Underpants-type absorbent article

Abstract

This underpants-type absorbent article (1) comprises an absorbent body (10) and a pair of leg gather parts (LG). In each leg gather part (LG), three or more leg gather elastic members (17) that stretch and contract in the longitudinal direction are arranged at intervals of 5 mm or more in the left-right direction. The contraction force of a first leg gather elastic member (17a) is greater than the contraction force of second leg gather elastic members (17b, 17c) located at an outer side of the first leg gather elastic member (17a) in the left-right direction. Each leg gather part (LG) has a rigidity-imparting means in a region (ER) from the most outer side end (10es) in the left-right direction to the leg gather elastic member (17a) that is disposed at the most inner side. At least a part of the rigidity-imparting means does not overlap the leg gather elastic members (17) and has a portion continuous in the longitudinal direction.

Description

Pants-type absorbent article

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

[0002] Conventionally, in pants-type diapers and the like having stretchable leg gathers (LG) along the leg openings, a technique for improving the fit of the leg openings and suppressing side leakage of excrement such as urine by widening the width of the leg gathers has been known. For example, Patent Document 1 discloses a pants-type diaper having a pair of extension portions (corresponding to leg gathers) extending outward in the width direction from both side edges of the absorbent body, and the extension portions (leg gathers) can be made to fit a wide range of the wearer's legs by making the length of the extension portions greater than the height of the leakage-preventing cuffs.

[0003] JP 2017-12459 A

[0004] In the pants-type disposable diaper of Patent Document 1, the leg gathers are provided with elasticity by a plurality of leg elastic members that stretch along the longitudinal direction of the extensions (leg gathers) (the longitudinal direction of the absorbent body). However, if the leg gathers have a large number of closely spaced leg elastic members, the surface pressure of the leg gathers increases, which may cause rashes or redness in the wearer's legs. Conversely, if the leg gathers have a small number of leg elastic members, the wide leg gathers tend to fold inward (toward the crotch), which may result in poor fit or anxiety about leakage.

[0005] The present invention has been made in consideration of the above-mentioned problems, and its purpose is to provide a pants-type absorbent article with leg gathers that do not have excessively high surface pressure and are less likely to fold inward.

[0006] The main invention for achieving the above object is a pants-type absorbent article having an absorbent main body, a front waistline portion, and a rear waistline portion, which have a vertical direction and a horizontal direction that intersect each other, and which comprises an absorbent main body, a front waistline portion, and a rear waistline portion, the front waistline portion and the rear waistline portion being joined to each other at both ends in the horizontal direction by a pair of side joining portions, and a pair of leakage preventing walls and a pair of leg gather portions are provided on each side in the horizontal direction of the absorbent main body, and three or more leg gather elastic members that stretch along the longitudinal direction of the absorbent main body are arranged in the leg gather portions at intervals of 5 mm or more in the horizontal direction, and the leg gather elastic members comprise a first leg gather elastic member and a second leg gather elastic member that is arranged outward in the horizontal direction from the first leg gather elastic member, and the first leg gather elastic members are arranged in the leg gather portions at intervals of 5 mm or more in the horizontal direction. a contractile force of the first leg gather elastic member when stretched to 0.9 times its maximum length along the longitudinal direction and then returned to 0.7 times its maximum length is greater than a contractile force of the second leg gather elastic member when stretched to 0.9 times its maximum length along the longitudinal direction and then returned to 0.7 times its maximum length, the leg gather portion has a stiffening means for stiffening the leg gather portion in a region from the outermost end to the innermost leg gather elastic member in the left-right direction, at least a portion of the stiffening means does not overlap the leg gather elastic member when viewed in the thickness direction, and has a portion that is continuous in the longitudinal direction in a region below the lower end of the side joint portion. 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 having leg gathers that do not have an excessively high surface pressure and are less likely to fold inward.

[0008] 1 is a schematic perspective view of a pants-type disposable diaper 1 (diaper 1). It is a plan view of the diaper 1 in an unfolded and stretched state. It is a schematic cross-sectional view taken along the line A-A in FIG. 2. It is a plan view and a cross-sectional view of the absorbent main body 10 in a stretched state. FIGS. 5A and 5B are diagrams illustrating the fit of the leg gathers LG in the crotch area (leg openings) of a wearer when wearing a conventional pants-type diaper. It is a schematic cross-sectional view illustrating the structure of the leg gathers LG of the diaper 1. FIGS. 7A to 7C are diagrams illustrating a method for measuring the contractile force of the LG elastic members 17. It is a plan view and a cross-sectional view illustrating modified examples of the absorbent main body 10. It is a plan view of the front waistline portion 20 and the absorbent main body 10 in a stretched state. It is a diagram illustrating a wearer wearing the diaper 1 as viewed from the side. It is a plan view of the front waistline portion 20 and the absorbent main body 10 in a natural state.

[0009] At least the following matters will become clear from the description of this specification and the accompanying drawings.

[0010] (Aspect 1) A pants-type absorbent article having a vertical direction and a horizontal direction that intersect each other, comprising an absorbent main body, a front waistline portion, and a rear waistline portion, the front waistline portion and the rear waistline portion being joined to each other at both ends in the horizontal direction by a pair of side joining portions, a pair of leakage preventing walls and a pair of leg gather portions being provided on each side of the absorbent main body in the horizontal direction, and three or more leg gather elastic members that stretch along the longitudinal direction of the absorbent main body are arranged in the leg gather portions at intervals of 5 mm or more in the horizontal direction, the leg gather elastic members comprising a first leg gather elastic member and a second leg gather elastic member that is arranged outward of the first leg gather elastic member in the horizontal direction, and the first leg gather elastic member is arranged along the longitudinal direction. a contractile force of the first leg gather elastic member when the first leg gather elastic member is stretched to 0.9 times its maximum length and then returned to 0.7 times its maximum length along the longitudinal direction is greater than a contractile force of the second leg gather elastic member when the second leg gather elastic member is stretched to 0.9 times its maximum length along the longitudinal direction and then returned to 0.7 times its maximum length; and the leg gather portion has stiffening means in a region from the outermost end to the leg gather elastic member arranged in the innermost position in the left-right direction, which stiffens the leg gather portion, and at least a part of the stiffening means does not overlap with the leg gather elastic member when viewed in the thickness direction, and has a portion that is continuous in the longitudinal direction in a region below the lower end of the side joint portion.

[0011] According to the pants-type absorbent article of Aspect 1, by arranging the LG elastic members at a wider pitch and by making the contractile force of the LG elastic members arranged on the outer side in the left-right direction weaker than that on the inner side, the leg gathers can easily follow the movement of the wearer's legs and fit well when worn. Furthermore, the stiffening means increases the stiffness of the leg gathers over a wide area, making it easier for the leg gathers to maintain their surface shape. These features result in a pants-type absorbent article with leg gathers that do not apply excessively high surface pressure and are less likely to fold inward. Furthermore, the leg gathers can easily fit well around the wearer's legs, making it less likely for the user to experience concerns about side leakage of body exudates.

[0012] (Aspect 2) The pants-type absorbent article according to Aspect 1, wherein, of the two leg gather elastic members arranged adjacent to each other in the left-right direction, the leg gather elastic member arranged on the inner side in the left-right direction has a contractile force when stretched to a length 0.9 times its maximum length along the longitudinal direction and then returned to 0.7 times its maximum length, which is equal to or greater than the contractile force of the leg gather elastic member arranged on the outer side in the left-right direction when stretched to a length 0.9 times its maximum length along the longitudinal direction and then returned to 0.7 times its maximum length.

[0013] In the pants-type absorbent article of Aspect 2, the contractile force of the LG elastic members gradually decreases from the inside to the outside in the left-right direction, which allows the leg gathers to more easily follow the movement of the wearer's legs and reduces curling, thereby improving the fit along the shape of the wearer's legs while preventing the surface pressure of the leg gathers from becoming excessively high.

[0014] (Aspect 3) A pants-type absorbent article according to Aspect 1 or 2, wherein, of the two leg gather elastic members arranged adjacent to each other in the left-right direction, the value obtained by dividing the length in a natural state of the leg gather elastic member arranged on the inner side in the left-right direction by the length when stretched to the maximum along the longitudinal direction is equal to or less than the value obtained by dividing the length in a natural state of the leg gather elastic member arranged on the outer side in the left-right direction by the length when stretched to the maximum along the longitudinal direction.

[0015] According to the pants-type absorbent article of Aspect 3, the rate at which the LG elastic members contract (the contraction rate) gradually decreases from the inside to the outside in the left-right direction, which allows the leg gathers to more easily follow the movement of the wearer's legs and reduces curling, thereby improving the fit along the shape of the wearer's legs while preventing the surface pressure of the leg gathers from becoming excessively high.

[0016] (Aspect 4) The pants-type absorbent article according to any one of Aspects 1 to 3, wherein, of the two leg gather elastic members arranged adjacent to each other in the left-right direction, the cross-sectional area of ​​the leg gather elastic member arranged on the inner side in the left-right direction in its natural state is equal to or greater than the cross-sectional area of ​​the leg gather elastic member arranged on the outer side in the left-right direction in its natural state.

[0017] In the pants-type absorbent article of Aspect 4, since the larger the cross-sectional area of ​​the LG elastic member, the larger the diameter of the LG elastic member, the more easily it is possible to suppress an increase in pressure acting per unit area toward the inside in the left-right direction of the leg gathers. Therefore, even if the contractile force of the LG elastic member is increased toward the inside in the left-right direction of the leg gathers, an excessive increase in surface pressure is suppressed, and it is easy to suppress linear marks caused by the LG elastic member on the wearer's skin.

[0018] (Aspect 5) A pants-type absorbent article according to any one of Aspects 1 to 4, wherein, when a region from the outermost end of the leg gather portion to the innermost arranged leg gather elastic member in the left-right direction is defined as a leg gather elastic region, the length of the leg gather elastic region in the left-right direction in a stretched state is at least half of the length of the leg gather portion in the left-right direction in the leg gather elastic region in the stretched state, and when the leg gather elastic region is equally divided in the left-right direction by the number of leg gather elastic members arranged in the leg gather elastic region, a leg gather elastic member is arranged in each of the divided regions.

[0019] According to the pants-type absorbent article of Aspect 5, since the LG elastic members are evenly arranged in the leg gathers, localized differences in stiffness are less likely to occur, making it easier to maintain the surface shape. In addition, since localized pressure is less likely to be applied to the leg openings of the wearer, skin irritation and redness can be suppressed.

[0020] (Aspect 6) The pants-type absorbent article according to any one of Aspects 1 to 5, wherein the leg gather elastic region is equally divided in the left-right direction, and the stiffening means is provided in each of the divided regions.

[0021] According to the pants-type absorbent article of aspect 6, the rigidity of each area in the leg gather elastic region where the contractile force of the LG elastic member acts is increased, thereby suppressing curling of the leg gather portion and making it easier to maintain the surface shape.

[0022] (Aspect 7) The pants-type absorbent article according to any one of Aspects 1 to 6, wherein the stiffening means is provided between two of the leg gather elastic members arranged adjacent to each other in the left-right direction when viewed in the thickness direction.

[0023] According to the pants-type absorbent article of aspect 7, the stiffness imparting means increases the stiffness in the area between two adjacent LG elastic members, making it less likely that a bending point will form between the LG elastic members, thereby making it easier to suppress curling of the leg gathered portion.

