Underpants-shaped absorbent article

Abstract

This underpants-shaped absorbent article (1) has an absorbent body (10), a front waist member (20), and a rear waist member (30), and has crotch elastic members (17) that are stretchable in the longitudinal direction. As the underpants-shaped absorbent article (1) in an unfolded and stretched state is viewed along the longitudinal direction, the length (L2) from the center position to the rear end of the absorbent body is greater than the length (L1) from the center position to the front end of the absorbent body, the length (SH2) from the center position to the rear end of each crotch elastic member is greater than the length (SH1) from the center position to the front end of each crotch elastic member, the length (HMA2) of a rear joint part of the body is greater than the length (HMA1) of a front joint part of the body, and the length (GA2) from the center position to the front end of an extension part is smaller than the length (GA1) from the center position to the rear end of the front waist portion.

Description

Pants-type absorbent article

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

[0002] In a conventional pants-type absorbent article (e.g., a shorts-type napkin) having an absorbent main body and waistband members arranged so as to cover the front and rear of the absorbent main body from the non-skin side, a technique has been known in which an elastic member (crotch elastic member) that stretches along the longitudinal direction of the absorbent main body is provided to improve the fit of the crotch area of ​​the absorbent main body. For example, Patent Document 1 discloses a technique relating to a pants-type disposable diaper that has a central elastic member that stretches along the longitudinal direction in the central part of the width direction of the absorbent body, so that the crotch area is easily pulled up.

[0003] Japanese Patent Application Laid-Open No. 2021-151

[0004] When wearing such pants-type absorbent articles, it is expected that the user will remain in a seated position for long periods of time, so a good fit around the buttocks is important. Furthermore, when the user changes position from a seated position to a standing position or moves their legs forward, the front waistband member is likely to be pulled towards the crotch area due to the stretch of the SHG, so it is necessary to make the front waistband member less likely to slip down.

[0005] The present invention has been made in consideration of the above-mentioned problems, and its purpose is to improve the fit around the buttocks while making the front waistband member less likely to slip down in a three-piece pants-type absorbent article with crotch elastic members.

[0006] The main invention for achieving the above object is a pants-type absorbent article having a vertical direction, a horizontal direction, and a front-to-back direction which intersect with each other, and comprising an absorbent main body, a front waistline member, and a rear waistline member, wherein a front end of the absorbent main body is joined to the front waistline member at a front main body joint and a rear end of the absorbent main body is joined to the rear waistline member at a rear main body joint, the front waistline member and the rear waistline member are joined to each other by a pair of side joints provided on both sides in the horizontal direction, the article has crotch elastic members which stretch along the longitudinal direction of the absorbent main body, and the rear waistline member has extensions which extend below lower ends of the side joints in the vertical direction, a pant-type absorbent article characterized in that, in the longitudinal direction when the pant-type absorbent article is in a stretched state, the length from the central position of the pant-type absorbent article to the rear end of the absorbent main body is longer than the length from the central position to the front end of the absorbent main body, the length from the central position to the rear end of the portion where the stretchable force of the crotch elastic member is acting is longer than the length from the central position to the front end of the portion where the stretchable force of the crotch elastic member is acting, the length from the front end to the rear end of the rear main body joint is longer than the length from the front end to the rear end of the front main body joint, and the length from the central position to the front end of the extension portion is shorter than the length from the central position to the rear end of the front waistband member. 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, in a three-piece pants-type absorbent article having crotch elastic members, it is possible to improve the fit around the buttocks and prevent the front waistband member from slipping down.

[0008] FIG. 3A is a front view of the pants-type absorbent article 1 as seen from the ventral side. FIG. 3B is a plan view of the pants-type absorbent article 1 in an unfolded and stretched state as seen from the skin side. FIG. 3A is a schematic cross-sectional view taken along the first center line CL1 in FIG. 2, and FIG. 3B is a schematic cross-sectional view taken along the second center line CC1 in FIG. 2. FIG. 3B is a plan view illustrating the detailed arrangement of each part constituting the absorbent article 1. FIG. 5A and FIG. 5B are diagrams illustrating an example of a folding method for the absorbent article 1. FIG. 7A is a table showing the results of a menstrual blood drop test for the pants-type absorbent article 1 (Examples A to D) of the present embodiment and Comparative Example A. FIG. 7B is a table showing the results of a reference test for the menstrual blood drop test.

[0009] The present specification and the accompanying drawings make clear at least the following: (Aspect 1) A pants-type absorbent article having a vertical direction, a horizontal direction, and a front-to-back direction that intersect with one another, comprising an absorbent main body, a front waistline member, and a rear waistline member, wherein a front end of the absorbent main body is joined to the front waistline member at a front main body joint, and a rear end of the absorbent main body is joined to the rear waistline member at a rear main body joint, the front waistline member and the rear waistline member are joined to each other by a pair of side joints provided on both sides in the horizontal direction, the pants-type absorbent article has crotch elastic members that stretch along the longitudinal direction of the absorbent main body, and the rear waistline member has extensions that extend below the lower ends of the side joints in the vertical direction, and in an unfolded and stretched state a length from the central position to the rear end of the absorbent main body in the longitudinal direction when the pants-type absorbent article is in the folded position is longer than the length from the central position to the front end of the absorbent main body; a length from the central position to the rear end of the portion where the stretchable force of the crotch elastic member acts is longer than the length from the central position to the front end of the portion where the stretchable force of the crotch elastic member acts; a length from the front end to the rear end of the rear main body joint is longer than the length from the front end to the rear end of the front main body joint; and a length from the central position to the front end of the extension portion is shorter than the length from the central position to the rear end of the front waistband member.

[0010] According to the pants-type absorbent article of Aspect 1, when worn, the absorbent main body widely covers the wearer's buttocks. Furthermore, the elasticity of the crotch elastic members allows the absorbent main body, which widely covers the buttocks, to easily conform to the shape of the buttocks' groove and surrounding area. This improves fit around the buttocks and helps prevent rearward leakage of body waste. Furthermore, the front side of the leg openings, extending from the rear end of the front waistband member to the front end of the rear waistband member, is longer than the rear side. This provides more space in front of the leg openings, reducing interference with forward leg movement by the front waistband member. This facilitates free leg movement even while wearing the absorbent article. Furthermore, the longitudinal length of the front body joint is shorter than the longitudinal length of the rear body joint, reducing the transmission of force from the absorbent main body to the front body joint when moving the legs forward. This makes it difficult for the front waistband member to be pulled and therefore difficult for the front waistband member to slip off the wearer's body.

[0011] (Aspect 2) A pants-type absorbent article according to Aspect 1, wherein in the longitudinal direction when in an unfolded and stretched state, the length from the front end of the extension portion to the rear end of the portion where the stretch force of the crotch elastic member acts is longer than the length from the front end of the portion where the stretch force of the crotch elastic member acts to the front end of the extension portion.

[0012] According to the pants-type absorbent article of Aspect 2, the effective length of the crotch elastic member is longer at the rear side in the front-to-rear direction, so that even when the wearer changes posture from sitting to standing or vice versa, the contractile force of the crotch elastic member is more likely to act on the extension portion (buttocks cover) of the rear waistband member, making it easier to maintain the wearer's buttocks securely covered. Conversely, because the effective length of the crotch elastic member is shorter at the front side in the front-to-rear direction, even if force acts on the extension portion (buttocks cover) when the wearer's posture changes, the force transmitted to the front side via the crotch elastic member is less likely to be excessively large. Therefore, when the wearer moves, the front waistband member is less likely to be pulled rearward and slip down.

[0013] (Aspect 3) A pants-type absorbent article according to aspect 1 or 2, wherein the front waistline member has a plurality of front waistline elastic members that stretch in the left-right direction, and when unfolded and stretched, in the longitudinal direction, the length from the rear end of the front waistline member to the front end of the portion where the stretching force of the crotch elastic member acts is longer than the length from the rearmost front waistline elastic member to the rear end of the front waistline member.

