conventionally, in tape-type disposable diapers, a technique is known to provide a waist-stretchable section that expands in the width direction around the wearer's waist in order to maintain a good fit around the wearer's waist. Japanese Patent Application Publication No. 10-225481 However, with the conventional disposable diapers mentioned above, the rigidity of the absorbent material hinders the stretching of the waist area, making it difficult to properly fit the diaper around the wearer's waist. This can lead to leakage of waste from the wearer's back. Therefore, the present invention has been made in view of the above-mentioned problems, and aims to provide a tape-type disposable diaper that can improve the fit around the wearer's waist. The first feature of the present invention is a disposable garment having a front waist area, a rear waist area, and a crotch area located between the front waist area and the rear waist area, having a longitudinal direction from the front waist area toward the rear waist area and a width direction perpendicular to the longitudinal direction, extending along the width direction in the rear waist area and fastened to the front waist area, an absorbent body extending across the crotch area toward at least one of the front waist area and the rear waist area, and a waist elastic portion disposed between the pair of fasteners and expanding and contracting in the width direction. The gist of this invention is a diaper in which, in a plan view of the disposable diaper, the longitudinal centerlines of the pair of fastening tapes are configured to overlap with the waist elastic portion but not with the absorbent material, the length of the waist elastic portion in the width direction is configured to be longer than the length of the absorbent material in the width direction, and the elongation rate of the region of the waist elastic portion located outside the absorbent material in the width direction is different from the elongation rate of the region of the waist elastic portion located inside the absorbent material in the width direction. This is a developed plan view of the disposable diaper according to the present embodiment. It is a cross-sectional view of the disposable diaper along the F1-F1 line shown in FIG. 1. It is a cross-sectional view of the disposable diaper along the F2-F2 line shown in FIG. 1. It is a diagram schematically showing the wearing mode of the disposable diaper according to the present embodiment on the wearer. FIG. 4(a) shows a state where the fastening tape is fixed to the front torso area and the wearer is lying down, and FIG. 4(b) shows a state where the fastening tape is fixed to the front torso area and the wearer is awake. Next, an embodiment of the disposable diaper 10 according to the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic, and the ratios of the respective dimensions are different from the actual ones. Therefore, specific dimensions and the like should be determined in consideration of the following description. Also, there may be portions where the dimensional relationships and ratios are different between the drawings. (1) Overall schematic configuration of the disposable diaper FIG. 1 is a developed plan view of the disposable diaper 10 according to the present embodiment. FIG. 2 is a cross-sectional view of the disposable diaper along the F1-F1 line shown in FIG. 1. FIG. 3 is a cross-sectional view of the disposable diaper along the F2-F2 line shown in FIG. 1. The developed view shown in FIG. 1 is a view in a state where the elastic members of the leg stretch portion 75 and the leg side stretch portion 80 are extended until wrinkles such as the top sheet 50 and the side flap 70 constituting the disposable diaper are not formed. As shown in FIG. 1, the disposable diaper 10 has a front torso area 20, an inseam area 25, and a rear torso area 30. The front torso area 20 is a portion that contacts the front torso portion (abdomen) of the wearer. Also, the rear torso area 30 is a portion that contacts the rear torso portion (back) of the wearer. The inseam area 25 is located between the front torso area 20 and the rear torso area 30. In addition, a pair of leg openings 35 are formed in the disposable diaper 10. The leg openings 35 are provided at the outer edge (outer end in the width direction W) of the disposable diaper 10, and are portions that are arranged along the circumference of the wearer's legs when the disposable diaper 10 is worn on the wearer. In this embodiment, the direction from the front waist area 20 to the rear waist area 30 of the disposable diaper 10 is called the longitudinal direction L, and the direction perpendicular to the longitudinal direction L is called the width direction W. The disposable diaper 10 has an absorbent body 40. The absorbent body 40 has an absorbent core 40a and a core wrap 40b. The absorbent core 40a spans the crotch area 25 and extends from the crotch area 25 toward at least one of the front torso area 20 and the rear torso area 30. The absorbent core 40a is similar to that of conventional disposable diapers and can be appropriately constructed using known components and materials such as crushed pulp and superabsorbent polymer. The absorbent core 40a is wrapped in a sheet-like core wrap 40b. The core wrap 40b is a sheet that covers the absorbent core 40a. The rear edge of the absorbent core 40a and the rear edge of the core wrap 40b are approximately coincident. More specifically, the distance between the rear edge of the absorbent core 40a and the rear edge of the core wrap 40b is 5 mm or less. The absorbent core 40a has a low basis weight region 110 formed therein, where the basis weight of the absorbent material is lower than in other parts of the absorbent core 40a. The low basis weight region 110 is located in the center of the width direction W of the rear edge of the absorbent core 40a. The width of the low basis weight region 110 in the width direction W increases towards the rear edge of the absorbent core 40a. More specifically, the low basis weight region 110 is wedge-shaped in a plan view of the disposable diaper 10. As shown in Figures 2 and 3, the absorbent body 40 is provided with a liquid-permeable top sheet 50 on its surface side (skin-facing side). The absorbent body 40 is also provided with a liquid-impermeable back sheet 60a