[0024] (Aspect 8) The pants-type absorbent article according to any one of Aspects 1 to 7, wherein the stiffening means is provided such that the value obtained by dividing the contractile force when the leg gathered portions are stretched to a length 0.9 times the length at which they are fully stretched along the longitudinal direction and then returned to 0.7 times that length by the width of the leg gathered portions is equal to or less than the value obtained by dividing the contractile force when the leakage preventing wall portions are stretched to a length 0.9 times the length at which they are fully stretched along the longitudinal direction and then returned to 0.7 times that length by the width of the leakage preventing wall portions.

[0025] According to the pants-type absorbent article of aspect 8, the surface pressure of the leg gathered portions is relatively smaller compared to when the contraction force per unit width of the leg gathered portions is greater than the contraction force per unit width of the leakage preventing walls, making it less likely that the wearer will develop rashes or redness in their legs when wearing the article.

[0026] (Aspect 9) The pants-type absorbent article according to any one of Aspects 1 to 8, wherein the leg gather portion has at least two layers of sheet members stacked in a thickness direction, the leg gather elastic member is provided between the stacked sheet members, and the stiffening means stiffens the leg gather portion by joining the stacked sheet members together.

[0027] According to the pants-type absorbent article of Aspect 9, the sheet members stacked in the thickness direction in the leg gathers are joined together to increase the rigidity, and the sheet members constituting the leg gathers are more likely to be maintained in a flat shape. This makes it less likely for the leg gathers to curl. Furthermore, since the joining parts themselves (e.g., welded parts or adhesive parts) have rigidity, the rigidity of the leg gathers is more likely to be ensured.

[0028] (Aspect 10) The pants-type absorbent article according to any one of Aspects 1 to 9, wherein the stiffening means stiffens the leg gathers by bonding the stacked sheet members together with an adhesive.

[0029] According to the pants-type absorbent article of Aspect 10, the rigidity of the leg gathers is increased, the sheet member constituting the leg gathers is more likely to be maintained in a flat state, and the leg gathers are less likely to curl. Furthermore, since adhesives such as hot melt adhesives are solidified at room temperature, the adhesive itself has rigidity, making it easier to ensure the rigidity of the leg gathers.

[0030] (Aspect 11) The pants-type absorbent article according to any one of Aspects 1 to 10, wherein when a region from the outermost end of the leg gathered portion in a stretched state to the innermost arranged leg gathered elastic member in the left-right direction is defined as a leg gathered elastic region, the stiffening means is provided in at least half of the area of ​​the leg gathered elastic region.

[0031] According to the pants-type absorbent article of aspect 11, the rigidity of more than half of the leg gather elastic region is increased by the stiffening means, which makes it easier for the leg gather elastic region to maintain its planar shape and makes it easier to prevent the leg gather portion from curling.

[0032] (Aspect 12) A pants-type absorbent article according to any one of Aspects 1 to 11, wherein the absorbent main body has a liquid-absorbing absorber, a liquid-impermeable sheet is provided on the non-skin side of the absorber, and an outer edge of the liquid-impermeable sheet is located between the outermost leg gather elastic member and the second outermost leg gather elastic member in the left-right direction.

[0033] In the pants-type absorbent article of Aspect 12, the provision of the leakproof film up to the vicinity of the tips of the leg gathers increases the rigidity of the leg gathers and makes it easier to maintain their surface shape compared to when the leakproof film is not provided. Furthermore, because the leakproof film is not provided outside the outermost LG elastic member, the tip edges of the leg gathers are less likely to become hard, and even if the tip edges come into contact with the wearer's skin, they are less likely to cause discomfort or annoyance to the wearer.

[0034] (Aspect 13) The pants-type absorbent article according to any one of Aspects 1 to 12, wherein the stiffening means is not provided outside the leg gather elastic members that are arranged outermost in the left-right direction.

[0035] According to the pants-type absorbent article of Aspect 13, the rigidity of the leading edges of the leg gathered portions is not excessively increased, and flexibility is maintained. Therefore, even if the leading edges come into contact with the wearer's skin when worn, the wearer is unlikely to experience discomfort or annoyance.

[0036] (Aspect 14) The pants-type absorbent article according to any one of Aspects 1 to 13, wherein the shortest distance from the outer ends of the leg gathered portions in the left-right direction to the rising starting points of the leakage preventing wall portions in the stretched state is equal to or greater than the shortest distance from the rising starting points of the leakage preventing wall portions to the tip ends of the leakage preventing wall portions in the stretched state.

[0037] According to the pants-type absorbent article of Aspect 14, even if the leakage preventing wall portions are collapsed outward in the left-right direction from their upright state when worn, the collapsed leakage preventing wall portions are prevented from protruding outward beyond the tips of the leg gathers. Therefore, gaps are less likely to form between the leg gathers and the wearer's skin, and the leg gathers can be more easily fitted to the wearer's leg movements.

[0038] (Aspect 15) The pants-type absorbent article according to any one of Aspects 1 to 14, wherein the absorbent main body has a liquid-absorbing absorber, and has crotch elastic members that stretch along the longitudinal direction of the absorbent main body in an area between an outer end of the absorber and an upright starting point of the leakage preventing wall portion in the left-right direction.

[0039] According to the pants-type absorbent article of Aspect 15, when worn, both outer sides of the absorber in the left and right direction are pushed up against the skin by the stretchability of the crotch elastic members, making it easier for the absorber to fit around the crotch of the wearer. In addition, the stretchability of the crotch elastic members pushes up the base sides of the leg gathered portions against the skin, making it easier for the leg gathered portions to fit around the skin of the wearer.

[0040] (Aspect 16) The pants-type absorbent article according to any one of Aspects 1 to 15, wherein the absorbent main body has a liquid-absorbing absorber, a top sheet is provided closer to the skin than the absorber, and at least a portion of the top sheet is disposed outside the rising starting points of the leakage preventing wall portions in the left-right direction.

[0041] In the pants-type absorbent article of Aspect 16, the portions of the top sheet disposed outward from the rising points function as stiffening means that stiffen the leg gathered portions, making it easier for the leg gathered portions to maintain a flat shape and less likely to curl up. This makes it less likely for gaps to form between the leg gathered portions and the wearer's skin when worn, making it easier for the leg gathered portions to fit snugly around the legs.

[0042] (Aspect 17) The pants-type absorbent article according to any one of Aspects 1 to 16, wherein the front waistline portion and the rear waistline portion have waistline elastic members that stretch in the left-right direction, and when viewed in the thickness direction, at least one of the front waistline portion and the rear waistline portion has a portion where the waistline elastic members and the leg gather elastic members intersect.

[0043] According to the pants-type absorbent article of aspect 17, the contraction force of the waist elastic member and the contraction force of the LG elastic member work together, making it easier for the LG elastic member to be pulled upward, so that the entire pants-type absorbent article is less likely to sag downward, and deterioration of the fit of the waist and leg gathers is suppressed.

[0044] (Aspect 18) A pants-type absorbent article having a vertical direction and a horizontal direction that intersect each other, comprising an absorbent main body, a front waistline portion, and a rear waistline portion, the front waistline portion and the rear waistline portion being joined to each other at both ends in the horizontal direction by a pair of side joining portions, a pair of leakage preventing walls and a pair of leg gather portions being provided on each side of the absorbent main body in the horizontal direction, and three or more leg gather elastic members that stretch along the longitudinal direction of the absorbent main body are arranged in the leg gather portions at intervals of 5 mm or more in the horizontal direction, the leg gather elastic members comprising a first leg gather elastic member and a second leg gather elastic member arranged outward in the horizontal direction from the first leg gather elastic member, and a length of the first leg gather elastic member when the first leg gather elastic member is stretched to a length that is 0.9 times its maximum stretched length along the longitudinal direction and then returned to a length that is 0.7 times its maximum stretched length. the contractile force of the third front waistline region when the third front waistline region is stretched to 0.9 times its maximum length along the left-right direction and then returned to 0.7 times its maximum length, the front waistline portion and the rear waistline portion have stretchability along the left-right direction, and when the front waistline portion is divided into four equal parts in the up-down direction between the upper and lower ends of the side joint portions, the third region from the top is a third front waistline region and the fourth region from the top is a fourth front waistline region, the contractile force of the third front waistline region when the third front waistline region is stretched to 0.9 times its maximum length along the left-right direction and then returned to 0.7 times its maximum length, is greater than the contractile force of the fourth front waistline region when the fourth front waistline region is stretched to 0.9 times its maximum length along the left-right direction and then returned to 0.7 times its maximum length.

[0045] According to the pants-type absorbent article of Aspect 18, the fit of the front waistline can be improved by increasing the contractile force of the third front waistline region and the fourth front waistline region in the front waistline. In this case, by making the contractile force of the fourth front waistline region smaller than that of the third front waistline region, the lower end of the fourth front waistline region is less likely to interfere with the wearer's leg movement, and displacement of the front waistline is suppressed. This improves the fit of the front waistline without interfering with the wearer's leg movement or abdominal movement due to breathing. Furthermore, the improved fit of the front waistline, which reduces displacement, allows the wide leg gathers to more snugly fit the wearer's legs.

[0046] (Aspect 19) When the front waistline portion is divided into four equal parts in the vertical direction between the upper and lower ends of the side joint portion, the first region from the top is a first front waistline region and the second region from the top is a second front waistline region, the magnitude of the contractile force when each of the first to fourth front waistline regions is stretched along the left-right direction to a length 0.9 times the length when fully stretched and then returned to a length 0.7 times the length is the largest in the third front waistline region, in the pants-type absorbent article according to Aspect 18.

[0047] According to the pants-type absorbent article of Aspect 19, the portion of the garment against which the third front waist region abuts when worn has a small abdominal protrusion and is subject to small fluctuations due to breathing, etc., so that even if the contractile force of the third front waist region is increased, the wearer is unlikely to feel uncomfortable. Furthermore, by tightly fitting the third front waist region to a portion of the garment that experiences small abdominal movements (fluctuations) and fixing its position, the entire front waist region is less likely to slip down, and the fit of the front waist region and the leg gathers can be further improved.

[0048] (Aspect 20) The pants-type absorbent article according to Aspect 18 or 19, wherein a sum of the contractile forces of the third front waist region and the fourth front waist region is greater than a sum of the contractile forces of the first front waist region and the second front waist region.

[0049] According to the pants-type absorbent article of Aspect 20, the upper regions of the front waistline (the first front waistline region 20 and the second front waistline region) are located in areas where the wearer's abdomen bulges or fluctuates significantly, and therefore excessively tight tightening can easily cause discomfort to the wearer. On the other hand, the lower regions of the front waistline (the third front waistline region and the fourth front waistline region) are located in areas where the wearer's abdomen bulges or fluctuates less, and therefore by tightening them more than the upper regions, discomfort to the wearer is less likely to occur, and fit can be efficiently improved. This is particularly suitable for infants, who are prone to abdominal protrusion, as it can improve fit while ensuring safety.

[0050] (Aspect 21) The pants-type absorbent article of any of Aspects 18 to 20, wherein when the rear waistline portion is divided into four equal parts in the up-down direction between the upper end and the lower end of the side joint portion, the first region from the top is a first rear waistline region, the second region from the top is a second rear waistline region, the third region from the top is a third rear waistline region, and the fourth region from the top is a fourth rear waistline region, and when each of the first to fourth rear waistline regions is stretched to a length that is 0.9 times the length of the maximum stretch along the left-right direction and then returned to a length that is 0.7 times the length, the magnitude of the contractile force of the third rear waistline region is the largest.