[0014] In the pants-type absorbent article of Aspect 3, the length from the front end of the crotch elastic member to the rear end of the front waistline member is long, making it difficult for force to be transmitted from the crotch elastic member to the front waistline member, preventing the front waistline member from being pulled and slipping down. On the other hand, the length from the rearmost front waistline elastic member to the rear end of the front waistline member is short, so the force acting on the rear end of the front waistline member by the front waistline elastic member has a greater effect than the force acting on the crotch elastic member. Therefore, the front waistline member can more easily resist the force pulling it rearward by the crotch elastic member, preventing the front waistline member from slipping down.

[0015] (Aspect 4) A pants-type absorbent article according to any one of Aspects 1 to 3, wherein in the longitudinal direction when in an unfolded and stretched state, the length from the front end of the rear waistline member to the rear end of the absorbent main body is longer than the length from the rear end of the front waistline member to the front end of the rear waistline member.

[0016] According to the pants-type absorbent article of Aspect 4, the length of the portion of the absorbent main body where the absorbent main body overlaps with the rear waistband member is longer than the length of the portion of the absorbent main body that forms the circumference of the leg openings. Therefore, even if the portion of the absorbent main body that forms the circumference of the leg openings is pulled forward by, for example, the wearer moving their legs forward, the portion of the absorbent main body that overlaps with the rear waistband member fits tightly around the buttocks, making it less likely that the absorbent main body will shift position. This makes it easier to maintain a good fit around the buttocks.

[0017] (Aspect 5) A pants-type absorbent article according to any one of Aspects 1 to 4, wherein the front waistline member has a plurality of front waistline elastic members that stretch in the left-right direction, the rear waistline member has a plurality of rear waistline elastic members that stretch in the left-right direction, and when viewed in the thickness direction, at a central position in the left-right direction, the front waistline elastic members and the absorbent main body have overlapping portions, and the rear waistline elastic members and the absorbent main body do not have overlapping portions.

[0018] According to the pants-type absorbent article of Aspect 5, at the front side, the contractile force of the front waist elastic member presses the absorbent main body against the wearer's skin (abdomen) and holds it firmly, making it difficult for the absorbent main body and the front waist elastic member to slip off the wearer's body. On the other hand, at the rear side, the contractile force of the rear waist elastic member is less likely to act on the absorbent main body, making it difficult for the contractile force of the crotch elastic member to be interfered with by the rear waist elastic member, making it easier for the absorbent main body to fit into the buttocks crease and surrounding areas, and preventing rear leakage of excrement, etc.

[0019] (Aspect 6) The pants-type absorbent article according to any one of Aspects 1 to 5, wherein, in the longitudinal direction when the article is in an unfolded and stretched state, the crotch elastic members do not straddle an intermediate position between the central position and the front end of the front waistline member.

[0020] According to the pants-type absorbent article of Aspect 6, the fold line along which the absorbent article is folded in four does not intersect with the crotch elastic members at the front side in the front-to-rear direction, which prevents the loss of stretchability of the crotch elastic members due to creases formed when the absorbent article is folded in four. This makes it easier to maintain a good fit on the abdominal side of the absorbent main body.

[0021] (Aspect 7) The pants-type absorbent article according to any one of Aspects 1 to 6, wherein, in the longitudinal direction when the article is in an unfolded and stretched state, the crotch elastic members do not straddle an intermediate position between the central position and the rear end of the rear waistband member.

[0022] According to the pants-type absorbent article of Aspect 7, even at the rear side in the front-to-rear direction, the folding line along which the absorbent article is folded in four does not intersect with the crotch elastic members, so that the loss of stretchability of the crotch elastic members due to creases is suppressed, and this makes it easier to maintain a good fit on the back side of the absorbent main body.

[0023] (Aspect 8) The pants-type absorbent article according to any one of Aspects 1 to 7, wherein a rear non-joined portion where no adhesive is provided is between the lower end of the rear main body joint portion and the lower end of the rear waistband member in the up-down direction, and the crotch elastic members straddle the rear non-joined portion in the longitudinal direction when the article is in an unfolded and stretched state.

[0024] According to the pants-type absorbent article of Aspect 8, the front longitudinal end (bottom end) of the rear waistband member (buttocks cover) is stretched firmly by the crotch elastic members, improving fit. Furthermore, the bottom end of the buttocks cover is raised away from the skin at the rear non-joined portion, covering the crotch elastic members, making the presence of the crotch elastic members less visible from the outside. This helps maintain an underwear-like appearance.

[0025] (Aspect 9) A pants-type absorbent article according to any one of Aspects 1 to 8, which has a front non-joined portion in the vertical direction between the lower end of the front main body joint portion and the lower end of the front waistband member, where no adhesive is provided, and the length of the rear non-joined portion in the vertical direction is longer than the length of the front non-joined portion in the vertical direction.

[0026] According to the pants-type absorbent article of Aspect 9, the length of the rear non-joined portion is long at the rear side (back side), which makes it easier for the vertical lower end of the rear waistline member (buttocks cover) to cover the crotch elastic member. On the other hand, the length of the front non-joined portion is short at the front side (ventral side), which makes it harder for the vertical lower end of the front waistline member to roll up significantly, making it easier to form a silhouette that resembles underwear.

[0027] (Aspect 10) A pant-type absorbent article according to any one of Aspects 1 to 9, wherein the absorbent main body comprises an absorbent core containing water-retentive fibers, and when a menstrual blood drop test is conducted in which artificial menstrual blood is dropped onto a central portion in the longitudinal direction and the left-right direction of the absorbent core in an unfolded and stretched state, the thickness of the central portion of the pant-type absorbent article after the menstrual blood drop test is smaller than the thickness of the central portion of the pant-type absorbent article before the menstrual blood drop test.

[0028] According to the pants-type absorbent article of Aspect 10, even after absorbing menstrual blood, unevenness is prevented from forming on the skin-side surface of the absorbent article at the position where the absorbent article contacts the excretory opening and its surrounding area, allowing the stretchability of the crotch elastic members to act more effectively on the absorbent core. This makes it easier for the absorbent core to maintain close contact with the wearer's excretory opening and its surrounding area. This reduces the risk of menstrual blood leaking through gaps that form between the absorbent article and the wearer.

[0029] (Aspect 11) The pants-type absorbent article according to any one of Aspects 1 to 10, wherein the absorbent main body includes an absorbent core containing a water-retentive fiber, a back sheet disposed on the side away from the skin of the absorbent core, and a sheet member disposed on the side away from the skin of the back sheet, and the bonding strength between the rear waistband member and the absorbent main body is higher than the bonding strength between the back sheet and the sheet member.

[0030] According to the pants-type absorbent article of Aspect 11, the joining strength between the rear waistline member and the absorbent main body is appropriately ensured, thereby preventing separation of the rear waistline member and the absorbent main body.

[0031] (Aspect 12) A pants-type absorbent article according to any one of Aspects 1 to 11, wherein the absorbent main body comprises an absorbent core containing a water-retentive fiber, a back sheet arranged on the non-skin side of the absorbent core, and a sheet member arranged on the non-skin side of the back sheet, the rear waistband member comprises a skin side sheet and a non-skin side sheet arranged on the non-skin side of the skin side sheet, and the bonding strength between the skin side sheet and the non-skin side sheet is higher than the bonding strength between the back sheet and the sheet member.

[0032] According to the pants-type absorbent article of aspect 12, even if the skin-side sheet and non-skin-side sheet that make up the rear waistband member tend to move relative to the absorbent body when in a lying-down position and tend to rub against the floor or bed, the bonding strength between the skin-side sheet and non-skin-side sheet is ensured to an appropriate level, thereby preventing separation of the skin-side sheet and non-skin-side sheet.

[0033] ===Embodiment=== Hereinafter, a pants-type absorbent article 1 according to an embodiment of the present invention will be described. The pants-type absorbent article 1 according to this embodiment is a pants-type disposable diaper, a shorts-type sanitary napkin, or the like.

