Pants-type disposable diapers

Abstract

To provide an underpants type disposable diaper capable of being compacted by suppressing an increase in a thickness of a whole diaper while maintaining fitness.SOLUTION: An underpants type disposable diaper 1 comprises: an absorbent body 10 comprising an abdominal side part A, a crotch part C and a back side part B, and having a longitudinal direction X and a lateral direction Y, and an absorber 4; and an exterior body 5 arranged at a non-skin facing side of the absorbent body 10. The absorber 4 includes an absorber elastic member 31 which is continuous from the abdominal side part A to the back side part B, and is arranged in a stretched state in the longitudinal direction X in the side part of the absorber 4 or its vicinity. The exterior body 5 includes a lateral elastic member 33 which is arranged in a stretched state in the lateral direction Y at least at the abdominal side part A side in the crotch part C. In plane view, the lateral elastic member 33 and the absorber elastic member 31 are not superposed. A width W of a part forming a pair of leg openings in the exterior body 5 is wider than a width of the absorber.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a pants-type disposable diaper. [Background technology]

[0002] Disposable diapers generally have an absorbent main body with an absorber and an outer body arranged on the non-skin-facing side of the absorbent main body. From the viewpoint of improving fit by deforming the absorbent body, elastic members arranged in a stretched state on the sides of the absorbent body or in the vicinity thereof have been proposed. For example, the present applicant previously disclosed a disposable diaper (Patent Document 1) that includes a central absorbent body and a pair of side absorbent bodies separated in the crotch region, with elastic members arranged on both sides for raising the side absorbent bodies along the longitudinal direction, so that both sides of the crotch region of the absorbent main body are raised.

[0003] Furthermore, disposable diapers are known that are provided with elastic members that stretch laterally in the crotch area in order to form gathers in the crotch area. The present applicant previously disclosed such a disposable diaper that has multiple front thigh elastic members in the front region of the crotch area, and the front thigh elastic members are continuously arranged across the entire width of the diaper between the constituent sheets of the outer body (Patent Document 2). Furthermore, Patent Document 3 discloses a disposable diaper in which crotch elastic members that stretch laterally in the crotch portion are arranged so as to overlap the rear end of the absorber. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-341061 [Patent Document 2] Japanese Patent Application Laid-Open No. 2008-142316 [Patent Document 3] Japanese Patent Application Laid-Open No. 2013-223690 Summary of the Invention [Problem to be solved by the invention]

[0005] In disposable diapers, the contraction of the elastic members of the outer body and absorbent body forms gathers that fit around the wearer's waist and legs. While this contraction of the elastic members is effective in improving fit and comfort, it can also cause the gathers (wrinkles) to increase the bulk of the diaper. In particular, if wrinkles occur in the absorbent body, which is thicker than the other components, the overall thickness of the diaper can increase excessively. The disposable diapers described in Patent Documents 1 to 3 did not specifically address the issue of reducing the diaper's thickness and making it more compact while maintaining the fit provided by the contraction of the elastic members.

[0006] SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a compact disposable diaper that maintains a good fit while suppressing an increase in the overall thickness of the diaper. [Means for solving the problem]

[0007] The present invention relates to a pants-type disposable diaper having a waist opening and a pair of leg openings, and comprising a ventral portion located on the ventral side of a wearer when worn, a crotch portion located in the crotch area, and a dorsal portion located on the dorsal side, and having a vertical direction extending from the ventral portion through the crotch portion to the dorsal portion and a horizontal direction perpendicular to the vertical direction, and comprising an absorbent main body having an absorber, and an outer body located on the non-skin-facing side of the absorbent main body. The absorber preferably extends continuously from the ventral portion to the dorsal portion and includes absorber elastic members disposed in a stretched state in the longitudinal direction at or near the sides of the absorber. The exterior body preferably includes a lateral elastic member disposed in a stretched state in the lateral direction at least on the abdominal side of the crotch portion. It is preferable that the transverse elastic members and the absorber elastic members do not overlap in a plan view. It is preferable that the width of the portion of the exterior body that forms the pair of leg openings is wider than the width of the absorber. [Effects of the Invention]

[0008] According to the pants-type disposable diaper of the present invention, the diaper can be made compact by suppressing an increase in the overall thickness of the diaper while maintaining a good fit. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a plan view showing a disposable diaper according to one embodiment of the present invention in an unfolded and extended state. [Figure 2] FIG. 2 is a cross-sectional view taken along line II in FIG. [Figure 3] FIG. 3 is a cross-sectional view taken along line II-II in FIG. [Figure 4] FIG. 4(a) is a schematic cross-sectional view of a diaper for explaining the effects of the present invention, and FIG. 4(b) is a schematic cross-sectional view of a conventional diaper. [Figure 5] FIG. 5 is an enlarged plan view showing the transverse elastic member and its vicinity in FIG. [Figure 6] FIG. 6 is an enlarged plan view showing a transverse elastic member and its vicinity in another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] The present invention will now be described based on preferred embodiments with reference to the drawings. Figs. 1 to 3 show a pants-type disposable diaper 1 (hereinafter simply referred to as "diaper 1"), which is one embodiment of the absorbent article of the present invention. The diaper 1 has a ventral section A that is located on the ventral side of a wearer when worn, a dorsal section B that is located on the dorsal side of the wearer, and a crotch section C located between the ventral section A and the dorsal section B. The diaper 1 has a longitudinal direction X that corresponds to the front-to-rear direction of the wearer, i.e., the direction extending from the ventral section A to the dorsal section B via the crotch section C, and a lateral direction Y that is perpendicular to the longitudinal direction X. The longitudinal direction X coincides with the longitudinal direction of an absorbent main body 10, which will be described later. The diaper 1 comprises an absorbent body 10 and an exterior body 5 disposed on the non-skin-facing side of the absorbent body 10. The exterior body 5 forms the non-skin-facing side of the diaper 1, i.e., the outer surface of the diaper 1.