on its back side (non-skin-facing side). An outer sheet 60 is provided on the back side of the back sheet 60a. As shown in Figures 1 and 2, side flaps 70 are provided on the outer edges of the absorbent material 40. The side flaps 70 span the front waist area 20, the crotch area 25, and the rear waist area 30, and are positioned outside the absorbent material 40 in the width direction W. The side flap 70 is made of one or more layers of nonwoven fabric. As shown in Figure 2, the side flap 70 is located on the skin-facing side of the absorbent core 40a and extends outward in the width direction W from the absorbent core 40a. As shown in Figure 2, the inner edge of the side flap 70 (the inner end in the width direction W) covers the absorption core 40a, and the outer edge of the side flap 70 is positioned outside the absorption core 40a in the width direction W. As shown in Figure 1, the side flap 70 is provided with a pair of leg extension sections 75 that are positioned inward in the width direction W from the leg opening 35 and are extendable in the longitudinal direction L. The leg extension sections 75 only need to be configured to extend and retract the leg opening 35 in the longitudinal direction L, and may be positioned along the leg opening 35, or a portion of them may be positioned at an angle to the leg opening 35. Here, as shown in Figure 1, the pair of leg extension sections 75 may be configured to widen outward in the width direction W as they approach the rear torso area 30. Furthermore, as shown in Figure 1, a pair of leg side stretchable sections 80 extending along the longitudinal direction L are provided on the inside of the pair of leg stretchable sections 75 in the width direction W. The leg side stretchable sections 80 are provided at the inner ends of the side flaps 70 in the width direction W and are upright stretchable gathers. Furthermore, the disposable diaper 10 includes a crotch elastic portion 200 positioned in the area overlapping the absorbent material 40 in the crotch area 25. The crotch elastic portion 200 is configured to maintain a flatter shape in a part of the crotch area 25 when the disposable diaper 10 is worn, compared to other parts of the absorbent material 40. The crotch elastic portion 200 is configured to be stretchable at least in the longitudinal direction L or the width direction W. As shown in Figure 1, a first notch 115 and a second notch 125 are formed in the absorbing core 40a in the crotch area. The first notch 115 and the second notch 125 are slits formed in the absorber 40. A slit is a portion where no absorbent material is present. The first notch 115 and the second notch 125 are notch shapes that extend inward in the width direction W from the outer edge of the absorbing core 40a. Furthermore, the disposable diaper 10 does not necessarily have to have a crotch elastic portion 200, a first notch 115, and a second notch 125. The fastening tapes 90 are a pair and are configured to hold the disposable diaper 10 to the wearer's body by extending along the width direction W in the rear waist area 30 and being fastened to the non-skin-facing surface of the front waist area 20. The fastening tape 90 is attached to the area of ​​the side flap 70 corresponding to the rear body area 30. Each of the fastening tapes 90 comprises a base sheet 91 connected to the side flap 70 and a hook sheet 92 fixed to the base sheet 91 and provided with a plurality of engaging hooks (not shown) as engaging members. The hook sheet 92 is the area where the engaging members are provided. Here, as shown in Figure 1, the absorber 40 (or absorbent core 40a) may be positioned further inward in the longitudinal direction L than the inner end 92E1 of the hook sheet 92 in the longitudinal direction L. The target portion 95 is provided on the non-skin-facing side of the outer sheet 60 in the front torso area 20. The target portion 95 is configured so that the engaging hook of the fastening tape 90 catches on it, and functions as a loop in a hook-and-loop locking system. For example, an air-through nonwoven fabric can be used as the target portion 95. Alternatively, the disposable diaper 10 may be configured so that the fastening tape 90 is attached to the outer sheet 60 in the front waist area 20 without having a target portion 95. Furthermore, as shown in Figures 1 and 2, a waist-length expandable portion 85 is provided between a pair of fastening tapes 90 in the width direction W, and is expandable in the width direction W. The waist-length expandable portion 85 is configured to contract the space between the fastening tapes 90 in the width direction W. In this embodiment, the waist-area stretchable portion 85 is made of an elastic sheet. The waist-area stretchable portion 85 is a part that stretches substantially in the width direction W, and is a concept that excludes the part in which the elastic sheet is positioned when no stretching force is exerted. Therefore, the outer edge of the waist-area stretchable portion 85, which will be described later, is not the outer edge of the elastic sheet, but the outer edge of the stretchable portion. In the disposable diaper 10 according to this embodiment, the waist elastic portion 85 has a basis weight of 20 to 45 g / m². ２A stretchable film was used. However, the waist stretchable portion 85 may be made of other components such as multiple elastic threads. The waist stretchable portion 85 is stretched to a predetermined ratio relative to its length in the non-stretched state (natural state), and then bonded to the outer sheet 60 by hot melt adhesive or heat treatment. The waist-length stretchable portion 85 extends from the center of the width direction W of the disposable diaper 10 toward both outer sides in the width direction W, and is composed of a continuous sheet extending in the width direction W. The rear end edge (outer end in the longitudinal direction L) 85E2 of the waist-length stretchable portion 85 is located in front of the rear end edge 10E2 of the disposable diaper 10. The rear end edge 85E2 of the waist-length stretchable portion 85 may coincide with the rear end edge 10E2 of the disposable diaper 10. Furthermore, the front edge 85E1 of the waist elastic portion 85 is located in front of the rear edge 40E2 of the absorbent body 40 (or the absorbent core 40a and core wrap 40b) and behind the rear