[0034] <Basic structure of pants-type absorbent article 1> Fig. 1 is a front view of the pants-type absorbent article 1 as seen from the ventral side. Fig. 2 is a plan view of the pants-type absorbent article 1 in an unfolded and stretched state as seen from the skin side. Fig. 3A is a schematic cross-sectional view taken along the first center line CL1 in Fig. 2, and Fig. 3B is a schematic cross-sectional view taken along the second center line CC1 in Fig. 2. In the following description, the pants-type absorbent article will also be simply referred to as the "absorbent article." The first center line CL1 is a line extending in the left-right direction at a center point that divides the product (absorbent article 1) in half in the longitudinal direction, and the second center line CC1 is a line extending in the longitudinal direction at a center point that divides the product in half in the left-right direction.

[0035] The unfolded state of the pants-type absorbent article 1 is a state in which the pair of side joining portions 2 provided on both sides of the absorbent article 1 are separated and the absorbent article 1 is opened and unfolded in a plane. The stretched state of the pants-type absorbent article 1 is a state in which the absorbent article 1 is stretched to an extent that wrinkles in the absorbent article 1 are no longer visible. Specifically, it is a state in which the absorbent article 1 is stretched until the dimensions of each component constituting the absorbent article 1 match or are close to the dimensions of the component alone.

[0036] As shown in Fig. 1, the pants-type absorbent article 1 has a vertical direction, a horizontal direction, and a front-to-rear direction (directions passing through the paper in Fig. 1) that are perpendicular to one another, and has a waist opening BH and a pair of leg openings LH. The upper side in the vertical direction corresponds to the waist opening BH side, and the lower side corresponds to the crotch side. The front side in the front-to-rear direction corresponds to the wearer's abdomen side, and the rear side corresponds to the wearer's back side.

[0037] 2, the absorbent article 1 has a longitudinal direction, a left-right direction, and a thickness direction (a direction passing through the paper in FIG. 2) that intersect with one another. The left-right direction in the unfolded state of FIG. 2 is the same as the left-right direction in the pants-type state of FIG. 1. The longitudinal direction in the unfolded state is a direction along the up-down direction in the pants-type state. One side in the longitudinal direction corresponds to the ventral side (front side), and the other side corresponds to the dorsal side (rear side). As shown in FIGS. 3A and 3B, the direction in which the materials constituting the absorbent article 1 are layered is referred to as the thickness direction. In the thickness direction, the side that comes into contact with the wearer's skin is referred to as the skin side, and the opposite side is referred to as the non-skin side.

[0038] The pants-type absorbent article 1 is a so-called three-piece pants-type absorbent article that includes at least three members: an absorbent main body 10, a front waistline member 20 that covers the abdominal region of the wearer, and a rear waistline member 30 that covers the dorsal region of the wearer and is configured as a separate member from the front waistline member 20. In the following description, the front waistline member 20 and the rear waistline member 30 will also be collectively referred to as the waistline members 20, 30.

[0039] As shown in Fig. 2, in the unfolded absorbent article 1, the front waistline member 20 and the rear waistline member 30 are positioned side by side at a longitudinal interval, and the absorbent main body 10 is suspended between them in the longitudinal direction. One longitudinal end 10F of the absorbent main body 10 is joined and fixed to the skin side of the front waistline member 20, and the other longitudinal end 10B of the absorbent main body 10 is joined and fixed to the skin side of the rear waistline member 30. From this state, the absorbent main body 10 is folded in half longitudinally, and the opposing front waistline member 20 and rear waistline member 30 are joined at their left and right side ends by a pair of side joining portions 2, resulting in the pants-type absorbent article 1 as shown in Fig. 1. In other words, the front waistline member 20 and the rear waistline member 30 are joined in an annular shape by the pair of side joining portions 2. Examples of the joining method using the side joining portion 2 include heat welding, ultrasonic welding, and joining methods using adhesives.

[0040] The absorbent body 10 includes an absorbent core 11 that absorbs and retains excreted liquids such as urine, a liquid-permeable topsheet 12 (e.g., nonwoven fabric, perforated film, etc.) arranged closer to the skin than the absorbent core 11, a liquid-impermeable backsheet 13 (e.g., resin film, etc.) arranged closer to the skin than the absorbent core 11, and a sheet member 14 (e.g., hydrophobic nonwoven fabric, etc.). The outer peripheral surface of the absorbent core 11 may be covered with a liquid-permeable core wrap sheet 15 such as tissue paper or nonwoven fabric. Both left and right sides of the topsheet 12 are folded back toward the skin side so as to wrap around the absorbent core 11. The sheet member 14 is arranged closer to the skin than the backsheet 13 and forms a leakage prevention wall portion 3 closer to the skin than the topsheet 12.

[0041] The absorbent core 11 is a molded body obtained by molding a predetermined liquid-absorbent material into a rectangular shape in a plan view, which is an example of a predetermined shape (see FIG. 2 ). Examples of the liquid-absorbent material include water-retentive fibers and liquid-absorbent granular materials such as superabsorbent polymers (so-called SAPs). The water-retentive fibers are not particularly limited as long as they have the property of absorbing and retaining moisture, and examples thereof include cellulosic fibers (e.g., pulp fibers, non-wood fibers such as cotton and hemp, and recycled fibers such as rayon). However, the shape of the absorbent core 11 is not limited to the rectangular shape shown in FIG. 2 . For example, the absorbent core 11 may be roughly hourglass-shaped, with a narrow width in the left-right direction between one end (front) and the other end (rear) in the longitudinal direction.

[0042] As shown in Figures 2 and 3A, a pair of leakage preventing walls 3 is provided along the longitudinal direction of the absorbent main body 10 on both left and right side portions of the absorbent main body 10. The pair of leakage preventing walls 3 is formed integrally with the absorbent main body 10 by folding a sheet member 14 constituting the exterior of the absorbent main body 10. Specifically, the sheet member 14 covers the non-skin side of the back sheet 13, and portions extending outward in the left and right direction are folded at multiple locations to form the leakage preventing walls 3 on both left and right side portions of the skin side of the top sheet 12. Leak preventing wall elastic members 16 (e.g., rubber thread) are attached to the leakage preventing walls 3 in a stretched state along the longitudinal direction. When the absorbent article 1 is worn, the leakage preventing walls 3 rise up toward the wearer's skin due to the longitudinal stretchability of the leakage preventing wall elastic members 16.

[0043] The absorbent body 10 also has a longitudinally stretchable crotch elastic member 17 in the left-right center and on the non-skin side in the thickness direction of the absorbent core 11. Specifically, the crotch elastic member 17 in this embodiment is sandwiched and joined between the core wrap sheet 15 covering the absorbent core 11 and the back sheet 13 arranged on the non-skin side in the thickness direction of the core wrap sheet 15 (absorbent core 11). The position of the crotch elastic member 17 in the longitudinal direction will be described in detail later.

[0044] The front waistline member 20 includes a skin-side sheet 21, a non-skin-side sheet 22 laminated on the non-skin side of the skin-side sheet 21, and a plurality of front waistline elastic members 23 (e.g., rubber thread) that stretch in the left-right direction. Similarly, the back waistline member 30 includes a skin-side sheet 31, a non-skin-side sheet 32 ​​laminated on the non-skin side of the skin-side sheet 31, and a plurality of rear waistline elastic members 33 (e.g., rubber thread) that stretch in the left-right direction. The plurality of front (rear) waistline elastic members 23 (33) are arranged vertically (longitudinally) between the skin-side sheet 21 (skin-side sheet 31) and the non-skin-side sheet 22 (non-skin-side sheet 32) and are attached in a stretched state in the left-right direction. The stretchability of the front and rear waistline elastic members 23, 33 allows the front waistline member 20 and the rear waistline member 30 to fit the waist of the wearer.

[0045] A cover sheet (not shown) may be provided so as to cover the upper end portions (the front end portion and the rear end portion in the longitudinal direction of FIG. 3B ) of the absorbent main body 10 from the skin side. By providing the cover sheet, it is possible to prevent the upper end edge of the absorbent main body 10 from digging into the wearer's skin and to prevent the absorbent main body 10 from opening open.