[0011] In this specification, the "skin-facing side" refers to the side of the absorbent article or its constituent member (e.g., the topsheet 12) that faces the skin of the wearer when the absorbent article is worn, i.e., the side that is relatively close to the wearer's skin, and the "non-skin-facing side" refers to the side of the absorbent article or its constituent member that faces the opposite side from the skin side when the absorbent article is worn, i.e., the side that is relatively far from the wearer's skin. Note that "when worn" here refers to the normal, appropriate wearing position, i.e., a state in which the absorbent article is maintained in the correct wearing position.

[0012] As shown in FIG. 1, the diaper 1 is formed symmetrically with respect to a longitudinal centerline CL that extends in a longitudinal direction X and divides the diaper 1 into two equal parts in a transverse direction Y when in an unfolded and stretched state. The "unfolded and stretched state" of the diaper 1 refers to the state in which the diaper 1 is unfolded by separating the side seals S, and then unfolding the diaper 1 in the unfolded state by stretching the elastic members of each part to the design dimensions (the same dimensions as when the diaper 1 is unfolded flat without any influence of the elastic members). In this specification, unless otherwise specified, the dimensions of each part of the diaper 1, such as the length in the longitudinal direction X or the lateral direction Y, refer to the dimensions (design dimensions) when the elastic members of each part are stretched and each part is stretched.

[0013] As shown in Fig. 2, the absorbent main body 10 comprises a liquid-permeable top sheet 12, a leak-barrier sheet 13, a liquid-retentive absorbent body 4 interposed between these sheets 12, 13, and a pair of leak-barrier cuffs 6, 6. In the absorbent main body 10, the top sheet 12, the absorbent body 4, the pair of leak-barrier cuffs 6, 6, and the leak-barrier sheet 13 are integrated together by a known joining means such as an adhesive. The absorbent main body 10 has a rectangular shape that is long in the longitudinal direction X in a plan view, and extends in the longitudinal direction X from a ventral side portion A to a dorsal side portion B. In this embodiment, the positions of both ends of the absorbent main body 10 in the longitudinal direction X substantially coincide with the positions of both ends of the absorbent body 4 in the longitudinal direction X.

[0014] As shown in Fig. 1, the absorbent body 4 has a rectangular shape in plan view and is continuous in the longitudinal direction X from the ventral portion A to the dorsal portion B. The longitudinal direction of the absorbent body 4 coincides with the longitudinal direction X of the diaper 1. The absorbent body 4 is located in the center of the exterior body 5 (described later) in the lateral direction Y in plan view, and is bonded to the leak-barrier sheet 13 with an adhesive.

[0015] The absorbent body 4 is configured to include a liquid-retaining absorbent core 40 and a core wrap sheet 41 that covers the outer surface of the absorbent core 40 . As shown in FIG. 2, the absorbent core 40 of this embodiment has a pair of side absorbent cores 40S, 40S in the crotch region C and a pair of central absorbent cores 40C located between the pair of side absorbent cores 40S, 40S. Each of the pair of side absorbent cores 40S, 40S and the central absorbent core 40C extends in the longitudinal direction X in the crotch region C. The absorbent core 40 of this embodiment has side fold guide portions 45S between the side absorbent cores 40S and the central absorbent core 40C, and further has a central fold guide portion 45C between the pair of central absorbent cores 40C. In the absorbent body 4, the pair of side absorbent cores 40S, 40S can deform so as to rise toward the wearer's skin, starting from the side fold guide portions 45S, 45S (see FIG. 2). That is, the pair of side absorbent cores 40S, 40S rise from the central absorbent core 40C, starting from the side fold guide portions 45S. The absorbent body 4 can also be deformed such that the pair of central absorbent cores 40C are folded in a mountain fold starting from the central folding guide portions 45C (not shown).

[0016] The side fold guide portions 45S, 45S and the central fold guide portion 45C in the absorbent body 4 of this embodiment are formed as through-holes that extend in the longitudinal direction X and penetrate the absorbent core 40. Alternatively, the side fold guide portions 45S, 45S and the central fold guide portion 45C may be recesses formed on the skin-facing surface or non-skin-facing surface of the absorbent core 40.