[0051] According to the pants-type absorbent article of Aspect 21, in an area of ​​the wearer's abdomen that protrudes little and is subject to little change due to breathing, etc., the third front waist region and the third rear waist region, which are connected in an annular shape, work together to easily apply a large contractile force along the waist. This makes it difficult for the waist portion to shift position in this area, further improving the fit without causing discomfort to the wearer.

[0052] (Aspect 22) The pants-type absorbent article of any of Aspects 18 to 21, wherein when the rear waistline portion is divided into four equal parts in the up-down direction between the upper end and the lower end of the side joint portion, the first region from the top is a first rear waistline region, the second region from the top is a second rear waistline region, the third region from the top is a third rear waistline region, and the fourth region from the top is a fourth rear waistline region, and when each of the first to fourth rear waistline regions is stretched to a length that is 0.9 times the length of the maximum stretch along the left-right direction and then returned to a length that is 0.7 times the length, the magnitude of the contractile force of the second rear waistline region is the largest.

[0053] According to the pants-type absorbent article of aspect 22, by increasing the contractile force of the second rear waist region at the area on the back side of the wearer where the narrowing becomes larger at the boundary between the back and buttocks, the waist region is more likely to be firmly fixed, slipping down is suppressed, and the fit is improved.

[0054] (Aspect 23) The pants-type absorbent article according to any one of Aspects 18 to 22, wherein, in a natural state, the length of the third front waist region in the left-right direction is shorter than the length of the fourth front waist region in the left-right direction.

[0055] According to the pants-type absorbent article of aspect 23, a contraction fold point is formed in the third front waist region between the upper and lower ends of the front waist portion, making it easier for the front waist portion to fit into the depression in the wearer's lower abdomen, making the front waist portion less likely to slip down and improving fit.

[0056] (Aspect 24) A pants-type absorbent article according to any one of Aspects 18 to 23, wherein when the front waistline portion is divided into four equal parts in the up-down direction between the upper and lower ends of the side joint portion, the first region from the top is a first front waistline region and the second region from the top is a second front waistline region, and in the natural state, the average length in the left-right direction of the third front waistline region and the fourth front waistline region is shorter than the average length in the left-right direction of the first front waistline region and the second front waistline region.

[0057] According to the pants-type absorbent article of Aspect 24, the amount of contraction in the left-right direction is small in the upper half of the front waistband, where abdominal movement is large, so the front waistband is less likely to interfere with the wearer's abdominal movement and cause discomfort to the wearer. On the other hand, the amount of contraction in the left-right direction is large in the lower half of the front waistband, where abdominal movement is small, so the front waistband is more likely to be fixed in the concave part of the wearer's lower abdomen and is less likely to shift out of position. This improves the fit of the front waistband.

[0058] (Aspect 25) The pants-type absorbent article according to any one of Aspects 18 to 24, further comprising a main body joint portion that joins the absorbent main body and the front waistline portion, and an upper end of the main body joint portion is located higher than an upper end of the third front waistline region in the vertical direction.

[0059] In the pants-type absorbent article of Aspect 25, the entire third front waist region is joined to the absorbent main body in the up-down direction via the main body joining portion, so that the large contractile force of the third front waist region presses the absorbent main body against the wearer's skin, making it difficult for the absorbent main body to slip down. This further improves the fit of the absorbent main body and the leg gathers provided at both ends thereof.

[0060] (Aspect 26) The pants-type absorbent article according to any one of Aspects 18 to 25, wherein the absorbent main body has a liquid-absorbing absorber, and an upper end of the absorber is located lower than an upper end of the third front waistline region in the up-down direction.

[0061] According to the pants-type absorbent article of Aspect 26, in the area where the third front waist region and the absorbent body do not overlap, the contractile force of the third front waist region is less likely to be inhibited by the highly rigid absorbent body, allowing a large contractile force to act on the depression of the wearer's lower abdomen, thereby further improving the fit of the absorbent body and making it easier to prevent the leg gathered portions from folding inward.

[0062] (Aspect 27) The pants-type absorbent article according to any one of Aspects 18 to 26, wherein the front waist portion has a plurality of waist elastic members that stretch in the left-right direction and are spaced apart in the up-down direction, and an average pitch in the left-right direction of the leg gather elastic members arranged in the leg gather portion is greater than an average pitch in the up-down direction of the waist elastic members arranged in the third front waist region.

[0063] According to the pants-type absorbent article of Aspect 27, the pitch of the LG elastic members is relatively large, so that the surface pressure of the leg gathers is unlikely to become excessively large, and the LG elastic members are unlikely to leave marks on the wearer's skin.

[0064] Embodiment A pants-type absorbent article according to this embodiment will be described using a pants-type disposable diaper 1 for infants (hereinafter simply referred to as "diaper 1"). However, pants-type absorbent articles are not limited to disposable diapers for infants, and can also be used as disposable diapers for adults, sanitary shorts, etc.

[0065] <Configuration of pants-type disposable diaper 1> Fig. 1 is a schematic perspective view of a pants-type disposable diaper 1. Fig. 2 is a plan view of the diaper 1 in an unfolded and stretched state. Fig. 3 is a schematic cross-sectional view taken along the line AA in Fig. 2.

[0066] In the pants-type state shown in Fig. 1, the diaper 1 has a vertical direction, a horizontal direction, and a front-to-back direction, which intersect with one another, and is formed with a waist opening BH and a pair of leg openings LH. In the vertical direction, the waist opening BH side is referred to as the upper side, and the crotch side is referred to as the lower side. As shown in the cross-sectional view of Fig. 3, the direction in which the materials constituting the diaper 1 are layered is referred to as the thickness direction. The side in the thickness direction that comes into contact with the wearer's body (skin) is referred to as the skin side, and the side that does not come into contact with the wearer's body (skin) is referred to as the non-skin side.

[0067] Furthermore, the "stretched state" of the diaper 1 refers to a state in which the entire diaper 1 (the entire product) is stretched without wrinkles by stretching each of the elastic members of the diaper 1 (for example, the LG elastic member 17 and waist elastic members 23, 33 described below, etc.), specifically, a state in which the dimensions of each of the members constituting the diaper 1 (for example, the absorbent body 10 and waist portions 20, 30 described below, etc.) are stretched to the same dimensions as or close to the dimensions of the individual members.

[0068] 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 and the waistbands 20, 30 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."

[0069] The diaper 1 has three components, each rectangular in plan view, namely, an absorbent main body 10, a front waist portion 20, and a rear waist portion 30. When the diaper 1 is worn, the front waist portion 20 (ventral waist portion) is placed against the wearer's abdominal region, and the rear waist portion 30 (dorsal waist portion) is placed against the wearer's dorsal region.

[0070] In the diaper 1 in the unfolded state shown in Fig. 2, the front waistline section 20 and the rear waistline section 30 are arranged so that their longitudinal directions are aligned with the left-right direction of the diaper 1. An end portion on one longitudinal side (front side) of the absorbent main body 10 is joined to the center of the front waistline section 20 in the left-right direction, and an end portion on the other longitudinal side (rear side) of the absorbent main body 10 is joined to the center of the rear waistline section 30 in the left-right direction.

[0071] In the diaper 1 in the unfolded state shown in Fig. 2, the absorbent main body 10 is folded in half at a predetermined longitudinal position (which is also a predetermined longitudinal position) FL so that the longitudinal direction of the absorbent main body 10 is aligned with the vertical direction of the diaper 1, and the front waistband portion 20 and the rear waistband portion 30 are joined at both lateral ends thereof by a joining method such as thermal welding or ultrasonic welding to form a pair of side joining portions 2, 2. This results in the diaper 1 being in a pants-type state (see Fig. 1) having a waist opening BH and a pair of leg openings LH. The predetermined position FL is the bottom end in the vertical direction and the center in the front-to-back direction of the diaper 1 in the pants-type state.

[0072] (Absorbent main body 10) Fig. 4 is a plan view and a cross-sectional view of the absorbent main body 10 in a stretched state. As shown in the cross-sectional views of Fig. 3 and Fig. 4, the absorbent main body 10 comprises an absorbent body 11, a top sheet 12 arranged closer to the skin than the absorbent body 11, a leak-proof film 13 arranged closer to the skin than the absorbent body 11, and an exterior sheet 14 arranged closer to the skin than the leak-proof film 13 and forming an exterior of the absorbent main body 10. Furthermore, a pair of leakage-proof wall portions LSG and a pair of leg gather portions LG are provided on each of the left and right sides of the absorbent main body 10.

[0073] The absorbent body 11 has an absorbent core 11a that absorbs and retains excreted liquids such as urine, and a liquid-permeable core wrap sheet 11b that covers the absorbent core 11a. The absorbent core 11a can be, for example, a liquid-absorbent fiber such as pulp containing superabsorbent polymer (SAP) molded into a predetermined shape. Alternatively, a so-called SAP sheet, which does not contain liquid-absorbent fiber and is formed into a flat plate by bonding SAP particles together, can also be used. On the other hand, the core wrap sheet 11b can be, for example, tissue paper or a nonwoven fabric such as an SMS nonwoven fabric.

[0074] The absorbent core 11a of this embodiment has a constricted portion 11c between its longitudinal front and rear ends that is shorter in length (narrower in width) in the left-right direction than the front and rear ends, and has a generally hourglass-shaped shape in plan view as shown in Fig. 4. This constricted portion 11c is the portion that is sandwiched between the wearer's legs when the diaper 1 is worn, and the shorter left-right length (narrower width) of the absorbent core 11a at this constricted portion 11c allows the absorber 11 to fit more easily between the wearer's crotch. However, the shape of the absorbent core 11a is not limited to this; for example, the absorbent core 11a (absorber 11) may be rectangular.

[0075] The top sheet 12 is a liquid-permeable sheet member that covers the absorbent body 11 from the skin side, and is made of, for example, a hydrophilic air-through nonwoven fabric or a spunbond nonwoven fabric. In this embodiment, both left and right side edges are folded back to the non-skin side so as to roll up the absorbent body 11, as shown in the cross-sectional view of Figure 4. A second sheet (not shown) equivalent to the top sheet 12 may also be provided between the top sheet 12 and the absorbent body 11.

[0076] 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 11, 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.

[0077] 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.

[0078] The exterior sheet 14 extends outward in the left-right direction beyond the outer ends 11es, 11es of the absorbent body 11, and this extended portion is folded inward in the left-right direction and toward the skin in the thickness direction, with the outer ends 10es, 10es of the absorbent main body 10 in the left-right direction as folding positions, to form a folded-back portion 14f. The unfolded portion of the exterior sheet 14 and the folded-back portion 14f are joined to each other via leg gather joints 50 (hereinafter also referred to as "LG joints 50") in a state where they are overlapped in the thickness direction, thereby forming a pair of leg gathers LG, LG. In Fig. 4, the unfolded portion of the exterior sheet 14 and the folded-back portion 14f are joined by first to fourth LG joints 51 to 54 with the leak-proof film 13 sandwiched between them in the thickness direction.

[0079] Furthermore, a plurality of leg gather elastic members 17, 17... (hereinafter also referred to as "LG elastic members 17") such as rubber threads are provided between the outer sheet 14 and the folded-back portion 14f in the thickness direction, forming the leg gather portion LG, at predetermined intervals in the left-right direction, each stretched at a predetermined stretch ratio in the longitudinal direction. This provides the leg gather portion LG with stretchability in the longitudinal direction (up-down direction). As a result of the plurality of LG elastic members 17, 17 being arranged side by side in the left-right direction, the leg gather portion LG has a planar shape that protrudes outward from both left-right sides of the absorbent main body 10, as shown in Figure 1.

