Underpants-type absorbent article

Abstract

This underpants-type absorbent article (1) has an absorber (20) containing a liquid absorbent fiber (201) and a highly absorbent polymer. An absorbent body (10) including the absorber (20) has a pair of leg gather parts (LG), and the leg gather parts (LG) are provided with leg gather elastic members (17). In a torsion test of the underpants-type absorbent article (1) in a bi-folded state in which the article is folded in two at a fold (F) in the center in the longitudinal direction in an absorbed state where the skin-side surface of the underpants-type absorbent article (1) has absorbed artificial urine, the torque value of the article (1) is 44.1 mN・m or less. The leg gather elastic members (17) are disposed such that the length of the article (1) in the up-down direction in a natural state before absorption is at least 85.3% of the length of the article (1) in the up-down direction during maximum extension.

Description

Pants-type absorbent article

[0001] The present invention relates to a pants-type absorbent article.

[0002]

[0003] There are known absorbent articles including an absorbent body using a superabsorbent polymer or an absorbent body in which a superabsorbent polymer is mixed with a liquid-absorbent fiber. For example, Patent Document 1 discloses an absorbent article including an absorbent body having an absorbent layer mainly composed of a fiber aggregate and containing two or more fibers selected from synthetic fibers, water-absorbent natural fibers, and water-absorbent polymers, and an absorbent sheet provided on the non-skin side of the absorbent layer and containing a water-absorbent polymer.

[0003] JP 2023-001810 A

[0004] However, the absorbent article in Patent Document 1 has a portion of the absorbent core where the non-skin-facing layer (absorbent sheet) containing a water-absorbent polymer and the leg-hole elastic members overlap in the thickness direction, and contraction of the elastic members causes the absorbent article to shrink, reducing its apparent dimensions before use and potentially reducing the sense of security it provides. Unlike the absorbent article in Patent Document 1, even if the absorbent body using a sheet made of a superabsorbent polymer and the leg-hole elastic members do not overlap, if the absorbent body uses a thin, flexible superabsorbent polymer sheet material and the leg-hole elastic members are contracted too strongly to prevent leakage, the product may shrink vertically and similarly reduce its apparent dimensions. On the other hand, if the leg-hole elastic members are contracted too little to maintain a large apparent dimension before use, the superabsorbent polymer swells and becomes highly rigid after absorbing excrement, resulting in poor fit, and the absorbent body may sag, creating a gap between the body and the absorbent article, potentially resulting in leakage.

[0005] The present invention has been made in consideration of the above-mentioned problems, and its object is to provide a pants-type absorbent article that prevents leakage while giving the user a sense of security before using the product.

[0006] The main invention for achieving the above object is a pants-type absorbent article having a top-bottom direction, a width direction, and a front-to-back direction which are perpendicular to one another, and having an absorbent body containing a liquid-absorbent fiber and a superabsorbent polymer, the absorbent body having an absorbent main body which has a pair of leg gather portions on both sides in the width direction, and in the leg gather portions, leg gather elastic members which stretch along the top-to-bottom direction are provided outside the absorbent body in the width direction, and the pants-type absorbent article is in an unfolded and stretched state, and 40 ml of artificial urine is dropped three times over five seconds onto the skin-side surface of the pants-type absorbent article in an unfolded and stretched state, at a position 50 mm forward of the center in the longitudinal direction which is perpendicular to the width direction and at a center position in the width direction, and In a torsion test in which the pant-type absorbent article is folded in half at the central fold in the longitudinal direction and the central portions of both widthwise ends are gripped in the up-down direction and twisted around imaginary axes along the width direction, and the pant-type absorbent article is folded in half at the central fold in the longitudinal direction and the central portions of both widthwise ends are gripped in the up-down direction and twisted around imaginary axes along the up-down direction, the torque value of the pant-type absorbent article is 44.1 mN m or less, and the leg gather elastic members are arranged so that the length from the top to the bottom in the up-down direction of the pant-type absorbent article in its natural state before absorption is 85.3% or more of the length from the top to the bottom in the up-down direction of the pant-type absorbent article at its maximum stretched state. Other features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[0007] According to the present invention, it is possible to provide a pants-type absorbent article that prevents leakage and gives the user a sense of security before using the product.

[0008] 1 is a schematic perspective view of the diaper 1; 2 is a plan view of the diaper 1 in an unfolded and stretched state, viewed from the skin side; 3 is a schematic cross-sectional view taken along line CC in FIG. 2; 4 is a plan view and a cross-sectional view of the absorbent main body 10 in a stretched state; 5 is a schematic cross-sectional view of the absorbent body 20; 6 is a plan view of the absorbent cores 21-23 superimposed on each other; 7A is a plan view of the skin side layer 21 and the intermediate layer 22, and FIG. 7B is a plan view of the non-skin side layer 23; 7B is a plan view of the non-skin side layer 23; 8 is a diagram illustrating the state in which a weight W is placed; 9 is a diagram illustrating the process for achieving an absorbent state; 10A and 10B are explanatory diagrams for a torsion test; and 11C is a diagram illustrating measurement of the fold F. 12A is a diagram illustrating the state in which a test doll DL is placed on a horizontal surface Hr; 12B is a diagram illustrating the state in which the diaper 1 is worn on the test doll DL; and 12C is a diagram illustrating the state in which the diaper 1 has absorbed artificial urine. Fig. 1 is a diagram illustrating the results of a measurement test for measuring the amount of sagging and protrusion. Fig. 2 is a schematic plan view of the diaper 1 as viewed from the front side (belly side). Fig. 3 is a schematic plan view of the absorbent body 20 as viewed from the skin side. Fig. 4 is a diagram illustrating the adhesive HMA for adhering the top sheet 12. Fig. 5 is a diagram illustrating the adhesive HMA for adhering the leak-barrier film 13. Fig. 6 is a plan view and a cross-sectional view of a modified example of the absorbent main body 10. Fig. 7 is a schematic cross-sectional view showing a modified example of the non-skin-side layer 23. Fig. 8 is a plan view of a modified example of the diaper 1. Fig. 9 is an explanatory diagram of a modified example of the diaper 1.

[0009] The present specification and the accompanying drawings make clear at least the following: (Aspect 1) A pants-type absorbent article having a top-bottom direction, a width direction, and a front-to-back direction which are orthogonal to one another, and having an absorbent body containing a liquid-absorbent fiber and a superabsorbent polymer, the absorbent body having a pair of leg gather portions on both sides in the width direction, the leg gather portions having leg gather elastic members which stretch along the top-to-bottom direction and are provided on the outside in the width direction of the absorbent body, and 40 ml of artificial urine is dropped three times over 5 seconds onto the skin-side surface of the pants-type absorbent article in an unfolded and stretched state, at a position 50 mm forward of the center in the longitudinal direction orthogonal to the width direction and at a position in the center in the width direction, and in an absorbed state in which the artificial urine has been absorbed, In a torsion test in which the pant-type absorbent article is folded in half at the central fold and the central portions of both widthwise ends are grasped and twisted around an imaginary axis along the width direction, and the central portions of both widthwise ends of the pant-type absorbent article are grasped and twisted around an imaginary axis along the vertical direction, the torque value of the pant-type absorbent article is 44.1 mN·m or less, and the leg gather elastic members are arranged so that the length from the top to the bottom in the vertical direction of the pant-type absorbent article in its natural state before absorption is 85.3% or more of the length from the top to the bottom in the vertical direction of the pant-type absorbent article when it is fully stretched.

[0010] According to Aspect 1, since the bending resistance (torque value) after absorption is low, i.e., the article remains soft even after absorption, even if the contraction of the leg-gathered elastic members around the legs is weak, the contraction force of the leg-gathered elastic members is easily transmitted, and the contraction does not weaken. Therefore, the article fits easily around the legs and prevents leakage. Furthermore, the article shrinks little in the vertical direction before absorption, and the apparent dimensions of the article before use are large, giving the user a sense of security.

[0011] (Aspect 2) The pant-type absorbent article according to aspect 1, wherein in a torsion test in which the central portions of the longitudinal direction at both widthwise ends of the pant-type absorbent article in the folded state are grasped and twisted around an imaginary axis along the width direction, and the central portions of the widthwise ends of the pant-type absorbent article in the folded state are grasped and twisted around an imaginary axis along the longitudinal direction, the torque value of the pant-type absorbent article before absorption is 21.1 mN·m or less.

[0012] According to the second aspect, the article is soft even before absorption, so that even if the contraction around the legs due to the leg gather elastic members is weak, the contraction force of the leg gather elastic members is easily transmitted, and the fit before absorption can be maintained.

[0013] (Aspect 3) In a measurement test using a test doll to measure the amount of sagging and protrusion of the pants-type absorbent article after absorbing liquid, the length L1 in the up-down direction from the urination opening of the test doll to the bottom end of the pants-type absorbent article after absorbing liquid was measured, and the length L2 in the front-to-back direction from the urination opening of the test doll to the front end of the pants-type absorbent article after absorbing liquid was measured. When the length L1 is the sagging length and the length L2 is the protrusion length, the value obtained by multiplying the length L1 and the length L2 is 2004 mm. ２ The pants-type absorbent article according to Aspect 1 or 2 is as follows:

[0014] According to Aspect 3, by keeping the value below this level, the absorbent body is prevented from expanding even after absorbing liquid. Since the absorbent body is less likely to expand after absorption and has a low post-absorption stiffness and softness, even if the leg-gathering elastic members cause weak contraction around the legs, the contraction force of the leg-gathering elastic members is easily transmitted, and the fit is less likely to deteriorate. Furthermore, by weakening the contraction of the leg-gathering elastic members, vertical contraction is suppressed, allowing the apparent dimensions to be increased.

[0015] (Aspect 4) A pants-type absorbent article according to any one of aspects 1 to 3, which has a front waistline portion and a rear waistline portion joined by a pair of side joints on both sides in the width direction, and when an intersection C1 is defined as the point of intersection between a line segment connecting the lower ends of the pair of side joints on both sides in the width direction and the leg gather elastic member, the ratio of a length L5 of the line segment connecting the intersection C1 to the lower end position of the leg gather elastic member to a length L3 in the vertical direction from the lower end position of the side joint to the lower end position of the pants-type absorbent article is 45% or more.

[0016] According to Aspect 4, the leg gather elastic members do not contract too much, which reduces the apparent size of the product before use, thereby reducing the wearer's anxiety about leakage before use and providing a sense of security before use.

[0017] (Aspect 5) In the unfolded state, the leg gather portion is provided with three or more leg gather elastic members that stretch along the longitudinal direction, and in the width direction, a region between the innermost leg gather elastic member and the outermost leg gather elastic member is defined as a leg gather elastic region, and when the leg gather elastic region is divided into two equal parts in the width direction, the inner region is defined as an inner leg gather elastic region, and the outer region is defined as an outer leg gather elastic region. In this case, the stretching force of the leg gather elastic members disposed in the outer leg gather elastic region in the longitudinal direction is a leg gather intermittent portion, where a portion where an elastic force of at least some of the leg gather elastic members arranged in the inner leg gather elastic region is applied overlaps with a portion where an elastic force of at least some of the leg gather elastic members arranged in the inner leg gather elastic region is not applied, is provided only forward of a center position of the pant-type absorbent article, and the force required to stretch the inner leg gather elastic region by a unit length from its natural state in the longitudinal direction in the leg gather intermittent portion is smaller than the force required to stretch the outer leg gather elastic region by a unit length from its natural state in the longitudinal direction.

[0018] According to the fifth aspect, the force of the leg gather elastic members (inner leg gather elastic regions) close to the absorbent body is small, so that the absorbent body is less likely to shrink before use, thereby reducing anxiety about leakage before use.

[0019] (Aspect 6) A pants-type absorbent article according to any one of Aspects 1 to 5, wherein a plurality of the leg gather elastic members are provided, and the absorbent main body has a pair of leakage prevention wall portions on both sides in the width direction, the leakage prevention wall portions stretch along the up-down direction and have one or more leakage prevention wall elastic members that make the leakage prevention wall portions stand up against the skin, and the elongation ratio of each of the leakage prevention wall elastic members is greater than the elongation ratio of each of the leg gather elastic members.

[0020] According to Aspect 6, the leakage preventing wall elastic members are elastic members that make the leakage preventing wall portions stand up toward the skin, and even if the extension ratio of such elastic members is large, the effect of shrinking the absorbent body is small, but if the extension ratio of the leg gather elastic members is large, the effect of shrinking the absorbent body is large. Therefore, by reducing the extension ratio of the leg gather elastic members (by weakening the contraction force), the absorbent body is less likely to shrink, and it is easier to maintain a large apparent size before use.

[0021] (Aspect 7) In the pants-type absorbent article according to Aspect 6, the leg gather elastic member provided on the innermost side in the width direction among the plurality of leg gather elastic members is located at the same position as the rising point of the leakage preventing wall portion or outside the rising point in the width direction.

[0022] According to aspect 7, if the elastic members of the leakage preventing wall and the leg gather elastic members are located inside the rising point of the leakage preventing wall, the positions at which the elastic forces of the leakage preventing wall and the leg gather elastic members are exerted will be close to each other, which may cause the absorbent body to shrink. However, the above configuration reduces the shrinkage of the absorbent body.

[0023] (Aspect 8) In the pants-type absorbent article according to any one of Aspects 1 to 7, the leg gather elastic members have an elongation ratio of 2.4 times or less, a number of the leg gather elastic members is 1 to 6, and a thickness is 310 dtex or more and 780 dtex or less.

[0024] According to aspect 8, the weak contraction of the leg gather elastic members suppresses shrinkage of the article in the vertical direction, and the apparent dimensions of the article before use become larger, giving the user a sense of security.

[0025] (Aspect 9) The pants-type absorbent article according to any one of Aspects 1 to 8, wherein in the unfolded and stretched state, the absorbent body has a constricted portion in a crotch region corresponding to the crotch of a wearer, the constricted portion having a width in the width direction that is narrower than the maximum width of one end of the absorbent body in the longitudinal direction.

[0026] According to Aspect 9, the width of the absorber in the crotch area is narrow, so that the rigidity of the crotch area after absorption can be reduced and the groin area can be easily fitted. Therefore, leakage is less likely even when urination is performed multiple times.

[0027] (Aspect 10) The pants-type absorbent article according to any one of Aspects 1 to 9, wherein the absorber has a low-basis-weight region in a crotch portion corresponding to the crotch of a wearer, the low-basis-weight region having a lower basis weight than the surrounding area and extending in the up-down direction.

[0028] According to Aspect 10, by providing a low basis weight region, the stiffness after absorption can be reduced and the diaper can be easily fitted to the leg openings. Therefore, leakage is less likely even when urination is performed multiple times.

[0029] (Aspect 11) The pants-type absorbent article according to any one of Aspects 1 to 10, wherein the absorbent body has a plurality of compression portions formed so as to compress the absorbent body in the thickness direction.

[0030] According to aspect 11, the rigidity before use is increased to make the absorbent body less likely to shrink. Since the absorbent body is less likely to shrink, it is possible to prevent the apparent dimensions before use from becoming smaller, giving the wearer a sense of security.

[0031] (Aspect 12) The pants-type absorbent article according to any one of Aspects 1 to 11, wherein the absorbent body has a greater number of layers of materials at both side edges in the width direction than at a central portion in the width direction.

[0032] According to Aspect 12, the rigidity of the absorbent body is higher at the widthwise ends than at the widthwise center, and shrinkage of the widthwise ends near the leg gather elastic members located widthwise outward of the absorbent body is suppressed, thereby suppressing a reduction in the apparent dimensions before use and reducing anxiety about leakage before use.

[0033] (Aspect 13) The pants-type absorbent article according to any one of Aspects 1 to 12, wherein the absorbent main body has a top sheet provided closer to the skin than the absorbent body, and the top sheet extends further in the width direction than the absorbent body.