edge 75E2 of the leg elastic portion 75. Therefore, in a plan view of the disposable diaper 10, at least a portion of the waist elastic portion 85 is configured to overlap the absorbent body 40 (or the absorbent core 40a). Here, the thickness of the absorbent material 40 in the area overlapping with the waist elastic portion 85 may be configured to be thinner than the thickness of the absorbent material 40 in other areas. Furthermore, the waist-length expandable portion 85 is configured to straddle the rear edge of the absorbent body 40 (or the absorbent core 40a and core wrap 40b) and extend further back than the rear edge of the absorbent body 40 (or the absorbent core 40a and core wrap 40b). The outer edge 85WO of the waist elastic portion 85 is located inward in the width direction W from the inner edge (inner end in the width direction W) of the fastening tape 90. The waist elastic portion 85 and the fastening tape 90 are spaced apart in the width direction W. As shown in Figure 1, the waist-length expandable portion 85 has a first region 851 extending inward in the width direction W from both outer edges 85WO of the waist-length expandable portion 85, a second region 852 extending inward in the width direction W from the inner edge 851WI of the first region 851, and a third region 853 extending inward in the width direction W from the inner edge 852WI of the second region 852. The first region 851, the second region 852, and the third region 853 are connected in the width direction W. Therefore, there are no non-stretchable regions that do not expand or contract in the width direction W between the first region 851 and the second region 852, and between the second region 852 and the third region 853. Furthermore, the inner edge 851WI of the first region 851 coincides with the outer edge 852WO of the second region 852, and the inner edge 852WI of the second region 852 coincides with the outer edge 853WO of the third region 853. The first region 851, the second region 852, and the third region 853 are configured to have different elongation rates in the width direction W. Specifically, the elongation rate in the width direction W of the second region 852 is lower than that of the first region 851. Also, the elongation rate in the width direction W of the third region 853 is higher than that of the second region 852. Furthermore, the relationship between the elongation rate in the width direction W of the first region 851 and the elongation rate in the width direction W of the third region 853 may be the same, or either may be higher. Preferably, the elongation rate in the width direction W of the third region 853 is higher than the elongation rate in the width direction W of the first region 851. The outer edge 851WO of the first region 851 is located outside the outer edge of the absorption core 40a in the width direction W. The inner edge 851WI of the first region 851 is located inside the outer edge of the absorption core 40a in the width direction W. Therefore, the first region 851 is positioned straddling the outer edge of the absorption core 40a. Furthermore, at least a portion of the first region 851 is located outside the width direction W of the absorption core 40a, and the inner edge of the first region 851 may be located outside the width direction W of the absorption core 40a, or the inner edge of the first region 851 may coincide with the outer edge of the absorption core 40a. The second region 852 is located between the first region 851 and the third region 853. Preferably, the second region 852 is located inward in the width direction W from the outer edge of the absorption core 40a. The third region 853 is positioned across the center of the width W of the disposable diaper 10. Preferably, the third region 853 overlaps with at least a portion of the low-profile region 110 in a plan view of the disposable diaper 10. In the disposable diaper 10 according to this embodiment, the waist-length stretchable portion 85 may be symmetrical or asymmetrical with respect to a center line that passes through the center of the width direction W of the disposable diaper 10 and extends in the longitudinal direction L. For example, both the left and right first regions 851 may straddle the outer edge of the absorption core 40a, or one of the first regions 851 may straddle the outer edge of the absorption core 40a. Also, both the left and right second regions 852 may be positioned inward in the width direction W from the outer edge of the absorption core 40a, or one of the second regions 852 may be positioned inward in the width direction W from the outer edge of the absorption core 40a. Furthermore, the disposable diaper 10 according to this embodiment may have an area outside the first area 851 in the width direction W, having an elongation rate lower than that of the first area 851. As shown in Figure 3, the waist-area expandable portion 85 is located on the non-skin-facing side of the absorbent core 40a. In this embodiment, the waist-area expandable portion 85 is positioned between the outer sheet 60 and the back sheet 60a. However, in a configuration in which the core wrap 40b extends outward in the longitudinal direction L than the absorbent core 40a, the waist extension portion 85 may be positioned between the core wrap 40b and the back sheet 60a or outer sheet 60. The position of the waist-area elastic portion 85 is not particularly limited. Furthermore, in areas where the absorbent material 40 is not placed, the waist-area elastic portion 85 may be positioned between the side flap 70 and the back sheet 60a or outer sheet 60, as shown in Figure 2. As shown in Figure 1, in a plan view of the disposable diaper 10, the center line O in the longitudinal direction L of the pair of fastening tapes 90 is configured to overlap with the waist elastic portion 85 and not overlap with the absorbent material 40. Furthermore, the length W1 in the width direction W of the waist-length stretchable portion 85 is configured to be longer than the length W2 in the width direction W of the absorbent body 40 (or the length W in the width direction W of the absorbent core 40a). Furthermore, the stretching rate of region A located outside the absorbent material 40 (or absorbent core 40a) in the width direction W of the waist-stretchable portion 85 is configured to be different from the stretching