[0080] In this embodiment, three LG elastic members 17 are provided on each of the left and right leg gather portions LG. Hereinafter, the LG elastic member 17 located on the innermost side in the left-right direction is referred to as the inner LG elastic member 17a, the LG elastic member 17 located on the outermost side in the left-right direction is referred to as the outer LG elastic member 17c, and the LG elastic member 17 located between the inner LG elastic member 17a and the outer LG elastic member 17c in the left-right direction is referred to as the middle LG elastic member 17b. While FIG. 4 shows only one middle LG elastic member 17b between the inner LG elastic member 17a and the outer LG elastic member 17c, multiple middle LG elastic members 17b may be provided. In other words, four or more LG elastic members 17 may be provided depending on the length (width) of the leg gather portion LG in the left-right direction. Each of the LG elastic members 17a to 17c exhibits stretchability at least in the portion indicated by the solid line in the plan view of FIG. 4 (the range in the longitudinal direction of the absorbent main body 10).

[0081] As shown in Fig. 4 , crotch elastic members 18, such as rubber threads, are provided inwardly of the LG elastic members 17 (inner LG elastic members 17a) and outwardly of the outer ends 11es of the absorbent body 11 in the left-right direction, stretched in the longitudinal direction. The crotch elastic members 18 exhibit stretchability at least in the portions indicated by solid lines in the plan view of Fig. 4 . When the diaper 1 is worn, the stretchability of the crotch elastic members 18 pushes the leg gathers LG and the absorbent body 11 toward the wearer's skin. This allows the leg gathers LG and the absorbent body 11 to fit more easily around the wearer's leg openings and crotch area, effectively preventing side leakage of body waste (such as urine).

[0082] 2, when viewed in the thickness direction, a portion of the crotch elastic member 18 overlaps with the ventral waist elastic member 23 and the dorsal waist elastic member 33. This makes it easier for the stretching force in the longitudinal direction of the crotch elastic member 18 to cooperate with the stretching force in the left-right direction of the waist elastic members 23, 33, thereby further improving fit. However, the crotch elastic member 18 may intersect with only one of the waist elastic members 23, 33 (either the ventral side or the dorsal side), or it may not intersect with either of the waist elastic members 23, 33.

[0083] Furthermore, a part of the folded portion 14f of the exterior sheet 14 forms a standing portion 14s that stands toward the skin in the left-right direction at a predetermined position outside the absorbent body 11. In Fig. 4, the standing portion 14s stands toward the skin in the thickness direction from the inner end 51ei in the left-right direction of the first LG joint 51 that is provided on the skin side in the thickness direction and on the innermost side in the left-right direction among the multiple LG joints 50.

[0084] 4, the standing portions 14s are folded back from the inside to the outside in the left-right direction at the positions of the tips 14st, and a plurality of leakage preventing wall elastic members 19 such as rubber threads are provided between the standing portions 14s, 14s overlapping in the thickness direction in a state stretched in the longitudinal direction. When the diaper 1 is worn, the stretchability exhibited by the leakage preventing wall elastic members 19 causes the tips 14st of the standing portions 14s to rise from the rising starting points 51ei toward the skin, thereby forming a pair of leakage preventing wall portions LSG, LSG.

[0085] (Front waistband portion 20) The front waistband portion 20 includes a waistband sheet 21 and multiple waistband elastic members 23, 23.... The waistband sheet 21 is a sheet member having a rectangular shape in a plan view. As shown in FIG. 3 , the waistband sheet 21 is folded back at an upper end 20et in the vertical direction of the front waistband portion 20 and joined in a stacked state in the thickness direction. Examples of the waistband sheet 21 include SMS nonwoven fabric (spunbond, meltblown, spunbond nonwoven fabric), spunbond nonwoven fabric, and air-through nonwoven fabric. Furthermore, multiple waistband elastic members 23, 23..., such as rubber thread, are provided between the skin side and non-skin side in the thickness direction of the waistband sheet 21 folded back at the upper end 20et, stretched in the left-right direction at a predetermined stretch ratio and spaced apart in the vertical direction. The elasticity of the multiple waistband elastic members 23 provides the front waistband portion 20 with elasticity in the left-right direction. Some of the plurality of waist elastic members 23, 23 . . . have cut portions in the center in the left-right direction.

[0086] The front waist portion 20 may also have a skin-contact sheet 25. As shown in Fig. 3, the skin-contact sheet 25 is a sheet member arranged to cover the upper end of the absorbent main body 10 from the skin side, and functions as a cover sheet. This prevents the upper end edge of the absorbent main body 10 from digging into the wearer's skin when the diaper 1 is put on. The skin-contact sheet 25 is formed from a sheet member such as a nonwoven fabric similar to that of the waist sheet 21. However, the skin-contact sheet 25 is not necessarily provided.

[0087] (Rear waistline portion 30) The rear waistline portion 30 has substantially the same configuration as the front waistline portion 20. That is, the rear waistline portion 30 has a waistline sheet 31 and multiple waistline elastic members 33, 33.... Similar to the waistline sheet 21, the waistline sheet 31 is folded back at the top end 30et in the vertical direction of the rear waistline portion 30 and joined in a stacked state in the thickness direction. In addition, multiple waistline elastic members 33, 33... such as rubber thread are provided between the skin side and non-skin side in the thickness direction of the folded waistline sheet 31, stretched in the left-right direction at a predetermined stretch ratio, and spaced apart in the vertical direction. The rear waistline portion 30 may also have a skin-contact sheet 35 substantially similar to the skin-contact sheet 25.

[0088] <Regarding the Fit of the Leg Gathered Portion LG> Next, the fit of the leg gathered portion LG when wearing the diaper 1 will be described. First, as a comparative example, problems with the leg gathered portion that have occurred in conventional pants-type absorbent articles will be described. Figures 5A and 5B are diagrams illustrating the fit of the leg gathered portion LG around the crotch area (leg openings) of a wearer when wearing a conventional pants-type diaper.

[0089] In the past, in pants-type absorbent articles, the leg gathers LG were sometimes made longer in the left-right direction (wider) to improve the fit at the leg openings and prevent side leakage of body exudates. In such cases, it is important that the wide leg gathers fit snugly against the wearer's skin (leg openings). In other words, when worn, it is required that the leg gathers LG fit tightly to the wearer's skin without creating any gaps between them.

[0090] In contrast, the diaper shown in Figure 5A narrows the pitch (lateral spacing) of the elastic members (LG elastic members) provided in the leg gathers LG and arranges a large number of LG elastic members, thereby increasing the stretchability of the leg gathers LG as a whole. This reduces the likelihood of gaps forming between the leg gathers LG and the wearer's skin when the diaper is worn. However, with the configuration shown in Figure 5A, the stretchability provided by the large number of LG elastic members tends to increase the surface pressure of the leg gathers LG excessively, which may cause discomfort due to the leg gathers LG digging into the wearer's leg openings. In particular, for infants and young children with sensitive skin, the leg gathers LG may be pressed strongly against the skin, potentially causing rashes or redness in the leg openings.

[0091] On the other hand, in the diaper shown in Figure 5B, the elastic members (LG elastic members) provided in the leg gathers LG are spaced farther apart in the lateral direction, reducing the number of LG elastic members, thereby preventing excessive surface pressure on the leg gathers LG. In this case, the reduced surface pressure prevents the leg gathers LG from digging into the wearer's legs, but the reduced number of LG elastic members reduces the rigidity of the leg gathers LG. As a result, the leg gathers LG may be prone to curling from the outside (tip side) to the inside (base side) as the LG elastic members contract. For example, if the position of the LG elastic members shifts from the outside to the inside when the wearer moves their legs, the LG elastic members may act like nodes, as shown in Figure 5B, causing the leg gathers LG to deform like bellows, making them prone to curling and resulting in a poor fit.

[0092] Therefore, in the diaper 1 of this embodiment, the surface pressure of the leg gathers LG is prevented from becoming excessively high, and the rigidity of the leg gathers LG is increased, so that the leg gathers LG are less likely to fold inward when worn. Fig. 6 is a schematic cross-sectional view illustrating the structure of the leg gathers LG of the diaper 1. Fig. 6 corresponds to an enlarged view of a portion of the cross-sectional view of Fig. 4.

[0093] 6, the leg gathers LG of the diaper 1 are formed in the left-right direction between the outer end 10es of the absorbent main body 10 and the inner end 51ei of the first LG joint 51, which is the rising starting point of the leakage barrier wall LSG. The leg gathers LG are provided with a plurality of leg gather elastic members (LG elastic members) 17. When an elastic member is arranged at a position overlapping with the rising starting point (inner end 51ei) of the leakage barrier wall LSG in the left-right direction, the elastic member is treated as a crotch elastic member 18, not as an LG elastic member 17.

[0094] In this embodiment, three LG elastic members 17 are provided from the inside to the outside in the left-right direction: an inner LG elastic member 17a, a middle LG elastic member 17b, and an outer LG elastic member 17c. The LG elastic members 17a to 17c are arranged so that the interval between any two adjacent LG elastic members 17 in the left-right direction is 5 mm or more. By providing the LG elastic members 17 at intervals of 5 mm or more, the stretching force acting per unit area of ​​the leg gather portion LG is smaller than when the intervals are narrower than 5 mm, and the surface pressure of the leg gather portion LG can be reduced.

[0095] Furthermore, in the diaper 1, of the multiple LG elastic members 17 provided in the leg gather portion LG, the LG elastic members 17 arranged on the outer side in the left-right direction are arranged so that the contractile force of the LG elastic member 17 arranged on the outer side in the left-right direction is as small as possible. That is, when one of the multiple LG elastic members 17 is designated as a first leg gather elastic member and the LG elastic member 17 arranged on the outer side in the left-right direction of the first leg gather elastic member is designated as a second leg gather elastic member, the LG elastic members 17 are arranged so that the contractile force of the first leg gather elastic member is greater than the contractile force of the second leg gather elastic member.

[0096] For example, in Figure 6, if the inner LG elastic member 17a is the first leg gather elastic member, then at least one of the middle LG elastic member 17b and the outer LG elastic member 17c is the second leg gather elastic member. The LG elastic members 17a-17c are arranged so that the contractile force of the inner LG elastic member 17a is greater than that of at least one of the middle LG elastic member 17b and the outer LG elastic member 17c. The LG elastic members 17 arranged on the inner side (the base side of the leg gather portion LG) in the left-right direction have a stronger contractile force, while the LG elastic members 17 arranged on the outer side (the distal end side of the leg gather portion LG) have a weaker contractile force. This allows the leg gather portion LG to more easily follow the movement of the wearer's legs and provide a better fit when wearing the diaper 1. This prevents the outer side (the distal end side) of the LG elastic member 17 from moving inward (toward the base), thereby preventing the leg gather portion LG from folding inward as shown in Figure 5B.

[0097] The leg gathers LG of the diaper 1 are provided with stiffening means for stiffening the leg gathers LG. Specifically, leg gather joints 50 (51-54) that join the sheet members constituting the leg gathers LG in the thickness direction function as stiffening means, thereby increasing the stiffness of the leg gathers LG. In this embodiment, the leg gather joints 50 (hereinafter also referred to as "LG joints 50") are formed of an adhesive such as a hot melt adhesive.