[0034] According to aspect 13, leg gathers are provided on both sides of the absorbent body in the width direction, and the presence of the top sheet up to the vicinity of the leg gathers increases the rigidity of the vicinity of the leg gathers, thereby reducing the stretching force of the leg gathers transmitted to the absorbent body.

[0035] (Aspect 14) The pants-type absorbent article according to Aspect 13, wherein in an unfolded state, the pants-type absorbent article has a thickness direction that intersects with the longitudinal direction and the width direction, and an adhesive is continuously provided in the longitudinal direction on the non-skin side surface of the top sheet in the thickness direction in an area that overlaps with at least a portion where the stretching force of the leg gather elastic member acts in the longitudinal direction.

[0036] According to Aspect 14, the adhesive is continuously provided in the longitudinal direction, which increases the rigidity in the longitudinal direction and makes the absorbent body less likely to shrink in the longitudinal (vertical) direction. This prevents the apparent dimensions before use from becoming smaller, providing a sense of security.

[0037] (Aspect 15) The pants-type absorbent article according to any one of Aspects 1 to 14, wherein, in the unfolded and stretched state, the region from the end of the absorber to the end of the absorbent main body in the width direction is divided into three and the leg gather elastic members are not provided in the innermost region.

[0038] According to aspect 15, by not providing leg gather elastic members in the region close to the absorbent body among the three regions divided in the width direction, deformation of the absorbent body can be suppressed, making the absorbent body less likely to shrink in the vertical direction.

[0039] (Aspect 16) A pants-type absorbent article according to any one of aspects 1 to 15, which has, in an unfolded state, a thickness direction that intersects with the longitudinal direction and the width direction, and the absorbent main body has a non-skin-side sheet that is provided on the non-skin-side side of the absorbent body in the thickness direction, and a leak-proof film that is provided between the absorbent body and the non-skin-side sheet in the thickness direction, and the leak-proof film and the leg gather elastic member have overlapping portions when viewed in the thickness direction.

[0040] According to Aspect 16, the overlapping portions of the leak-barrier film and the leg gather elastic members have high rigidity, which can reduce the force that contracts the absorbent body, thereby preventing the apparent dimensions from becoming smaller before use and reducing concerns about leakage before use.

[0041] (Aspect 17) In the pants-type absorbent article according to Aspect 16, the leak-proof film is adhered by an adhesive that is continuously provided in the up-down direction at least in an area that overlaps with a portion where the stretching force of the leg gather elastic member acts in the up-down direction.

[0042] According to Aspect 17, the adhesive is provided continuously in the vertical direction, which increases the rigidity in the vertical direction and makes the absorbent body less likely to shrink in the vertical direction. This prevents the apparent dimensions from decreasing before use, reduces anxiety about leakage before use, and provides a sense of security.

[0043] (Aspect 18) A pants-type absorbent article according to Aspect 16 or 17, which has a front waistline portion and a rear waistline portion that is configured as a separate member from the front waistline portion, the front waistline portion and the rear waistline portion being joined at both sides in the width direction by a pair of side joining portions, and at least in the crotch portion corresponding to the crotch of the wearer, a portion in which a plurality of sheet materials are provided on the non-skin side in the thickness direction of the leakproof film.

[0044] According to Aspect 18, the rigidity of the crotch area (the center of the product) is increased, suppressing vertical shrinkage of the entire product. This prevents the apparent dimensions from decreasing before use, reduces anxiety about leakage before use, and provides a sense of security.

[0045] (Aspect 19) A pants-type absorbent article according to any one of Aspects 16 to 18, comprising a front waistband and a rear waistband that is configured as a separate member from the front waistband, the front waistband and the rear waistband being joined at both sides in the width direction by a pair of side joining portions, and in the crotch portion corresponding to the crotch of a wearer, when the area that is closer to the skin in the thickness direction than the leakproof film is defined as an outer area, the basis weight of the outer area is higher than the basis weight of the sheet material that is arranged outermost in the thickness direction in the front waistband or the rear waistband.

[0046] According to Aspect 19, the increased rigidity of the crotch area (the center of the product) suppresses vertical shrinkage of the entire product, thereby preventing the apparent dimensions before use from becoming smaller, reducing anxiety about leakage before use and providing a sense of security.

[0047] (Aspect 20) The pants-type absorbent article according to any one of Aspects 1 to 19, wherein in an unfolded state, the pants-type absorbent article has a thickness direction that intersects with the longitudinal direction and the width direction, and a sheet material other than the sheet material that constitutes the leg gathered portions is provided closer to the skin than the leg gathered portions as viewed in the thickness direction.

[0048] According to Aspect 20, the sheet material is further layered on the skin-facing side of the leg gathers, increasing their rigidity and reducing the stretching force of the leg gathers. This suppresses shrinkage of the absorbent body in the vertical direction (longitudinal direction) and prevents the apparent dimensions before use from becoming smaller, thereby reducing concerns about leakage before use.

[0049] (Mode 21) A pants-type absorbent article according to any one of modes 1 to 20, which has a pair of leakage prevention wall portions on both sides in the width direction of the absorbent main body, the leakage prevention wall portions stretch along the up-down direction and have one or more leakage prevention wall elastic members that make the leakage prevention wall portions stand up against the skin, the leakage prevention wall portions have a plurality of compression portions formed to compress the leakage prevention wall portions in the thickness direction, and has portions where the leg gather portions and the compression portions overlap when viewed in the thickness direction of the pants-type absorbent article.

[0050] According to Aspect 21, the compressed portions increase the rigidity of the leg areas and reduce the stretching force of the leg gathers, thereby suppressing shrinkage of the absorbent body in the vertical direction, reducing the reduction in the apparent dimensions before use, and providing a sense of security before use.

[0051] (Aspect 22) A pants-type absorbent article according to any one of Aspects 1 to 21, wherein in an unfolded state, the absorbent body has a thickness direction perpendicular to the longitudinal direction and the width direction, the absorbent body has a plurality of layers stacked in the thickness direction, one of the plurality of layers is a superabsorbent polymer layer in which the volume occupied by the superabsorbent polymer is larger than the volume occupied by the liquid-absorbent fiber, the superabsorbent polymer layer has high basis weight regions in which the basis weight of the superabsorbent polymer is higher than that of surrounding areas, the high basis weight regions are arranged so that points of maximum thickness in the thickness direction are located intermittently in the longitudinal direction and the width direction, the maximum thickness is within 3 mm, and the distance between adjacent points of maximum thickness is 5 times or less the maximum thickness.

[0052] According to Aspect 22, the superabsorbent polymer layer has a low-basis-weight region formed around a high-basis-weight region, and the low-basis-weight region serves as a folding point, making it easier to deform and improving fit. Furthermore, because the superabsorbent polymer layer is thin, the absorbent body can maintain its thinness. Therefore, with an article having such a thin absorbent body, even if the contraction around the legs due to the leg-gathered elastic members is weak, the contraction force of the leg-gathered elastic members is easily transmitted, and the contraction does not weaken.

[0053] (Aspect 23) The pants-type absorbent article according to any one of Aspects 1 to 22, wherein the absorbent main body has an absorbent core including a skin-side layer, an intermediate layer, and a non-skin-side layer laminated at least in the thickness direction, and the intermediate layer does not include a nonwoven fabric.

[0054] According to Aspect 23, the skin-side layer and the intermediate layer of the absorbent core are laminated adjacently in the thickness direction without a nonwoven fabric in between, which prevents the adhesive or the nonwoven fabric from interfering with the transfer of excreted fluid from the skin-side layer to the intermediate layer, thereby increasing the rate of absorption by the intermediate layer.

[0055] (Aspect 24) The pants-type absorbent article according to any one of Aspects 1 to 23, wherein the layer of the absorbent core closest to the skin does not contain a water-absorbent resin powder.

[0056] According to aspect 24, since the layer closest to the skin does not contain water-absorbent resin powder such as SAP, it is less likely to give a granular, gritty feeling to the wearer's skin, thereby reducing the discomfort felt when worn.

[0057] (Aspect 25) The pants-type absorbent article according to any one of Aspects 1 to 23, wherein the superabsorbent polymer in the layer closest to the skin of the absorbent core has a liquid permeation rate under load of more than 10 seconds.

[0058] According to aspect 25, by making the liquid permeation rate under load in the layer closest to the skin exceed 10 seconds, the water retention of the absorbent core is improved compared to the opposite case, leading to prevention of leakage and also preventing the absorbent core from becoming thicker locally.

[0059] Embodiments The absorbent article according to the present invention will be described using a pants-type disposable diaper 1 for infants (hereinafter also referred to as "diaper 1") as an example. However, the absorbent article according to the present invention also includes absorbent articles such as tape-type disposable diapers and shorts-type napkins. Furthermore, the wearer of the absorbent article is not limited to infants, but may also be an adult, an animal, or other living being.

[0060] <Configuration of Diaper 1> Fig. 1 is a schematic perspective view of the diaper 1. Fig. 2 is a plan view of the diaper 1 in an unfolded and stretched state, as seen from the skin side. Fig. 3 is a schematic cross-sectional view taken along line CC in Fig. 2.

[0061] In the pants-type state shown in Fig. 1, the diaper 1 has a vertical direction, a width direction, and a front-to-rear direction that are perpendicular to each other, and has a waist opening BH and a pair of leg openings LH. In the vertical direction, the waist opening BH side is the upper side, and the crotch side (the leg opening LH side) is the lower side. In the front-to-rear direction, the front side corresponds to the wearer's abdomen, and the rear side corresponds to the wearer's back. The width direction is a direction along the stretch direction of the waist elastic members 33, 43 of the front waist portion 30 and the rear waist portion 40. The vertical direction is a direction perpendicular to the stretch direction.

[0062] The diaper 1 is a so-called three-piece pants-type diaper having a liquid-absorbent main body 10 and a pair of waist-surrounding sections 30, 40. Of the pair of waist-surrounding sections, the one covering the wearer's abdominal region is also referred to as the front waist-surrounding section 30, and the other covering the wearer's dorsal region is also referred to as the rear waist-surrounding section 40.

[0063] In the unfolded and stretched state shown in Fig. 2, the diaper 1 has a longitudinal direction, a width direction, and a thickness direction that are perpendicular to one another. The longitudinal direction is along the longitudinal direction of the absorbent main body 10 and along the vertical direction of the pants-type diaper 1. Line CL in Fig. 2 etc. is a center line in the longitudinal direction. One side in the longitudinal direction corresponds to the ventral side (front side), and the other side corresponds to the dorsal side (rear side). The thickness direction is the direction in which the materials constituting the diaper 1 are layered, as shown in Fig. 3. In the thickness direction, the side that comes into contact with the wearer's skin is referred to as the skin side, and the opposite side is referred to as the non-skin side.

[0064] The "stretched state" of the diaper 1 refers to a state in which the diaper 1 as a whole is stretched without wrinkles by stretching each elastic member of the diaper 1 (e.g., the leg gather elastic member 17 and the waist elastic members 33, 43, etc., which will be described later), specifically, a state in which each component constituting the diaper 1 (e.g., the absorbent main body 10 and the waist portions 30, 40, etc., which will be described later) is stretched until its dimensions match or are close to those of the individual components. The "unfolded state" of the diaper 1 refers to a state in which the pair of side joining portions 2, which are provided on both sides of the diaper 1, are separated, and the diaper 1 is opened and unfolded flat.

[0065] On the other hand, the state of the diaper 1 after it has been left for a predetermined period of time is referred to as the "natural state." For example, the diaper 1 is removed from the package in its finished state, and the waistbands 30, 40 are pulled outward in both the left and right directions to create a "stretched state." After this stretched state is maintained for 15 seconds, the tension on the diaper 1 is released and the diaper 1 is placed on a flat surface such as a desk. The state of the diaper 1 after being left flat for 5 minutes is referred to as the "natural state."

[0066] In the unfolded state, the front waistline section 30 and the rear waistline section 40 are aligned parallel to each other with a longitudinal gap between them, with the absorbent main body 10 draped between them, with each longitudinal end of the absorbent main body 10 joined and fixed to the skin-facing side of the nearest waistline section 30, 40, resulting in a generally H-shaped appearance in a plan view. From this state, the absorbent main body 10 is folded in half at a fold F along the longitudinal centerline CL of the absorbent main body 10. In this folded state (hereinafter also referred to as the "folded state"), the opposing front waistline section 30 and rear waistline section 40 are joined and connected at their widthwise opposite sides to form a pair of side joints 2. This results in the diaper 1 being in a pants-like state (see FIG. 1 ) having a waistline opening BH and a pair of leg openings LH. The side joints 2 are formed by known joining methods such as welding or adhesive bonding.

[0067] (Absorbent main body 10) Fig. 4 is a plan view and a cross-sectional view of the absorbent main body 10 in an extended state. As shown in the cross-sectional views of Fig. 3 and Fig. 4, the absorbent main body 10 comprises an absorbent body 20 (details will be described later), a liquid-permeable top sheet 12 arranged on the skin side of the absorbent body 20, a liquid-impermeable leak-proof film 13 arranged on the non-skin side of the absorbent body 20, an exterior sheet 14 arranged on the non-skin side of the leak-proof film 13 and forming an exterior of the absorbent main body 10, and a pair of side sheets 15, 15 provided on the skin side of the top sheet 12 at both widthwise end portions of the absorbent main body 10. Furthermore, a pair of leg gather portions LG, LG is formed by the exterior sheet 14, and a pair of leakage barrier portions LSG, LSG is formed by the side sheet 15.

[0068] The top sheet 12 is a liquid-permeable sheet member that covers the absorbent body 20 from the skin side, and is made of, for example, a hydrophilic air-through nonwoven fabric or a spunbond nonwoven fabric. A second sheet (not shown) equivalent to the top sheet 12 may also be provided between the top sheet 12 and the absorbent body 20.

[0069] The leak-proof film 13 is a breathable and liquid-impermeable sheet member that is placed on the non-skin side of the absorbent body 20, and can be, for example, a microporous breathable resin film that has multiple fine holes in a sheet made primarily of a resin such as polyethylene or polypropylene.

[0070] The exterior sheet 14 is a sheet member that is provided on the side of the absorbent body 10 closest to the skin and that constitutes the exterior of the absorbent body 10, and can be made of, for example, an air-through nonwoven fabric or a spunbond nonwoven fabric.

[0071] The exterior sheet 14 extends outward in the width direction beyond the outer ends 20es, 20es of the absorbent body 20, and this extending portion is folded inward in the left-right direction and toward the skin in the thickness direction, with the outer ends 10es, 10es in the left-right direction of the absorbent main body 10 as folding positions, to form folded-back portions 14f. Then, the unfolded portion of the exterior sheet 14 and the folded-back portions 14f are joined together in a state in which at least a part of the leakproof film 13 is sandwiched between them in the thickness direction, thereby forming a pair of leg gathered portions LG, LG.

[0072] A plurality of leg gather elastic members 17, 17... such as rubber threads are provided at predetermined intervals in the width direction between the outer sheet 14 and the folded-back portion 14f forming the leg gather portion LG in the thickness direction, each stretched at a predetermined stretch ratio in the longitudinal direction. The leg gather elastic members 17 impart stretchability to the leg gather portion LG in the longitudinal direction (vertical direction).

[0073] In FIG. 4, six leg gather elastic members 17 are provided in each of the leg gather portions LG on both sides in the width direction. Specifically, six leg gather elastic members 17, numbered the first leg gather elastic member 17a through the sixth leg gather elastic member 17f, are provided from the inside to the outside in the width direction. Note that FIGS. 2 and 4 only show the stretchable portions (i.e., the effective length portions) of each leg gather elastic member 17a through 17f. In other words, the stretchability of the leg gather elastic members 17 is exerted in the portions indicated by dashed lines. However, the arrangement and number of the leg gather elastic members 17 are not limited to these and can be changed as appropriate. Furthermore, in the cross-sectional view of FIG. 4, the leg gather elastic members 17 are primarily provided closer to the skin than the leakage barrier film 13, but leg gather elastic members 17 closer to the skin than the leakage barrier film 13 may also be provided.