rate of region B located inside the absorbent material 40 (or absorbent core 40a) in the width direction W of the waist-stretchable portion 85. In other words, as shown in Figure 1, region A is located outside the width direction W relative to the imaginary line VL1, and region B is located inside the width direction W relative to the imaginary line VL1. Here, the imaginary line VL1 is a line extending from the outer edge of the absorbent material 40 in the portion of the absorbent material 40 with the longest width direction W, along the longitudinal direction L, to the rear edge 10E2 of the disposable diaper 10. For example, the stretching rate of region A located outside the width direction W of the absorbent material 40 (or absorbent core 40a) in the waist-length stretchable portion 85 may be configured to be greater than the stretching rate of region B located inside the width direction W of the absorbent material 40 (or absorbent core 40a) in the waist-length stretchable portion 85, or it may be configured to be less than the stretching rate of region B located inside the width direction W of the absorbent material 40 (or absorbent core 40a) in the waist-length stretchable portion 85. Furthermore, as shown in Figure 1, in a plan view of the disposable diaper 10, the waist elastic portion 85 and the pair of leg elastic portions 75 may be configured so as not to overlap. On the other hand, as shown in Figure 1, in a plan view of the disposable diaper 10, the waist elastic portion 85 and the pair of leg side elastic portions 80 may be configured to overlap. Furthermore, as shown in Figure 1, the inner end (front edge) 85E1 of the waist-length expandable portion 85 in the longitudinal direction L may be positioned further inward in the longitudinal direction L than the inner end 92E1 of the hook sheet 92 in the longitudinal direction L. Furthermore, as shown in Figure 1, the rear end edge 85E2 of the waist-length expandable portion 85 may be positioned further outward in the longitudinal direction L than the outer end 92E2 of the hook sheet 92 in the longitudinal direction L. In this embodiment of the disposable diaper 10, the waist elastic portion 85 is configured to expand and contract in the width direction W, but the waist elastic portion 85 may also be configured to expand and contract in both the width direction W and the longitudinal direction L. Furthermore, the waist-length elastic portion 85 and the absorbent body 40 are joined together via an adhesive. The adhesive joining the waist-length elastic portion 85 and the absorbent body 40 is arranged in multiple rows continuously in the longitudinal direction L, and each row is arranged overlapping in the width direction W. Specifically, examples of adhesives include configurations in which multiple rows of spiral shapes are arranged in the longitudinal direction L and these rows overlap in the width direction W, and configurations in which multiple rows of wave shapes are arranged that oscillate in the width direction W and are continuous in the longitudinal direction L and these rows overlap in the width direction W. In this embodiment of the disposable diaper 10, the waist-length stretchable portion 85 and the absorbent core 40a are not directly joined, but are indirectly joined via the back sheet 60a and the core wrap 40b. It is preferable that the adhesives for bonding the waist elastic portion 85 to the back sheet 60a, the adhesives for bonding the back sheet 60a to the core wrap 40b, and the adhesives for bonding the core wrap 40b to the absorbent core 40a are arranged in multiple rows continuously in the longitudinal direction L, and that each row overlaps in the width direction W. In this specification, "elongation rate" means the degree of elongation and shall be measured by the following method. Firstly, if the disposable diaper 10 is sealed in a package, remove the disposable diaper 10 from the package. Secondly, the area where the elastic sheet constituting the waist-length stretchable portion 85 is placed is cut out to prepare the sample to be measured. The "natural state" is defined as the state in which such a sample is left for 24 hours in an atmosphere of 20°C ± 2°C and a relative humidity of 60% ± 5% RH. Thirdly, in this natural state, points (marks) are intermittently made along the width direction W at the midpoint in the longitudinal direction L, between the end of the stretchable sheet on the side of the absorbent core 40a (front end) and the end of the stretchable sheet on the side of the waist opening (rear end). These points are made with the center of the width direction W of the stretchable sheet as the reference point, and are made at 5 mm intervals to the left and right of this reference point in the width direction W, up to the ends of the stretchable sheet sample in the width direction W. Fourth, measure the distance between adjacent points. This distance is defined as the length in the natural state (since marks are made at 5 mm intervals, this distance is 5 mm). Fifth, measure the distance between the marks mentioned earlier when the material is stretched from its natural state to a state where wrinkles caused by the elastic material are no longer visible on the stretchable sheet. Sixth, the elongation rate of each part is calculated using the formula: Elongation rate (times) = (distance between marks in the elongated state) / (distance between marks in the natural state). (2) Method for manufacturing disposable diapers 10 Next, an example of a method for manufacturing the disposable diaper 10 according to this embodiment will be described. Note that existing methods can be used for methods not described in this embodiment. Furthermore, the manufacturing method described below is just one example, and the diaper can be manufactured by other methods. The manufacturing method for the disposable diaper 10 includes at least a component forming step, a component placement step, a leg area forming step, and a cutting step. In the component formation process, components that make up the disposable diaper 10 are formed. Specifically, for example, absorbent materials are laminated to form an absorbent body 40, or a fastening tape 90 is formed. In the component placement process, components that make up the disposable diaper 10, such as the stretchable sheet that makes up the waist stretchable