[0046] 2, the front waistline member 20 and the rear waistline member 30 have different planar shapes in the unfolded and stretched state. The front waistline member 20 has a rectangular shape that is elongated in the left-right direction and has a vertical length that is roughly the same as that of the side joint portion 2. On the other hand, the rear waistline member 30 has a rectangular waist side portion 30A that overlaps with the front waistline member 20, and further has an extension portion 30B that is located below the side joint portion 2 (to one side of one longitudinal end of the side joint portion 2) and whose width in the left-right direction narrows from the upper side to the lower side in the vertical direction (from the other longitudinal side to one side). This extension portion 30B functions as a buttocks cover that covers the wearer's buttocks on the rear side (back side) when the absorbent article 1 is worn.

[0047] The extension portion 30B is also provided with rear extension portion elastic members 35 (e.g., rubber threads) extending in the left-right direction. A plurality of rear extension portion elastic members 35 are provided in the extension portion 30B at predetermined intervals in the longitudinal direction (vertical direction) as shown in FIG. 2 . The rear extension portion elastic members 35 are also attached in a stretched state between the skin side sheet 31 and the non-skin side sheet 32. The stretchability of the rear extension portion elastic members 35 allows the extension portion 30B of the rear waistband member 30 to fit easily around the wearer's buttocks and to be less likely to roll up from the buttocks. Although FIG. 2 illustrates three rubber threads as the rear extension portion elastic members 35, the number of rubber threads is not particularly limited.

[0048] The basic configuration of the absorbent article 1 has been described above, but the configuration of the absorbent article 1 described above is merely an example and is not limited thereto. For example, a liquid-permeable intermediate sheet may be provided between the topsheet 12 and the core wrap sheet 15. Furthermore, the rear waistband member 30 may not have the extension portion 30B or the rear extension portion elastic member 35 and may have the same planar shape as the front waistband member 20, or the front waistband member 20 may have a portion extending toward the crotch. Furthermore, thread-like front and rear waistband elastic members 23, 33 may be provided at the upper ends (waist portions) of the waistband members 20, 30 to provide a secure fit, and a stretchable sheet may be provided below them instead of the thread-like waistband elastic members 23, 33. By providing a stretchable sheet between the skin-side sheet 21 (skin-side sheet 31) and the non-skin-side sheet 22 (non-skin-side sheet 32) and intermittently joining the laminated sheets, the waistband members 20, 30 exhibit stretchability and provide a soft surface fit around the wearer's waist.

[0049] As described above, the absorbent article 1 of this embodiment is provided with the crotch elastic member 17 to improve the fit at the left-right center of the absorbent main body 10. Even in conventional pants-type absorbent articles, elastic members that stretch in the longitudinal direction may be attached to the left-right center so as to extend to both the front waistline member 20 and the rear waistline member 30 so as to prevent the absorbent main body from slipping off while being worn. In such a configuration, the elastic members facilitate close contact with the wearer's body, but in the case of a woman, for example, they also facilitate close contact with the female urethral opening, and continuous pressure on the absorbent main body may cause discomfort such as pain near the urethral opening.

[0050] Furthermore, unlike the present embodiment, for example, if the components constituting the exterior body of the absorbent article 1 are an integrated exterior member that is continuous from the ventral waistband portion to the back waistband portion, the exterior member and the absorbent main body are joined even near the woman's urethral opening, and therefore deformation of the exterior member during wear extends to the absorbent main body, and a deformation force is also exerted on the absorbent main body near the urethral opening, which may cause discomfort. In this regard, the rear waistband member 30 of the present embodiment is configured as a separate member from the front waistband member 20. In other words, the absorbent main body 10 is firmly held in place by the joined portions between the ventral and back waistband members 20, 30, while the unjoined portions (i.e., the crotch portion) are not held by the ventral and back waistband members 20, 30. Therefore, compared to the case of an integrated exterior member, the rear waistband member 30 is less susceptible to the movement of the ventral and back waistband members 20, 30, and the crotch portion is more likely to deform independently.

[0051] 2 shows only the stretchable portion (the so-called "effective length") of each crotch elastic member 17. In this embodiment, the crotch elastic members 17 extend at least rearward (to the other side) from the longitudinal center position (first center line CL1) of the absorbent article 1. By having the crotch elastic members 17 extend rearward (to the other side) from the longitudinal first center line CL1, when the crotch elastic members 17 contract, the absorbent main body 10 can be more easily aligned with the grooves of the wearer's buttocks, thereby preventing body waste from running through the gaps in the buttocks.

[0052] <Regarding the Fit of the Absorbent Article 1> Such an absorbent article 1 may be worn for long periods of time. That is, a wearer (user) of a pants-type absorbent article 1 may go about their daily life wearing the pants-type absorbent article 1 for long periods of time like underwear. For example, when a wearer sits for long periods of time while wearing the absorbent article 1, fit around the buttocks becomes important. Furthermore, when a user transitions from a sitting position to a standing position while wearing the absorbent article 1, the stretching force of the crotch elastic members 17 tends to pull the front waistline member 20 toward the crotch (toward the rear in the front-to-rear direction in FIG. 2 ), which may cause the front waistline member 20 to slip off the wearer's body and deteriorate the fit.

[0053] To address this issue, the absorbent article 1 of this embodiment achieves a good fit when worn by appropriately adjusting the positions of the crotch elastic members 17 and each part. The specific configuration and position of each part will be described below.

[0054] Fig. 4 is a plan view illustrating the detailed arrangement of each component constituting the absorbent article 1. Similar to Fig. 2, Fig. 4 illustrates the absorbent article 1 in an unfolded and stretched state. In the longitudinal direction of Fig. 4, a length L2 from the central position (first center line CL1) to the rear end 10be of the absorbent main body 10 is longer than a length L1 from the central position (first center line CL1) to the front end 10fe of the absorbent main body 10 (L1<L2). Also, in the longitudinal direction, a length SH2 from the central position (first center line CL1) to the rear end 17be of the portion (effective length) where the stretch force of the crotch elastic member 17 acts is longer than a length SH1 from the central position (first center line CL1) to the front end 17fe of the portion (effective length) where the stretch force of the crotch elastic member 17 acts (SH1<SH2).

[0055] That is, in the absorbent article 1 of this embodiment, the absorbent main body 10 is disposed longer at the rear side (the other side) in the longitudinal direction than at the front side (one side), and the portion where the stretching force of the crotch elastic members 17 is exerted (effective length) is longer at the rear side (the other side) in the longitudinal direction than at the front side (one side). Therefore, when the absorbent article 1 is worn, the absorbent main body 10 widely covers the wearer's buttocks (the rear side in the front-to-back direction), and further, the absorbent main body 10 widely covering the buttocks easily conforms to the shape of the buttock groove and surrounding area due to the stretching force of the crotch elastic members 17. Therefore, gaps are less likely to occur between the buttock groove and surrounding area and the absorbent main body 10, improving fit and making it easier to suppress leakage of excrement backward.

[0056] The absorbent main body 10 and the front waistline member 20 are joined to each other at a front main body joint 41, which is indicated by diagonal lines in Fig. 4 . Similarly, the absorbent main body 10 and the rear waistline member 30 are joined to each other at a back main body joint 42, which is indicated by diagonal lines in Fig. 4 . The front main body joint 41 and the rear main body joint 42 are each formed by applying an adhesive, such as a hot melt adhesive, to a predetermined region (the region indicated by diagonal lines in Fig. 4 ) on the non-skin-facing surface of the absorbent main body 10. The adhesive may be applied completely over the entire surface of the front main body joint 41 and the rear main body joint 42, i.e., solid coating, or may be applied in a known application pattern (e.g., spiral pattern, Ω pattern, line pattern, etc.). When the adhesive is applied in a predetermined application pattern, such as a spiral pattern, any region that is spaced less than 1.5 mm from surrounding adhesive is considered to be included in the front main body joint 41 or the rear main body joint 42.