[0074] The side sheets 15 are generally rectangular sheet members, and are made of, for example, an air-through nonwoven fabric or a spunbond nonwoven fabric similar to the top sheet 12 and the exterior sheet 14. The side sheets 15 are folded back at their widthwise inner ends 15ei and overlapped in the thickness direction, and are joined with the leakage preventing wall elastic members 16 sandwiched between them in the thickness direction. The widthwise inner ends 15ei of the side sheets 15 are the portions that become the leading ends of the leakage preventing wall portions LSG when they are erected.

[0075] The leak preventing wall elastic members 16 are made of, for example, rubber thread, and are arranged at predetermined intervals in the width direction while being stretched in the longitudinal direction at a predetermined stretch ratio. This gives the leak preventing wall portion LSG stretchability in the longitudinal direction (up-down direction). In Figure 4, two leak preventing wall elastic members 16 are provided: a first leak preventing wall elastic member 16a arranged near the inner end 15ei in the width direction, and a second leak preventing wall elastic member 16b arranged at a predetermined interval outside the first leak preventing wall elastic member 16a in the width direction. However, the arrangement and number of the leak preventing wall elastic members 16 are not limited to this and can be changed as appropriate.

[0076] 4 shows only the stretchable portions (i.e., the effective length portions) of the leakage preventing wall elastic members 16a, 16b. When the diaper 1 is worn, the leakage preventing wall portions LSG rise up toward the wearer's skin due to the stretchable force exerted by the leakage preventing wall elastic members 16a, 16b.

[0077] The front waistband portion 30 and the back waistband portion 40 each include a non-skin-side sheet 31, 41, a skin-side sheet 32, 42, and multiple waistband elastic members 33, 43 (corresponding to transverse elastic members) such as rubber threads. As shown in FIG. 2 , the non-skin-side sheet 31 and the skin-side sheet 32 ​​are each rectangular in plan view and are laminated and bonded together in the thickness direction. Examples of materials that can be used for the non-skin-side sheet 31 and the skin-side sheet 32 ​​include SMS nonwoven fabric (spunbond, meltblown, spunbond nonwoven fabric), spunbond nonwoven fabric, and air-through nonwoven fabric. The multiple waistband elastic members 33, 43 are arranged vertically between the skin-side sheet 32, 42 and the non-skin-side sheet 31, 41 in the thickness direction and are attached in a stretched state in the width direction. The stretchability exhibited by the waist elastic members 33, 43 allows the front waist portion 30 and the rear waist portion 40 to fit the waist of the wearer.

[0078] In addition, some of the multiple waistline elastic members 33, 43 (transverse elastic members) are cut at the center in the width direction (see FIG. 2 ), making it difficult for stretching forces along the width direction to act in the areas where the waistline elastic members 33, 43 are cut in the front waistline section 30 and the rear waistline section 40. In addition, a cover sheet (not shown) may be provided so as to cover the upper end of the absorbent main body 10 from the skin side. The cover sheet can prevent the absorbent main body 10 from opening, etc.

[0079] The basic configuration of the diaper 1 has been described above, but the above configuration is merely an example and is not intended to be limiting. For example, the front waistline portion 30 and the rear waistline portion 40 may be formed from a single continuous member, or an outer member may be provided in the crotch area connecting the front waistline portion 30 and the rear waistline portion 40. Furthermore, the elastic members such as the waistline elastic members 33, 43 may be sheet-like elastic members instead of rubber threads.

[0080] Regarding the absorbent body 20: Fig. 5 is a schematic cross-sectional view of the absorbent body 20 of this embodiment. Fig. 6 is a plan view of the absorbent cores 21 to 23 stacked together. Fig. 7A is a plan view of the skin side layer 21 and the intermediate layer 22, and Fig. 7B is a plan view of the non-skin side layer 23.

[0081] As shown in FIG. 5 , the absorbent body 20 has absorbent cores 21-23 between a core wrap sheet 25 on the skin side and a core wrap sheet 26 on the non-skin side. The absorbent cores 21-23 are components that absorb and retain excretory fluids such as urine, and include a liquid-absorbent fiber 201 and a super absorbent polymer. The liquid-absorbent fiber 201 and the super absorbent polymer (hereinafter also referred to as SAP) are not particularly limited as long as they can be used as the absorbent core of an absorbent article. For example, the liquid-absorbent fiber 201 can be wood pulp fiber, non-wood pulp fiber such as bagasse, kenaf, bamboo, hemp, or cotton, regenerated cellulose fiber such as rayon fiber, or semi-synthetic fiber such as acetate fiber. Examples of SAP include starch-based, cellulose-based, and synthetic polymer-based polymer absorbents. The core wrap sheets 25 and 26 are liquid-permeable sheets, and examples thereof include tissue and nonwoven fabric.

[0082] The absorbent cores 21-23 each include a skin-side layer 21, an intermediate layer 22, and a non-skin-side layer 23. The intermediate layer 22 is located closer to the skin side in the thickness direction than the skin-side layer 21, and the non-skin-side layer 23 is located closer to the skin side in the thickness direction than the intermediate layer 22. The skin-side layer 21 has a first thickness t1, and is a layer in which the volume occupied by SAP is larger than the volume occupied by the liquid-absorbent fibers 201. The intermediate layer 22 has a second thickness t2, and is a layer in which the volume occupied by the liquid-absorbent fibers 201 is larger than the volume occupied by SAP. The non-skin-side layer 23 has a third thickness t3, and is a layer in which the volume occupied by SAP is larger than the volume occupied by the liquid-absorbent fibers 201.

[0083] Furthermore, the absorbent body 20 of this embodiment further includes a skin-side upper layer 24, which is located closer to the skin in the thickness direction than the skin-side layer 21 and has a fourth thickness t4 that is thinner than the first thickness t1 of the skin-side layer 21. The skin-side upper layer 24 is a layer in which the volume occupied by the liquid-absorbent fiber 201 is greater than the volume occupied by the SAP. Specifically, the skin-side upper layer 24 of this embodiment is composed only of the liquid-absorbent fiber 201. That is, the skin-side upper layer 24, which is the layer closest to the skin among the multiple layers constituting the absorbent core, does not contain water-absorbent resin powder such as superabsorbent polymer (SAP). The absence of water-absorbent resin powder such as SAP in the layer closest to the skin reduces the granular, gritty feel on the wearer's skin and reduces discomfort during wear. However, the skin-side upper layer 24 is not necessarily provided in the absorbent body 20 of this embodiment.

[0084] 5, in this embodiment, the skin side layer 21 and the intermediate layer 22 are integrally formed, and therefore the volume occupancy of SAP decreases and the volume occupancy of liquid-absorbent fiber 201 increases from the skin side layer 21 toward the intermediate layer 22. Such an absorbent core can be manufactured, for example, by adjusting the order, amount, timing, etc. of feeding the SAP and liquid-absorbent fiber 201 into a forming mold (recess) that corresponds to the shape of the absorbent core and is provided on the outer circumferential surface of a rotating drum.

[0085] In this embodiment, the skin side layer 21 and the intermediate layer 22 are laminated integrally, i.e., adjacent to each other in the thickness direction, without any adhesive or nonwoven fabric in between. This prevents the adhesive or nonwoven fabric from interfering with the transfer of excreted fluid from the skin side layer 21 to the intermediate layer 22, and increases the rate of absorption by the intermediate layer 22.

[0086] Furthermore, in this embodiment, the non-skin side layer 23 is not formed integrally with the intermediate layer 22, but is laminated adjacent to the intermediate layer 22 in the thickness direction via the non-woven fabric 27. The presence of the non-woven fabric 27 allows the excreted liquid to diffuse in the planar direction on the non-woven fabric 27 before transferring from the intermediate layer 22 to the non-skin side layer 23. Therefore, the excreted liquid diffused in the planar direction can transfer to the non-skin side layer 23, allowing the absorbent cores 21-23 to be effectively utilized in the planar direction.

[0087] The comparison of the volumes occupied by the liquid-absorbent fiber 201 and the SAP in each of the skin-side layer 21, the middle layer 22, the non-skin-side layer 23, and the skin-side upper layer 24 can be confirmed by the following method. For example, with the diaper 1 in its natural, dry state, in which no external force is acting, the diaper 1 (absorbent body 20) is cut widthwise at any position in the longitudinal direction of the absorbent body 20, specifically at a position where the four layers 21 to 24 are stacked and away from the product folding position. Next, the cut surface is magnified (e.g., 30 to 100 times) and photographed using an optical microscope (e.g., Keyence Corporation's Digital Microscope VHX-7000 or equivalent). The liquid-absorbent fiber 201 and the SAP are identified in the photographed cross-sectional image. Then, in the cross-sectional image, it is confirmed that the following layers are stacked in this order from the skin side in the thickness direction: a skin-side upper layer 24 in which the area occupied by the liquid-absorbent fibers 201 is larger than the area occupied by the SAP, a skin-side layer 21 in which the area occupied by the SAP is larger than the area occupied by the liquid-absorbent fibers 201, a middle layer 22 in which the area occupied by the liquid-absorbent fibers 201 is larger than the area occupied by the SAP, and a non-skin-side layer 23 in which the area occupied by the SAP is larger than the area occupied by the liquid-absorbent fibers 201. If the above is confirmed, the four layers 21 to 24 of this embodiment are defined. Cross-sectional images are prepared at multiple locations (e.g., 10 locations) along the longitudinal direction of the absorbent body 20 in which such four layers 21 to 24 can be confirmed, and if the area occupied by SAP in any of the cross-sectional images is larger than the area occupied by the liquid-absorbent fiber 201, then that layer is a layer in which "the volume occupied by SAP is larger than the volume occupied by the liquid-absorbent fiber," and if the area occupied by the liquid-absorbent fiber 201 in any of the cross-sectional images is larger than the area occupied by SAP, then that layer is a layer in which "the volume occupied by the liquid-absorbent fiber is larger than the volume occupied by SAP."

[0088] In addition, a comparison of the volumes occupied by the liquid-absorbent fibers 201 and the SAP in each layer can also be made by visualizing the liquid-absorbent fibers 201 and the SAP using X-ray microtomography (X-ray CT), for example, by the method described below: ScienceDirect, Carbohydrate Polymers 254, Mathias A. Hobisch et al., February 15, 2021, "How cellulose nanofibrils and cellulose microparticles impact paper strength - A visualization approach", Section "3.6. X-ray microtomography", https: / / www.sciencedirect.com / science / article / pii / S0144861720315794.

[0089] Conventionally, absorbers 20 having layers (skin-side layer 21, non-skin-side layer 23) in which the volume occupied by SAP is larger than the volume occupied by the liquid-absorbent fiber 201, or absorbers constituted only by SAP, have been thin and flexible, but if the contraction of the leg gathers (LG) is made too strong to prevent leakage, the product shrinks vertically, reducing its apparent dimensions and making it difficult to provide a sense of security before use. On the other hand, if the contraction of the leg gathers (LG) is weakened to increase the apparent dimensions before use, the SAP swells and becomes highly rigid after absorbing excrement, resulting in poor fit, and the absorber sagging, creating a gap between the body and the diaper, which could result in leakage.

[0090] In this regard, the diaper 1 of this embodiment has the following configuration: When the diaper 1 is folded in half at the fold F at the center CL in the longitudinal direction, the bottom area is 150 cm ２A 5 kg weight was placed on the diaper 1 for 24 hours, and then the weight was removed. 40 ml of artificial urine was dropped three times over 5 seconds onto the skin-side surface of the diaper 1 in an open and stretched state, at a position 50 mm forward of the longitudinal center CL and at the widthwise center C-C position (hereinafter referred to as the "drop position Pt"), to bring the diaper 1 into an absorbed state in which the artificial urine was absorbed into the diaper 1. In this absorbed state, a torsion test was conducted in which the diaper 1, folded in half, was gripped at the vertical (longitudinal) centers of both widthwise ends and twisted around an imaginary axis along the widthwise direction, and the diaper 1, folded in half, was gripped at the vertical (longitudinal) centers of both widthwise ends and twisted around an imaginary axis along the vertical direction (longitudinal direction). In this torsion test, the torque value of the diaper 1 was 44.1 mN m or less. Furthermore, the leg gather elastic members 17 are arranged so that the length LA (see FIG. 1) from the top to the bottom in the vertical direction of the diaper 1 in its natural state before absorption is at least 85.3% of the length LB from the top to the bottom in the vertical direction of the diaper 1 at its maximum extension. The state in which the weight is placed and each measurement method will be described later.

[0091] The lower the value of the torsion test result of the diaper 1, the lower the torsional rigidity of the diaper 1, making it easier to make the diaper 1 flexible. The higher the value of the torsion test result, the higher the torsional rigidity of the diaper 1, making the diaper 1 stiffer and more likely to cause discomfort to the wearer. Therefore, by ensuring that the torsion test value of the diaper 1 in the absorbent state is 44.1 mN·m or less, the diaper 1 can be made softer than when the torsion test value is greater than 44.1 mN·m. Even if the contraction of the leg-gathering elastic members 17 around the legs is weak, the contraction force of the leg-gathering elastic members 17 is easily transmitted, and the contraction of the leg-gathering elastic members 17 is not weakened. This allows the diaper 1 to fit easily around the legs and prevent leakage.

[0092] Specifically, the "length LB from the top to bottom of the diaper 1 in the vertical direction when fully stretched" is half the longitudinal length LC of the pants-type diaper 1 in the unfolded and stretched state, as shown in Fig. 2 (LB = LC / 2). The higher the ratio of the length LA from the top to bottom of the diaper 1 in the vertical direction when in the natural state before absorption to the length LB from the top to bottom of the diaper 1 in the vertical direction when fully stretched, the less the diaper 1 shrinks in the vertical direction, and the larger the apparent dimensions of the diaper 1 before use. The lower the ratio of the length LA from the top to bottom of the diaper 1 in the vertical direction when in the natural state before absorption to the length LB from the top to bottom of the diaper 1 in the vertical direction when fully stretched, the more the diaper 1 shrinks in the vertical direction, and the smaller the apparent dimensions of the diaper 1 before use. Therefore, by setting the length LA from the top to the bottom in the vertical direction of the diaper 1 in its natural state before absorption to at least 85.3% of the length from the top to the bottom in the vertical direction of the diaper 1 at its maximum extension, the apparent dimensions of the diaper 1 before use can be larger than when this ratio is less than 85.3%. The larger apparent dimensions can reduce anxiety about leakage before use and give the user a sense of security before use.

[0093] The "folded state" mentioned above refers to a state in which the diaper 1 in the unfolded state (see Fig. 2) is folded at a fold F at the center CL in the longitudinal direction, and in the case of a pants-type disposable diaper 1, this refers to the pants-type state shown in Fig. 1. In the case of an absorbent article such as a tape-type disposable diaper or an absorbent pad, it is sufficient that the absorbent article is folded at a fold F at the center in the longitudinal direction of the unfolded absorbent article, and the fold F in the folded state does not necessarily correspond to the lower end of the absorbent article when worn.

[0094] Here, the state with the weight placed, the absorption state, and the method of the torsion test will be described. <State with weight W placed on diaper 1> Generally, absorbent articles such as diapers 1 are stored in a package in which they are distributed and stored as a commodity, with a predetermined pressure being applied. The effect of the pressure applied to the diaper 1 varies depending on the state in which it is stored, and the thickness of the center of the width direction of the folded portion F of the diaper 1 changes depending on the pressure applied to the diaper. Therefore, after removing the diaper 1 from the package, a weight W (with a base area of ​​150 cm) is placed on the diaper 1 in a folded state. ２ By placing a weight of 5 kg on the diaper 1 for 24 hours, the pressure applied to the diaper 1 is equalized.