part 85, the web that makes up the top sheet 50, the leak-proof sheet, the absorbent body 40, and the leg stretchable parts 75, are placed on the web that makes up the back sheet 60a. The following are examples of methods for changing the stretching rate of the waist elastic portion 85. Before attaching the waist-length stretchable portion 85 to the backsheet 60a, etc., the waist-length stretchable portion 85 is stretched in the width direction W by a gear. When the gear is stretched, the gear stretching is weakened in areas where the stretching rate is low (for example, the second area 852). The gear stretching is strengthened in areas where the stretching rate is high (for example, the first area 851 and the third area 853). The strength of the gear stretching can be adjusted by changing the depth of the gear's protrusions, the pitch of the gear's protrusions, and the number of gear stretches. The stretching rate in strongly stretched areas will be relatively high, and the stretching rate in weakly stretched areas will be relatively low. The leg section forming process involves cutting the top sheet 50, the outer sheet 60, and the back sheet 60a. This forms the leg openings 35 that are positioned around the wearer's legs. In the cutting process, the continuous material containing the top sheet 50, back sheet 60a, absorbent material 40, etc., is cut along the width direction W to the size of a single product. This is how a disposable diaper 10 is manufactured. (3) Action and Effects In the disposable diaper 10 according to this embodiment, the length W1 in the width direction W of the waist elastic portion 85 is configured to be longer than the length W2 in the width direction W of the absorbent material 40 (or absorbent core 40a), and in a plan view of the disposable diaper 10, the center line O in the longitudinal direction L of the fastening tape 90 is configured to overlap with the waist elastic portion 85 but not with the absorbent material 40. Therefore, when putting on the disposable diaper 10, the problem of the rigidity of the absorbent material 40 hindering the expansion and contraction of the waist elastic portion 85 when an assistant pulls the fastening tape 90 can be resolved, and the disposable diaper 10 can be fitted securely around the wearer's waist. Figure 4 schematically shows how the disposable diaper 10 is attached to the wearer. Figure 4(a) shows the fastening tape 90 fastened to the front waist area 20 and the wearer lying down, while Figure 4(b) shows the fastening tape 90 fastened to the front waist area 20 and the wearer standing up. When the tape-type disposable diaper 10 is worn on the wearer, the caregiver places the wearer's back on the rear body circumferential region 30 of the disposable diaper 10, pulls the fastening tape 90 outward in the width direction W, and fastens the fastening tape 90 to the front body circumferential region 20. As shown in Fig. 4(a), in such a case, the body pressure of the wearer is applied to the rear body circumferential region 30 of the disposable diaper 10. In such a case, since the force generated when the caregiver pulls the fastening tape 90 outward in the width direction W does not reach the region B located inside the absorber 40 (absorption core 40a) in the width direction W at the waist circumferential elastic part 85, when the wearer gets up after wearing the disposable diaper 10, a gap may occur between the wearer and the disposable diaper 10. Here, in the disposable diaper 10 according to the present embodiment, in the case where the elongation rate of the region A located outside the absorber 40 (or absorption core 40a) in the width direction W at the waist circumferential elastic part 85 is configured to be larger than the elongation rate of the region B located inside the absorber 40 (absorption core 40a) in the width direction W at the waist circumferential elastic part 85, when the wearer gets up, the region B is stretched in the width direction W by the region A having a larger elongation rate than the region B, so that the problem that a gap may occur between the wearer and the disposable diaper 10 can be solved. On the other hand, in the disposable diaper 10 according to the present embodiment, in the case where the elongation rate of the region A located outside the absorber 40 (or absorption core 40a) in the width direction W at the waist circumferential elastic part 85 is configured to be smaller than the elongation rate of the region B located inside the absorber 40 (absorption core 40a) in the width direction W at the waist circumferential elastic part 85, when the disposable diaper 10 is worn on the wearer, even if the caregiver pulls the fastening tape 90 with a weak force, since the amount of elongation of the region A in the width direction W becomes large, when the wearer gets up after wearing the disposable diaper 10, the region B is stretched in the width direction W by the region A and a gap may occur between the wearer and the disposable diaper 10, and the problem can be solved. In addition, in the plan view of the disposable diaper 10 according to the present embodiment, since the waist stretchable portion 85 and the pair of leg stretchable portions 75 are configured not to overlap, after the disposable diaper 10 is worn, the waist stretchable portion 85 is pulled inward in the longitudinal direction L following the movement of the wearer's legs, and it is possible to avoid a situation where the waist stretchable portion 85 does not fit firmly around the wearer's waist. In addition, in the plan view of the disposable diaper 10 according to the present embodiment, since the waist stretchable portion 85 and the pair of leg side stretchable portions 80 are configured to overlap, it is possible to suppress a situation where the disposable diaper 10 is pulled up toward the body circumference stretchable portion 85 and the wearer's body and the disposable diaper 10 are separated from each other. In addition, in the plan view of the disposable diaper 10 according to the present embodiment, the waist stretchable portion 85 and the absorber 40 (or the absorbent core 40a) are configured to overlap, and the thickness of the absorber 40 (or the absorbent core 40a) in the region overlapping the waist stretchable portion 85 is thinner than the thickness of the absorber 40 (or the absorbent