[0057] In the absorbent article 1, the length HMA2 of the rear main body joint 42 (i.e., the length between the front end 42fe and the rear end 42be of the rear main body joint 42) is longer than the length HMA1 of the front main body joint 41 (i.e., the length between the front end 41fe and the rear end 41be of the front main body joint 41) (HMA1<HMA2). In addition, in the longitudinal direction of Fig. 4, the length GA1 from the center position (first center line CL1) to the rear end 20be (bottom end in the vertical direction) of the front waistline member 20 is shorter than the length GA2 from the center position (first center line CL1) to the front end 30fe (bottom end in the vertical direction) of the rear waistline member 30 (extension 30B) (GA1>GA2).

[0058] In the longitudinal direction, the portion between the rear end 20be of the front waistline member 20 and the front end 30fe of the rear waistline member 30 constitutes the leg openings LH in the absorbent article 1. Since the front length GA1 is longer than the rear length GA2, the space in front of the leg openings LH is wider, and when the wearer moves their legs forward while walking, for example, the leg movement is less likely to be interfered with by the front waistline member 20. Therefore, the wearer can move their legs freely even while wearing the absorbent article 1. Furthermore, when the wearer moves their legs forward, the force that moves the legs is transmitted to the front waistline member 20 via the absorbent main body 10, which may pull the front waistline member 20 toward the crotch area and cause it to become misaligned. However, because the longitudinal length HMA1 of the front main body joint 41 joining the front waistline member 20 and the absorbent main body 10 is shorter than the longitudinal length HMA2 of the rear main body joint 42, the area of ​​the front main body joint 41 becomes relatively small, making it difficult for the force exerted when moving the legs forward to be transmitted from the absorbent main body 10 to the front main body joint 41. This makes it difficult for the front waistline member 20 to be pulled, making it difficult for it to slip off the wearer's body.

[0059] Furthermore, in the absorbent article 1, it is preferable that the length SH4 from the front end 17fe of the portion where the stretching force of the crotch elastic member 17 acts to the rear end 17be of the portion where the stretching force of the crotch elastic member 17 acts is longer than the length SH3 from the front end 30fe to the front end (vertically lower end) 30fe of the rear waistband member 30 (extension 30B) (SH3 < SH4). With this configuration, the range (effective length) where the stretching force of the crotch elastic member 17 acts on the rear side in the longitudinal direction is longer. Therefore, even when the wearer repeatedly changes posture from sitting to standing or vice versa, the contraction force of the crotch elastic member 17 is more likely to act on the extension 30B (buttocks cover) of the rear waistband member 30, and the wearer's buttocks are more likely to be securely covered. This prevents the buttocks cover from being turned up when the wearer changes posture. Conversely, because the range (effective length) over which the stretching force of the crotch elastic member 17 acts is short on the front side in the front-to-rear direction, even if force acts on the extension portion 30B (buttocks cover) when the wearer's posture changes, the force transmitted to the front side via the crotch elastic member 17 is unlikely to become excessively large. Therefore, when the wearer moves, the front waistline member 20 is more likely to be prevented from being pulled rearward and slipping down.

[0060] Furthermore, in the absorbent article 1, the front end 17fe (one side) in the longitudinal direction of the portion where the stretching force of the crotch elastic member 17 acts is located rearward (the other side) of the front waistline elastic member 23dm (the most rearward (the other side) in the longitudinal direction) among the plurality of front waistline elastic members 23, 23... that are arranged in a row at a predetermined interval in the longitudinal direction. Note that "rearward (the other side) of the front waistline elastic member 23dm (the most rearward (the other side) in the longitudinal direction)" means "rearward (the other side) of the rearward (the other side) end of the front waistline elastic member 23dm (the most rearward (the other side) in the longitudinal direction)" when, for example, the front waistline elastic member 23dm is a strip-shaped elastic member or a stretchable sheet.

[0061] In the absorbent article 1 of this embodiment, in the longitudinal direction, the length g1 from the rearmost front waistline elastic member 23dm to the rear end 20be of the front waistline member 20 is longer than the length g2 from the rear end 20be to the front end 17fe of the portion where the stretching force of the crotch elastic member 17 acts (g1 < g2). For example, when the wearer changes posture from sitting to standing as described above, the force acting on the extension portion 30B (buttocks cover) of the rear waistline member 30 is transmitted to the front side via the crotch elastic member 17. At this time, if the length g2 from the front end 17fe of the effective length of the crotch elastic member 17 to the rear end 20be of the front waistline member 20 is long, the force is less likely to be transmitted from the crotch elastic member 17 to the front waistline member 20, and the front waistline member 20 is prevented from being pulled and slipping down.

[0062] On the other hand, in the front waistline member 20, the length g1 from the front waistline elastic member 23dm to the rear end 20be of the front waistline member 20 is short, so that the contractile force in the left-right direction by the front waistline elastic member 23dm is more likely to act on the rear end 20be of the front waistline member 20. That is, the force acting on the rear end 20be of the front waistline member 20 by the front waistline elastic member 23dm has a greater effect than the force acting on the rear end 20be of the front waistline member 20 by the crotch elastic member 17. Therefore, the front waistline member 20 can more easily resist the force of the crotch elastic member 17 pulling it rearward (downward in the up-down direction), and slipping down of the front waistline member 20 is suppressed.

[0063] Furthermore, in the front-to-rear direction, the length h2 from the rear end 20be of the front waistline member 20 to the front end 30fe of the rear waistline member 30 (extension 30B) is longer than the length h1 from the front end 30fe to the front end 30fe of the rear waistline member 30 (extension 30B) (h1 < h2). That is, the length (h2) of the portion of the absorbent main body 10 overlapping the rear waistline member 30 is longer than the length (h1) of the portion of the absorbent main body 10 that constitutes the perimeter of the leg openings LH. For example, when walking or the like while wearing the absorbent article 1, even if the wearer moves their legs forward significantly and the portion of the absorbent main body 10 with length h1 is pulled forward, the portion of the absorbent main body 10 with length h2 (the portion longer than h1) fits tightly around the buttocks, making it less likely for the absorbent main body 10 to shift position. This makes it easier to maintain a good fit around the buttocks.

[0064] Furthermore, when the absorbent article 1 is viewed in the thickness direction, there is an overlapping portion between the front waist elastic members 23 and the absorbent main body 10 at the center position in the left-right direction (second center line CC1). On the other hand, there is no overlapping portion between the rear waist elastic members 24 and the absorbent main body 10 at the center position in the left-right direction (second center line CC1). With this configuration, on the front side (belly side), the contractile force of the front waist elastic members 23 presses the front end portion 10F of the absorbent main body 10 in the longitudinal direction against the wearer's skin side (abdomen) and holds it firmly, making it difficult for the absorbent main body 10 and the front waist member 20 to slip off the wearer's body. On the other hand, on the rear side (back side), the contractile force of the rear waist elastic members 33 is unlikely to act on the absorbent main body 10. Therefore, the contraction force of the crotch elastic member 17 acting on the rear side of the absorbent body 10 is less likely to be interfered with by the rear waist elastic member 33, making it easier for the absorbent body 10 to fit into the grooves and surrounding areas of the buttocks, thereby suppressing rear leakage of excreted liquid, etc.

[0065] The absorbent article 1 is folded from its pant-type shape in the longitudinal direction (vertical direction) to a compact shape, packaged, and distributed to the market. Figures 5A and 5B are diagrams illustrating an example of a method for folding the absorbent article 1. Figure 5A is a schematic cross-sectional view of the pant-type absorbent article 1 folded in half at the longitudinal center position (first center line CL1) as viewed from one side in the left-right direction. That is, Figure 5A shows the cross-sectional shape of the pant-type absorbent article 1 shown in Figure 1. When the absorbent article 1 is further folded in the front-rear direction from this state at the longitudinal (vertical) center position (second center line CL2), it becomes folded in four as shown in Figure 5B. The absorbent article 1 is then packaged in a predetermined packaging material in this folded-in-four state and shipped.