[0095] FIG. 8 is a diagram illustrating the state in which the weight W is placed. As shown in FIG. 8 , the diaper 1 folded in half (in a pants-type state) is placed on a flat surface with either the front waistline portion 30 or the rear waistline portion 40 facing downward. Then, the weight W is placed on top of the diaper 1 so that the widthwise center of the absorbent main body 10 (the center C-C of the diaper 1) is aligned with the widthwise center of the weight W and the weight W fits inside the absorbent main body 10 when viewed in the thickness direction. In this embodiment, the diaper 1 is placed on a flat surface with the front waistline portion 30 facing downward and the rear waistline portion 40 facing upward, and the weight W is placed on the rear waistline portion 40 side. In FIG. 8 , the weight W may be placed on one diaper 1, or on a stack of multiple diapers 1. Because absorbent articles such as the diaper 1 are lightweight, even when multiple diapers 1 are stacked, the difference in pressure applied to each diaper 1 is within the margin of error and is virtually negligible. However, when multiple absorbent articles are stacked, the number of stacked absorbent articles must be such that the stacked state can be maintained and the stacked absorbent articles do not collapse. In this embodiment, five diapers 1 were stacked in the thickness direction (front-to-back direction), and a weight W was placed on top of them, and the stacked diapers were left to stand for 24 hours. A torsion test (and thickness measurement, described later) was performed on all diapers 1 using the method described below.

[0096] The sinker W has a base area of ​​150 cm ２In this embodiment, a rectangular weight W is used, the length Lw1 of which is 15 cm in the longitudinal direction (vertical direction) and the length Lw2 of which is 10 cm in the width direction (Lw1 × Lw2 = 150 cm). ２ ) Since the weight of the weight W is 5 kg, a pressure of 3267 Pa is applied to the diaper 1 on which the weight W is placed. The weight W may be made of any material, and may be made of metal such as stainless steel or iron.

[0097] <Regarding the absorption state> The "absorption state" refers to the state in which the diaper 1 is in an unfolded and stretched state with the weight W removed from the diaper 1 described above, after 40 ml of artificial urine is dropped over 5 seconds onto the skin-side surface of the diaper 1 at a position 50 mm forward of the center C-C in the longitudinal direction and at the center C-C in the width direction, and this drop is repeated three times to allow the diaper 1 to absorb the artificial urine. The amount of excrement absorbed by the diaper 1 when worn varies, and this absorption state is considered to be equivalent to the average state in which the diaper 1 absorbs excrement when worn.

[0098] FIG. 9 illustrates the process for achieving an absorbent state. Specifically, as described above, a weight W is placed on the diaper 1 and left for 24 hours, after which the weight W is removed from the diaper 1. As shown in FIG. 9 , the drip position Pt is set at a position 50 mm forward of the longitudinal center of the diaper 1 in the unfolded and stretched state and at the center C-C in the width direction. This drip position Pt is the position where urination occurs when the diaper 1 is worn. A cylinder EN is placed on the skin-side surface of the diaper 1 in the unfolded and stretched state. At this time, the center of the cylinder EN is aligned with the drip position Pt. The cylinder EN is a hollow cylindrical body with an inner diameter Li of 60 mm, an outer diameter Lo of 70 mm, and a height of 50 mm. Although the artificial urine is dripped toward the drip position Pt, there is a risk of slight error or splashing. Therefore, the provision of the cylinder EN facilitates absorption of the artificial urine in the area corresponding to the urination position when the diaper 1 is worn. The artificial urine used was prepared by dissolving 200 g of urea, 80 g of sodium chloride, 8 g of magnesium sulfate, 3 g of calcium chloride, and approximately 1 g of blue No. 1 dye in 10 L of ion-exchanged water. Then, a first 40 ml dose of artificial urine was dripped onto drip position Pt (inside cylinder EN) over 5 seconds. One minute after the start of the first drip, a second 40 ml dose of artificial urine was dripped onto drip position Pt over 5 seconds. One minute after the start of the second drip, a third 40 ml dose of artificial urine was dripped onto drip position Pt over 5 seconds. This state in which the artificial urine has been absorbed into the diaper 1 is referred to as the absorbed state.

[0099] The diaper 1 in this absorbent state is subjected to a torsion test as follows. <<About the Torsion Test>> Figures 10A and 10B are explanatory diagrams of the "torsion test." Figure 10A shows a measurement method in which the diaper 1 is twisted around an imaginary axis Va1 along the width direction of the diaper 1. Figure 10B shows a measurement method in which the diaper 1 is twisted around an imaginary axis Va2 along the up-down direction of the diaper 1. Note that in the drawings, the absorbent cores 21-24 are shown to have a rectangular shape to avoid complexity. The torque value of the diaper 1 in the torsion test can be measured using an Imada torque tester (model number: EX-0762) or an equivalent device. The test environment is a room temperature of 20±2°C and a humidity of 60±5%.

[0100] (1) First, prepare the diaper 1 to be measured (the diaper 1 immediately after being removed from the package and before absorption), and identify the position to be clamped by the chuck 60 of the torque tester. As shown in the left diagrams of Figures 10A and 10B, the maximum width of the absorbent body 20 is divided into two equal parts in the width direction, and a line C1 extending along the vertical direction is drawn on the diaper 1. Another line C2 extending along the width direction is drawn on the diaper 1, and a line C2 extending along the width direction is drawn on the diaper 1. The intersection of the two lines C1 and C2 is designated as the reference point o.

[0101] (2) In the torque tester, a pair of chucks 60 are arranged at a distance in the vertical direction, and the direction perpendicular to the vertical direction of the torque tester is defined as the horizontal direction. The width W60 of the chucks 60 in the horizontal direction is approximately 25 mm. When the diaper 1 is set between the pair of chucks 60, the tension applied to the diaper 1 is set to 1 N. The load cell is set to 50 N of tension / compression, and the torque is set to 1 N.

[0102] (3) When twisting the diaper 1 around the imaginary axis Va1 along the width direction as shown in Figure 10A, the gripping positions of the zippers 60 are set at positions p1 and p2, which are 30 mm to the right and left of the reference point o in the width direction, respectively. In other words, the zipper spacing is set to 60 mm. Specifically, the lower end of the upper zipper 60 is aligned with position p2 of the diaper 1, and the upper end of the lower zipper is aligned with position p1 of the diaper 1, so that the waist side of the diaper 1 is positioned on the right side in the horizontal direction. Furthermore, the center of the zipper 60 in the horizontal direction is aligned with the reference point o of the diaper 1. This allows the diaper 1 to be twisted around the imaginary axis Va1 along the width direction of the diaper 1 by gripping the vertical centers of both widthwise ends of the diaper 1 (more specifically, the vertical centers of the absorbent cores 21-24).

[0103] (4) With the diaper 1 set as described above, the upper zipper 60 is rotated clockwise (positive rotation) to twist the diaper 1 (the diaper 1 is twisted so that the waist portion of the diaper 1 in the right drawing of FIG. 10A is positioned toward the front of the page). The diaper 1 is then returned to its initial state, and the upper zipper 60 is rotated counterclockwise (negative rotation) to twist the diaper 1 and return it to its initial state. When twisting around the imaginary axis Va1 along the width direction, the rotation speed is 50 rpm, the rotation angle is 65°, and the measurement angle is 60°. The average torque value (mN·m) at a measurement angle of 60° during clockwise rotation and a measurement angle of 60° during counterclockwise rotation is calculated.

[0104] (5) When twisting the diaper 1 around the imaginary axis Va2 in the up-down direction as shown in Figure 10B, the gripping positions of the zippers 60 are set to positions p3 and p4, which are 50 mm above and below the reference point o in the up-down direction, respectively. In other words, the zipper spacing is set to 100 mm. Specifically, the lower end of the upper zipper 60 is aligned with position p3 of the diaper 1, and the upper end of the lower zipper 60 is aligned with position p4 of the diaper 1. The center of the zipper 60 in the horizontal direction is also aligned with the reference point o of the diaper 1. This allows the diaper 1 to be twisted around the imaginary axis Va2 in the up-down direction by gripping the widthwise center of both vertical end portions of the diaper 1.

[0105] (6) With the diaper 1 set as described above, rotate the upper zipper 60 clockwise (positive rotation) to twist the diaper 1 (twist the diaper 1 so that the right-hand portion of the diaper 1 in the width direction in the right drawing of Figure 10B is positioned toward the front of the page). Then, return the diaper 1 to its initial state, and rotate the upper zipper 60 counterclockwise (negative rotation) to twist the diaper 1 and return it to its initial state. When twisting around the imaginary axis Va2 along the vertical direction, the rotation speed is 50 rpm, the rotation angle is 75°, and the measurement angle is 60°. The average torque value (mN·m) at a measurement angle of 60° during clockwise rotation and a measurement angle of 60° during counterclockwise rotation is calculated.

[0106] (7) The torque value when twisting around the virtual axis Va1 ( FIG. 10A ) and the torque value when twisting around the virtual axis Va2 ( FIG. 10B ) are measured multiple times (e.g., n = 3 times) for each measurement. Regardless of the measurement direction, multiple measurements are not performed on the same diaper 1; a different diaper 1 is prepared for each torque measurement. The average value of all the multiple (e.g., three) torque values ​​around the virtual axis Va1 and the multiple (e.g., three) torque values ​​around the virtual axis Va2 is then calculated (rounded to one decimal place). This average value is the torque value of the diaper 1 (pants-type absorbent article) before absorption.

[0107] A pants-type absorbent article (diaper 1) of this embodiment, including the absorbent body 20 configured as shown in FIGS. 4 to 7, was actually fabricated and subjected to a torsion test after being placed in the above-described absorbent state. The torque value of the diaper 1 of this embodiment after absorption in a size S was 44.1 mN·m, and the torque value of the diaper 1 of this embodiment after absorption in an XL size was 38.6 mN·m. As comparative examples, a torsion test was also conducted on commercially available pants-type diapers for infants, Products A, B, and C (Products A and B have absorbent cores composed of SAP sheets, while Product C has an absorbent body containing liquid-absorbent fibers and SAP). The torque value of Product A after absorption was 46.3 mN·m, that of Product B was 46.5 mN·m, and that of Product C was 62.8 mN·m. These results demonstrate that the diaper 1 of this embodiment has a lower torque value and higher flexibility than the commercially available comparative diapers (Products A, B, and C).

[0108] A torsion test was also conducted on the diaper 1 before it was placed in an absorbent state, i.e., after placing the weight W on the diaper 1 for 24 hours as described above and then removing the weight W from the diaper 1, before the diaper 1 was absorbed. The torque value of the XL-size diaper 1 of the present embodiment before absorption was 21.1 mN·m. The torsion test was also conducted on the comparative products A, B, and C described above before absorption. The torque value of Product A before absorption was 26.0 mN·m, the torque value of Product B was 30.7 mN·m, and the torque value of Product C was 35.4 mN·m. These results demonstrate that the diaper 1 of the present embodiment exhibits lower torque values ​​and higher flexibility, even in the pre-absorption state, compared to the commercially available comparative diapers (Products A, B, and C).

[0109] Therefore, when the torsion test value of the diaper 1 before absorption is 21.4 mN·m or less, the diaper 1 can be made softer than when the torsion test value is greater than 21.1 mN·m. Since the diaper 1 before absorption is also soft, even if the contraction around the legs due to the leg gather elastic members 17 is weak, the contraction force of the leg gather elastic members 17 is easily transmitted, and the fit before absorption can be maintained.

[0110] In this embodiment, when the diaper 1 is folded in half at the fold F (FIG. 2) at the center CL in the longitudinal direction, the bottom area is 150 cm ２In the diaper 1, a 5 kg weight was placed on the diaper 1 for 24 hours, and then the weight was removed. The thickness of the diaper 1 at the center in the width direction (center C-C) of the folded portion F was 6.4 mm or less. Specifically, for the diaper 1, after the weight was placed on the diaper 1 in a folded state for 24 hours and then the weight was removed, the thinner the thickness of the diaper 1 at the center in the width direction (center C-C) of the folded portion F, the thinner the thickness of the diaper 1 before wear. Details of the thickness measurement method will be described later. Using the thickness measurement method described later, the thickness of the folded portion F of the diaper 1 before absorption was measured. The thickness of the folded portion F of the diaper 1 of the present embodiment in the XXL size before absorption was 6.4 mm, the thickness of the diaper 1 of the present embodiment in the XL size before absorption was 5.6 mm, and the thickness of the folded portion F of the diaper 1 of the present embodiment in the S size before absorption was 4.7 mm. Therefore, by setting the thickness of the folded portion F of the diaper 1 to 6.4 mm or less before wearing, the diaper 1 can be made thinner than when the thickness of the folded portion F of the diaper 1 before wearing is greater than 6.4 mm. Because the diaper 1 has such a thin shape before wearing, even if the contraction of the leg-gathered elastic members 17 around the legs is weak, the contraction force of the leg-gathered elastic members 17 is easily transmitted, and the contraction of the leg-gathered portions LG is not weakened.

[0111] Furthermore, when the thickness of the folded portion F of the diaper 1 in the absorbent state was measured using the thickness measurement method described below, the thickness of the folded portion F of the diaper 1 after absorption was 20.3 mm. Specifically, since the absorbent cores 21-24 tend to expand in proportion to the amount of body exudates absorbed, by setting the thickness of the folded portion F of the diaper 1 in the absorbent state to 20.3 mm or less, the risk of the diaper 1 becoming excessively thick due to the absorption of body exudates during wear is reduced compared to when the thickness of the folded portion F of the diaper 1 in the absorbent state is greater than 20.3 mm. Therefore, even after the diaper 1 has absorbed body exudates, the absorber 20 is prevented from expanding and sagging downward, and leakage is prevented by forming gaps around the legs.

[0112] <Measuring the Thickness of the Folded Portion F of the Diaper 1> The thickness of the widthwise center (center C-C) of the folded portion F of the diaper 1 after the weight W has been placed thereon for 24 hours can be measured by the following well-known method. For example, the thickness can be measured using an Ozaki Seisakusho dial thickness gauge, large type J-B with spring, or an equivalent. Specifically, using an Ozaki Seisakusho dial thickness gauge, large type J-B with spring, the measurement point (the widthwise center of the folded portion F) is clamped between a pair of measuring terminals st, and a pressure of 9.0-12.0 gf / cm is measured using the pair of measuring terminals st. ２ In this embodiment, a pressure of 10.5 gf / cm is applied. ２ The measurement is performed by applying pressure to the folded portion F. Figure 11 is a diagram illustrating the measurement of the folded portion F. As shown in Figure 11, the pair of measurement terminals st are circular plates each having a diameter of 50 mm, and are arranged parallel to each other in the vertical direction (thickness direction of the diaper 1). The pair of measurement terminals st sandwich the folded portion F of the diaper 1 in the thickness direction (front-to-back direction), and the maximum value at the portion where both measurement terminals st abut against the diaper 1 is measured as the "thickness." At this time, the measurement is performed with the center C-C of the folded portion F of the diaper 1 in the width direction and the lower end of the diaper 1 in the longitudinal direction (vertical direction) aligned with the center of the measurement terminals st.

[0113] In a measurement test using a test doll to measure the amount of sagging and protrusion of the diaper 1 after absorbing liquid, the vertical length L1 from the urination opening of the test doll to the bottom end of the diaper 1 after absorbing liquid was measured, and the front-rear length L2 from the urination opening of the test doll to the front end of the diaper 1 after absorbing liquid was measured. When the length L1 is the sagging length and the length L2 is the protrusion length, the product of the length L1 and the length L2 is 2004 mm. ２ The "measurement test for measuring the amount of sagging and protrusion" is a test for measuring the amount of sagging downward in the up-down direction and the amount of protrusion forward in the front-to-back direction after the diaper 1 has absorbed excrement. Details of this measurement test will be described later.