core 40a) in other regions. Therefore, the absorber 40 (or the absorbent core 40a) can be pressed by the waist stretchable portion 85 to improve the fit with the wearer. In addition, in the disposable diaper 10 according to the present embodiment, since the absorber 40 (or the absorbent core 40a) is disposed inside the longitudinal direction L of the end portion 92E1 inside the longitudinal direction L of the hook sheet 92, the influence on the force region B generated when the fastening tape 90 is pulled outward in the width direction W can be more reliably reduced. In addition, in the disposable diaper 10 according to the present embodiment, the inner end portion (front edge) 85E1 in the longitudinal direction L of the waist stretchable portion 85 is disposed inside the longitudinal direction L of the end portion 92E1 inside the longitudinal direction L of the hook sheet 92, and the outer end portion (rear edge) 85E2 in the longitudinal direction L of the waist stretchable portion 85 is disposed outside the longitudinal direction L of the end portion 92E2 outside the longitudinal direction L of the hook sheet 92. Therefore, the force generated when the fastening tape 90 is pulled outward in the width direction W can efficiently affect the body circumference stretchable portion 85, and the fit of the body circumference stretchable portion 85 with the wearer can be improved. Furthermore, in the disposable diaper 10 according to this embodiment, the pair of leg extension portions 75 are configured to spread outward in the width direction W as they approach the rear waist area 30. Therefore, after the disposable diaper 10 is put on, the force pulling the waist extension portion 85 in the longitudinal direction L can be distributed outward in the width direction W. Generally, when the fastening tape is worn, the wearer's body is positioned so as to cover the entire width of the absorbent core 40a. Therefore, when the fastening tape 90 is pulled, the portion located outside the wearer's body in the width direction W, that is, the region outside the absorbent core 40a in the width direction W, is pulled. For example, if the part of the fastening tape 90 that is pulled is difficult to stretch, the person assisting with the installation may not be able to determine how much to stretch the fastening tape 90 and may not be able to fasten it in the correct position. However, since a first region 851 with a relatively high elongation rate is located outside the width direction W of the absorbing core 40a, the installation assistant stretches the first region 851 to fasten the fastening tape 90. Because the first region 851 is easy to stretch, the installation assistant can easily grasp the range in which the first region 851 can be stretched. Therefore, the installation assistant can grasp the range in which to stretch the fastening tape 90 and fasten the fastening tape 90 in the correct position. Furthermore, when fastening the fastening tape 90, the first region 851 is positioned at the hip bone on the wearer's side. On the other hand, when fastening the fastening tape 90, the second region 852 and the third region 853 are subjected to the wearer's body pressure and are in a state where they are difficult to stretch or contract. However, after the disposable diaper 10 has been put on the wearer, for example, when the wearer is sitting up, the body pressure on the rear waist area 30 of the disposable diaper 10 is reduced. When the wearer's body pressure on the rear waist area 30 is reduced, as shown in Figure 4(b), the first area 851, the second area 852, and the third area 853 move in conjunction, and the second area 852 and the third area 853 expand and contract, respectively, with the first area 851 as the starting point. Specifically, the first region 851 is already stretched when the fastening tape 90 is attached, compared to the second region 852 and the third region 853. In this state, when the second region 852 and the third region 853 expand and contract, the second region 852, which has a relatively low rate of expansion, is pulled towards the first region 851 with the first region 851 as the base point, while the third region 853, which has a relatively high rate of expansion, pulls the second region 852 inward in the width direction W, causing the second region 852 to expand. At this time, the first region 851 is located closer to the fastening tape 90, so it stretches when the fastening tape 90 is fastened to the target portion 95. In this case, because there is a third region 853 that is less stretchable in the width direction W than the second region 852, the second region 852, which is sandwiched between the first region 851 and the third region 853, stretches evenly in the width direction W. As a result, the second region 852 can fit evenly to the baby's body without constricting it with a weak force. As the disposable diaper 10 fits the wearer's body, the first region 851 provides a stronger fit around the wearer's hip bones on their sides. On the other hand, the area behind the wearer's hip bones has fewer hip bones and is relatively softer. The second region 852 provides a weaker fit in this area with fewer hip bones. Because the diaper fits more strongly in the relatively firmer parts of the wearer's body and weaker in the relatively softer parts, it fits the wearer's body without strain and improves the fit around the waist. In other words, the present invention achieves two seemingly contradictory goals: the mother's (caregiver's) desire to avoid constricting the baby with a diaper, and the need to increase the fit (tighten it) to prevent leakage of waste by eliminating gaps between the disposable diaper 10 and the wearer's body. The third region 853 is positioned across the center of the width W of the disposable diaper 10. The center of the wearer's back is where the spine is located and is indented ventrally compared to the left and right sides. This indented area (Michael's rhombus) is the indentation of the sacrum, and the third region 853 is positioned in this indented area. In Figure 4(a), this indented area is indicated by "CR". After the disposable diaper 10 is put on, when body pressure decreases, the third region 853 contracts while pulling on the second region 852. This contracted portion can be positioned in the wearer's recessed area. Therefore, it