[0098] It should be noted that the stiffness imparting means does not include the LG elastic member 17 itself. At least the portion of the LG joint 50 that does not overlap with the LG elastic member 17 when viewed in the thickness direction functions as the stiffness imparting means. In the case of Figure 6, at least a portion of the first LG joint 51 to the third LG joint 53 and the fourth LG joint 54 function as the stiffness imparting means.

[0099] In the diaper 1, the stiffening means (LG joints 51-54) are continuously provided along the longitudinal direction of the absorbent main body 10 in a region below the lower end 2eb of the side joint 2, which joins the front waistline 20 and the rear waistline 30 (see FIG. 4 ). This increases the stiffness of the leg gathers LG over a wide area, making it easier for the leg gathers LG to maintain their surface shape and more likely to prevent the leg gathers LG from folding inward. This results in a diaper 1 with leg gathers LG that do not apply excessively high surface pressure and are less likely to fold inward. In other words, even if the spacing between the LG elastic members 17 is increased to reduce surface pressure, the leg gathers LG easily fit the wearer's legs, making it less likely for the user to experience concerns about side leakage of body exudates.

[0100] The contractile force of the LG elastic members 17 can be measured as follows. Figures 7A to 7C are diagrams illustrating a method for measuring the contractile force of the LG elastic members 17. First, a test piece TP is prepared by cutting out a portion of the diaper 1 to be measured, including the LG elastic members 17. Specifically, the absorbent main body 10 of the diaper 1 in an unfolded and stretched state as shown in Figure 7A, is cut in the vertical direction (longitudinal direction of the absorbent main body 10) at the lower end 20eb of the front waistline portion 20 (corresponding to the lower end 2eb of the side joint 2 in the diaper 1) and the lower end 30eb of the rear waistline portion 30 (the lower end 2eb of the side joint 2). Next, the cut absorbent main body 10 is cut in the horizontal direction at the rising starting point of the leakage preventing wall portion LSG (the inner end 51ei of the first LG joint 51) to separate the leg gather portion LG and the leakage preventing wall portion LSG.

[0101] Next, each of the multiple LG elastic members 17 provided in the leg gather portion LG was cut 2.5 mm from both sides of the LG elastic member 17 in the left-right direction to obtain a 5 mm-wide test piece TP, centered on the LG elastic member 17. Figure 7B shows a case in which a 5 mm-wide strip-shaped portion, indicated by diagonal lines and centered on the middle LG elastic member 17b, was cut out as the test piece TP. Similarly, 5 mm-wide strip-shaped portions were cut out as test pieces TP for the inner LG elastic member 17a and the outer LG elastic member 17c. Note that if a 2.5 mm-wide area can only be secured on one side of the LG elastic member 17 in the left-right direction (for example, if the outer LG elastic member 17c is provided at the tip of the leg gather portion LG), the test piece TP will have a 2.5 mm width on only one side.

[0102] Next, as shown in FIG. 7C , both longitudinal ends of the test piece TP 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 Lc between the chucks is adjusted to 100 mm. From this state, the distance Lc is increased at a predetermined rate (100 mm / min) until the test piece TP is elongated to 0.9 times its maximum elongation. In other words, the test piece TP is elongated until its longitudinal length is 0.9 times its elongated length. Next, the test piece TP is contracted to 0.7 times its maximum elongation. In other words, the test piece TP is contracted until its longitudinal length is 0.7 times its elongated length. This cycle is repeated twice, and the magnitude of the force (N) when the test piece TP is contracted until its longitudinal length (the distance Lc between the chucks) is 0.7 times its elongated length during the second contraction cycle is measured. Such measurements are repeated a predetermined number of times (for example, three times), and the average of the measured values ​​is taken as the contractile force of the LG elastic member 17 being measured.

[0103] Furthermore, in the leg gather portion LG of the diaper 1, of the two LG elastic members 17, 17 arranged adjacent to each other in the left-right direction, it is preferable that the contractile force of the LG elastic member 17 arranged on the outer side in the left-right direction is equal to or less than the contractile force of the LG elastic member 17 arranged adjacent to each other in the inside direction. In other words, when comparing the contractile forces of the two LG elastic members 17, 17 arranged adjacent to each other in the left-right direction, it is preferable that the contractile force of the LG elastic member 17 arranged on the outer side is equal to or less than the contractile force of the LG elastic member 17 arranged on the inner side.

[0104] With this configuration, the contractile force of the LG elastic members 17 gradually decreases from the inside to the outside in the left-right direction, which allows the leg gathers LG to more easily follow the movement of the wearer's legs and also helps prevent the leg gathers LG from curling up. Therefore, the fit can be improved by following the shape of the wearer's legs while preventing the surface pressure of the leg gathers LG from becoming excessively high.

[0105] Furthermore, of the two LG elastic members 17, 17 arranged adjacent to each other in the left-right direction in the leg gathered portion LG, it is preferable that the value obtained by dividing the length in its natural state of the LG elastic member 17 arranged on the outer side in the left-right direction by the length when it is stretched to its maximum length along the longitudinal direction (i.e., the length of the LG elastic member 17 in its stretched state) is equal to or less than the value obtained by dividing the length in its natural state of the LG elastic member 17 arranged adjacent to each other on the inner side by the length in its stretched state. In other words, when comparing the contraction rates of the two LG elastic members 17, 17 arranged adjacent to each other in the left-right direction, it is preferable that the contraction rate of the LG elastic member 17 arranged on the outer side be equal to or less than the contraction rate of the LG elastic member 17 arranged on the inner side.

[0106] With this configuration, the rate at which the LG elastic members 17 contract (contraction rate) gradually decreases from the inside to the outside in the left-right direction. That is, the contractile force of the LG elastic members 17 gradually decreases. This allows the leg gathers LG to more easily follow the movement of the wearer's legs and also helps prevent the leg gathers LG from curling. Therefore, the fit can be improved by following the shape of the wearer's legs while preventing the surface pressure of the leg gathers LG from becoming excessively high.

[0107] Furthermore, of the two LG elastic members 17, 17 arranged adjacent to each other in the left-right direction in the leg gather portion LG, it is preferable that the cross-sectional area of ​​the LG elastic member arranged on the outside in the left-right direction in its natural state is equal to or greater than the cross-sectional area of ​​the LG elastic member 17 arranged adjacent to each other on the inside in its natural state.

[0108] Normally, the larger the cross-sectional area of ​​the LG elastic members 17, the larger the diameter of the LG elastic members 17, and therefore the larger the area over which the contractile force acts on the leg gathered portions LG. In other words, the increase in force (pressure) acting per unit area of ​​the leg gathered portions LG can be suppressed. Therefore, even if the contractile force of the LG elastic members 17 is increased on the inner side of the leg gathered portions LG in the left-right direction, the surface pressure is suppressed from becoming excessively high, and the LG elastic members 17 are less likely to leave linear marks on the wearer's skin.

[0109] 6, the region from the outermost end 10es of the leg gather portion LG to the innermost inner LG elastic member 17a in the left-right direction is defined as the leg gather elastic region ER. The length We of the leg gather elastic region ER in the left-right direction in the stretched state is at least half the length Wlg of the leg gather portion LG in the left-right direction in the stretched state. In other words, the stretching force of the LG elastic member 17 acts on at least half of the leg gather portion LG.

[0110] When the leg gather elastic region ER is divided equally in the left-right direction (in thirds in the diaper 1) based on the number of LG elastic members 17 arranged in the leg gather elastic region ER (three in the diaper 1), an LG elastic member 17 is arranged in each divided region. In Fig. 6, when the leg gather elastic region ER is divided into thirds, an inner LG elastic member 17a is arranged in the inner region ERa in the left-right direction, a middle LG elastic member 17b is arranged in the central region ERb, and an outer LG elastic member 17c is arranged in the outer region ERc in the left-right direction.

[0111] In other words, the LG elastic members 17 are evenly distributed over more than half of the leg gathers LG. If the LG elastic members 17 were unevenly distributed in the left-right direction, pressure would be high in areas of the leg gathers LG where there is a high concentration of elastic members, and areas with fewer elastic members would be prone to curling. In contrast, in the diaper 1, the LG elastic members 17 are evenly distributed in the leg gathers LG, which reduces the likelihood of localized stiffness differences and makes it easier to maintain the surface shape. Furthermore, because localized pressure is less likely to act on the wearer's leg openings, it is easier to prevent skin irritation and redness.

[0112] Furthermore, in the leg gather portion LG of the diaper 1, stiffening means are provided in each of the three equal regions (i.e., three equal parts) of the leg gather elastic region ER. In Fig. 6, of the three equal parts of the leg gather elastic region ER, the inner region ERa in the left-right direction is provided with the second LG joint 52 and the fourth LG joint 54. Similarly, the central region ERb in the left-right direction is provided with a part of the third LG joint 53 and the fourth LG joint 54, and the outer region ERc in the left-right direction is provided with a part of the third LG joint 53. This increases the stiffness of each region (ERa to ERc) where the contractile force of the LG elastic member 17 acts, thereby suppressing curling of the leg gather portion LG and making it easier to maintain its surface shape.

[0113] In addition, in the leg gather portion LG, when viewed in the thickness direction, a stiffening member is provided between two LG elastic members 17, 17 arranged adjacent to each other in the left-right direction. In Fig. 6, when viewed in the thickness direction, a second LG joint 52 and a fourth LG joint 54 are provided between the inner LG elastic member 17a and the middle LG elastic member 17b, which are adjacent to each other in the left-right direction. Similarly, a third LG joint 53 and a fourth LG joint 54 are provided between the middle LG elastic member 17b and the outer LG elastic member 17c.

[0114] By increasing the rigidity of the region between the LG elastic members 17, 17 with the stiffening means, it becomes difficult for bending points to form between the LG elastic members 17, 17, and curling of the leg gathered portion LG is more easily suppressed. Note that the LG joint 50 (stiffening means) may be arranged in a configuration other than that shown in Fig. 6. For example, a configuration may be adopted in which the inner LG elastic member 17a and the middle LG elastic member 17b are provided closer to the skin in the thickness direction than the leak barrier film 13, and stiffening means corresponding to the second LG joint 52 is provided closer to the skin in the thickness direction than the leak barrier film 13.

[0115] Furthermore, in the diaper 1 of this embodiment, the contractile force per unit width of the leg gathers LG is equal to or less than the contractile force per unit width of the leakage barrier walls LSG. That is, the value obtained by dividing the contractile force when the leg gathers LG are stretched to a length 0.9 times their maximum length (stretched state) along the longitudinal direction and then returned to 0.7 times their maximum length by the width of the leg gathers LG (length Wlg in the left-right direction in Fig. 6 ) is equal to or less than the value obtained by dividing the contractile force when the leakage barrier walls LSG are stretched to a length 0.9 times their maximum length (stretched state) along the longitudinal direction and then returned to 0.7 times their maximum length by the width of the leakage barrier walls LSG (length Wlsg in the thickness direction in Fig. 6 ).

[0116] With this configuration, the surface pressure of the leg gathers LG is relatively smaller than in the opposite case (where the contractile force per unit width of the leg gathers LG is greater than the contractile force per unit width of the leakage barrier walls LSG), making it less likely that a wearer will develop rash or redness in their leg cuffs when wearing the diaper 1. The contractile forces per unit width of the leg gathers LG and the leakage barrier walls LSG can be measured in accordance with the method described with reference to FIG. 7. That is, the leg gathers LG and the leakage barriers LSG shown in FIG. 7A are cut out as test pieces TP. Then, a tensile test is performed on each test piece TP as shown in FIG. 7C to measure the contractile force, and the measured contractile force is divided by the lateral length (width) of the test piece TP to determine the contractile force per unit width of the leg gathers LG and the leakage barrier walls LSG.