[0114] The longer the length L1, which is the length of the sagging of the diaper 1, the greater the sagging after absorbing liquid, and the shorter the length L1, the less (smaller) the sagging after absorbing liquid. The longer the length L2, which is the length of the protruding of the diaper 1, the greater the protruding after absorbing liquid, and the shorter the length L2, the less (smaller) the protruding after absorbing liquid. The value (2004 mm) obtained by multiplying such lengths L1 and L2 is ２ ) represents the area, and the larger the area, the more (larger) the amount of sagging and protrusion of the diaper after absorbing liquid, and the smaller the area (i.e., the multiplied value is 2004 mm ２ Therefore, for the diaper 1, the product of the length L1 of the diaper after absorbing liquid and the length L2 is 2004 mm. ２ Therefore, the product of the length L1 of the diaper after absorbing liquid and the length L2 is 2004 mm. ２ In this case, sagging and protrusion of the diaper 1 after absorbing liquid can be suppressed more effectively than when the length is larger than the above.

[0115] Therefore, the product of the length L1 of the diaper 1 after absorbing liquid and the length L2 is 2004 mm. ２ Since the length of the diaper 1 is less than or equal to the length of the leg gather elastic members 17, the diaper 1 is less likely to sag after absorbing liquid and is less likely to protrude, thereby preventing gaps from forming around the legs and preventing leakage, even if the apparent dimensions of the diaper 1 are maintained large by weakening the contraction of the leg gather elastic members 17. Furthermore, since the diaper 1 is less likely to sag after absorbing liquid and is less likely to protrude, and the torque value after absorption is low and soft, even if the contraction around the legs due to the leg gather elastic members 17 is weak, the contraction force of the leg gather elastic members 17 is easily transmitted, and the fit is less likely to deteriorate.

[0116] <Measurement Test for Measuring Drooping and Protrusion Amounts> Figure 12A shows a test doll DL placed on a horizontal surface Hr, Figure 12B shows a test doll DL with a diaper 1 on it, and Figure 12C shows the diaper 1 after absorbing artificial urine. The test doll used in the measurement test was a silicone doll with a standard M-size body type (waist circumference at the navel: 40.0 cm, groin circumference at the ankles: 30.0 cm, waist circumference at the top of the buttocks: 45.0 cm). (Measurement Method) (1) Before putting the diaper 1 on the test doll, the test doll DL was placed on a horizontal surface Hr, and a wall W was prepared in front of the test doll DL, perpendicular to the horizontal surface Hr (see Figure 12A). As a premise, the direction parallel to the horizontal surface Hr is defined as the front-to-back direction, and the direction parallel to the wall W is defined as the up-to-down direction. A predetermined mark FL is made on a horizontal plane Hr extending downward from the urination opening Hn of the test doll DL in the vertical direction. Similarly, a predetermined mark WA is made on a wall W extending forward from the urination opening Hn of the test doll DL in the front-to-back direction. (2) The vertical length Ln from the mark FL to the urination opening Hn is measured. Similarly, the front-to-back length Lm from the mark WA to the urination opening Hn is measured. (3) As shown in FIG. 12B , the diaper 1 is put on the test doll DL. When putting on the diaper 1, the diaper 1 is pulled up so that the crotch portion of the test doll DL and the crotch portion of the diaper 1 come into contact with each other. At this time, the waist portions 30, 40 of the diaper 1 are not only pulled up by holding both widthwise sides but also by pulling up the front and rear portions of the waist portions 30, 40 together, so that the upper ends of the waist portions 30, 40 (the upper end of the diaper 1) are approximately straight. It is not necessary to raise the leakage prevention wall portion LSG when putting on the diaper. After putting on the diaper 1, the test doll DL is placed again in the exact same position as when the marks FL and WA were attached. (4) With the diaper 1 on the test doll DL, 40 ml of artificial urine is discharged from the test doll's urination outlet Hr over 20 seconds. In the same manner, artificial urine is discharged a total of three times (40 ml x 3). The interval between the end of the first urination and the start of the next urination is 5 minutes, and the interval between the end of the second urination and the start of the next urination is also 5 minutes.The artificial urine used was prepared by dissolving 200 g of urea, 80 g of sodium chloride, 8 g of magnesium sulfate, 3 g of calcium chloride, and approximately 1 g of blue No. 1 dye in 10 L of ion-exchange water. (5) After the third urination, the vertical length Ly from mark FL to the bottom edge of the diaper 1 worn by the test doll DL was measured. Next, the longitudinal length Lx from mark WA to the front edge of the diaper 1 worn by the test doll DL was measured. The difference between the previously measured lengths Ln and Ly (Ln - Ly) was defined as "the vertical length L1 from the test doll's urination opening to the bottom edge of the diaper 1 after absorbing liquid (see Figure 13)." The difference between the previously measured lengths Lm and Lx (Lm - Lx) was defined as "the longitudinal length L2 from the test doll's urination opening to the front edge of the diaper 1 after absorbing liquid (see Figure 13)." (6) Let length L1 be the length of hanging down and length L2 be the length of protrusion, and calculate the value (L1 x L2) by multiplying length L1 and length L2, and use this multiplied value as the amount of hanging down and protrusion.

[0117] 13 is a diagram illustrating the results of the measurement test for measuring the amount of sagging and protrusion. The results of the above-mentioned "measurement test for measuring the amount of sagging and protrusion" comparing Diaper 1 with Products A and C are as follows (see FIG. 13).

[0118] As a result of the measurement test, the diaper 1 had a hanging length L1 of 36.9 mm and a protruding length L2 of 54.3 mm, and the multiplied value (L1 x L2) was 2003.67 mm. ２ Furthermore, for product A, the hanging length L1 was 37.0 mm and the protruding length L2 was 68.2 mm, and the multiplied value (L1 x L2) was 2523.4 mm. ２ Product C had a hanging length L1 of 61.8 mm and a protruding length L2 of 62.4 mm, and the multiplied value (L1 x L2) was 3856.32 mm. ２ This shows that sagging and protrusion of the diaper 1 after absorbing liquid were suppressed more than those of the products C and D after absorbing liquid.

[0119] Fig. 14 is a schematic plan view of the diaper 1 as viewed from the front (ventral side). As shown in Fig. 14, when the diaper 1 is in its natural state, the intersection point C1 of a line segment LP connecting the lower ends 2e of a pair of side joints 2 and the leg gather elastic member 17 is defined as the intersection point C1. The ratio L5 of the length L5 of the line segment connecting the intersection point C1 to the lower end C2 of the leg gather elastic member 17 to the vertical length L3 from the lower end 2e of the side joint 2 to the lower end 1e of the diaper 1 (L5 / L3) is 45% or more. When multiple leg gather elastic members 17 are provided, the measurement is made for the elastic member (leg gather elastic member 17f in this embodiment) located on the outermost side in the width direction. Furthermore, if the leg gather elastic members 17 are tucked inside when the diaper 1 is removed from the product package, the measurement should be performed after they are pulled out (so that the non-skin facing side is visible).

[0120] The smaller the ratio of length L3 to length L5, the greater the contraction of the leg gather elastic members 17 in the natural state of the diaper 1, resulting in a smaller apparent size of the diaper 1. On the other hand, the greater the ratio of length L5 to length L3, the less the contraction of the leg gather elastic members 17 in the natural state of the diaper 1, resulting in a larger apparent size of the diaper 1. Preventing excessive contraction of the leg gather elastic members 17 reduces the reduction in the apparent size of the diaper 1 before use. This reduces the user's anxiety about leakage before use and provides a sense of security before use.

[0121] Furthermore, the leakage preventing wall portions LSG, LSG of the diaper 1 of this embodiment include one or more leakage preventing wall elastic members 16 (16a, 16b) that stretch in the up-down direction and cause the leakage preventing wall portions LSG to stand up against the skin, and the extension ratio of each leakage preventing wall elastic member 16 is greater than the extension ratio of each leg gather elastic member 17. Here, the "extension ratio" refers to the value of "length at maximum extension / length in natural state," and more specifically, it refers to the value (LX / LY) that indicates how many times the total length LX of each elastic member in the extended state is compared with the total length LY in the natural, unloaded state (how many times the elastic member is stretched when fixed to a material). The leakage preventing wall elastic members 16 are elastic members that cause the leakage preventing wall portions LSG to stand up against the skin, and even if the extension ratio of such elastic members is high, the effect of shortening the absorber 20 is small, whereas a high extension ratio of the leg gather elastic members 17 has a significant effect of shortening the absorber 20. Therefore, by reducing the extension ratio of the leg gather elastic members 17 (by weakening the contraction force), the absorbent body 20 is made less likely to shrink, and the apparent dimensions before use are maintained large.

[0122] The relationship between the extension ratios of the leakage preventing wall elastic members 16 and the leg gather elastic members 17 mentioned above also means that the force required to extend each leakage preventing wall elastic member 16 by a unit length in the vertical direction from its natural state is greater than the force required to extend each leg gather elastic member 17 by a unit length in the vertical direction from its natural state. Even if the force required to extend the leakage preventing wall elastic members 16 is strong, the effect of contracting the absorbent body 20 is small, but if the force required for the leg gather elastic members 17 is strong, the effect of contracting the absorbent body 20 is large. Therefore, by reducing the force required to extend the leg gather elastic members 17 (i.e., by weakening the contracting force), the absorbent body 20 becomes less likely to contract, and it becomes easier to maintain a large apparent size before use.

[0123] The leg gather elastic members 17 preferably have an elongation ratio of 2.4 or less. The number of leg gather elastic members 17 in the diaper 1 is preferably 1 to 6, and the thickness is preferably 310 dtex to 780 dtex. By reducing the contraction of the leg gather elastic members 17, shrinkage of the diaper 1 in the vertical direction is suppressed, and the apparent dimensions of the diaper 1 before use are maintained large, providing a sense of security to the user.

[0124] The contraction force of the leg gather elastic member 17 is preferably 0.62 N or less. The "contraction force" mentioned above refers to the load applied to the tensile tester when each sample of the leg gather elastic member 17 cut to a predetermined length is pulled in the width direction by a tensile tester to an elongated state (for example, an elongated state of 90% of the maximum elongation), and then the sample is shrunk from that elongated state to a predetermined contraction rate (for example, 70%), i.e., the force (unit: N (sample width L / 4)) that causes the sample to contract and return to its original state.

[0125] Furthermore, in this embodiment, among the multiple leg gather elastic members 17a-17f, the leg gather elastic member 17a located at the innermost position in the width direction is located outside the rising starting point 18ei of the leakage preventing wall portion LSG in the width direction. Note, however, that this is not limitative, and for example, the leg gather elastic member 17a located at the innermost position in the width direction may be located at the same position in the width direction as the rising starting point 18ei of the leakage preventing wall portion LSG. If the leg gather elastic member 17a located at the innermost position in the width direction were located inside the rising starting point 18ei of the leakage preventing wall portion LSG, the positions at which the stretching force of the leakage preventing wall elastic member 16 and the stretching force of the leg gather elastic member 17 would be close to each other, which could cause the absorbent body 20 to shrink. However, the above configuration reduces shrinkage of the absorbent body 20 (absorbent main body 10).

[0126] In this embodiment, as shown in Figures 6, 7A, and 7B, the skin-side layer 21 and the intermediate layer 22 among the multiple layers have narrower constricted portions 212, 222 in the crotch region M (Figure 2) that corresponds to the wearer's crotch. The skin-side layer 21 and the intermediate layer 22 illustrated in Figures 6 and 7A are integrally formed and have the same planar shape. The width of the constricted portions 212, 222 does not necessarily have to be narrower than the width of the skin-side layer 21 and the intermediate layer 22 (absorbent body 20) in the longitudinal direction, but only needs to be narrower than the maximum width of one longitudinal end of the skin-side layer 21 and the intermediate layer 22 (absorbent body 20). The narrow width of the absorbent body 20 in the crotch region M reduces the rigidity of the crotch region M after absorption, improving the fit to the leg openings. Therefore, even if urination is performed multiple times, leakage is less likely to occur.

[0127] When the diaper 1 is worn, the absorbent body 20 (absorbent core) has a basis weight (i.e., the total basis weight of the liquid-absorbent fiber 201 and the SAP: g / m) in the crotch region M corresponding to the crotch of the wearer, which is smaller than the surrounding area. ２ ) is low and has a low basis weight region along the longitudinal direction (vertical direction). Specifically, it is preferable that at least one of the skin side layer (constricting layer) 21, the intermediate layer (constricting layer) 22, and the non-skin side layer (extension layer) 23 has the low basis weight region. In the absorbent body 20 of this embodiment, as shown in Fig. 5, the skin side layer 21 and the intermediate layer 22 have low basis weight regions 211, 221, and similarly, the non-skin side layer 23 also has a low basis weight region 231.

[0128] Therefore, when the wearer excretes in the diaper 1 and the absorbent body 20 receives the excreted liquid, the excreted liquid is quickly drawn from the low basis weight region 211 into the interior of the absorbent body 20 (intermediate layer 22). The liquid-absorbent fiber 201 has a faster liquid absorption rate than SAP. Because the volume occupancy of the liquid-absorbent fiber 201 is high in the intermediate layer 22, the excreted liquid that migrates from the low basis weight region 211 to the intermediate layer 22 is quickly and temporarily absorbed by the intermediate layer 22. Thereafter, the excreted liquid absorbed between the fibers of the liquid-absorbent fiber 201 in the intermediate layer 22 gradually migrates to the non-skinside layer 23 due to gravity. Furthermore, because the intermediate layer 22 also has a low basis weight region 221, excreted liquid is more likely to migrate from the low basis weight region 221 to the non-skinside layer 23, and more likely to migrate from the low basis weight region 231 of the non-skinside layer 23 to a deeper portion of the non-skinside layer 23.

[0129] The low-basis-weight regions 211, 221, and 231 allow absorbed excrement to be more easily dispersed, improving absorbency. The low-basis-weight regions 211, 221, and 231 also reduce the rigidity of the diaper 1 after absorbing excrement, allowing the diaper 1 to fit more easily around the leg openings. This reduces leakage even after multiple urinations.

[0130] Furthermore, the low basis weight region 211 of the skin side layer 21 is preferably a slit penetrating the skin side layer 21 in the thickness direction. In this case, excreted liquid falls into the low basis weight region 211, and therefore the migration speed of excreted liquid from the skin side layer 21 to the intermediate layer 22 increases.

[0131] Although not shown, the liquid-absorbent fiber 201 or SAP may be present in the low basis weight region 211 of the skin side layer 21. Alternatively, the low basis weight region 211 may be a region in which a part of the skin side layer 21 is recessed in the thickness direction.

[0132] Similarly, the low basis weight region 231 of the non-skin side layer 23 may be a slit penetrating in the thickness direction, or the low basis weight region 231 may contain liquid absorbent fibers 201 or SAP, or the low basis weight region 231 may be partially recessed in thickness.

[0133] 7B has three longitudinally elongated rectangular divided regions 23a-23c. The three divided regions 23a-23c are arranged side by side at intervals in the width direction. Two regions between the three divided regions 23a-23c form low basis weight regions 231 (slits) of the non-skin side layer 23. The two low basis weight regions 231 are arranged symmetrically in the width direction across a center line CL2 of the non-skin side layer 23 in the width direction.

[0134] 6, in a plan view of the absorbent cores 21-23, it is preferable that the low basis weight region 211 of the skin-side layer 21, the low basis weight region 221 of the intermediate layer, and the low basis weight region 231 of the non-skin-side layer have overlapping portions. The skin-side layer 21 and the intermediate layer 22 of this embodiment each have two low basis weight regions 211, 221. The two low basis weight regions 211, 221 of the skin-side layer 21 and the intermediate layer 22 each overlap with two low basis weight regions 231 of the non-skin-side layer 23.

[0135] This makes it easier for excreted liquid that has flowed into the low basis weight region 211 of the skin-side layer 21 and the low basis weight region 221 of the intermediate layer 22 to flow directly into the low basis weight region 231 of the non-skin-side layer 23. This allows excreted liquid to be more quickly drawn deep into the absorbent cores 21 to 23. Furthermore, in the low basis weight regions 211 to 231, absorption is less likely to be hindered by swelling of the SAP, improving the absorption rate.

[0136] Furthermore, the shape, size, number, and position of the low basis weight regions 211-231 in each layer are not particularly limited. For example, each layer may have one low basis weight region 211-231, which may be located on the center line CL2 in the width direction of the absorbent cores 21-23. The low basis weight regions 21-23 in each layer 21-23 may completely overlap, or multiple low basis weight regions 221-231 may be arranged spaced apart in the longitudinal direction.