is possible to prevent a gap from forming between the center of the wearer's back and the disposable diaper 10, and to fit the disposable diaper 10 to the entire waist area. In addition, because there is a difference in thickness of the absorbent core 40a before and after the rear edge of the absorbent core 40a, a gap is likely to form between the wearer's body and the disposable diaper 10. However, because the rear edge of the waist elastic portion 85 extends beyond the rear edge of the absorbent core 40a towards the waist, and because the stretch rate of the third region 853 is relatively high, leakage from the recessed area on the back can be prevented more reliably. Because the absorbent core 40a is relatively more rigid than the other components (top sheet 50) that make up the disposable diaper 10, it is difficult to position it to conform to the wearer's body. However, since at least a portion of the waist elastic portion 85 overlaps with the absorbent core 40a, and the waist elastic portion 85 is positioned on the non-skin-facing side of the absorbent core 40a, the absorbent core 40a can be made to fit the wearer's body by contracting the waist elastic portion 85. If the third region 853 is placed over the entire width W of the absorbent core 40a, the natural contraction of the third region 853 may cause the width of the absorbent core 40a to become too short. As a result, the width of the disposable diaper 10 cannot be secured when fastening the fastening tape 90, making it difficult for the person assisting with fastening to grasp the fastening tape 90, which may worsen the ease of fastening. However, because the second region 852 is located inward in the width direction W from the outer edge of the absorption core 40a, the second region 852 and the third region 853 are arranged within the entire width direction W of the absorption core 40a. Therefore, in its natural state, the width of the absorption core 40a does not become too short, and deterioration of the fit can be suppressed. The inner edge of the first region 851 is located inward in the width direction W compared to the outer edge of the absorbent core 40a. When the fastening tape 90 is pulled and attached, the assistant stretches the first region 851 to fasten the fastening tape 90. Also, when the first region 851 is stretched and the fastening tape 90 is fastened, the absorbent core 40a is positioned under the wearer's body and is subjected to body pressure. Because the inner edge of the first region 851 is located inward in the width direction W compared to the outer edge of the absorbent core 40a, the inner edge of the absorbent core 40a is less likely to move under the wearer's body when the fastening tape 90 is pulled and attached. Therefore, when the inner edge of the first region 851 is located inward in the width direction W compared to the outer edge of the absorbent core 40a, the inner edge of the first region 851 becomes a pivot point, making it easier to stretch the first region 851 when the fastening tape 90 is pulled. The adhesive used to bond the waist-length expandable portion 85 and the absorbent core 40a may be arranged in multiple rows continuously in the longitudinal direction L, with each row overlapping in the width direction W. With this configuration, the waist-length expandable portion 85 and the absorbent core 40a can be continuously bonded in both the longitudinal direction L and the width direction W, preventing the waist-length expandable portion 85 from lifting away from the absorbent core 40a. The elongation rate in the width direction W of the third region 853 may be set to be higher than the elongation rate in the width direction W of the first region 851. With this configuration, because the elongation rate of the third region 853 is higher than that of the first region 851, after the fastening tape 90 has been fastened, the second region 852 is pulled toward the third region 853 while the body pressure on the rear torso area 30 is reduced. Therefore, the portion contracted by the third region 853 can be gathered in the concave area of ​​the wearer's back. The third region 853 overlaps with at least a portion of the low-weight region 110 in a plan view of the disposable diaper 10. With this configuration, the third region 853 shrinks the low-weight region 110 in the width direction W, and the rear edge of the absorbent core 40a deforms toward the center in the width direction W. Thus, the rear part of the absorbent core 40a can be formed into a cup shape. This cup-shaped absorbent core 40a can cover the wearer's buttocks and further improve the fit around the waist. The rear edge of the absorption core 40a and the rear edge of the core wrap 40b are substantially aligned, and the waist-length expandable portion 85 extends further rearward than the rear edge of the absorption core 40a and the rear edge of the core wrap 40b. For example, if the core wrap 40b extends further rearward than the absorption core 40a, the core wrap 40b may hinder the expandability of the waist-length expandable portion 85. However, since the waist-length expandable portion 85 extends further rearward than the rear edge of the absorption core 40a and the rear edge of the core wrap 40b, the core wrap 40b and the like do not hinder the expandability of the waist-length expandable portion 85 further rearward than the rear edge of the absorption core 40a and the rear edge of the core wrap 40b. Furthermore, the rear edge of the disposable diaper 10 does not have a waist-stretching portion 85, and the side flaps 70 of the rear edge of the disposable diaper 10 have notches formed on the inside in the width direction W and the inside in the longitudinal direction L. More specifically, the rear edge of the side flap 70 is recessed inward in the longitudinal direction L over a certain range extending inward in the width direction W from the outer edge of the side flap 70. In other words, the outer edge of the side flap 70 is recessed inward in the width direction W over a certain range extending inward in the longitudinal direction L from the rear edge of the side flap 70. In this way, the rear edge of the disposable diaper 10 is configured in a way that prevents the rear edge of the disposable diaper 10 from curling up, and more reliably covers the wearer's waist. As described above, the scope of the present invention has been disclosed through embodiments of the present invention, but the descriptions and drawings that constitute part of this disclosure should not be understood as limiting the present invention. Various alternative embodiments, examples, and operational techniques will become apparent to those skilled in the art from this disclosure. Therefore, the technical scope of the present invention is defined solely by the inventive features relating to the claims that are reasonable from the above description. Furthermore, the entire contents of Japanese Patent Application No. 2015-038605, dated February 27, 2015, which formed the basis of the priority claim of this application, are incorporated herein by reference. According to the present invention, it is possible to provide an absorbent article that can be folded in a stable position and made smaller. 