[0117] As described above, the stiffening means for stiffening the leg gathers LG of the diaper 1 is realized by an adhesive that bonds the sheet members constituting the leg gathers LG together in the thickness direction. Specifically, stiffness is imparted to the leg gathers LG by the first LG joint 51 to the third LG joint 53 (adhesive) that join the folded-back portion 14f of the outer sheet 14 to the leakproof film 13 in the thickness direction (see FIG. 6). Similarly, stiffness is imparted to the leg gathers LG by the fourth LG joint 54 (adhesive) that joins the outer sheet 14 (non-folded portion) to the leakproof film 13 in the thickness direction (see FIG. 6).

[0118] By bonding the sheet members stacked in the thickness direction together with an adhesive, the rigidity of the leg gathered portion LG is increased even in areas where the LG elastic members 17 are not provided (areas that do not overlap with the LG elastic members 17). Furthermore, by bonding the multiple sheet members constituting the leg gathered portion LG in a stacked state in the thickness direction, each sheet member is more likely to be maintained flat, making the leg gathered portion LG less likely to curl. Furthermore, adhesives such as hot-melt adhesives solidify at room temperature, and therefore the adhesive itself has rigidity, making it easier to ensure the rigidity of the leg gathered portion LG. Note that the means for providing rigidity is not limited to adhesives, and may be achieved by welding (described later) or by providing other sheet members (see FIG. 8 ).

[0119] Furthermore, in the diaper 1, stiffening means are provided over more than half of the area of ​​the leg gather elastic region ER. In Fig. 6, when the leg gather elastic region ER is divided into thirds in the left-right direction, the fourth LG joint 54 is provided in a region occupying most of the area of ​​the inner region ERa and the central region ERb, and the second LG joint 52 and the third LG joint 53 are also provided. In other words, the stiffening means is provided in a region occupying about two-thirds of the entire area of ​​the leg gather elastic region ER. Since the stiffening means increases the stiffness of more than half of the leg gather elastic region ER, where the contractile force of the LG elastic members 17 acts, the leg gather elastic region ER is more likely to maintain its planar shape and to suppress curling, etc.

[0120] The leg gathers LG are provided with a leak-barrier film 13, which is a liquid-impermeable sheet member. The outer edge 13es of the leak-barrier film 13 is located between the outermost outer LG elastic member 17c and the second-outer middle LG elastic member 17b in the left-right direction (see FIG. 6 ). The provision of the leak-barrier film 13 up to the tip of the leg gathers LG (the outer edge 10es in the left-right direction) enhances the rigidity of a wider area of ​​the leg gathers LG compared to a case where the leak-barrier film 13 is not provided, making it easier to maintain the surface shape. On the other hand, the absence of the leak-barrier film 13 outside the outer LG elastic member 17c in the left-right direction prevents the leading edge (outer edge 10es) of the leg gathers LG from becoming stiff. This reduces discomfort to the wearer, even if the leading edge comes into contact with the wearer's skin when the diaper 1 is worn.

[0121] Furthermore, no stiffening means is provided outside the outer LG elastic members 17c, which are located at the outermost positions in the left-right direction, in the leg gathers LG of the diaper 1 (see FIG. 6). Therefore, the leading edges (outer edges 10es) of the leg gathers LG are not stiffened and remain flexible. This reduces the likelihood of the wearer experiencing discomfort or unease, even if the leading edges come into contact with the wearer's skin while wearing the diaper 1.

[0122] Furthermore, the width in the left-right direction of the leg gathers LG in the stretched state is equal to or greater than the standing height of the leakage preventing wall portions LSG in the stretched state (the maximum height when the leakage preventing wall portions LSG stand from their standing starting points). In Fig. 6, the distance Wlg in the left-right direction between the outer end 10es of the leg gathers LG and the standing starting point 51ei of the leakage preventing wall portions LSG is longer than (or may be the same as) the distance Wlsg between the standing starting point 51ei of the leakage preventing wall portions LSG and the tip 14st of the leakage preventing wall portions LSG (standing height of the leakage preventing wall portions LSG). With this configuration, even if the leakage preventing wall portions LSG collapse outward in the left-right direction from their standing state when the diaper 1 is worn, the collapsed leakage preventing wall portions LSG are prevented from protruding outward beyond the tip (outer end 10es) of the leg gathers LG. Therefore, the formation of gaps caused by the leakage prevention wall portion LSG being pinched between the leg gathered portion LG and the wearer's skin is suppressed, and the leg gathered portion LG can be made to fit easily to the wearer's leg movements as a surface.

[0123] The leg gathers LG of the diaper 1 are provided with crotch elastic members 18 that stretch along the longitudinal direction. As shown in Fig. 6, the crotch elastic members 18 are arranged in the left-right direction between the outer end 11es of the absorber 11 and the rising starting point 51ei of the leakage barrier wall LSG (i.e., the inner end of the leg gathers LG). Therefore, when the diaper 1 is worn, both outer sides of the absorber 11 in the left-right direction are pushed up toward the wearer's skin by the stretchability of the crotch elastic members 18, making the absorber 11 more easily fit to the wearer's crotch area. In particular, since the absorber 11 is less likely to sag downward even when its weight increases due to the absorption of bodily waste, the fit of the absorbent main body 10 as a whole is improved, and leakage and the like are more effectively prevented. Furthermore, the base side of the leg gathers LG is pushed up toward the skin due to the stretchability of the crotch elastic members 18, making it easier for the leg gathers LG to fit the skin of the wearer.

[0124] <Modifications> Fig. 8 is a plan view and a cross-sectional view showing a modification of the absorbent main body 10. Fig. 8 shows the absorbent main body 10 in a stretched state, similar to Fig. 4. The absorbent main body 10 of the modification is different from the absorbent main body 10 described in Fig. 4 in that the leg gathered portions LG and the top sheet 12 are partially configured differently.

[0125] The absorbent main body 10 of the modified example has a welding portion 60 that joins, in the thickness direction, the outer sheet 14 constituting the leg gather portion LG and a folded-back portion 14f formed by folding back the outer edge 10es of the outer sheet 14. The welding portion 60 is formed by a number of first welding patterns 61 and second welding patterns 62 regularly arranged along the longitudinal direction, and each of the welding patterns 61, 62 is formed using known heat welding or ultrasonic welding. In FIG. 8, the first welding patterns 61 and the second welding patterns 62 are arranged so as to have overlapping portions in the longitudinal direction (up-down direction), and the welding portion 60 as a whole is formed so as to be continuous in the longitudinal direction. Note that in FIG. 8, the first welding patterns 61 and the second welding patterns 62 are also arranged so as to have overlapping portions in the lateral direction (left-right direction).

[0126] 8, the leakage preventing wall portion LSG rises from the inner end 60ei in the left-right direction of the welded portion 60. That is, the welded portion 60 is provided on the base side of the leg gather portion LG in the left-right direction (the side of the rising starting point of the leakage preventing wall portion LSG), but the welded portion 60 may also be provided on the tip side of the leg gather portion LG (the side closer to the outer end 10es in the left-right direction than the rising starting point 60ei).

[0127] Such welded portions 60 increase the joining strength between the sheet members laminated in the thickness direction of the leg gathered portion LG, making the leg gathered portion LG more stable. The welded portions 60 also function as a stiffening means for stiffening the leg gathered portion LG. Note that, in Fig. 8, the leg gathered portion LG is provided with two types of joints, the welded portions 60 and the LG joints 50, but the welded portions 60 may be formed instead of the LG joints 50.

[0128] In the leg gather portion LG, the sheet members stacked in the thickness direction are joined together by the welded portion 60 (LG joint portion 50), thereby increasing the rigidity of the leg gather portion LG even in areas where the LG elastic members 17 are not provided (are not overlapping). This makes it easier for the sheet members constituting the leg gather portion LG to be maintained flat, making the leg gather portion LG less likely to curl. Furthermore, since the welded portion 60 and the LG joint portion 50 (such as adhesive) themselves have rigidity, the rigidity of the leg gather portion LG is more easily ensured.

[0129] In the cross-sectional view of the absorbent main body 10 shown in Fig. 4, the left and right edges of the top sheet 12 are folded toward the non-skin side of the absorbent body 11. In contrast, in the modified absorbent main body 10 shown in Fig. 8, the left and right outer edges 12es of the top sheet 12 extend outward from the rising starting points 60ei of the leakage preventing wall portions LSG and form part of the sheet members constituting the leg gather portions LG. In this case, the portions of the top sheet 12 that are positioned outward from the rising starting points 60ei function as stiffening means that stiffen the leg gather portions LG. This makes it easier for the leg gather portions LG to maintain a flat shape and less likely to curl. When the diaper 1 is worn, gaps are less likely to form between the leg gather portions LG and the wearer's skin, and the diaper 10 provides a more even fit to the leg openings.

[0130] <Regarding Elasticity of the Waist Regions 20, 30> Next, we will explain the elasticity in the left-right direction of the front waist region 20 and the rear waist region 30. When the diaper 1 is worn, the front waist region 20 and the rear waist region 30 contract in the left-right direction to fit around the waist of the wearer, thereby preventing the absorbent body 10 from slipping down. Conversely, if the contractile force of the waist regions 20, 30 is weak, the entire diaper 1 may slip down, which may result in a poor fit of the leg gathers LG when the wearer moves their legs.

[0131] On the other hand, if the contractile force of the waist portions 20, 30 is excessively high, the waist portion 20 will tighten too much around the wearer's waist, which is likely to cause discomfort and discomfort to the wearer. Furthermore, since the lower end region of the front waist portion 20 is located near the base of the wearer's legs when the diaper 1 is worn, if the contractile force at the lower end of the front waist portion 20 is excessively high, it will likely interfere with the movement of the wearer's legs. In this case, the front waist portion 20 will shift position due to the wearer's leg movement, which will significantly deteriorate the fit of the waist portion 20 and the leg gathers LG.

[0132] Therefore, in the diaper 1 of this embodiment, the front waist portion 20 has an appropriate contractile force while being less likely to interfere with leg movement during wear, thereby improving the fit of the waist portions 20, 30 and the leg gathers LG. The contractile force of the front waist portion 20 and the rear waist portion 30 will be described below. Since the front waist portion 20 and the rear waist portion 30 of the diaper 1 have substantially the same structure as described above, the following description will primarily focus on the front waist portion 20, and a description of the rear waist portion 30 will be omitted. However, the rear waist portion 30 may also be described as necessary.

[0133] 9 is a plan view showing the front waistline portion 20 and the absorbent main body 10 in a stretched state. In Fig. 9, when the front waistline portion 20 is divided into four equal parts in the up-down direction, the respective regions are designated, from top to bottom, as a first front waistline region 20A1, a second front waistline region 20A2, a third front waistline region 20A3, and a fourth front waistline region 20A4. Here, dividing the front waistline portion 20 into four equal parts in the up-down direction means dividing into four equal parts in the up-down direction a region sandwiched in the up-down direction by a line connecting the upper ends 2et, 2et of a pair of side joint portions 2, 2 formed at both left-right ends of the front waistline portion 20 and a line connecting the lower ends 2eb, 2eb of a pair of side joint portions 2, 2. Similarly, when the rear waistline portion 30 is divided into four equal parts in the vertical direction, the respective regions are designated, from top to bottom, as a first rear waistline region 30A1, a second rear waistline region 30A2, a third rear waistline region 30A3, and a fourth rear waistline region 30A4.

