Underpants type absorbent article

Abstract

To provide an underpants type absorbent article having a crotch elastic member in which a front side waistline member hardly falls down and fitting performance in the hip is enhanced.SOLUTION: There is provided an underpants type absorbent article (1) having an absorbent body (10), a front side waistline member (20), a back side waistline member (30), and a crotch elastic member (17) stretchable in a longitudinal direction. In a longitudinal direction in an expanded and stretched state, the length (L2) from a central position to a back side end of the absorbent body is greater than the length (L1) from the central position to a front side end of the absorbent body. The length (SH2) from the central position to a back side end of the crotch elastic member is greater than the length (SH1) from the central position to a front side end of the crotch elastic member. The length (HMA2) of a back side body joined part is greater than the length (HMA1) of a front side body joined part. The length (GA2) from the central position to a front side end of an extension part is smaller than the length (GA1) from the central position to the back side end of the front side waistline member.SELECTED DRAWING: Figure 4

Description

[Technical Field]

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

[0002] Conventionally, in a 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, and that makes it easy for the crotch area to be pulled up. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-151 Summary of the Invention [Problem to be solved by the invention]

[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. Also, when the user changes position from sitting to standing or moves their legs forward, the front waistband member is likely to be pulled toward the crotch area due to the stretchability 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. [Means for solving the problem]

[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, and a length from the central position of the pants-type absorbent article to the rear end of the absorbent main body in the longitudinal direction when the pants-type absorbent article is in a stretched state 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 stretch 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 stretch 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. Other features of the present invention will become apparent from the description of this specification and the accompanying drawings. [Effects of the Invention]

[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. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a front view of a pants-type absorbent article 1 as seen from the ventral side. [Figure 2]1 is a plan view of a pants-type absorbent article 1 in an unfolded and stretched state, as viewed from the skin side. [Figure 3] 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. [Figure 4] FIG. 2 is a plan view illustrating the detailed arrangement of each part that constitutes the absorbent article 1. [Figure 5] 5A and 5B are diagrams illustrating an example of a method for folding the absorbent article 1. FIG. [Figure 6] 1A and 1B are diagrams illustrating a menstrual blood drop test and a saline drop test. [Figure 7] Fig. 7A is a table showing the results of a menstrual blood drip test for the pants-type absorbent article 1 of the present embodiment (Examples A to D) and Comparative Example A. Fig. 7B is a table showing the results of a reference test for the menstrual blood drip test. DETAILED DESCRIPTION OF THE INVENTION

[0009] At least the following matters will become clear from the description of this specification and the accompanying drawings. (Aspect 1) 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 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 which stretch along the longitudinal direction of the absorbent main body, and the rear waistline member has extensions which extend below the lower ends of the side joints in the vertical direction, and 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 the first aspect, 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 areas. 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 main body joint is shorter than the longitudinal length of the rear main body joint, reducing the transmission of force from the absorbent main body to the front main 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 as described in 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 members is longer at the rear side in the front-to-rear direction. Therefore, even when the wearer changes posture from sitting to standing or vice versa, the contractile force of the crotch elastic members is more likely to act on the extensions (buttocks covers) of the rear waistband member, making it easier to keep the wearer's buttocks securely covered. Conversely, because the effective length of the crotch elastic members is shorter at the front side in the front-to-rear direction, even if force acts on the extensions (buttocks covers) when the wearer's posture changes, the force transmitted to the front side via the crotch elastic members 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) The pants-type absorbent article of aspect 1 or 2, wherein the front waistband member has a plurality of front waistband 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 waistband member to the front end of the portion where the stretch 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.

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

[0015] (Aspect 4) A pants-type absorbent article as described in 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 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.

[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 defines the circumference of the leg openings. Therefore, even if the portion of the absorbent main body that defines 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, and 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 members 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 members to slip off the wearer's body. On the other hand, at the rear side, the contractile force of the rear waist elastic members is less likely to act on the absorbent main body, making it difficult for the contractile force of the crotch elastic members to be interfered with by the rear waist elastic members, 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) A pants-type absorbent article according to any one of aspects 1 to 5, wherein, in the longitudinal direction when 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.

[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 stretchability of the crotch elastic members from being impaired by creases formed when the absorbent article is folded in four, thereby making it easier to maintain a good fit on the abdominal side of the absorbent main body.

[0021] (Aspect 7) A pants-type absorbent article according to any one of aspects 1 to 6, wherein, in the longitudinal direction when in an unfolded and stretched state, the crotch elastic members do not straddle the 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, which prevents the creases from impairing the stretchability of the crotch elastic members, making it easier to maintain a good fit on the back side of the absorbent main body.

[0023] (Aspect 8) A pants-type absorbent article as described in any one of aspects 1 to 7, wherein in the vertical direction, there is a rear non-joined portion where no adhesive is provided between the lower end of the rear main body join portion and the lower end of the rear waistband member, and when in an unfolded and stretched state, the crotch elastic member straddles the rear non-joined portion in the longitudinal direction.