10... Disposable diapers 20... Front body circumference 25...Inseam area 30...Rear body area 35... Leg opening 40... Absorbent 40a... Absorption core 40b... Covering sheet 50... Top sheet 60... Exterior seats 60a...back seat 70... Side flaps 75...Leg extension section 80...Leg side elastic section 85... Elastic waistband 851...First area 852...Second area 853...Third area 90... Fastening tape 110... Low-grain area 115...First notch 125...Second notch 200... Crotch stretch part L... Longest direction W... width direction

Claims

1. A disposable diaper having a front waist area, a rear waist area, and a crotch area located between the front waist area and the rear waist area, having a longitudinal direction extending from the front waist area to the rear waist area and a width direction perpendicular to the longitudinal direction, a pair of fastening tapes extending along the width direction in the rear waist area and fastened to the front waist area, an absorbent body extending across the crotch area toward at least one of the front waist area and the rear waist area, and a waist elastic portion positioned between the pair of fastening tapes and expanding and contracting in the width direction, wherein in a plan view of the disposable diaper, the longitudinal centerlines of the pair of fastening tapes are configured to overlap with the waist elastic portion but not with the absorbent body, and the length of the waist elastic portion in the width direction is configured to be longer than the length of the absorbent body in the width direction. A disposable diaper characterized in that the stretching rate of the area located outside the absorbent material in the width direction in the waist-stretching portion is different from the stretching rate of the area located inside the absorbent material in the width direction in the waist-stretching portion.

2. The stretch rate of the area located outside the absorbent material in the width direction in the waist elastic portion is greater than the stretch rate of the area located inside the absorbent material in the width direction in the waist elastic portion, characterized in that 1 Disposable diapers as described above.

3. It has a pair of leg openings and a pair of leg extensions positioned inward in the width direction from the pair of leg openings and extending and retracting in the longitudinal direction, and in a plan view of the disposable diaper, the waist extension and the pair of leg extensions The disposable diaper according to claim 1 or 2, characterized in that the contracted portions are configured so as not to overlap.

4. The pair of leg-side stretchable portions are located on the inside of the widthwise direction of the pair of leg-stretchable portions, and in a plan view of the disposable diaper, the waist-stretchable portion and the pair of leg-side stretchable portions are configured to overlap. A disposable diaper as described in claim 3.

5. In a plan view of the disposable diaper, the waist elastic portion and the absorbent material are configured to overlap, and the thickness of the absorbent material in the area overlapping with the waist elastic portion is thinner than the thickness of the absorbent material in other areas. The components A disposable diaper according to any one of claims 1 to 4, characterized by the following:

6. The fastening tape has side flaps that extend outward in the width direction from the absorbent, and each of the pair of fastening tapes comprises a base sheet connected to the side flap and a hook sheet provided with an engaging hook and fixed to the base sheet, and the absorbent is positioned inward in the longitudinal direction from the longitudinal inner end of the hook sheet. A disposable diaper according to any one of claims 1 to 5.

7. The fastening tape has side flaps that extend outward in the width direction from the absorbent, and each of the pair of fastening tapes comprises a base sheet connected to the side flap and a hook sheet provided with an engaging hook and fixed to the base sheet, the inner end of the waist elastic portion in the longitudinal direction is positioned further inward in the longitudinal direction than the inner end of the hook sheet in the longitudinal direction, and the outer end of the waist elastic portion in the longitudinal direction is positioned further outward in the longitudinal direction than the outer end of the hook sheet in the longitudinal direction. A disposable diaper according to any one of claims 1 to 6, characterized by the following:

8. The pair of leg extension sections widen outward in the width direction as they move towards the rear torso area. A disposable diaper according to claim 3, characterized in that it is configured to be such.

9. The waist-length stretchable portion comprises: a first region extending inward in the width direction from both outer edges of the waist-length stretchable portion; a second region extending inward in the width direction from the inner edge of the first region and having a lower stretch rate than the first region; and a third region extending inward in the width direction from the inner edge of the second region and having a higher stretch rate than the second region, wherein at least a portion of the first region is located on the outside in the width direction of the absorbent body. The disposable diaper according to any one of claims 1 to 8, which is configured to do so.

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