[0017] The absorbent body 4 includes absorber elastic members 31 arranged in a stretched state in the longitudinal direction X at or near the side portions of the absorbent body 4. The side portions of the absorber 4 are the regions on both sides when the entire width of the absorber 4, including the core wrap sheet 41, is divided into three equal parts. "Via the side portions of the absorber 4" refers to the region within 5 mm outward in the lateral direction Y from the side edges of the absorber 4. The absorber elastic members 31 are arranged closer to the non-skin-facing side than the topsheet 12 and closer to the skin-facing side than the leak-barrier sheet 13. The absorber elastic members 31 may be adjacent to the absorber 4, and may be located, for example, on the skin-facing side or the non-skin-facing side of the absorber 4. When the absorbent core 40 has a side fold guide portion 45S, assuming a first imaginary line that bisects the length between the side edge of the absorbent body 4 and the side fold guide portion 45S in the horizontal direction Y and that extends in the vertical direction X, and a second imaginary line that is symmetrical to the first imaginary line with the side edge of the absorbent body 4 as its axis, the region between the side edge of the absorbent body 4 and the second imaginary line is preferably "the vicinity of the side of the absorbent body 4." When the absorbent body 4 consists only of the absorbent core 40 and the absorbent core 40 has a constricted portion described below, a third imaginary line that passes through a position on the outermost side in the horizontal direction Y on the periphery of the absorbent core 40 and that extends in the vertical direction X is defined as "the side edge of the absorbent body 4." When the absorbent core 40 has side fold guide portions 45S, it is preferable that the absorber elastic members 31 are arranged outward in the horizontal direction Y from the side fold guide portions 45S, 45S. The side fold guide portions 45S, 45S are arranged symmetrically with respect to the vertical center line CL and are fold guide portions that are located furthest outward in the horizontal direction Y in the absorbent core 40.

[0018] The absorbent body 4 of this embodiment includes absorber elastic members 31 adjacent to each of the two side edges of the absorbent body 4 along the longitudinal direction X and arranged in a stretched state in the longitudinal direction X (see FIGS. 1 and 2). The absorber elastic members 31 are arranged near the sides of the absorber 4, and are arranged between the core wrap sheet 41 and the topsheet 12 on both sides of the absorber 4 along the longitudinal direction X. Contraction of the absorber elastic members 31 in the longitudinal direction X can assist deformation of the side absorbent cores 40S starting from the side fold guide portions 45S. In other words, the side absorbent cores 40S are more likely to deform so as to be lifted toward the wearer's skin. In this embodiment, the end of the abdominal portion A of the absorber elastic member 31 is disposed inward in the longitudinal direction X from the lateral elastic member 33 .

[0019] As shown in FIG. 1, the absorbent main body 10 is provided with a pair of leakage-preventing cuffs 6, 6 on both sides of its skin-facing surface along the longitudinal direction X. That is, the pair of leakage-preventing cuffs 6, 6 are arranged on both sides of the absorbent main body 10 in the transverse direction Y and extend in the longitudinal direction X. As shown in FIG. 2, the leakage-preventing cuffs 6 of this embodiment are formed by folding a liquid-resistant or water-repellent and breathable leakage-preventing cuff-forming sheet 61 in half along the longitudinal direction X and joining the two opposing leakage-preventing cuff-forming sheets 61 together. The leakage-preventing cuffs 6 of this embodiment are provided with cuff elastic members 35 between the two opposing leakage-preventing cuff-forming sheets 61. The cuff elastic members 35 are arranged at the inner end of the leakage-preventing cuffs 6 in the transverse direction Y (see FIGS. 2 and 3). More specifically, the cuff elastic members 35 are arranged near the fold line where the leakage-preventing cuff-forming sheet 61 is folded in half. The cuff elastic members 35 are arranged in a stretched state in the longitudinal direction X. Each leakage-preventing cuff 6 has a base end fixed between the absorber 4 and the leakage-preventing sheet 13 in the absorbent main body 10, and a free end to which the cuff elastic members 35 are fixed. The leakage-preventing cuffs 6 are configured so that the free ends of the leakage-preventing cuffs 6 stand up at least in the crotch region C when the cuff elastic members 35, arranged in a stretched state in the longitudinal direction X, contract.

[0020] The outer cover 5 comprises an outer sheet 55 that forms the outer surface, i.e., the non-skin-facing surface, of the diaper 1, and an inner sheet 56 located on the skin-facing side of the outer sheet 55 (see Figs. 1 and 2). In the outer cover 5, the leak-barrier sheet 13 and the inner sheet 56, as well as the inner sheet 56 and the outer sheet 55, that are adjacent in the thickness direction Z of the diaper 1, are bonded together with an adhesive. In the exterior body 5, both side edges of the ventral side portion A and the dorsal side portion B along the longitudinal direction X of the exterior body 5 are joined together by a known joining means such as an adhesive such as a hot melt adhesive, heat sealing, ultrasonic sealing, etc., to form a pair of side seal portions S, S, a waist opening through which the wearer's torso is inserted, and a pair of leg openings through which the wearer's lower legs are inserted (not shown). In other words, the crotch portion C is the region between the side seal portions S in the longitudinal direction X of the diaper 1.