[0024] According to the pants-type absorbent article of aspect 8, the front longitudinal end (bottom end in the up-down direction) 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 makes it easier to maintain an outer appearance similar to underwear.

[0025] (Aspect 9) A pants-type absorbent article as described in any of aspects 1 to 8, which has a front non-bonded portion in the vertical direction between the lower end of the front main body bonded portion and the lower end of the front waistband member, where no adhesive is provided, and the length of the rear non-bonded portion in the vertical direction is longer than the length of the front non-bonded 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 on 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 on the front side (ventral side), which makes it harder for the vertical lower end of the front waistline member to roll up significantly, which makes 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 the center of the absorbent core in the longitudinal direction and the left-right direction in an unfolded and stretched state, the thickness of the center of the pant-type absorbent article after the menstrual blood drop test is smaller than the thickness of the center 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 a state of close contact with the wearer's excretory opening and its surrounding area. This makes it possible to prevent menstrual blood from leaking through gaps that form between the absorbent article and the wearer.

[0029] (Aspect 11) A pants-type absorbent article according to any one of aspects 1 to 10, wherein the absorbent main body has an absorbent core containing a water-retentive fiber, 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.

[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] === Implementation form === A pants-type absorbent article 1 according to an embodiment of the present invention will be described below. 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 configuration of pants-type absorbent article 1> Fig. 1 is a front view of a 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 a first center line CL1 in Fig. 2, and Fig. 3B is a schematic cross-sectional view taken along a second center line CC1 in Fig. 2. In the following description, pants-type absorbent articles will also be simply referred to as "absorbent articles." The first center line CL1 is a line extending in the left-right direction at a center point that bisects the product (absorbent article 1) in the longitudinal direction, and the second center line CC1 is a line extending in the longitudinal direction at a center point that bisects the product 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-back 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-back direction corresponds to the wearer's abdomen, and the rear side corresponds to the wearer's back.

[0037] Furthermore, in the unfolded and stretched state of the pants-type absorbent article 1 shown in FIG. 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). Furthermore, 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 is configured as a separate member from the front waistline member 20 and covers the dorsal region of the wearer. In the following description, the front waistline member 20 and the rear waistline member 30 will also be collectively referred to as 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 distance from each other in the longitudinal direction, 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 in the longitudinal direction, 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 comprises an absorbent core 11 that absorbs and retains excreted liquids such as urine, a liquid-permeable topsheet 12 (e.g., nonwoven fabric or perforated film) arranged closer to the skin than the absorbent core 11, a liquid-impermeable backsheet 13 (e.g., resin film) arranged closer to the skin than the absorbent core 11, and a sheet member 14 (e.g., hydrophobic nonwoven fabric). 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-proof 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 Figs. 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-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 that constitutes 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-right direction are folded at multiple locations to form the leakage preventing walls 3 on both left-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 stand up towards the wearer's skin due to the longitudinal stretchability of the leakage preventing wall elastic members 16.

[0043] The absorbent main body 10 also has longitudinally stretchable crotch elastic members 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 members 17 in this embodiment are 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 of the core wrap sheet 15 (absorbent core 11) in the thickness direction. The position of the crotch elastic members 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 side by side in the vertical direction (longitudinal direction) 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 back 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 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 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 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 waistline member 30 may have the same planar shape as the front waistline member 20 without the extension portion 30B or the rear extension portion elastic member 35, or the front waistline member 20 may have a portion extending toward the crotch. Furthermore, thread-like front and back waistline elastic members 23, 33 may be provided at the upper ends (waist portions) of the waistline members 20, 30 to provide a secure fit, and a stretchable sheet may be provided below them instead of the thread-like waistline 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 waistline 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 crotch elastic members 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 that the absorbent main body is less likely to slip while being worn. In such a configuration, the elastic members facilitate close contact with the wearer's body, but if the wearer is a woman, for example, they may also easily fit close to the female urethral opening, and continued pressure on the absorbent main body may cause discomfort such as pain near the urethral opening.

[0050] Furthermore, unlike the present embodiment, if the member constituting the exterior body of the absorbent article 1 is, for example, 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 also acts 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 of 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 of each crotch elastic member 17 (the so-called "effective length" portion). 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 crease of the wearer's buttocks, thereby preventing body waste from running through the gaps in the buttocks.

[0052] <Regarding the Fit of Absorbent Article 1> Such an absorbent article 1 may be worn for a long time. That is, the wearer (user) of the pant-type absorbent article 1 may carry out daily life while wearing the pant-type absorbent article 1 like underwear for a long time. For example, when the wearer takes a sitting posture for a long time while wearing the absorbent article 1, the fit at the buttocks becomes important. Also, when the user shifts from a sitting posture to a standing posture while wearing the absorbent article 1, the front torso member 20 is easily pulled downward (the rear side in the front-back direction in FIG. 2) by the expansion and contraction force of the crotch elastic member 17, and there is a risk that the front torso member 20 may shift and fall from the wearer's body, deteriorating the fit.