[0066] As shown in Fig. 4, the crotch elastic members 17 of the absorbent article 1 are arranged so as not to straddle the second center line CL2f provided on the front side in the longitudinal direction. In other words, in the longitudinal direction, the front end 17fe of the crotch elastic member 17 is arranged behind the midpoint (second center line CL2f) between the center position (first center line CL1) of the absorbent article 1 and the front end of the front waistline member 20. In other words, on the front side (one side) in the front-to-back direction, the crotch elastic members 17 do not intersect with the folding line (second center line CL2f) along which the absorbent article 1 is folded in four. This prevents the stretchability of the crotch elastic members 17 from being impaired by creases formed when the absorbent article 1 is folded in four. Therefore, when a user who has purchased the absorbent article 1 opens the package and uses (wears) the absorbent article 1, the fit of the abdominal side of the absorbent main body 10 is more likely to be maintained in a good state.

[0067] Similarly, the crotch elastic members 17 of the absorbent article 1 may be arranged so as not to straddle the second center line CL2b provided on the rear side in the longitudinal direction. In other words, the rear end 17be of the crotch elastic member 17 may be arranged in front of the midpoint (second center line CL2b) between the center position (first center line CL1) of the absorbent article 1 and the rear end of the rear waistband member 30 in the longitudinal direction. In this case, the crotch elastic members 17 do not intersect with the folding line (second center line CL2b) along which the absorbent article 1 is folded in four on the rear side (the other side) in the front-to-rear direction, thereby preventing the stretchability of the crotch elastic members 17 from being impaired by creases. This makes it easier to maintain a good fit on the back side of the absorbent main body 10.

[0068] Furthermore, a so-called dry edge, which is not joined to the absorbent main body 10, is formed at the front end 30fe of the rear waistline member 30 in the longitudinal direction (the lower end of the extended portion 30B in the vertical direction). In FIG. 4, the front end 42fe of the rear main body joint portion 42 joining the rear waistline member 30 and the absorbent main body 10 is spaced a predetermined distance from the front end 30fe of the rear waistline member 30 (extended portion 30B), and the portion between the front end 42fe and the front end 30fe forms a dry edge (rear non-joined portion) where no adhesive is provided. Furthermore, the crotch elastic members 17 are arranged across the dry edge (rear non-joined portion) in the longitudinal direction of the absorbent article 1. This allows the stretchability of the crotch elastic members 17 to be fully exerted at the front end (lower end in the vertical direction) of the rear waistline member 30 (buttocks cover) in the longitudinal direction, improving fit. Furthermore, the lower end of the buttocks cover is raised away from the skin at the dry edge (rear non-jointed portion) and covers the crotch elastic members 17, making it difficult to see the presence of the crotch elastic members 17 from the outside. This makes it easier to maintain an outer appearance that resembles underwear.

[0069] Similarly, a dry edge (front non-joined portion) that is not joined to the absorbent main body 10 is also formed at the rear end 20be in the longitudinal direction of the front waistline member 20 (the lower end in the up-down direction). In Fig. 4, the rear end 41be in the front-to-back direction of the front main body joint portion 41 that joins the front waistline member 20 and the absorbent main body 10 is spaced a predetermined distance from the rear end 20be of the front waistline member 20, and the portion between this rear end 41be and the rear end 20be is a dry edge (front non-joined portion) that is not provided with adhesive.

[0070] It is preferable that the length in the front-to-back direction of the dry edge (front non-joined portion) formed on the rear side (the distance between the front end 30fe and the front end 42fe) is longer than the length in the front-to-back direction of the dry edge (front non-joined portion) formed on the front side (the distance between the rear end 41be and the rear end 20be). The longer length of the dry edge (rear non-joined portion) on the rear side (back side) makes it easier for the vertical lower end of the rear waistline member 30 (buttocks cover) to cover the crotch elastic member 17. On the other hand, the shorter length of the dry edge (front non-joined portion) on the front side (belly side) makes it harder for the vertical lower end of the front waistline member 20 to roll up significantly, making it easier to form a silhouette that resembles underwear.

[0071] 6 is a diagram illustrating a menstrual blood drop test and a saline solution drop test. In the pants-type absorbent article 1 of this embodiment, when a menstrual blood drop test is conducted in which artificial menstrual blood is dropped onto a central region R1 in the longitudinal direction and the left-right direction of the absorbent core 11 in an unfolded and stretched state, the thickness of the central region R1 of the absorbent article 1 after the menstrual blood drop test is smaller than the thickness of the central region R1 of the absorbent article 1 before the menstrual blood drop test.

[0072] In the menstrual blood dripping test, assuming a situation in which the absorbent article 1 is actually used, artificial menstrual blood is dripped onto the longitudinal and lateral central portion R1 of the absorbent core 11, which abuts against the wearer's excretory opening (vaginal opening). The amount of artificial menstrual blood dripped was also set to 10 ml, which is the average amount discharged into the absorbent article 1, as a result of research by the applicant.

[0073] Unlike this embodiment, napkins in which the thickness of the central region R1 increases after the menstrual blood drop test are more likely to develop unevenness on the skin-side surface after absorbing menstrual blood. This is thought to be because, compared to when the spaces between the water-retentive fibers become smaller and the thickness becomes thinner due to menstrual blood absorption, when the thickness increases due to the water-retentive fibers widening and the superabsorbent polymer (SAP) expanding due to menstrual blood absorption, the way the thickness changes (the way it expands) is more likely to vary due to various causes (such as the distribution of the constituent materials of the absorbent core 11 and the degree of diffusion of menstrual blood). It is also thought that as the thickness increases, unevenness (thickness differences) also increases.

[0074] In contrast, in the absorbent article 1 of this embodiment, swelling of the central region R1 after the menstrual blood drop test is suppressed, resulting in a thinner thickness. Therefore, even after absorbing menstrual blood, unevenness is prevented from forming on the skin-side surface of the absorbent article 1 at the excretory opening contact position and its surrounding area, allowing the stretchability of the crotch elastic members 17 to more effectively act on the absorbent core 11. This makes it easier for the absorbent article 1 (absorbent core 11) to maintain a state of close contact with the wearer's excretory opening and its surrounding area. As a result, leakage of menstrual blood through gaps that occur between the absorbent article 1 and the wearer can be suppressed.

[0075] The method for the "menstrual blood drip test" will now be described. (1) First, the side seam 2 of the pants-type absorbent article 1 to be measured is torn, and the absorbent article 1 is unfolded and stretched, with the skin side facing up, and fixed (see FIG. 2). (2) Next, a center position P1 (see FIG. 6) is determined, which is the intersection of a line dividing the absorbent core 11 in half at its maximum length in the longitudinal direction and a line dividing the absorbent core 11 in half at its maximum width in the lateral direction. A circular region R1 having a diameter of 8 cm and centered at this center position P1 is determined as the longitudinal and lateral central region R1 of the absorbent core 11. (3) Next, the thickness of the entire absorbent article 1 is measured at five locations within the central region R1, and the average value of the thicknesses at these five locations is calculated. This average value is the thickness of the central region R1 of the pants-type absorbent article 1 before the menstrual blood drip test. (4) Next, a cylindrical jig 50 (outer diameter 8 cm, inner diameter 7 cm, thickness (outer radius - inner radius) 0.5 cm, weight 200 g) is placed in the central portion R1. 10 ml of artificial menstrual blood is dripped onto the inside of the jig 50, and after the artificial menstrual blood has permeated the absorbent body, the jig 50 is removed and the article is left for one hour. (5) After the artificial menstrual blood has been dripped and left for one hour, the thickness of the entire absorbent article 1 is measured at five points within the inner (hollow) region of the central portion R1 where the jig 50 was placed, and the average value of the thicknesses at these five points is calculated. This average value is the thickness of the central portion R1 of the pants-type absorbent article 1 after the menstrual blood drip test. It is then compared with the thickness before the test.