[0021] The exterior body 5 forms the outer shape of the diaper 1 in an unfolded and stretched state as shown in Fig. 1, and the peripheral edges of the exterior body 5 form the contour lines of the diaper 1 in an unfolded and stretched state, i.e., the contour lines of the ventral portion A, the crotch portion C, and the back portion B. As shown in Fig. 1, in the crotch portion C, both side edges of the exterior body 5 along the longitudinal direction X are curved in a convex arc shape toward the center in the lateral direction Y, and the central region in the longitudinal direction X is narrowed inward in the lateral direction Y. The exterior body 5 and the absorbent main body 10 are joined by a known joining means such as an adhesive. In addition, at least one of the outer layer sheet 55 and the inner layer sheet 56 of the exterior body 5 may be folded back along the peripheral edge of the waist opening toward the skin-facing surface side.

[0022] In the outer cover 5, the outer sheet 55 forms the outer surface, i.e., the non-skin-facing surface, of the diaper 1, and the inner sheet 56 is disposed on the skin-facing side of the outer sheet 55. The outer cover 5 has a plurality of thread-like or strip-like elastic members 33, 34, 36, 37 disposed between the inner sheet 56 and the outer sheet 55. Specifically, the outer cover 5 has waist elastic members 36 and waist elastic members 34 disposed along the lateral direction Y in the ventral side portion A and the dorsal side portion B, leg elastic members 37 disposed along the leg openings, and lateral elastic members 33 extending in the lateral direction Y in the crotch portion C.

[0023] In the ventral portion A and the back portion B of this embodiment, the waist elastic members 34 arranged in positions overlapping the absorbent main body 10 in the longitudinal direction X are arranged so as not to exhibit elastic stretchability in the region overlapping the absorber 4 in the transverse direction Y by processing such as fine division. On the other hand, the waist elastic members 36 may exhibit elastic stretchability in the region overlapping the absorber 4 in the transverse direction Y. In the ventral portion A and the back portion B, the waist elastic members 36 and the waist elastic members 34 are each arranged intermittently at predetermined intervals in the longitudinal direction X in a stretched state in the transverse direction Y. In this way, the waist elastic members 36 are arranged in a state in which they exhibit elastic stretchability, so that substantially continuous annular waist gathers (pleats) are formed around the entire periphery of the opening edge of the waist opening.

[0024] The leg edges LS that form the opening edges of the leg openings in the exterior body 5 extend outward in the lateral direction Y beyond the absorbent body 4. In other words, the width of the portions of the exterior body 5 that form the pair of leg openings is wider than the width of the absorbent body 4. In order to further suppress an increase in the thickness of the diaper 1, which will be described later, the minimum width W (see Figure 1) of the portion forming the pair of leg openings is preferably 110% or more, more preferably 114% or more, and is preferably 150% or less, more preferably 145% or less, and is preferably 110% or more and 150% or less, more preferably 114% or more and 145% or less, of the total width of the absorbent core 4 in the crotch region C.

[0025] One or more thread- or strip-shaped leg elastic members 37 for forming leg gathers are stretchably arranged along the leg edge portions LS. The leg elastic members 37 extend in the longitudinal direction X toward the crotch portion C, i.e., from a portion of the back portion B at the center of the longitudinal direction X, through the crotch portion C, to a portion of the abdominal portion A at the center of the longitudinal direction X (see FIG. 1). By arranging the leg elastic members 37 in a stretched state, a substantially continuous annular leg gather is formed along the entire periphery of the opening edge portion (leg edge portion LS) of the leg opening. The leg elastic members 37 are also sandwiched and fixed between the outer layer sheet 55 and the inner layer sheet 56 that constitute the exterior body 5 by a joining means such as an adhesive.

[0026] The outer cover 5 further has transverse elastic members 33 arranged in a stretched state in the transverse direction Y at least on the abdominal side A side of the crotch portion C (see Fig. 1). Fig. 3 shows a cross section of the diaper 1 at the position where the transverse elastic member 33 is arranged, together with a cross section of the transverse elastic member 33. In Figs. 1 and 3, portions of the transverse elastic member 33 that do not exhibit stretchability are omitted from the illustration. The lateral elastic members 33 of this embodiment are arranged so as not to exhibit elastic stretchability in the region overlapping with the absorbent body 4 in the lateral direction Y by processing such as dividing them into small pieces. Such lateral elastic members 33 exhibit elastic stretchability outward in the lateral direction Y from the absorbent body 4. This allows the exterior body 5 to contract in the lateral direction Y in the crotch portion C, ensuring a good fit to the wearer's skin. The exterior body 5 may include one lateral elastic member 33, or two or more lateral elastic members 33.

[0027] As shown in Fig. 1, the lateral elastic members 33 and the absorber elastic members 31 do not overlap in a plan view of the diaper 1. In other words, the lateral elastic members 33 and the absorber elastic members 31 do not coincide in position in the longitudinal direction X, and also do not coincide in position in the lateral direction Y. In this embodiment, as shown in Fig. 3, the absorber elastic members 31 are not present in the position in the longitudinal direction X where the lateral elastic members 33 are present. The "plan view of the diaper 1" refers to a plan view of the diaper 1 in an unfolded and stretched state.