[0134] As described above, the front waistline portion 20 is provided with stretchability (contractility) in the left-right direction by having the plurality of waistline elastic members 23, 23 attached in a stretched state in the left-right direction. In this case, a better fit can be achieved by appropriately adjusting the magnitude of the stretching force (contraction force) exerted by the waistline elastic members 23 in each of the first front waistline region 20A1 to the fourth front waistline region 20A4 of the front waistline portion 20.

[0135] Specifically, in the front waist portion 20 of the diaper 1, the contractile force of the third front waist region 20A3 is set to be greater than that of the fourth front waist region 20A4. That is, the contractile force of the third front waist region 20A3 when stretched to a length 0.9 times its maximum length in the left-right direction and then returned to 0.7 times its maximum length is set to be greater than the contractile force of the fourth front waist region 20A4 when stretched to a length 0.9 times its maximum length in the left-right direction and then returned to 0.7 times its maximum length.

[0136] In the diaper 1, the pitch (spacing) of the LG elastic members 17 provided in the leg gathers LG is wider (5 mm or more) than in conventional diapers, so that the surface pressure of the leg gathers LG is not excessively high, making it less likely for the wearer to develop rashes or redness in their leg areas. On the other hand, the lower surface pressure of the leg gathers LG may cause gaps to form between the leg gathers LG and the wearer's skin when the wearer moves their legs, such as when walking. In response to this, the fit of the front waistband 20 is improved, making it less likely for the front waistband 20 to slip off the wearer's body (abdomen) when the diaper 1 is worn, thereby making it less likely for gaps to form between the leg gathers LG and the wearer's skin. In other words, even if the pitch of the LG elastic member is wider compared to conventional diapers, thereby reducing the surface pressure of the leg gather portion LG, the front waist portion 20 is less likely to slip off the wearer's abdomen, making it less likely that a gap will form between the leg gather portion LG and the wearer's skin.

[0137] In this case, by making the contractile force of the third front waistline region 20A3 greater than the contractile force of the fourth front waistline region 20A4 in the front waistline portion 20, the fit of the diaper 1 around the wearer's abdomen can be further improved. Fig. 10 is a diagram showing a wearer wearing the diaper 1 as seen from the side.

[0138] Typically, a person's (wearer's) abdomen gradually protrudes forward (toward the abdomen) from the chest to the waist, and then protrudes less toward the lower abdomen. When the diaper 1 is worn, the wearer's abdomen protrudes more in the first and second front waist regions 20A1 and 20A2, and less in the third and fourth front waist regions 20A3 and 20A4, as shown in Fig. 10. When the wearer breathes, the abdomen expands and contracts significantly in the first and second front waist regions 20A1 and 20A2, whereas the abdomen moves less in the third and fourth front waist regions 20A3 and 20A4. Therefore, by increasing the contractile force of the third front waist region 20A3 and the fourth front waist region 20A4 in the front waist portion 20 of the diaper 1, the wearer is less likely to experience discomfort due to tightness, and the fit of the front waist portion 20 can be improved.

[0139] However, because the lower end of the fourth front waist region 20A4 constitutes part of the leg openings LH of the diaper 1 (see FIG. 1 ), excessive contractile force of the fourth front waist region 20A4 could interfere with the wearer's leg movement and result in poor fit. In contrast, in the diaper 1, the contractile force of the fourth front waist region 20A4 is set smaller than that of the third front waist region 20A3, so that the lower end (leg openings LH) of the fourth front waist region 20A4 is less likely to interfere with the wearer's leg movement. This allows the front waist region 20 to fit the wearer's abdomen more easily without interfering with the wearer's body movements (leg movement and abdominal movement due to breathing). Furthermore, the improved fit of the front waist region 20 makes it less likely to slip down, allowing the wide leg gathers LG to fit snugly around the wearer's legs.

[0140] The contractile force of each of the regions 20A1 to 20A4 of the front waistband portion 20 can be measured as follows, in accordance with the method described with reference to FIG. 7 . First, the absorbent main body 10 is peeled off from the front waistband portion 20 using a cold spray, preferably a dryer, and then divided (cut) into the four regions 20A1 to 20A4 shown in FIG. 9 to obtain four types of test specimens TP. Note that if waistline elastic members 23 are located on the boundaries between the regions 20A1 to 20A4, the waistline elastic members 23 should be included in the upper (waist end) region. Then, a tensile test is performed on each test specimen TP using the same method as in FIG. 7C . That is, both left-right ends of the test specimen TP are clamped between the chucks of a tensile tester, and the specimen is stretched in the left-right direction until its length is 0.9 times its original length, and then shrunk to 0.7 times its original length. This cycle is repeated twice, and the magnitude of the force (N) is measured when the test piece TP is contracted to 0.7 times its length in the extended state during the second cycle. This measurement is repeated a predetermined number of times (for example, three times), and the average of the measured values ​​is taken as the contractile force of the test object (areas 20A1 to 20A4).

[0141] Furthermore, in the diaper 1, the third front waist region 20A3 has the greatest contractile force among the regions 20A1 to 20A4 of the front waist region 20. When the wearer is wearing the diaper 1, the area where the third front waist region 20A3 is located has a small abdominal protrusion and is subject to small changes due to breathing, etc., so that even if the contractile force of the third front waist region 20A3 is increased, the wearer is unlikely to feel uncomfortable. By firmly fitting and fixing the third front waist region 20A3 in this area where abdominal movement (changes) is small, the entire front waist region 20 is less likely to slip down, thereby further improving the fit of the front waist region 20 and the leg gathers LG.

[0142] Furthermore, among the regions 20A1-20A4 of the front waistline portion 20, the total contractile force of the third front waistline region 20A3 and the fourth front waistline region 20A4 is greater than the total contractile force of the first front waistline region 20A1 and the second front waistline region 20A2. The upper regions of the front waistline portion 20 (the first front waistline region 20A1 and the second front waistline region 20A2) are located in areas where the wearer's abdomen bulges or fluctuates significantly, so excessively tight compression can easily cause discomfort to the wearer. On the other hand, the lower regions of the front waistline portion 20 (the third front waistline region 20A3 and the fourth front waistline region 20A4) are located in areas where the wearer's abdomen bulges or fluctuates less, so even if they are tighter than the upper regions, they are less likely to cause discomfort to the wearer, effectively improving fit.

[0143] In particular, infants, who are assumed to be the intended wearers of the diaper 1, generally have a body type that makes them prone to abdominal protrusion and are also sensitive to abdominal constriction. Therefore, by making the contractile force of the upper half of the front waistband portion 20 smaller than that of the lower half, it is possible to ensure safety when wearing the diaper while improving the fit for infants with protruding bellies.

[0144] The front waist portion 20 of the diaper 1 is adjusted so that the contractile forces decrease in the order of the third front waist region 20A3, the fourth front waist region 20A4, the first front waist region 20A1, and the second front waist region 20A2, thereby making it easier to achieve the above-mentioned good fit.

[0145] Furthermore, with respect to the rear waistline portion 30, the third rear waistline region 30A3 of the diaper 1 has the highest contractile force among the first to fourth rear waistline regions 30A1 to 30A4. That is, in the rear waistline portion 30, as in the front waistline portion 20, the third region (30A3) from the top of the quartered rear waistline region has the highest contractile force. This allows the third front waistline region 20A3 and the third rear waistline region 30A3, which are connected in a circular fashion, to work together, thereby facilitating the application of a large contractile force along the waistline. As described above, this region of the wearer's abdomen has little protrusion and is subject to minimal movement due to breathing, etc., and therefore is unlikely to cause discomfort to the wearer even if a strong tightening force is applied. Therefore, by tightening the smallest variation areas and loosening the tightening force in other areas, the diaper 1 can more easily follow the wearer's body movements. Therefore, by maximizing the contractile force of the waist portions 20, 30 in this region (20A3, 30A3), the entire waist portions 20, 30 are less likely to shift position, and the fit can be further improved without causing discomfort to the wearer.

[0146] On the other hand, the contractile force of the second rear waistline region 30A2 in the rear waistline portion 30 may be set to be the greatest. On the back side of the wearer, the area that the second rear waistline region 30A2 contacts is the area where the narrowing is greatest at the boundary between the back and buttocks, as shown in FIG. 10 . Therefore, by maximizing the contractile force acting on the area of ​​the wearer's back where the protrusion is small, the position of the rear waistline portion 30 on the back side is more easily fixed. This makes it easier to firmly fix the front waistline portion 20 and the rear waistline portion 30 to the wearer's waist on both the back and abdomen, preventing the waistline portions 20, 30 from slipping down and improving fit.

[0147] FIG. 11 is a plan view showing the front waistline portion 20 and the absorbent main body 10 in their natural state. FIG. 11 illustrates the state of the front waistline portion 20 when it is restored from the stretched state shown in FIG. 9 to its natural state. As shown in FIG. 11 , in the diaper 1 in its natural state, the left-right length W20A3 (the length of the shortest portion) of the third front waistline region 20A3 is shorter than the left-right length W20A4 (the length of the shortest portion) of the fourth front waistline region 20A4. This configuration facilitates the formation of a contraction folding point in the third front waistline region 20A3 between the upper and lower ends of the front waistline portion 20. This allows the third front waistline region 20A3 to more easily fit into the wearer's lower abdominal region (the concave portion of the abdomen shown in FIG. 10 ), which has a smaller protrusion on the abdominal side. This reduces the front waistline portion 20's slippage, improving fit.

[0148] Furthermore, in the natural state shown in Figure 11, the average left-right length of the third front waistline region 20A3 and the fourth front waistline region 20A4 is shorter than the average left-right length of the first front waistline region 20A1 and the second front waistline region 20A2. With this configuration, the amount of left-right contraction is reduced in the upper half of the front waistline 20 (20A1, 20A2), where abdominal movement (displacement) is greater. This reduces interference of the front waistline 20 with the wearer's abdominal movement and reduces discomfort to the wearer. On the other hand, the amount of left-right contraction is increased in the lower half of the front waistline 20 (20A3, 20A4), where abdominal movement (displacement) is smaller. This makes it easier for the front waistline 20 to be secured in the concave portion of the wearer's lower abdomen, reducing the likelihood of misalignment. This improves the fit of the front waistline 20.

[0149] The front waistline region 20 and the absorbent main body 10 are joined to each other by a main body joint 70. The main body joint 70 is formed by applying an adhesive such as a hot melt adhesive to multiple band-shaped regions extending in the vertical direction, as indicated by the hatched areas in FIG. 9 . The upper end 70et of the main body joint 70 is located above the upper end 20lc of the third front waistline region 20A3 in the vertical direction. That is, the entire third front waistline region 20A3 is joined to the absorbent main body 10 via the main body joint 70 in the vertical direction. This allows the large contractile force of the third front waistline region 20A3 to press the absorbent main body 10 against the wearer's skin, making it less likely for the heavy absorbent main body 10 to slip downward. This further improves the fit of the absorbent main body 10 and helps prevent the leg gathers LG from rolling inward.

[0150] Furthermore, in the vertical direction, the upper end 11et of the absorbent body 11 is located lower than the upper end 20lc of the third front waistline region 20A3. That is, there is a portion where the third front waistline region 20A3 and the absorbent body 11 do not overlap in the vertical direction. In the non-overlapping portion, the contractile force of the third front waistline region 20A3 is less likely to be inhibited by the highly rigid absorbent body 11, allowing a large contractile force to act on the depression in the wearer's lower abdomen. This further improves the fit of the absorbent main body 10 and makes it easier to prevent the leg gathered portions LG from folding inward.