[0137] Furthermore, when the absorbent body 20 of this embodiment does not include the above-described skin-side upper layer 24, i.e., when the skin-side layer 21 is the layer closest to the skin of the absorbent core, it is preferable that the liquid permeation rate under load of the SAP included in this skin-side layer exceeds 10 seconds. If the liquid permeation rate of the excreted liquid is excessively fast when the skin-side layer 21 receives excreted liquid, the excreted liquid will migrate to the intermediate layer 22 without sufficiently diffusing in the width or length directions of the skin-side layer 21, which may result in a deterioration in the water retention performance of the absorbent core as a whole. Furthermore, if the SAP swells only in the portion that receives the excreted liquid, the absorbent core may become locally thick. In contrast, by setting the liquid permeation rate under load in the skin-side layer to exceed 10 seconds, the water retention of the absorbent core is improved, leading to leakage prevention, and local thickening of the absorbent core can be suppressed, compared to the opposite case.

[0138] The liquid permeation rate under load of the SAP in the layer closest to the skin of the absorbent core can be measured, for example, by the method described in JP 2019-41876 A. Specifically, 0.32±0.005 g of superabsorbent polymer (SAP) was immersed in 100 mL of physiological saline (0.9% by mass sodium chloride solution) in a 100 mL glass beaker and left for 60 minutes. A separate cylindrical filtration tube was prepared, equipped with a wire mesh (150 μm mesh, Sansho Hanbai Biocolumn Sintered Stainless Steel Filter 30SUS) and a capillary tube (4 mm inner diameter, 8 cm length) with a stopcock (2 mm inner diameter) at the bottom end of the opening of a vertically standing cylinder (25.4 mm inner diameter). With the stopcock closed, the entire contents of the beaker, including the swollen test sample, were poured into the cylindrical tube. Next, a 2 mm diameter cylindrical rod equipped with a 25 mm diameter wire mesh at the tip with 150 μm mesh openings is inserted into the cylindrical filtration tube so that the wire mesh and the test sample come into contact, and a weight is placed on the test sample so that a load of 2.0 kPa is applied. After leaving it in this state for 1 minute, the stopcock is opened to allow the liquid to flow, and the time T1 (seconds) until the liquid level in the cylindrical filtration tube reaches the 40 mL scale line from the 60 mL scale line (i.e., 20 mL of liquid passes through) is measured. Using the measured time T1 (seconds), the liquid passage rate under load at 2.0 kPa is calculated using the formula: Liquid passage rate under load (seconds) = T1 - T0. Note that in this formula, T0 (seconds) is the time required for 20 mL of saline to pass through the wire mesh without the test sample in the cylindrical filtration tube. The measurement is carried out at a temperature of 23±2° C. and a relative humidity of 50±5%, and the superabsorbent polymer (SAP) is kept in the same environment for 24 hours or more before the measurement.

[0139] As shown in Fig. 4, in the diaper 1, the region in the width direction of the leg gather portion LG where the LG elastic members 17 are arranged is referred to as the "leg gather elastic region ER." In Fig. 4, the region between the first leg gather elastic member 17a, which is located at the innermost position in the width direction, and the sixth leg gather elastic member 17f, which is located at the outermost position in the width direction, is the leg gather elastic region ER. When the leg gather elastic region ER is divided into two equal parts in the width direction, the region located on the inner side is referred to as the "inner leg gather elastic region ERi," and when the leg gather elastic region ER is divided into two equal parts in the width direction, the region located on the outer side is referred to as the "outer leg gather elastic region ERo."

[0140] The overlapping area in the longitudinal direction between the portion of the leg gather elastic member 17 arranged in the outer leg gather elastic region ER0 that is subjected to the stretching force and the portion of at least some of the leg gather elastic members 17 arranged in the inner leg gather elastic region ERi that is not subjected to the stretching force of the LG elastic members 17 is referred to as the "leg gather intermittent portion NP." The leg gather elastic members 17, 17... arranged in the leg gather portion LG of the diaper 1 are all made of the same material and rubber thread of the same diameter. The leg gather intermittent portion NP is only arranged forward of the longitudinal center position CL of the diaper 1.

[0141] In the leg gather intermittent portion NP of the diaper 1, the force required to longitudinally stretch the inner leg gather elastic region ERi by a unit length from its natural state is preferably smaller than the force required to longitudinally stretch the outer leg gather elastic region ER0 by a unit length from its natural state. In other words, in the leg gather intermittent portion NP, the contractile force of the inner leg gather elastic region ERi is preferably weaker than the contractile force of the outer leg gather elastic region ER0. By weakening the longitudinal contractile force at the inner side in the width direction, i.e., by reducing the contractile force of the leg gather elastic member 17 (inner leg gather elastic region ERi) closer to the absorbent body 20, the absorbent body 20 is less likely to shrink before use, thereby reducing concerns about leakage before use.

[0142] The stretching force (contractile force) of the intermittent leg gather portions NP can be measured by the following method. First, a test specimen is prepared by cutting out the portion to be measured, including the LG elastic member 17, from the diaper 1. Specifically, the absorbent main body 10 is cut from the unfolded and stretched diaper 1. The leg gather elastic region ER of the cut absorbent article 10 is then separated. The leg gather elastic region ER is then divided into two equal parts at the midpoint in the width direction into an inner leg gather elastic region ERi and an outer leg gather elastic region ERo. The region of the intermittent leg gather portions NP is then cut in the longitudinal direction to prepare a test specimen. Then, both longitudinal ends of the test specimen in its natural state are clamped between the chucks of a known tensile testing machine (e.g., an Instron universal testing machine), and the distance between the chucks is adjusted to 100 mm. From this state, the gap is widened at a predetermined speed (100 mm / min) until the test piece TP is stretched to a predetermined length. For example, the test piece TP is stretched to a length 0.9 times its maximum stretch length. In other words, the test piece TP is stretched until its longitudinal length is 0.9 times its maximum stretch length. The test piece is then contracted to its original length. This cycle is repeated twice, and in the second cycle, the force (N) applied when the test piece is stretched to a length 0.8 times its maximum stretch length is measured. This measurement is repeated a predetermined number of times (for example, three times) to obtain the stretching force (contraction force) of the test piece.

[0143] The number of leg gather elastic members 17 provided in the leg gather portion LG is not limited to three or more, and may be two. In this case, the lengths of the portions where stretchable force is applied in the longitudinal direction for the two leg gather elastic members 17 may be the same, and the stretch ratio and thickness of the elastic members may also be the same. Even when three or more leg gather elastic members 17 are provided, the configuration is not limited to the above, and the lengths of the portions where stretchable force is applied in the longitudinal direction, the stretch ratio, and the thickness of the elastic members may all be the same. Furthermore, when three or more leg gather elastic members 17 are provided, the lengths of the portions where stretchable force is applied in the longitudinal direction may be the same but the stretch ratios and thicknesses of the elastic members may be different; the stretch ratios may be the same but the lengths and thicknesses of the portions where stretchable force is applied in the longitudinal direction may be different; or the thicknesses may be the same but the stretch ratios and lengths of the portions where stretchable force is applied in the longitudinal direction may be different. Alternatively, when three or more leg gather elastic members 17 are provided, the stretch ratio and the thickness of the elastic members may be the same, and the length of the portion where the stretching force is acting in the longitudinal direction may not be uniform; the stretch ratio and the length of the portion where the stretching force is acting in the longitudinal direction may be the same, and the thickness may not be uniform; or the length and thickness of the portion where the stretching force is acting in the longitudinal direction may be the same, and the stretch ratio may not be uniform.

[0144] FIG. 15 is a schematic plan view of the absorbent body 20 as viewed from the skin side. As shown in FIG. 13 , in this embodiment, the skin side layer 21 has a plurality of compressed dots 50 formed by compressing the skin side layer 21 (absorbent core 21) in a dotted pattern in the thickness direction. At these compressed dots 50, the absorbent core 21 is compressed in the thickness direction by embossing. The compression increases the fiber density of the absorbent core 21 compared to uncompressed portions. While the compressed dots 50 in this embodiment are formed as a collection of dots (circles), the compressed dots 50 may also be formed as lines (straight lines, curves), for example. Alternatively, the compressed dots or lines may be formed discretely within a predetermined region. Furthermore, the compressed dots 50 are arranged in a pattern that appears as a dotted grid pattern (a so-called quilting pattern) as a whole, as shown in FIG. 13 , but other patterns may also be used.

[0145] The portions where these dotted compressed portions 50 (compressed portions) are formed have increased rigidity, and increasing the rigidity before use makes the absorbent body 20 less likely to shrink. By reducing shrinkage of the absorbent body 20, it is possible to prevent the apparent dimensions before use from becoming smaller, reducing anxiety about leakage and providing the wearer with a sense of security. Note that the invention is not limited to providing multiple compressed portions 50 on the skin-side layer 21, as long as at least one of the skin-side layer 21 and the non-skin-side layer 23 has compressed portions 50.

[0146] As shown in the cross-sectional view of Figure 4, the absorbent body 20 has a greater number of laminated layers of materials at both widthwise ends than at its widthwise center. Specifically, the absorbent body 20 has folded-back portions 25f in which the skin-side core wrap sheet 25 is folded back to encase the absorbent cores 21-24. The number of laminated layers of materials constituting the absorbent body 20 at both widthwise ends of the absorbent body 20 is greater than that at its widthwise center by the amount of the folded-back portions 25f. This increases the rigidity of the absorbent body 20 at its widthwise ends compared to its widthwise center, thereby suppressing shrinkage at the widthwise ends near the leg gather elastic members 17 located widthwise outboard of the absorbent body 20. By suppressing shrinkage at both widthwise ends of the absorbent body 20, the apparent dimensions of the diaper 1 before use can be prevented from becoming smaller, thereby reducing concerns about leakage before use.

[0147] 4, in the absorbent main body 10, the top sheet 12, which is provided closer to the skin than the absorbent body 20, extends in the width direction beyond the absorbent body 20. In other words, leg gathered portions LG are present on both sides of the absorbent main body 10 in the width direction, and the top sheet 12 extends up to the vicinity of the leg gathered portions LG. The presence of the top sheet 12 up to the vicinity of the leg gathered portions LG increases the rigidity in the vicinity of the leg gathered portions LG, and the stretching force of the leg gathered portions LG transmitted to the absorbent body 20 can be reduced.

[0148] Figure 16 is a diagram showing the adhesive HMA used to bond the top sheet 12. The adhesive HMA for bonding the top sheet 12 to the absorbent body 20 and the folded-back portion 14f of the outer sheet 14 is applied to the non-skin-side surface of the top sheet in the thickness direction, and the adhesive HMA is applied continuously in the longitudinal direction, as shown in Figure 16. The continuous application of the adhesive HMA in the longitudinal direction increases the rigidity in the longitudinal direction, making the absorbent body 20 less susceptible to shrinkage in the longitudinal (up-down) direction. This prevents the apparent dimensions of the diaper 1 from decreasing before use, providing a sense of security to the wearer. Here, the adhesive HMA applied to the non-skin-side surface of the top sheet 12 is applied from the front end to the rear end of the absorbent body 20 in the longitudinal direction, but this is not limited thereto. It is sufficient that the adhesive HMA be applied continuously in the longitudinal direction at least in the region Q overlapping the portion where the stretching force of the leg gather elastic members 17 acts. The adhesive application pattern is not particularly limited, and any application pattern such as an Ω shape, a spiral shape, or a stripe shape can be applied.

[0149] Returning to Figure 4, in this embodiment, when the region from the end 20e of the absorbent body 20 to the end 10e of the absorbent main body 10 in the width direction is divided into three, the innermost region is designated as region GRi, and the leg gather elastic members 17 are not provided in this innermost region GRi. Of the regions obtained by dividing the region from the end 20e of the absorbent body 20 to the end 10e of the absorbent main body 10 in the width direction into three, the innermost region GRi is the region closest to the absorbent body 20, and by not providing the leg gather elastic members 17 in such a region close to the absorbent body 20, deformation of the absorbent body 20 can be suppressed. This makes the absorbent body 20 less likely to shrink in the vertical direction.

[0150] The absorbent main body 10 also has an outer sheet 14 (corresponding to the non-skin-side sheet) provided on the non-skin-side side of the absorbent body 20 in the thickness direction, and a leak-proof film 13 provided between the absorbent body 20 and the outer sheet 14 (non-skin-side sheet) in the thickness direction (see FIG. 4 ). The leak-proof film 13 and the leg gather elastic members 17 have overlapping portions in the thickness direction. The overlapping portions of the leak-proof film 13 and the leg gather elastic members 17 in the thickness direction are highly rigid, and the presence of such highly rigid portions can reduce the force that contracts the absorbent body 20. This prevents the apparent dimensions of the diaper 1 from becoming smaller before use, thereby reducing concerns about leakage before use.

[0151] FIG. 17 is a diagram showing the adhesive HMA used to bond the leakproof film 13. The non-skin-facing surface of the leakproof film 13 in the thickness direction is coated with the adhesive HMA, which bonds the leakproof film 13 to the outer sheet 14. As shown in FIG. 17 , the adhesive HMA is continuously applied in the longitudinal direction (vertical direction). Continuous application of the adhesive HMA in the longitudinal direction (vertical direction) increases the rigidity in the longitudinal direction (vertical direction) and makes the absorbent body 20 less susceptible to shrinkage in the vertical (longitudinal) direction. This prevents the apparent dimensions of the diaper 1 from decreasing before use, reduces pre-use anxiety about leakage, and provides the wearer with a sense of security. Here, the adhesive HMA applied to the non-skin-facing surface of the leakproof film 13 is applied from the front end to the rear end of the absorbent body 20 in the longitudinal direction. However, this is not limited thereto. It is sufficient that the adhesive HMA be continuously applied in the longitudinal direction (vertical direction) at least in the region Q overlapping the portion where the stretching force of the leg gather elastic members 17 acts. The adhesive application pattern is not particularly limited, and any application pattern such as an Ω shape, a spiral shape, or a stripe shape can be applied.

[0152] The absorbent main body 10 of the diaper 1 of this embodiment has an outer covering sheet 14 that forms the outer covering of the absorbent main body 10, located closer to the skin than the leakproof film 13 in the thickness direction and closest to the skin. However, the outer covering sheet 14 may be composed of, for example, two or more sheets of nonwoven fabric. Specifically, at least in the crotch region M corresponding to the wearer's crotch, a region where multiple sheet materials are provided may be located closer to the skin than the leakproof film 13 in the thickness direction. This increases the rigidity of the crotch region M (the central region of the diaper 1) and suppresses shrinkage of the entire product in the vertical direction. This prevents the apparent dimensions from shrinking before use, reduces anxiety about leakage before use, and provides the wearer with a sense of security.

[0153] The above-mentioned configuration of "having a portion in the crotch region M where a plurality of sheet materials are provided on the non-skin side in the thickness direction of the leakproof film 13" is not limited to providing two or more sheets of nonwoven fabric or the like as the outer sheet 14. In this embodiment, the leg gather elastic member 17 is provided between the outer sheet 14 and the folded-up portion 14f in the thickness direction, but for example, at both widthwise end portions of the crotch region M (FIG. 2), another sheet material different from the outer sheet 14 for forming the leg gather portion LG may be arranged closest to the skin side (i.e., arranged further away from the skin side than the outer sheet 14 arranged on the non-skin side of the leakproof film 13), and the leg gather elastic member 17 may be arranged on the skin side of this another sheet material, and the other sheet material may be folded back at the widthwise end portions to the skin side, thereby forming a configuration in which a plurality of sheet materials are provided on the non-skin side of the leakproof film 13 in the crotch region M. Even when multiple sheet materials are placed on both widthwise ends of the crotch area M rather than across the entire width of the crotch area M, the rigidity of the crotch area M is increased compared to when multiple sheet materials are not placed, and shrinkage of the entire product in the vertical direction is suppressed.