[0028] In the diaper 1, contraction of the absorber elastic members 31 causes the side absorbent cores 40S to deform and stand up, allowing the absorber 4 to conform well to the wearer's crotch area, resulting in an excellent fit. In addition, the width of the portions of the outer body 5 that form the pair of leg openings is wider than the width of the absorber 4, which effectively prevents twisting and leakage in the crotch region C. On the other hand, if the crotch region C includes both elastic members stretchable in the longitudinal direction X and elastic members stretchable in the transverse direction Y, the contraction of these elastic members improves the fit, but wrinkles are likely to occur in the absorbent body 4. Regarding such wrinkles, Figures 4(a) and 4(b) show cross-sectional views of a diaper having a waist opening and a pair of leg openings, taken along the longitudinal direction X. In a conventional pants-type disposable diaper 1', the absorbent body 10 and the outer body 5 of the front body F overlap with the absorbent body 10 and the outer body 5 of the rear body R, causing wrinkles to overlap (see Figure 4(b)). This tends to make the diaper bulky and excessively thick. In contrast, in the diaper 1 of this embodiment, the lateral elastic members 33 and the absorber elastic members 31 do not overlap in a plan view, which effectively prevents the overlapping of wrinkles caused by contraction of the lateral elastic members 33 and the absorber elastic members 31. As a result, the bulkiness of the diaper as a whole is reduced, and the thickness of the diaper can be made compact (see FIG. 4(a)). This effect is hereinafter also referred to as the compact effect. In this way, the diaper 1 of this embodiment can prevent an increase in the overall thickness of the diaper while maintaining a good fit, thereby enabling the diaper to be made compact.

[0029] The exterior body 5 has a fixing portion 57 to which the lateral elastic member 33 and the sheets 55 and 56 of the exterior body 5 are fixed. In this embodiment, the fixing portion 57 is disposed between the outer layer sheet 55 and the inner layer sheet 56 so as to sandwich the portion where the lateral elastic member 33 exhibits elastic stretchability (see FIG. 3). When the absorbent body 4 deforms so that the side absorbent cores 40S stand up, twisting may occur in the absorbent body 4. From the viewpoint of further suppressing the occurrence of such twisting, it is preferable that the fixing portions 57a located on the inner side in the lateral direction Y are located outward in the lateral direction Y from the folding guide portions. It is preferable that such folding guide portions are the side folding guide portions 45S, 45S that are arranged line-symmetrically with respect to the longitudinal center line CL and are located furthest outward in the lateral direction Y.

[0030] In order to suppress the effect of contraction of the lateral elastic member 33 and further suppress twisting of the side portions of the absorbent body 4, it is preferable that the fixing portion 57a ​​located on the inner side in the lateral direction Y be located outward in the lateral direction Y than the absorbent body elastic member 31.

[0031] The absorbent main body 10 has side elastic members located on both sides of the absorbent main body 10. These side elastic members refer to elastic members that are arranged in the absorbent main body 10 other than between the topsheet 12 and the leak-barrier sheet 13. In other words, the side elastic members do not include the absorbent body elastic members 31 that the absorbent body 4 has. The absorbent main body 10 of this embodiment is provided with, as side elastic members, cuff elastic members 35 in the leakage preventing cuffs 6. Examples of side elastic members include elastic members provided in the leakage preventing cuffs 6, such as the cuff elastic members 35 described above. Other examples include elastic members fixed between the leakage preventing cuff-forming sheets 61 other than the cuff elastic members 35. Examples of such elastic members include elastic members disposed near the standing ends of the leakage preventing cuffs 6. To further prevent overlapping of wrinkles caused by contraction of the elastic members and to further improve the compactness effect, it is preferable that the lateral elastic members 33 and the side elastic members do not overlap in a plan view. For example, it is preferable that the lateral elastic members 33 and the cuff elastic members 35 do not overlap in a plan view.

[0032] In order to reduce the contraction property in the longitudinal direction X and further prevent the diaper 1 from slipping down when worn, it is preferable that the elongation rate of the absorber elastic member 31 is equal to or lower than the elongation rate of the lateral elastic member 33, and more preferably lower than the elongation rate of the lateral elastic member 33. From the same viewpoint as above, the elongation rate of the absorbent elastic member 31 is preferably 50% or more, more preferably 55% or more, and is preferably 90% or less, more preferably 85% or less, and is preferably 50% or more and 90% or less, more preferably 55% or more and 85% or less, relative to the elongation rate of the lateral elastic member 33. The elongation rate is measured by the following method.

[0033] [Method for measuring elongation rate] The diaper 1 is separated at the side seals S and placed in its natural (contracted) state. Two marks are made with an oil-based pen at the location of each elastic member from the surface of the diaper 1, with a distance La between them in the direction of extension of the elastic members. The diaper 1 is then stretched to an unfolded and stretched state (see Figure 1), and the length Lb between the two marks is measured. This measurement is performed three times for each elastic member, and the arithmetic mean of the values ​​calculated using the formula "Lb / La" is used to determine the elongation ratio (times). The distance La can be, for example, 100 mm; however, if the stretchable range is less than 100 mm, the distance La should be as wide as possible.

[0034] The planar shape of the absorbent core 40 is not particularly limited and may be any shape such as a rectangle. From the viewpoint of further suppressing an increase in thickness due to wrinkles occurring in the crotch portion C, it is preferable that the absorbent core 40 has constricted portions in which both side edges are constricted laterally inward (see FIG. 1).