[0076] The thickness of the absorbent article 1 is measured using, for example, a spring-loaded thickness gauge (Peacock JB) manufactured by Ozaki Manufacturing Co., Ltd., or an equivalent device (the pressure used during measurement is determined by the jig of the gauge). If the absorbent article 1 has compressed portions (embossed) that are partially compressed in the planar direction, the thickness of the uncompressed portions is measured. The artificial menstrual blood is prepared by adding 80 g of glycerin, 8 g of sodium carboxymethylcellulose, 10 g of sodium chloride, 4 g of sodium bicarbonate, 8 g of Red No. 102, 2 g of Red No. 2, and 2 g of Yellow No. 5 to 1 L of ion-exchanged water and thoroughly stirring the mixture.

[0077] Pant-type absorbent article samples (Examples A to D, Comparative Example A) were actually prepared and subjected to a menstrual blood drip test. FIG. 7A is a table showing the results of the menstrual blood drip test for the pant-type absorbent article 1 of this embodiment (Examples A to D) and Comparative Example A. As shown in the table of FIG. 7A, the absorbent core 11 of each sample had the following structure. Example A used pulp fiber (basis weight 145 g / m ２ ) did not contain SAP (super absorbent polymer), and Example B contained pulp fiber (basis weight 145 g / m ２ ) with a total SAP weight of 1.3 g and a basis weight of 20.4 g / m ２ In Example C, pulp fibers (basis weight 145 g / m ２ ) with a total SAP weight of 1.95 g and a basis weight of 30.6 g / m ２ In Example D, pulp fibers (basis weight 145 g / m ２ ) with a total SAP weight of 2.6 g and a basis weight of 40.8 g / m ２ Comparative Example A contains pulp fibers (basis weight 145 g / m ２ ) with a total SAP weight of 8.5 g and a basis weight of 133.4 g / m ２ The top sheet 12 was made of a hydrophilic air-through nonwoven fabric (basis weight 25 g / m ２ ), the core wrap sheet 15 is made of tissue (basis weight 15 g / m ２ ), and the back sheet 13 is made of a breathable resin film (basis weight 20 g / m ２ ) was used.

[0078] 7A shows that the thickness after the menstrual blood dropping test was smaller than the thickness before the test in Examples A to D. It was also found that the smaller the basis weight of the SAP contained in the absorbent core 11, the greater the rate at which the thickness decreased (the value of (thickness after dropping) / (thickness before dropping) became smaller).

[0079] 7B is a table showing the results of a reference test of the menstrual blood drop test. As a reference test, an absorbent core (pulp fiber, basis weight 145 g / m) containing no SAP was used. ２The absorbent core of Reference Example A, which was subjected to a menstrual blood drip test, was subjected to flat pressing (a process of uniformly compressing the entire surface of the absorbent core) during production. The absorbent core of Reference Example B was an absorbent core that was not subjected to flat pressing, but was left as it was after the pulp fibers layered in the mold were released.

[0080] The results of the reference test shown in Figure 7B show that in Reference Example A, in which the absorbent core was flat-pressed, the thickness after the menstrual blood drop test was greater than the thickness before the test. On the other hand, in Reference Example B, in which the absorbent core was not flat-pressed, the thickness after the menstrual blood drop test was smaller than the thickness before the test. Therefore, it was found that the pressure applied in the thickness direction during the manufacture of the absorbent core also affects the thickness of the absorbent core (absorbent article 1) after absorbing menstrual blood.

[0081] From the above results, by adjusting the amount of SAP contained in the absorbent core 11 and adjusting the strength of the pressure applied during the manufacture of the absorbent core 11, it is possible to manufacture the absorbent article 1 of this embodiment in which the swelling of the central portion R1 of the absorbent article 1 after absorbing menstrual blood is suppressed.

[0082] The absorbent main body 10 also has a back sheet 13 arranged closer to the skin than the absorbent core 11, and a sheet member 14 arranged closer to the skin than the back sheet 13 (see FIG. 3A ). In this case, the bonding strength between the rear waistline member 30 and the absorbent main body 10 is preferably higher than the bonding strength between the back sheet 13 and the sheet member 14.

[0083] In the absorbent article 1 of this embodiment, a relatively large non-jointed portion where the rear waistline member 30 and the absorbent main body 10 are not joined is provided to make wrinkles in the crotch elastic members 17 less noticeable, but by doing so, an appropriate joining strength is ensured between the rear waistline member 30 and the absorbent main body 10. Therefore, separation of the rear waistline member 30 and the absorbent main body 10 can be suppressed.

[0084] Comparison of bonding strength can be performed by a well-known method using a tensile tester (e.g., Instron Model 5965 or equivalent). From the target absorbent article 1, the entire area where the rear waistband member 30 and the absorbent main body 10 overlap in the thickness direction is cut out as a sample. Furthermore, if necessary, using a cold spray or the like, the entire area where the backsheet 13 and the sheet member 14 overlap in the thickness direction is also cut out as a sample from the target absorbent article 1. The width (W0) of each sample is measured in the direction perpendicular to the measurement direction (peel direction).

[0085] Next, the sample is set in a tensile tester so that a predetermined direction (left-right or longitudinal direction) of the absorbent article 1 is set as the measurement direction, and the components constituting the sample (the rear waistline member 30 and the absorbent main body 10, or the back sheet 13 and the sheet member 14) are peeled along the measurement direction. That is, an end of the rear waistline member 30 or the back sheet 13 in the measurement direction is clamped by one chuck, and an end of the absorbent main body 10 or the sheet member 14 in the measurement direction is clamped by the other chuck. The chucks are then moved apart at a constant speed (e.g., 100 mm / min) until the components constituting the sample are completely peeled (separated). The load applied during this period is observed, and the maximum value (N) among the loads is obtained. The maximum measured value (N) of each sample is then converted from the measured width (W0) of each sample to a 25 mm width (measurement value / W0 x 25 mm) (N / 25 mm), and the resulting value is compared as the bond strength.

[0086] The rear waistband member 30 has a skin side sheet 31 and a non-skin side sheet 32 ​​disposed on the non-skin side of the skin side sheet 31 (see FIG. 3A ). In this case, the bonding strength between the skin side sheet 31 and the non-skin side sheet 32 ​​is preferably higher than the bonding strength between the back sheet 13 and the sheet member 14.

[0087] In the absorbent article 1 of this embodiment, a relatively large non-jointed portion is provided where the rear waistline member 30 and the absorbent main body 10 are not joined. Therefore, when in a lying position, the skin-side sheet 31 and the non-skin-side sheet 32 ​​that constitute the rear waistline member 30 tend to move relative to the absorbent main body 10 and rub against the floor or bed. However, as described above, by ensuring an appropriate joining strength between the skin-side sheet 31 and the non-skin-side sheet 32, separation of the skin-side sheet 31 and the non-skin-side sheet 32 ​​can be suppressed.

[0088] Comparison of bond strength can be performed using a tensile tester, as described above. A sample is prepared by cutting out the entire rear waistband member 30 (the portion laterally inward of the pair of side bond portions 2) from the target absorbent article 1. Note that, if the waist-side end of the non-skin-side sheet 32 ​​(or skin-side sheet 31) is folded back as shown in FIG. 3B , the folded back portion is not included in the sample. The backsheet 13 and sheet member 14 samples are prepared in the same manner as described above. The width (W0) of each sample is measured in a direction perpendicular to the measurement direction (peeling direction). Next, the sample is set in a tensile tester so that the components constituting the sample are peeled off along the measurement direction, with the specified direction (lateral or longitudinal direction) of the absorbent article 1 as the measurement direction. That is, the end of the skin-side sheet 31 or the backsheet 13 in the measurement direction is clamped by one chuck, and the end of the non-skin-side sheet 32 ​​or the sheet member 14 in the measurement direction is clamped by the other chuck. The chucks are then separated at a constant speed (e.g., 100 mm / min) until the components constituting the sample are completely peeled (separated). The load applied during this period is observed, and the maximum value (N) is obtained. The maximum measured value (N) for each sample is then converted from the measured width (W0) of each sample to a width of 25 mm (measured value / W0 x 25 mm) (N / 25 mm), and the resulting value is compared as the bonding strength.