[0154] Furthermore, as described above, when the outer sheet 14 is composed of, for example, two or more layers of nonwoven fabric, if the region in the crotch region M that is closer to the skin in the thickness direction than the leak-proof film 13 is defined as the outer region 13out (see FIG. 4), the basis weight of the outer region 13out is greater than the basis weight of the non-skin-side sheet 31, 41 (sheet material) that is located on the outermost side (closer to the skin) in the thickness direction in the front waistline 30 or the rear waistline 40. This increases the rigidity of the crotch region M and suppresses shrinkage of the entire product in the vertical direction. This prevents the apparent dimensions from shrinking before use, reduces anxiety about leakage before use, and gives the wearer a sense of security.

[0155] However, as in this embodiment, the outer region 13out, which is the region on the non-skin side in the thickness direction beyond the leak-proof film 13, may be composed only of the exterior sheet 14, and the basis weight of the non-skin side sheets 31, 41 may be higher than the basis weight of the outer region 13out (here, the exterior sheet 14).

[0156] As shown in FIG. 4 , a side sheet 15, which is a separate sheet material from the outer sheet 14 (sheet material) that constitutes the leg gathers LG, is provided closer to the skin than the leg gathers LG in the thickness direction. The side sheet 15 is a sheet material that forms a pair of leakage prevention walls LSG, LSG. The additional sheet material (side sheet 15) overlapping the leg gathers LG closer to the skin in the thickness direction increases rigidity and reduces the stretching force of the leg gathers LG. This suppresses shrinkage of the absorbent body 20 in the vertical direction (longitudinal direction), making it less likely for the apparent dimensions before use to decrease. Maintaining the apparent dimensions before use reduces concerns about leakage before use.

[0157] As described above, the skin-side layer 21 has a first thickness t1, the intermediate layer 22 has a second thickness t2, and the non-skin-side layer 23 has a third thickness t3 (see FIG. 5 ). The first thickness t1 to the third thickness t3 refer to average thicknesses. In this embodiment, the third thickness t3 of the non-skin-side layer 23 is thicker than the first thickness t1 of the skin-side layer 21. Specifically, the third thickness t3 of the non-skin-side layer 23 is preferably 0.38 mm to 0.58 mm for the S-size diaper 1 and 0.58 mm to 0.69 mm for the XXL-size diaper 1. The first thickness t1 of the skin-side layer 21 is preferably 0.3 mm to 0.48 mm for the S-size diaper 1 and 0.45 mm to 0.65 mm for the XXL-size diaper 1. The skin-side layer 21, which is thinner than the non-skin-side layer 23, also has a thinner thickness after absorbing liquid. The average thickness of the absorbent body 20 is preferably 2.0 to 2.5 mm.

[0158] The average thickness t2 of the intermediate layer 22 is preferably 0.5 mm or more. More preferably, it is 0.9 mm to 1.1 mm for an S-size diaper 1, and 1.28 mm to 1.61 mm for an XXL-size diaper 1. However, if the intermediate layer 22 is too thick, it may feel stiff, so the average thickness (second thickness t2) of the intermediate layer 22 is preferably 2.5 mm or less.

[0159] The thicknesses (t1 to t3) of the layers 21 to 23 can be measured using known methods. For example, with the diaper 1 in a natural, dry state without external forces, the diaper 1 (absorbent body 20) is cut widthwise at any longitudinal position in the portion of the diaper 1 where the absorbent body 20 is located, specifically, at a location where the three layers 21 to 23 are stacked and away from the product folding position. To prevent damage to the absorbent body 20 components, the diaper 1 is cut at a predetermined location and then measured. Next, using an optical microscope (e.g., Keyence Corporation's VHX-7000 Digital Microscope or equivalent), the cut surface is placed upright and magnified (e.g., 30 to 100 times) and photographed. The focus of the magnified photograph is on the liquid-absorbent fibers 201. In the captured cross-sectional image, the layer in which the liquid-absorbent fiber 201 is visible is determined to be the intermediate layer 22, and the portions of the absorbent core closer to the skin or closer to the skin are determined to be the skin-side layer 21 and the non-skin-side layer 23, respectively. Furthermore, measurement positions (e.g., five positions) are determined in the width direction of the cross-sectional image, and the thickness of each of the layers 21 to 23 at each measurement position is obtained. Preferably, cross-sectional images are captured at multiple positions in the longitudinal direction of the absorbent body 20 to obtain the thickness of each of the layers 21 to 23. The average values ​​of the obtained thicknesses are calculated for each of the layers 21 to 23, and are designated as the average thickness t1 (first thickness t1) of the skin-side layer 21, the average thickness t2 (second thickness t2) of the intermediate layer 22, and the average thickness t3 (third thickness t3) of the non-skin-side layer 23. Note that when measuring the thickness, portions other than the low basis weight regions 211, 221, and 231 are measured. Furthermore, when the absorbent layer is bonded to adjacent sheet portions (core wrap sheets 25, 26, nonwoven fabric 27) via adjacent adhesive, such as the skin-side upper layer 24, the skin-side layer 21, and the middle layer 22, it is difficult to identify the part where the material (liquid absorbent fiber, SAP) that constitutes each absorbent layer is actually bonded and fixed to the adjacent sheet portion with adhesive.Therefore, when it can be determined that adhesive exists between the absorbent layer and the adjacent sheet portion, the distance between adjacent sheet portions in the thickness direction is measured as the "thickness of the absorbent layer."

[0160] Using the above-mentioned method, five samples were prepared by cutting the longitudinal end of the absorbent body 20 and then cutting the absorbent body 20 so that the longitudinal length was 10 mm from that point.The average thicknesses measured were as follows: for the S size, the first thickness t1 was 0.41 mm, the second thickness t2 was 0.99 mm, and the third thickness t3 was 0.47 mm; and for the XXL size, the first thickness t1 was 0.56 mm, the second thickness t2 was 1.47 mm, and the third thickness t3 was 0.63 mm.

[0161] In this embodiment, the average basis weight of the non-skinside layer 23 is higher than the average basis weight of the skinside layer 21. A suitable average basis weight of the non-skinside layer 23 is 50 g / m ２ ~350g / m ２ Specifically, when the diaper 1 is a size S, the average basis weight of the non-skinside layer 23 is 173 g / m ２ The average basis weight of the skin side layer 21 is preferably about 82 g / m ２ When the diaper 1 is an XXL size, the average basis weight of the non-skinside layer 23 is about 300 g / m ２ The average basis weight of the skin side layer 21 is preferably about 171 g / m ２ The skin-side layer 21 with a low average basis weight is less likely to swell after absorbing liquid, reducing swelling in the crotch area M. Reducing swelling in the crotch area M prevents the crotch area M from becoming too rigid, making it easier to fit the leg openings. Therefore, leakage is less likely even when urination is performed multiple times.

[0162] The skin-side layer 21 may also contain a different type of SAP from that contained in the non-skin-side layer 23. For example, it is desirable that the SAP contained in the skin-side layer 21 has a liquid absorption rate, as measured by the vortex method, slower than that of the SAP contained in the non-skin-side layer 23.

[0163] This allows the excreted liquid to diffuse in the planar direction and migrate to the intermediate layer 22 before it is absorbed by the SAP in the skin-side layer 21. In other words, by not retaining the excreted liquid in the skin-side layer 21 and allowing it to penetrate and diffuse into the layers closer to the skin, the excreted liquid is more easily absorbed uniformly and swelling in the crotch area M can be reduced. Reducing swelling after absorption prevents an increase in rigidity and maintains the fit of the leg openings.

[0164] The liquid absorption rate of SAP using the vortex method can be measured by a known method. For example, 50.0 ml (±0.5 ml) of saline solution with a concentration of 0.900% (±0.009%) and a temperature of 25°C (±2°C) is placed in a 100 ml beaker. The beaker is then placed on a magnetic stirrer and a stir bar is inserted into the beaker. The stir bar is then rotated at 600 rpm (±30 rpm) to ensure that the saline solution in the beaker forms a stable vortex. A stopwatch is then started from the moment 2.00 g (±0.02 g) of the SAP to be measured, removed from the diaper 1, is placed in the beaker, and the time from when the vortex disappears and the liquid level becomes horizontal is measured. The longer this time, the slower the liquid absorption rate.

[0165] Regarding the absorbent cores 21 to 24, the density of the absorbent cores 21 to 24 is 0.2 g / cm ３ The higher the density of the absorbent cores 21 to 24, the thinner the absorbent cores 21 to 24 can be while increasing the amount of liquid absorbent fiber and SAP for absorbing excrement, making it easier to achieve a thinner absorbent core 21 to 24 and improve the diffusion of excrement. Therefore, it is preferable that the density of the absorbent cores 21 to 24 is 0.2 g / cm or more. ３ By setting the density of the absorbent cores 21 to 24 to 0.2 g / cm or more, ３ Since the absorbent cores 21-24 are more likely to diffuse excrement than when they are smaller, the risk of localized swelling of the absorbent cores 21-24 can be reduced, and wearability is less likely to deteriorate. Furthermore, when the density of the absorbent cores 21-24 is increased, the absorbent cores 21-24 are less likely to lose their shape, and similarly, wearability can be prevented from being deteriorated.

[0166] Furthermore, in the absorbent cores 21-23, it is preferable that a layer having a high volume occupancy of SAP that does not contain the liquid-absorbent fiber 201 is present as the skin-side layer 21 or the non-skin-side layer 23. In this embodiment, the non-skin-side layer 23 is a layer that does not contain the liquid-absorbent fiber 201. Such a layer that does not contain the liquid-absorbent fiber 201 is more susceptible to liquid transfer than a layer that does contain the liquid-absorbent fiber 201. The presence of the non-skin-side layer 23 having a high volume occupancy of SAP that does not contain the liquid-absorbent fiber 201 improves absorbency. Furthermore, a layer having a high volume occupancy of SAP that does not contain the liquid-absorbent fiber 201 may be provided as the skin-side layer 21. In such a case, rewet can be suppressed by the skin-side layer 21 thoroughly absorbing the liquid.

[0167] As described above, the skin-side layer 21 has a low-basis weight region 211 in which the absorbent core has a lower basis weight than the surrounding area, and the skin-side upper layer 24, which is disposed closer to the skin than the skin-side layer 21, is disposed so as to overlap the low-basis weight region 211 of the skin-side layer 21 in a planar view, although not shown. The skin-side upper layer 24 is laminated so as to cover at least the shape of the skin-side layer 21 shown in Fig. 6, and in the constricted portion 212, the skin-side upper layer 24 is also laminated on portions outer than both ends of the constricted portion 212 in the width direction. There is a risk that SAP may shift from the periphery of the low-basis weight region 211 and infiltrate into the low-basis weight region 211, but the presence of the skin-side upper layer 24 covering the low-basis weight region 211 from the skin side makes it less likely that the SAP contained in regions outer than the low-basis weight region 211 in the width direction and length direction will shift, making it easier to maintain the shape of the low-basis weight region 211.

[0168] 2 and 3, the rear waistband 40 of the diaper 1 is provided with a post-treatment tape 48. The post-treatment tape 48 is a tape-like member (tape member) that is elongated in the longitudinal direction and has a generally rectangular shape. The provision of a highly rigid portion of the post-treatment tape 48 in the longitudinal direction reduces shrinkage of the rear waistband 40 in the longitudinal direction (vertical direction). This allows the apparent dimensions before use to be maintained large, reducing concerns about leakage.

[0169] ===Other=== The above embodiments are intended to facilitate understanding of the present invention and are not intended to limit the present invention. The present invention may be modified or improved without departing from the spirit thereof, and it goes without saying that the present invention includes equivalents thereof.

[0170] Fig. 18 shows a plan view and a cross-sectional view of a modified absorbent main body 10. In the modified example shown in Fig. 18, similar to the above-described embodiment, a pair of leakage preventing wall portions LSG, LSG is provided on both sides in the width direction of the absorbent main body 10. The leakage preventing wall portions LSG are stretchable in the up-down direction (longitudinal direction) and have one or more leakage preventing wall elastic members 16 (16a and 16b) that cause the leakage preventing wall portions LSG to stand up against the skin. In this modified example, the leakage preventing wall portions LSG have a plurality of compressed portions 60 formed to compress the leakage preventing wall portions LSG in the thickness direction. As shown in the cross-sectional view of Fig. 18, there are portions where the leg gather portions LG and the compressed portions 60 overlap in the thickness direction. The compressed portions 60 are not limited to being formed by a collection of dot-like (circular) compressed portions, but may be formed in a line, for example, or dot-like or line-like compressed portions may be formed discretely within a predetermined region. The compression portions 60 increase the rigidity of the leg areas and reduce the stretching force of the leg gathers LG, thereby suppressing vertical shrinkage of the absorbent body 20 and reducing the apparent size reduction of the diaper 1 before use, providing a sense of security before use.

[0171] In the above-described embodiment, the non-skinside layer 23 illustrated in FIG. 6 has a shorter longitudinal length than the skinside layer 21 and the intermediate layer 22, but this is not limited thereto and the longitudinal lengths may be the same. Increasing the length of the non-skinside layer 23 leads to improved absorbency. Conversely, the longitudinal length of the back side (rear side) of the non-skinside layer 23 may be even shorter than the length in this embodiment. In this case, material can be reduced, and the rigidity of the back-side absorbent core is reduced, resulting in increased flexibility. Furthermore, because the back side region is also away from the wearer's urinary excretion opening, a short longitudinal length of the non-skinside layer 23 is less likely to cause problems with leakage of excreted fluid.

[0172] The absorbent core (skin side layer 21 and non-skin side layer 23) of the absorbent body 20 may be modified as follows. FIG. 19 is a cross-sectional schematic diagram showing a modified non-skin side layer 23 (corresponding to a superabsorbent polymer layer). As shown in FIG. 19 , the modified non-skin side layer 23 has a high basis weight region 233 in which the basis weight of SAP is higher than that of the surrounding areas. In the high basis weight region 233, points S of maximum thickness in the thickness direction are located intermittently in the longitudinal and width directions. As a result, the high basis weight regions 233 are arranged intermittently in the longitudinal and width directions. Furthermore, between adjacent points S of maximum thickness (i.e., around the high basis weight region 233), low basis weight regions 234 in which the basis weight of SAP is lower than that of the high basis weight region 233 are formed. However, as long as the points S of maximum thickness are located intermittently in the longitudinal and width directions, part of the area between adjacent points S of maximum thickness may be formed by the high basis weight region 233. In other words, the adjacent maximum thickness points S may be partially connected by the high basis weight region 233 .

[0173] The low basis weight region 234 has a low basis weight laminated region 234E where SAP is laminated, and a non-laminated region 234N where no SAP is present. Here, "no SAP present" not only means that no SAP particles are present, but also means that there are only a small number of laminated SAP particles, and that no SAP particles are present at all.

[0174] In the non-skinside layer 23 of the modified example, the low basis weight regions 234 (low basis weight laminated regions 234E and non-laminated regions 234N) serve as folding points, allowing the layer to easily deform along the contours of the wearer's body, improving fit. Furthermore, the low basis weight regions 234 serving as folding points include the low basis weight laminated regions 234E, which can absorb and retain excrement, and the non-laminated regions 234N, which are more easily bent due to the absence of SAP. As a result, even in the low basis weight regions 234, which have a lower basis weight of SAP than the high basis weight regions 233, it is possible to achieve both ease of deformation along the contours of the wearer's body and the ability to absorb and retain excrement.