[0035] The exterior body 5 of the embodiment shown in Figures 1 to 3 includes a plurality of lateral elastic members 33 arranged at intervals in the longitudinal direction X (see Figure 1). In this case, from the viewpoint of more reliably achieving the above-mentioned compact effect, it is preferable that none of the plurality of lateral elastic members 33 overlap the absorber elastic members 31 in a plan view. In other words, it is preferable that, of the plurality of lateral elastic members 33, the lateral elastic member 33 located most inward in the longitudinal direction X is located outward in the longitudinal direction X than the absorber elastic members 31. In order to achieve both a compact effect and a good fit, the distance L3 (see FIG. 5) between adjacent horizontal elastic members 33 in the vertical direction X is preferably 3 mm or more, more preferably 4 mm or more, and is preferably 30 mm or less, more preferably 28 mm or less, and is preferably 3 mm or more and 30 mm or less, more preferably 4 mm or more and 28 mm or less. From the same viewpoint as above, the distance L1 (see FIG. 5) in the longitudinal direction X between the horizontal elastic member 33 located most inward in the longitudinal direction X and the absorber elastic member 31 is preferably 2 mm or more, more preferably 3 mm or more, and also preferably 30 mm or less, more preferably 25 mm or less, and also preferably 2 mm or more and 30 mm or less, more preferably 3 mm or more and 25 mm or less.

[0036] Next, another embodiment of the pants-type disposable diaper according to the present invention will be described. Hereinafter, the other embodiment will be described mainly focusing on the components that differ from the embodiment shown in Figures 1 to 5, and the same components will be denoted by the same reference numerals and will not be described again. For components that are not specifically described, the description of the embodiment shown in Figures 1 to 5 will be applied as appropriate.

[0037] In the above-described embodiment, the lateral elastic members 33 extend in the lateral direction Y to the leg edges LS where the leg elastic members 37 are disposed. However, they do not have to extend to the leg edges LS. For example, as shown in Fig. 6, the lateral elastic members 33 and the leg elastic members 37 do not have to overlap in a plan view. By providing such a configuration, wrinkles caused by contraction of the lateral elastic members 33 and the leg elastic members 37 in the exterior body 5 are less likely to be continuous, thereby further suppressing the occurrence of large wrinkles and improving the compactness effect.

[0038] In the above-described embodiment, the exterior body 5 is provided with the lateral elastic members 33 only on the ventral portion A side of the crotch portion C. Alternatively, the exterior body 5 may be provided with the lateral elastic members 33 on both the ventral portion A side and the back portion B side of the crotch portion C (not shown). In this case, from the viewpoint of further improving the compactness effect, it is preferable that the lateral elastic members 33 on at least the ventral portion A side do not overlap with the absorber elastic members 31, and it is more preferable that the lateral elastic members 33 on both the ventral portion A side and the back portion B side do not overlap with the absorber elastic members 31 in a plan view.

[0039] The materials forming each part of the diaper 1 in the above-described embodiment will now be described in detail. The topsheet 12 and the leak-barrier sheet 13 may be made of any material that has been conventionally used in absorbent articles, without any particular restrictions. For example, a liquid-permeable nonwoven fabric or perforated film can be used as the topsheet 12. Examples of nonwoven fabrics include known nonwoven fabrics such as spunbond nonwoven fabrics, air-through nonwoven fabrics, spunlace nonwoven fabrics, heat-rolled nonwoven fabrics, and melt-blown nonwoven fabrics. A liquid-impermeable or water-repellent sheet can be used as the leak-proof sheet 13. Such a sheet can be a resin film or a laminate of a resin film and a nonwoven fabric, etc. Examples of resin films include films made of polymeric materials such as polyethylene terephthalate, polyester, polyethylene, polypropylene, cellophane, nylon, polyvinyl alcohol, polyvinyl chloride, and polycarbonate, as well as moisture-permeable films.

[0040] The absorbent body 4 can use, as the absorbent core 40, a stack of hydrophilic fibers such as wood pulp and synthetic fibers that have been hydrophilically treated, or a stack of such fibers in which a water-absorbent polymer is held in the assembly. Alternatively, the absorbent body 4 may be a polymer sheet in which a water-absorbent polymer is supported on a fiber sheet such as a nonwoven fabric. An example of such a polymer sheet is that described in JP 2009-022670 A, which is composed of two sheets containing a water-absorbent resin powder bonded between them with an adhesive. In pants-type disposable diapers, the absorbent body 4 is folded in half at the center in the longitudinal direction X, and when wrinkles generated in the absorbent body 4 overlap, the thickness of the diaper 1 increases. It is preferable that the absorbent body 4 be made of a polymer sheet, as this can further suppress such an increase in thickness.

[0041] The core wrap sheet 41 can be the same as the top sheet 12. From the viewpoint of maintaining softness even when wrinkles occur and further reducing thickness, the core wrap sheet 41 is preferably a nonwoven fabric. Examples of nonwoven fabrics include the known nonwoven fabrics mentioned above.

[0042] The above-mentioned known nonwoven fabrics can be used for the inner layer sheet 56 and the outer layer sheet 55 of the exterior body 5. Alternatively, a laminated nonwoven fabric in which nonwoven fabrics are laminated on each other can be used.