[0089] ===Other=== The above embodiments are intended to facilitate understanding of the present invention and are not intended to limit the present invention. The present invention may be modified or improved without departing from the spirit thereof, and it goes without saying that the present invention includes equivalents thereof.

[0090] Although an absorbent article has been illustrated as an embodiment of the present invention, disposable diapers, particularly for children or adults, may require space to store feces, and since the absorbent article 1 in the above embodiment is configured without a space for storing feces in the rear portion, it is preferably applied to a shorts-type sanitary napkin. Furthermore, the pants-type absorbent article in the above embodiment is preferably applied to a shorts-type napkin because it can be suitably applied to preventing menstrual blood leakage from the viewpoint of suppressing leakage.

[0091] In the above embodiment, it has been explained that there is a rear non-bonded portion (dry edge) where no adhesive is provided between the lower end of the rear main body joint 42 (the longitudinal front end 42fe in Figure 4) and the lower end of the rear waistline member 30 (30B) (the longitudinal front end 30fe in Figure 4). However, rear left and right non-bonded portions (left and right dry edges) where the absorbent main body 10 and the rear waistline member 30 are not bonded may be provided between both ends in the left and right direction (width direction) of the rear main body joint and both ends in the left and right direction (width direction) of the absorbent main body 10 (see Figure 4).

[0092] In this case, the length in the up-down direction (front-rear direction) of the rear non-joined portion is preferably longer than the length in the left-right direction (width direction) of the rear left-right non-joined portions. In order to maximize the effect of contraction of the crotch elastic member 17, it is preferable that the rear non-joined portion has a long position facing the crotch elastic member 17. On the other hand, by making the rear left-right non-joined portions as short as possible, the left-right (width direction) ends of the absorbent body 10 are less likely to roll up or rub when held by the rear waistband member 30, thereby reducing discomfort.

[0093] REFERENCE SIGNS LIST 1 pants-type absorbent article, 2 side joint portion, 3 leakage preventing wall portion, 10 absorbent main body, 10F end (front side), 10B end (rear side), 10fe end (front side), 10be end (rear side), 11 absorbent core, 12 topsheet, 13 backsheet, 14 sheet member, 15 core wrap sheet, 16 leakage preventing wall elastic member, 17 crotch elastic member, 17fe end (front side), 17be end (rear side), 18 leg opening elastic member, 20 front waistline member, 20be end (rear side), 21 skin-side sheet, 22 non-skin-side sheet, 23 front waistline elastic member, 23dm front waistline elastic member, 30 rear waistline member, 30fe end (front side), 30A waist side portion, 30B Extension portion (buttocks cover), 31 skin side sheet, 32 non-skin side sheet, 33 rear waist elastic member, 35 rear extension portion elastic member, 41 front main body joint portion, 41fe end (front side), 41be end (rear side), 42 rear main body joint portion, 42fe end (front side), 42be end (rear side), 50 jig, BH waist opening, LH leg opening, CL1 first center line (longitudinal direction), CL2 second center line (longitudinal direction)

Claims

1. A pants-type absorbent article having vertical, horizontal, and front-to-rear directions that intersect with one another, comprising an absorbent main body, a front waistline member, and a rear waistline member, wherein the front end of the absorbent main body is joined to the front waistline member at a front main body joint and the rear end of the absorbent main body is joined to the rear waistline member at a rear main body joint, the front waistline member and the rear waistline member are joined to each other by a pair of side joints provided on both sides in the horizontal direction, the pants-type absorbent article has crotch elastic members that stretch along the longitudinal direction of the absorbent main body, and the rear waistline member has extensions that extend below the lower ends of the side joints in the vertical direction, wherein in the longitudinal direction when the pants-type absorbent article is in an unfolded and stretched state, the length from the central position of the pants-type absorbent article to the rear end of the absorbent main body is longer than the length from the central position to the front end of the absorbent main body, A pants-type absorbent article characterized in that the length from the central position to the rear end of the portion where the stretchable force of the crotch elastic member acts is longer than the length from the central position to the front end of the portion where the stretchable force of the crotch elastic member acts; the length from the front end to the rear end of the rear main body joint is longer than the length from the front end to the rear end of the front main body joint; and the length from the central position to the front end of the extension portion is shorter than the length from the central position to the rear end of the front waistband member.

2. A pants-type absorbent article as described in claim 1, characterized in that in the longitudinal direction when the article is unfolded and stretched, the length from the front end of the extension portion to the rear end of the part where the stretch force of the crotch elastic member acts is longer than the length from the front end of the part where the stretch force of the crotch elastic member acts to the front end of the extension portion.

3. A pants-type absorbent article as claimed in claim 1 or 2, characterized in that the front waistband member has a plurality of front waistband elastic members that stretch in the left-right direction, and when the article is unfolded and stretched, in the longitudinal direction, the length from the rear end of the front waistband member to the front end of the part where the stretching force of the crotch elastic member acts is longer than the length from the rearmost front waistband elastic member to the rear end of the front waistband member.

4. A pants-type absorbent article as described in claim 1 or 2, characterized in that, in the longitudinal direction when unfolded and stretched, the length from the front end of the rear waistband member to the rear end of the absorbent main body is longer than the length from the rear end of the front waistband member to the front end of the rear waistband member.

5. A pants-type absorbent article according to claim 1 or 2, characterized in that the front waistband member has a plurality of front waistband elastic members that stretch in the left-right direction, the rear waistband member has a plurality of rear waistband elastic members that stretch in the left-right direction, and when viewed in the thickness direction, at a central position in the left-right direction, the front waistband elastic members and the absorbent main body have an overlapping portion, but the rear waistband elastic members and the absorbent main body do not have an overlapping portion.

6. A pants-type absorbent article as claimed in claim 1 or 2, characterized in that in the longitudinal direction when the article is in an unfolded and stretched state, the crotch elastic members do not straddle the intermediate position between the central position and the front end of the front waistband member.

7. A pants-type absorbent article as claimed in claim 1 or 2, characterized in that in the longitudinal direction when the article is in an unfolded and stretched state, the crotch elastic members do not straddle the midpoint between the central position and the rear end of the rear waistband member.

8. A pants-type absorbent article as claimed in claim 1 or 2, characterized in that it has a rear non-joined portion where no adhesive is provided between the lower end of the rear main body joint portion and the lower end of the rear waistband member in the vertical direction, and the crotch elastic member straddles the rear non-joined portion in the longitudinal direction when in an unfolded and stretched state.

9. A pants-type absorbent article as claimed in claim 8, characterized in that it has a front non-joined portion in the vertical direction between the lower end of the front main body joint portion and the lower end of the front waistband member, where no adhesive is provided, and the length of the rear non-joined portion in the vertical direction is longer than the length of the front non-joined portion in the vertical direction.

10. A pant-type absorbent article as claimed in claim 1 or 2, wherein the absorbent main body comprises an absorbent core containing water-retentive fibers, and wherein, when a menstrual blood drop test is conducted in which artificial menstrual blood is dropped onto the central portion of the absorbent core in the longitudinal direction and the left-right direction in an unfolded and stretched state, the thickness of the central portion of the pant-type absorbent article after the menstrual blood drop test is smaller than the thickness of the central portion of the pant-type absorbent article before the menstrual blood drop test.

11. A pants-type absorbent article as claimed in claim 1 or 2, characterized in that the absorbent main body has an absorbent core containing water-retentive fibers, a back sheet arranged on the side away from the skin of the absorbent core, and a sheet member arranged on the side away from the skin of the back sheet, and the bonding strength between the rear waistband member and the absorbent main body is higher than the bonding strength between the back sheet and the sheet member.

12. A pants-type absorbent article as claimed in claim 1 or 2, characterized in that the absorbent main body has an absorbent core containing water-retentive fibers, a back sheet arranged on the non-skin side of the absorbent core, and a sheet member arranged on the non-skin side of the back sheet, the rear waistband member has a skin-side sheet and a non-skin-side sheet arranged on the non-skin side of the skin-side sheet, and the bonding strength between the skin-side sheet and the non-skin-side sheet is higher than the bonding strength between the back sheet and the sheet member.

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