[0175] Furthermore, in the modified example shown in FIG. 19 , when the length in the thickness direction from the core wrap sheet 26 to the point S where the maximum thickness is reached is defined as the maximum thickness T, it is preferable that the maximum thickness T is within 3 mm, and the distance D between adjacent points S where the maximum thickness is reached is within 5 times the maximum thickness T. By including such a non-skin-side layer 23, it is possible to arrange multiple high-basis weight regions and low-basis weight regions while maintaining the overall thinness of the absorbent body 20. Therefore, the absorbent body 20 containing a superabsorbent polymer can maintain its thinness while improving its fit when worn. It is even more preferable that the maximum thickness T is within 2 mm, and the distance D between adjacent points S where the maximum thickness is reached is within 4 times the maximum thickness T. This allows the absorbent body 20 containing a superabsorbent polymer to maintain its thinness while improving its fit when worn. According to the diaper 1 having the absorbent body 20 that maintains such a thinness, even if the contraction around the legs due to the leg gather elastic members 17 is weak, the contraction force of the leg gather elastic members 17 is easily transmitted, so the contraction does not weaken and the fit around the legs can be maintained.

[0176] Fig. 20 is a plan view showing a modified example of the diaper 1. In the above-described embodiment, the front waistline portion 30 and the rear waistline portion 40 have the same planar shape in the unfolded and stretched state. However, this is not limited to this. As shown in Fig. 20, the front waistline portion 30 and the rear waistline portion 40 may have different planar shapes in the unfolded and stretched state. For example, the front waistline portion 30 may have a rectangular shape that is elongated in the width direction and has a length in the up-down direction that is approximately the same as that of the side joint portion 2, and the rear waistline portion 40 may have a rectangular portion overlapping the front waistline portion 30 and a generally trapezoidal portion 40E extending downward therefrom. The extending portion 40E can cover the wearer's buttocks. With this configuration, the overlap between the absorbent main body 10 and the rear waistline section 40 is greater at the rear longitudinal side of the diaper 1 compared to the present embodiment, and therefore a larger amount of adhesive is required to bond the absorbent main body 10 and the rear waistline section 40 together. As a result, the rigidity of the absorbent main body 10 is increased, making the absorber 20 less likely to shrink in the vertical direction and making it easier to maintain the apparent dimensions before use.

[0177] The diaper 1 of the modified example shown in Fig. 21 has a crotch section 70 connecting the front waistline section 30 and the rear waistline section 40, and is provided with an outer casing formed from a single continuous member. Inclined elastic members 71 are provided from the lower ends of the front waistline section 30 and the rear waistline section 40 to the crotch section. The inclined elastic members 71 have portions that slope downward from both widthwise sides of the front waistline section 30 and the rear waistline section 40 toward the center. The "portions that slope downward toward the center" of the inclined elastic members 71 function similarly to the leg gathers LG of this embodiment (here, the "downwardly sloping portions" are referred to as leg gathers LG2). In other words, the inclined elastic members 71 also correspond to leg gather elastic members that are arranged along the stretch direction of the leg gathers LG2 (a direction that slopes relative to the widthwise and longitudinal directions in Fig. 21). In this modification, the leg gather elastic members 17 arranged on both sides of the absorbent main body 10 in the width direction in the above-described embodiment are not present. In other words, when worn, the inclined elastic members 71 perform the same function as the leg gather elastic members 17, and the leg gather portions LG2 made of the inclined elastic members 71 fit around the legs and prevent leakage. Therefore, it is preferable that the elongation ratio of the inclined elastic members 71 is also 2.4 times or less. This makes it possible to suppress shrinkage of the absorbent cores 21-24 in the width and length directions.

[0178] Furthermore, the diaper 1 of this modification has, as lateral elastic members, waist elastic members 33, 43 and an inclined elastic member 71. Not only the waist elastic members 33, 43 but also the inclined elastic member 71 (effective length portion) are cut at least partially in the portion overlapping the absorbent cores 21-24 in the thickness direction, so that no stretching force acts on them. This prevents the absorbent cores 21-24 from shrinking due to the inclined elastic member 71, which would reduce their apparent dimensions before use.

[0179] The elongation ratio of the leg gather portion LG2 formed by the inclined elastic members 71 (see FIG. 21 ) can also be measured using the same method using the tensile tester described above. In this case, it is preferable to cut out the effective length portion (e.g., the area indicated by the dashed line in FIG. 21 ) of one or more (here, three) inclined elastic members 71 located below the waist elastic members 33, 43 and in a range outside the absorbent main body 10 in the width direction as a sample. However, if the sample is short, it may be cut out longer than the above range. The portions of the inclined elastic members 71 where they intersect with the waist elastic members 33, 43 and where they overlap with the absorbent main body 10 are then gripped with the chuck of the tensile tester. When measuring the contractile force of a single inclined elastic member 71, it is also preferable to cut out the effective length portion of one inclined elastic member 71 located in the above range as a sample.

[0180] DESCRIPTION OF SYMBOLS 1 Diaper (pants-type absorbent article) 2 Side joint portion 10 Absorbent body 12 Top sheet 13 Leakage barrier film 14 Outer sheet 14f Fold-up portion 15 Side sheet 16 Leakage barrier wall elastic member 16a First leakage barrier wall elastic member 16b Second leakage barrier wall elastic member 17 Leg gather elastic member 17a-f Leg gather elastic member 20 Absorbent body 21 Absorbent core, skin side layer, constriction layer 22 Absorbent core, intermediate layer, constriction layer 23 Absorbent core, non-skin side layer, extension layer 23a-c Divided region 24 Absorbent core, skin side upper layer 25 Core wrap sheet 26 Core wrap sheet 27 Nonwoven fabric 30 Front waistline portion 31 Non-skin side sheet 32 ​​Skin side sheet 33 Waistline elastic member 40 Rear waistline portion 41 Non-skin side sheet 42 Skin side sheet 43 Waist elastic member 48 Post-treatment tape 50 Dot-like compressed portion (compressed portion) 201 Liquid absorbent fiber 211 Low basis weight region 212 Necked portion 221 Low basis weight region 222 Necked portion 231 Low basis weight region 233 High basis weight region 234 Low basis weight region 234E Low basis weight laminated region 234N Non-laminated region

Claims

1. A pants-type absorbent article having a top-bottom direction, a width direction, and a front-to-back direction which are perpendicular to one another, and having an absorbent body containing a liquid-absorbent fiber and a superabsorbent polymer, wherein the absorbent body has an absorbent main body including the absorbent body, the absorbent main body having a pair of leg gather portions on both sides in the width direction, and the leg gather portions have leg gather elastic members that stretch along the top-to-bottom direction and are provided outside the absorbent body in the width direction, and 40 ml of artificial urine is dropped three times over 5 seconds onto the skin-side surface of the pants-type absorbent article in an unfolded and stretched state, at a position 50 mm forward of the center in the longitudinal direction perpendicular to the width direction and at the center in the width direction, and In a torsion test in which the pant-type absorbent article is folded in half at the central fold in the longitudinal direction and the central portions of both widthwise ends are grasped and twisted around imaginary axes along the width direction, and the pant-type absorbent article is folded in half at the central fold in the longitudinal direction and the central portions of both widthwise ends are grasped and twisted around imaginary axes along the vertical direction, the torque value of the pant-type absorbent article is 44.1 mN·m or less, and the leg gather elastic members are arranged so that the length from the top to the bottom in the vertical direction of the pant-type absorbent article in its natural state before absorption is 85.3% or more of the length from the top to the bottom in the vertical direction of the pant-type absorbent article when it is maximum stretched.

2. A pants-type absorbent article as described in claim 1, characterized in that in a torsion test in which the pant-type absorbent article in the folded state is gripped at the longitudinal center of both widthwise end portions and twisted around an imaginary axis along the width direction, and the pant-type absorbent article in the folded state is gripped at the widthwise center of both widthwise end portions and twisted around an imaginary axis along the longitudinal direction, the torque value of the pant-type absorbent article before absorption is 21.1 mN·m or less.

3. A pants-type absorbent article according to claim 1 or 2, wherein in a measurement test using a test doll to measure the amount of sagging and protrusion of the pants-type absorbent article after absorbing liquid, the length L1 in the up-down direction from the urination opening of the test doll to the bottom end of the pants-type absorbent article after absorbing liquid is measured, and the length L2 in the front-to-back direction from the urination opening of the test doll to the front end of the pants-type absorbent article after absorbing liquid is measured, and when the length L1 is the sagging length and the length L2 is the protrusion length, the value obtained by multiplying the length L1 and the length L2 is 2004 mm. ２ A pants-type absorbent article characterized by the following:

4. A pants-type absorbent article as claimed in claim 1 or 2, having a front waistband and a rear waistband joined at both sides in the width direction by a pair of side joining parts, wherein, when the intersection point C1 is defined as the point where a line segment connecting the lower ends of both sides in the width direction of the pair of side joining parts intersects with the leg gather elastic member, the ratio of the length L5 of the line segment connecting from the intersection C1 to the lower end position of the leg gather elastic member to the length L3 in the vertical direction from the lower end position of the side joining part to the lower end position of the pants-type absorbent article is 45% or more.

5. A pants-type absorbent article according to claim 1 or 2, wherein in the unfolded state, the leg gather portion is provided with three or more leg gather elastic members that stretch along the longitudinal direction, and when the region between the leg gather elastic member provided at the innermost position and the leg gather elastic member provided at the outermost position in the width direction is defined as a leg gather elastic region, and when the leg gather elastic region is divided into two equal parts in the width direction, the region located on the inner side is defined as an inner leg gather elastic region, and the region located on the outer side is defined as an outer leg gather elastic region, an intermittent leg gather portion where a portion to which the stretching force of the leg gather elastic member arranged in the outer leg gather elastic region acts and a portion to which the stretching force of at least some of the leg gather elastic members arranged in the inner leg gather elastic region does not act is overlapped in the longitudinal direction is provided only forward of the center position of the pants-type absorbent article, a force required to stretch the inner leg gathered elastic region from its natural state by a unit length in the longitudinal direction in the leg gather intermittent portion is smaller than a force required to stretch the outer leg gathered elastic region from its natural state by a unit length in the longitudinal direction.

6. A pants-type absorbent article according to claim 1 or 2, characterized in that a plurality of the leg gather elastic members are provided, a pair of leakage prevention wall portions is provided on both sides of the absorbent main body in the width direction, the leakage prevention wall portions are stretchable along the up-down direction and have one or more leakage prevention wall elastic members that cause the leakage prevention wall portions to stand up against the skin, and the elongation ratio of each of the leakage prevention wall elastic members is greater than the elongation ratio of each of the leg gather elastic members.

7. A pants-type absorbent article as described in claim 6, characterized in that, of the plurality of leg gather elastic members, the leg gather elastic member provided at the innermost position in the width direction is located at the same position as the rising point of the leakage preventing wall portion or outside said rising point in the width direction.

8. A pants-type absorbent article according to claim 1 or 2, characterized in that the leg gather elastic members have an elongation ratio of 2.4 times or less, the number of members is 1 to 6, and the thickness is 310 dtex or more and 780 dtex or less.

9. A pants-type absorbent article as claimed in claim 1 or 2, characterized in that in the unfolded and stretched state, the absorbent body has a constricted portion in the crotch area corresponding to the wearer's crotch, the width in the width direction of which is narrower than the maximum width of one end of the absorbent body in the longitudinal direction.

10. A pants-type absorbent article as claimed in claim 1 or 2, characterized in that the absorbent body has a low-basis weight area in the crotch area corresponding to the wearer's crotch, which has a basis weight lower than the surrounding area and which is aligned in the vertical direction.

11. A pants-type absorbent article according to claim 1 or 2, characterized in that the absorbent body has a plurality of compression portions formed to compress the absorbent body in the thickness direction.

12. A pants-type absorbent article as claimed in claim 1 or 2, characterized in that the number of layers of material at both side edges in the width direction of the absorbent body is greater than the number of layers of material at the central part in the width direction.

13. A pants-type absorbent article according to claim 1 or 2, characterized in that the absorbent main body has a top sheet provided closer to the skin than the absorbent body, and the top sheet extends further in the width direction than the absorbent body.

14. A pants-type absorbent article as described in claim 13, characterized in that in an unfolded state, it has a thickness direction that intersects with the longitudinal direction and the width direction, and in that in the longitudinal direction, in an area that overlaps at least with a portion where the stretching force of the leg gather elastic member acts, adhesive is continuously provided in the longitudinal direction on the non-skin side of the thickness direction of the top sheet.

15. A pants-type absorbent article as claimed in claim 1 or 2, characterized in that, in an unfolded and stretched state, the leg gather elastic member is not provided in the innermost region when the region from the end of the absorber to the end of the absorbent main body in the width direction is divided into three.

16. A pants-type absorbent article as claimed in claim 1 or 2, which, in an unfolded state, has a thickness direction that intersects with the longitudinal direction and the width direction, and the absorbent main body has a non-skin-side sheet provided on the non-skin-side side of the absorbent body in the thickness direction, and a leak-proof film provided between the absorbent body and the non-skin-side sheet in the thickness direction, and the leak-proof film and the leg gather elastic member have overlapping portions when viewed in the thickness direction.

17. A pants-type absorbent article as claimed in claim 16, characterized in that the leak-proof film is adhered by adhesive that is continuously provided in the vertical direction in at least the area that overlaps with the portion where the stretching force of the leg gather elastic member acts in the vertical direction.

18. A pants-type absorbent article as claimed in claim 16, comprising a front waistband and a rear waistband constructed as a separate member from said front waistband, said front waistband and said rear waistband being joined at both sides in the width direction by a pair of side joining sections, and at least in the crotch section corresponding to the wearer's crotch, a pants-type absorbent article having a portion in which a plurality of sheet materials are provided on the non-skin side of said leakproof film in the thickness direction.

19. A pants-type absorbent article as claimed in claim 16, comprising a front waistband and a rear waistband constructed as a separate member from the front waistband, the front waistband and the rear waistband being joined at both sides in the width direction by a pair of side joining sections, and in the crotch section corresponding to the wearer's crotch, when the area on the non-skin side of the leak-proof film in the thickness direction is defined as the outer region, the basis weight of the outer region is higher than the basis weight of the sheet material arranged outermost in the thickness direction in the front waistband or the rear waistband.

20. A pants-type absorbent article as claimed in claim 1 or 2, characterized in that in an unfolded state, it has a thickness direction that intersects with the longitudinal direction and the width direction, and when viewed in the thickness direction, a sheet material other than the sheet material that constitutes the leg gathered portion is provided closer to the skin than the leg gathered portion.

21. A pants-type absorbent article as claimed in claim 1 or 2, characterized in that it has a pair of leakage prevention wall portions on both sides in the width direction of the absorbent main body, the leakage prevention wall portions stretch along the up-down direction and have one or more leakage prevention wall elastic members that make the leakage prevention wall portions stand up against the skin, the leakage prevention wall portions have a plurality of compression portions formed to compress the leakage prevention wall portions in the thickness direction, and there are portions where the leg gather portions and the compression portions overlap when viewed in the thickness direction of the pants-type absorbent article.

22. A pants-type absorbent article as claimed in claim 1 or 2, characterized in that in an unfolded state it has a thickness direction perpendicular to the longitudinal direction and the width direction, the absorbent body has a plurality of layers stacked in the thickness direction, one of the plurality of layers is a superabsorbent polymer layer in which the volume occupied by the superabsorbent polymer is larger than the volume occupied by the liquid-absorbent fiber, the superabsorbent polymer layer has a high basis weight region in which the basis weight of the superabsorbent polymer is higher than the surrounding area, the high basis weight region is arranged so that points of maximum thickness in the thickness direction are located intermittently in the longitudinal direction and the width direction, the maximum thickness is within 3 mm, and the distance between adjacent points of maximum thickness is 5 times or less the maximum thickness.

23. A pants-type absorbent article according to claim 1 or 2, characterized in that the absorbent body has an absorbent core comprising a skin-side layer, an intermediate layer and a non-skin-side layer laminated at least in the thickness direction, and the intermediate layer does not contain nonwoven fabric.

24. A pants-type absorbent article according to claim 23, characterized in that the layer of the absorbent core closest to the skin does not contain water-absorbent resin powder.

25. A pants-type absorbent article according to claim 23, characterized in that the liquid permeation rate under load of the superabsorbent polymer contained in the layer of the absorbent core closest to the skin exceeds 10 seconds.

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