[0043] The absorber elastic members 31 in the absorber 4, the cuff elastic members 35 in the leak-proof cuffs 6, and the elastic members such as the lateral elastic members 33, waist elastic members 34, waist elastic members 36, and leg elastic members 37 in the outer casing 5 can be made of various known elastic materials commonly used in absorbent articles of this type, without any particular restrictions. Examples of elastic materials include synthetic rubbers such as styrene-butadiene, butadiene, isoprene, and neoprene, natural rubber, EVA, stretchable polyolefin, and polyurethane. Preferred forms of the elastic members include thread-like (e.g., rubber thread) or string-like (e.g., flat rubber) members with a rectangular, square, circular, or polygonal cross section, or multifilament thread-like members.

[0044] Although the present invention has been described above based on the preferred embodiments, the present invention is not limited to the above-described embodiments. For example, in the pants-type disposable diaper of the above-described embodiment, the absorbent core 40 includes the central fold guide portion 45C, but the absorbent core 40 may not include the central fold guide portion 45C. Also, the absorbent core 40 may not include the side fold guide portions 45S, 45S, either, nor the central fold guide portion 45C.

[0045] In addition to the above-described embodiment of the present invention, the following pants-type disposable diaper is also disclosed. <1> A pants-type disposable diaper having a waist opening and a pair of leg openings, and including a ventral side portion arranged on the ventral side of a wearer when worn, a crotch portion arranged in the crotch area, and a dorsal side portion arranged on the dorsal side, and having a longitudinal direction extending from the ventral side portion through the crotch portion to the dorsal side portion and a lateral direction perpendicular to the longitudinal direction, the diaper comprising an absorbent main body and an outer body arranged on the non-skin-facing side of the absorbent main body, the absorber is continuous from the ventral portion to the dorsal portion, and includes absorber elastic members disposed in a stretched state in the longitudinal direction at or near the side portions of the absorber; the exterior body includes a lateral elastic member disposed in a stretched state in the lateral direction at least on the abdominal side of the crotch portion, The transverse elastic members and the absorber elastic members do not overlap in a plan view, The pants-type disposable diaper is such that the width of the portion of the exterior body that forms the pair of leg openings is wider than the width of the absorbent body.

[0046] <2> In the disposable diaper, the width of the portion forming the pair of leg openings is 110% or more and 150% or less, preferably 114% or more and 145% or less, of the width of the absorbent body. <1> 1. The pants-type disposable diaper according to claim 1. <3> The absorbent body comprises an absorbent core, the absorbent core has a pair of side absorbent cores extending in the longitudinal direction in the crotch portion and a central absorbent core located between the pair of side absorbent cores, and the pair of side absorbent cores have fold guide portions standing up from the central absorbent core, The exterior body has a fixing portion to which the transverse elastic member and the sheet provided on the exterior body are fixed, and the fixing portion located on the inner side in the transverse direction is located outward in the transverse direction from the folding guide portion. <1> or <2> 1. The pants-type disposable diaper according to claim 1. <4> The exterior body has a fixing portion to which the transverse elastic member and a sheet provided on the exterior body are fixed, and the fixing portion located on the inner side in the transverse direction is located outward in the transverse direction from the absorber elastic member. <1> ~ <3> 10. The pants-type disposable diaper according to any one of the above. <5> The absorbent body has side elastic members located on both sides of the absorbent body, The lateral elastic members and the side elastic members do not overlap each other in a plan view. <1> ~ <4> 10. The pants-type disposable diaper according to any one of the above. <6> The absorbent main body has a pair of leakage-preventing cuffs arranged on both sides in the lateral direction, and the cuff elastic members arranged in a stretched state in the longitudinal direction in the leakage-preventing cuffs are the side elastic members. <5> 1. The pants-type disposable diaper according to claim 1. <7> the exterior body includes leg elastic members arranged along the leg openings, The transverse elastic members and the leg elastic members do not overlap each other in a plan view. <1> ~ <6> 10. The pants-type disposable diaper according to any one of the above. <8> the exterior body includes the transverse elastic members on both the ventral side and the dorsal side of the crotch portion, In a plan view, the transverse elastic members and the absorber elastic members do not overlap on either the ventral side or the back side. <1> ~ <7> 10. The pants-type disposable diaper according to any one of the above. <9> The elongation rate of the absorber elastic member is equal to or less than the elongation rate of the transverse elastic member. <1> ~ <8> 10. The pants-type disposable diaper according to any one of the above. <10> The elongation rate of the absorber elastic member relative to the elongation rate of the transverse elastic member is 50% or more and 90% or less, preferably 55% or more and 85% or less. <1> ~ <9> 10. The pants-type disposable diaper according to any one of the above.