[0151] Furthermore, the average vertical pitch of the waist elastic members 23, 23 arranged in the third front waist region 20A3 is preferably smaller than the average horizontal pitch of the LG elastic members 17, 17 arranged in the leg gather portion LG. A relatively large pitch of the LG elastic members 17 prevents excessive surface pressure on the leg gather portion LG, making it less likely for the LG elastic members 17 to leave linear marks on the wearer's skin. Generally, a wider pitch of the LG elastic members 17 makes the leg gather portion LG more prone to curling (see FIG. 5B ). However, in the diaper 1 of this embodiment, curling of the leg gather elastic members 17 can be suppressed by appropriately adjusting the contractile force of the LG elastic members 17.

[0152] Furthermore, when viewed in the thickness direction, there is a crossover portion between the waist elastic members 23 arranged in the front waist portion 20 and the LG elastic members 17 arranged in the leg gathers LG (see Fig. 9). As a result, the contractile forces of the waist elastic members 23 and the LG elastic members 17 work together to pull the LG elastic members 17 upward, which makes it difficult for the entire diaper 1 to sag downward and prevents the fit of the front waist portion 20 and the leg gathers LG from deteriorating.

[0153] Furthermore, when viewed in the thickness direction of the rear waistline portion 30, the waistline elastic members 33 arranged in the rear waistline portion 30 may intersect with the LG elastic members 17 arranged in the leg gathers LG. As with the ventral side, the contractile forces of the waistline elastic members 33 and the LG elastic members 17 on the back side cooperate to prevent the diaper 1 from sagging downward, thereby preventing deterioration of fit on the back side. Note that the above-mentioned effect can be achieved as long as there is an intersecting portion between the waistline elastic members 23, 33 and the LG elastic members 17 on at least either the front side (ventral side) or the back side (dorsal side).

[0154] ===Other Embodiments= ...

[0155] In the above-described embodiment, elasticity in the left-right direction is imparted to the waist portion 20 (30) by waist elastic members 23 (33) such as rubber thread, but elasticity may be imparted by other elastic members. For example, elasticity may be imparted by providing an elastic sheet (not shown) that stretches in the left-right direction so as to cover the upper end of the front waist portion 20 (near the first front waist region 20A1 in FIG. 9 ).

[0156] In the above-described embodiment, the outer sheet 14 is folded back at the outer edge 10es in the left-right direction of the absorbent body 10, and the leg gathered portion LG and the leakage preventing wall portion LSG are formed by the folded-back portion 14f (see FIG. 6, etc.). However, this is not limited to this. For example, the sheet member corresponding to the folded-back portion 14f may be formed from a separate sheet member (say, an LG nonwoven fabric) different from the outer sheet 14. In this case, the leg gathered portion LG is formed by attaching an LG elastic member in a stretched state between the separate sheet member (LG nonwoven fabric) and the outer sheet 14 in the thickness direction. Alternatively, a configuration may be adopted in which a portion of the LG nonwoven fabric is provided to cover the outer edge of the left-right direction of the outer sheet 14 from the non-skin side, and the LG elastic member is provided on the non-skin side of the outer sheet 14 (the skin side of the LG nonwoven fabric).

[0157] DESCRIPTION OF SYMBOLS 1 diaper (pants-type absorbent article), 2 side joint portion, 2et upper end, 2eb lower end, 10 absorbent main body, 10es outer end (left-right direction), 11 absorbent body, 11es outer end (left-right direction), 11et upper end, 11a absorbent core, 11b core wrap sheet, 11c constricted portion, 12 top sheet, 13 leak-proof film, 14 outer sheet, 14f folded portion, 14s standing portion, 14st tip, 17 LG elastic member (leg gather elastic member), 17a inner LG elastic member, 17b middle LG elastic member, 17c outer LG elastic member, 18 crotch elastic member, 19 leak-proof wall elastic member, 20 front waistline portion, 20A1 first front waistline region, 20A2 second front waistline region, 20A3 Third front waistline region, 20A4 Fourth front waistline region, 21 Waistline sheet, 23 Waistline elastic member, 25 Skin-facing sheet, 30 Rear waistline portion, 30A1 First rear waistline region, 30A2 Second rear waistline region, 30A3 Third rear waistline region, 30A4 Fourth rear waistline region, 31 Waistline sheet, 33 Waistline elastic member, 35 Skin-facing sheet, 50 LG joint (leg gather joint), 51 First LG joint, 51ei Inner end (standing origin), 52 Second LG joint, 53 Third LG joint, 54 Fourth LG joint, 60 Welded portion, 60ei Standing origin, 61 First welding pattern, 62 Second welding pattern, 70 Main body joint, BH Waist opening, LH leg opening, LG leg gathering part, LSG leak prevention wall part, ER leg gathering elastic area

Claims

1. A pants-type absorbent article having mutually intersecting vertical and horizontal directions, comprising an absorbent main body, a front waistline section, and a rear waistline section, the front waistline section and the rear waistline section being joined to each other at both ends in the horizontal direction by a pair of side joints, a pair of leakage prevention walls and a pair of leg gather sections are provided on each side of the absorbent main body in the horizontal direction, and the leg gather sections have three or more leg gather elastic members that stretch along the longitudinal direction of the absorbent main body and are arranged at intervals of 5 mm or more in the horizontal direction, the leg gather elastic members having a first leg gather elastic member and a second leg gather elastic member arranged outside the first leg gather elastic member in the horizontal direction, the contractile force of the first leg gather elastic member when the first leg gather elastic member is stretched to 0.9 times its length when it is most stretched along the longitudinal direction and then returned to 0.7 times its length is a contractile force greater than that of the second leg gather elastic member when the second leg gather elastic member is stretched to 0.9 times its length when it is fully stretched along the longitudinal direction and then returned to 0.7 times its length; and a stiffening means is provided in a region of the leg gather portion from the outermost end to the leg gather elastic member located in the left-right direction, which stiffens the leg gather portion; and at least a portion of the stiffening means does not overlap with the leg gather elastic member when viewed in the thickness direction, and has a portion that is continuous in the longitudinal direction in a region below the lower end of the side joint.

2. A pants-type absorbent article as described in claim 1, characterized in that, of the two leg gather elastic members arranged adjacent to each other in the left-right direction, the contraction force of the leg gather elastic member arranged on the inner side in the left-right direction when stretched to 0.9 times its length when fully stretched along the longitudinal direction and then returned to 0.7 times its length is greater than or equal to the contraction force of the leg gather elastic member arranged on the outer side in the left-right direction when stretched to 0.9 times its length when fully stretched along the longitudinal direction and then returned to 0.7 times its length.

3. A pants-type absorbent article as described in claim 1 or 2, characterized in that, of the two leg gather elastic members arranged adjacent to each other in the left-right direction, the value obtained by dividing the length in the natural state of the leg gather elastic member arranged on the inner side in the left-right direction by the length when it is stretched to the maximum along the longitudinal direction is equal to or less than the value obtained by dividing the length in the natural state of the leg gather elastic member arranged on the outer side in the left-right direction by the length when it is stretched to the maximum along the longitudinal direction.

4. A pants-type absorbent article as described in claim 1 or 2, characterized in that, of the two leg gather elastic members arranged adjacent to each other in the left-right direction, the cross-sectional area in the natural state of the leg gather elastic member arranged on the inner side in the left-right direction is greater than or equal to the cross-sectional area in the natural state of the leg gather elastic member arranged on the outer side in the left-right direction.

5. A pants-type absorbent article as claimed in claim 1 or 2, characterized in that, when the region from the outermost end of the leg gather portion to the leg gather elastic member arranged innermost in the left-right direction is defined as a leg gather elastic region, the length of the leg gather elastic region in the left-right direction in a stretched state is at least half the length of the leg gather elastic region in the left-right direction in a stretched state, and when the leg gather elastic region is divided evenly in the left-right direction by the number of leg gather elastic members arranged in the leg gather elastic region, a leg gather elastic member is arranged in each divided region.

6. A pants-type absorbent article according to claim 5, characterized in that the stiffening means is provided in each of the regions obtained by equally dividing the leg gather elastic region in the left-right direction.

7. A pants-type absorbent article according to claim 5, characterized in that, when viewed in the thickness direction, the stiffening means is provided between two of the leg gather elastic members arranged adjacent to each other in the left-right direction.

8. A pants-type absorbent article as claimed in claim 1 or 2, characterized in that the value obtained by dividing the contraction force when the leg gather portion is stretched to 0.9 times its maximum length along the longitudinal direction and then returned to 0.7 times its length by the width of the leg gather portion is equal to or less than the value obtained by dividing the contraction force when the leakage preventing wall portion is stretched to 0.9 times its maximum length along the longitudinal direction and then returned to 0.7 times its length by the width of the leakage preventing wall portion.

9. A pants-type absorbent article as claimed in claim 1 or 2, characterized in that the leg gather portion has at least two layers of sheet members stacked in the thickness direction, the leg gather elastic member is provided between the stacked sheet members, and the stiffening means imparts stiffness to the leg gather portion by joining the stacked sheet members together.

10. A pants-type absorbent article as claimed in claim 9, characterized in that the stiffening means provides stiffness to the leg gathers by bonding the laminated sheet members together with an adhesive.

11. A pants-type absorbent article as claimed in claim 1 or 2, characterized in that, when the region in the left-right direction from the outermost end of the leg gather portion in a stretched state to the leg gather elastic member located in the innermost position is defined as a leg gather elastic region, the stiffening means is provided over at least half of the area of ​​the leg gather elastic region.

12. A pants-type absorbent article as described in claim 1 or 2, characterized in that the absorbent main body has a liquid-absorbing absorbent body, a liquid-impermeable sheet is provided on the non-skin side of the absorbent body, and in the left-right direction, the outer end of the liquid-impermeable sheet is located between the leg gather elastic member that is arranged on the outermost side and the leg gather elastic member that is arranged second from the outside.

13. A pants-type absorbent article as claimed in claim 1 or 2, characterized in that the stiffening means is not provided outside the leg gather elastic member which is located outermost in the left-right direction.

14. A pants-type absorbent article as described in claim 1 or 2, characterized in that the shortest distance from the outer edge of the leg gather portion in the left-right direction to the rising point of the leakage prevention wall portion in the stretched state is greater than or equal to the shortest distance from the rising point of the leakage prevention wall portion to the tip of the leakage prevention wall portion in the stretched state.

15. A pants-type absorbent article as described in claim 1 or 2, characterized in that the absorbent main body has a liquid-absorbing absorbent body, and has a crotch elastic member that stretches along the longitudinal direction of the absorbent main body in the area between the outer end of the absorbent body and the rising starting point of the leakage prevention wall portion in the left-right direction.

16. A pants-type absorbent article as described in claim 1 or 2, characterized in that the absorbent main body has a liquid-absorbing absorbent body, a top sheet is provided on the skin side of the absorbent body, and at least a portion of the top sheet is positioned outside in the left-right direction from the rising starting point of the leakage prevention wall portion.

17. A pants-type absorbent article as described in claim 1 or 2, characterized in that the front waist portion and the rear waist portion have waist elastic members that stretch in the left-right direction, and when viewed in the thickness direction, at least one of the front waist portion and the rear waist portion has a portion where the waist elastic member and the leg gather elastic member intersect.

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