[0047] <11> The absorbent body is configured to include a liquid-retaining absorbent core, The absorbent core has, in the crotch portion, constricted portions in which both side edges are constricted inward in the lateral direction. <1> ~ <10> 10. The pants-type disposable diaper according to any one of the above. <12> The absorbent body is configured to include a liquid-retaining absorbent core and a core wrap sheet that covers the outer surface of the absorbent core, The core wrap sheet is a nonwoven fabric. <1> ~ <11> 10. The pants-type disposable diaper according to any one of the above. <13> the exterior body includes a plurality of the transverse elastic members arranged intermittently in the vertical direction, The transverse elastic member located most inward in the longitudinal direction is located outward in the longitudinal direction than the absorber elastic member. <1> ~ <12> 10. The pants-type disposable diaper according to any one of the above. <14> The absorbent body is a polymer sheet in which a water-absorbent polymer is supported on a fiber sheet. <1> ~ <13> 10. The pants-type disposable diaper according to any one of the above. [Explanation of symbols]

[0048] 1. Diapers (pants-type disposable diapers) 10 Absorbent body 12 Surface sheet 13 Leak-proof sheet 4. Absorber 40 absorbent core 41 Core Wrap Sheet 40C central absorbent core 40S Side Absorbent Core 45C Center bend guide section 45S Side folding guide section 5. Exterior body 55 outer layer sheet 56 Inner layer sheet 57(57a) Fixed part 6 Leak proof cuff 61 Leak-proof cuff forming sheet 35 Cuff elastic member 31 absorbent elastic member 33 Transverse elastic member 36 Waist elastic member 37 Leg elastic member A. Ventral part B Dorsal part C Inseam F Front R back LS Leg Edge S,S Side seal part X vertical direction Y horizontal direction Z direction

Claims

1. A pants-type disposable diaper having a waist opening and a pair of leg openings, and including a ventral side portion arranged on the ventral side of a wearer when worn, a crotch portion arranged in the crotch area, and a dorsal side portion arranged on the dorsal side, and having a longitudinal direction extending from the ventral side portion through the crotch portion to the dorsal side portion and a lateral direction perpendicular to the longitudinal direction, the diaper comprising an absorbent main body and an outer body arranged on the non-skin-facing side of the absorbent main body, the exterior body includes leg elastic members arranged along the leg openings, the absorber is continuous from the ventral portion to the dorsal portion, and includes absorber elastic members disposed in a stretched state in the longitudinal direction at or near the side portions of the absorber; the exterior body includes a lateral elastic member disposed in a stretched state in the lateral direction at least on the abdominal side of the crotch portion, The transverse elastic members and the absorber elastic members do not overlap in a plan view, a part or the whole of the lateral elastic member is disposed between the leg elastic member and the absorbent body in the lateral direction; The pants-type disposable diaper is such that the width of the portion of the exterior body that forms the pair of leg openings is wider than the width of the absorbent body.

2. The absorbent body comprises an absorbent core, the absorbent core has a pair of side absorbent cores extending in the longitudinal direction in the crotch portion and a central absorbent core located between the pair of side absorbent cores, and the pair of side absorbent cores have fold guide portions standing up from the central absorbent core, 2. The pants-type disposable diaper according to claim 1, wherein the outer body has a fixing portion to which the lateral elastic member and a sheet provided on the outer body are fixed, and the fixing portion located on the inner side in the lateral direction is located outward in the lateral direction from the folding guide portion.

3. 3. The pants-type disposable diaper according to claim 1, wherein the outer body has a fixing portion at which the lateral elastic member and a sheet provided on the outer body are fixed, and the fixing portion located on the inner side in the lateral direction is located outward in the lateral direction from the absorber elastic member.

4. The absorbent body has side elastic members located on both sides of the absorbent body, 4. The pants-type disposable diaper according to claim 1, wherein the lateral elastic members and the side elastic members do not overlap each other in a plan view.

5. 5. The pants-type disposable diaper according to claim 4, wherein the absorbent body has a pair of leakage-preventing cuffs arranged on both sides in the lateral direction, and the cuff elastic members arranged in a stretched state in the longitudinal direction in the leakage-preventing cuffs are the side elastic members.

6. 6. The pants-type disposable diaper according to claim 1, wherein the outer body has a structure in which the transverse elastic members and the leg elastic members do not overlap each other in a plan view.

7. the exterior body includes the transverse elastic members on both the ventral side and the dorsal side of the crotch portion, 7. The pants-type disposable diaper according to claim 1, wherein, in a plan view, the transverse elastic members and the absorber elastic members do not overlap on either the ventral side or the dorsal side.

8. 8. The pants-type disposable diaper according to claim 1, wherein the elastic members of the absorber have an elongation percentage equal to or lower than that of the transverse elastic members.

9. The absorbent body is configured to include a liquid-retaining absorbent core, 9. The pants-type disposable diaper according to claim 1, wherein the absorbent core has, in the crotch portion, constricted portions at both side edges that are constricted inward in the lateral direction.

10. The absorbent body is configured to include a liquid-retaining absorbent core and a core wrap sheet that covers the outer surface of the absorbent core, The pants-type disposable diaper according to any one of claims 1 to 9, wherein the core wrap sheet is a nonwoven fabric.

11. the exterior body includes a plurality of the transverse elastic members arranged intermittently in the vertical direction, 11. The pants-type disposable diaper according to claim 1, wherein the transverse elastic member located most inward in the longitudinal direction is located outward in the longitudinal direction from the absorber elastic member.

12. 12. The pants-type disposable diaper according to claim 1, wherein the absorbent body is a polymer sheet having a water-absorbent polymer supported on a fiber sheet.

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