[0053] In response to such problems, in the absorbent article 1 of the present embodiment, good fit during wearing is achieved by appropriately adjusting the crotch elastic member 17 and the arrangement of each part. Hereinafter, the specific configuration and arrangement of each part will be described.

[0054] FIG. 4 is a plan view for explaining the details of the arrangement of each part constituting the absorbent article 1. Similar to FIG. 2, FIG. 4 shows the absorbent article 1 in a developed and extended state. In the longitudinal direction of FIG. 4, the length L2 from the central position (first center line CL1) to the rear end 10be of the absorbent body 10 is longer than the length L1 from the central position (first center line CL1) to the front end 10fe of the absorbent body 10 (L1 < L2). Also, in the longitudinal direction, the length SH2 from the central position (first center line CL1) to the rear end 17be of the portion (effective length) where the expansion and contraction force of the crotch elastic member 17 acts is longer than the length SH1 from the central position (first center line CL1) to the front end 17fe of the portion (effective length) where the expansion and contraction 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 arranged 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 longitudinal direction), and further, the absorbent main body 10 widely covering the buttocks easily conforms to the shape of the buttocks groove and surrounding area due to the stretching force of the crotch elastic members 17. Therefore, gaps are less likely to occur between the buttocks groove and surrounding area and the absorbent main body 10, improving the fit and making it easier to prevent excreted liquid from leaking backward.

[0056] Furthermore, the absorbent main body 10 and the front waistline member 20 are joined to each other by a front main body joint 41, which is indicated by diagonal lines in Fig. 4. Similarly, the absorbent main body 10 and the back waistline member 30 are joined to each other by a back main body joint 42, which is indicated by diagonal lines in Fig. 4. The front main body joint 41 and the back 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 back 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.). Note that when the adhesive is applied in a predetermined application pattern such as a spiral pattern, any region where the distance from the surrounding adhesive is less than 1.5 mm is considered to be included in the front main body joint 41 or the back main body joint 42.

[0057] In the absorbent article 1, the length of the rear body joining portion 42 in the longitudinal direction (i.e., the length between the front end 42fe and the rear end 42be of the rear body joining portion 42) HMA2 is longer than the length of the front body joining portion 41 in the longitudinal direction (i.e., the length between the front end 41fe and the rear end 41be of the front body joining portion 41) HMA1 (HMA1 < HMA2). Also, in the longitudinal direction of FIG. 4, the length GA2 from the central position (the first center line CL1) to the front end (the lower end in the vertical direction) 30fe of the rear body circumferential member 30 (the extending portion 30B) is shorter than the length GA1 from the central position (the first center line CL1) to the rear end (the lower end in the vertical direction) 20be of the front body circumferential member 20 (GA1 > GA2).

[0058] In the longitudinal direction, the portion between the rear end 20be of the front body circumferential member 20 and the front end 30fe of the rear body circumferential member 30 constitutes the leg opening LH in the absorbent article 1. Among these, since the front length GA1 is longer than the rear length GA2, the space on the front side of the leg opening LH becomes wider, and when the wearer moves the leg forward during walking or the like, the movement of the leg is less likely to be interfered with by the front body circumferential member 20. Therefore, it is easy to move the legs freely even when the absorbent article 1 is worn. Also, when the wearer moves the leg forward, the force for moving the leg is transmitted to the front body circumferential member 20 via the absorbent main body 10, and there is a possibility that the front body circumferential member 20 may be pulled downward and displaced. However, since the longitudinal length HMA1 of the front body joining portion 41 joining the front body circumferential member 20 and the absorbent main body 10 is shorter than the longitudinal length HMA2 of the rear body joining portion 42, the area of the front body joining portion 41 becomes relatively small, and it becomes difficult for the force when moving the leg forward to be transmitted from the absorbent main body 10 to the front body joining portion 41. As a result, it becomes difficult to pull the front body circumferential member 20, and it can be made difficult to slip off from the body with a poor fit.

[0059] In the absorbent article 1, the length SH4 from the front end 30fe of the rear body circumferential member 30 (extension portion 30B) to the rear end 17be of the portion where the expansion and contraction force of the thigh elastic member 17 acts is longer than the length SH3 from the front end 17fe of the portion where the expansion and contraction force of the thigh elastic member 17 acts to the front end (lower end in the vertical direction) 30fe of the rear body circumferential member 30 (extension portion 30B) (SH3 < SH4). With such a configuration, since the range (effective length) in which the expansion and contraction force of the thigh elastic member 17 acts on the rear side in the front-rear direction becomes longer, even when the wearer repeatedly changes the posture from sitting to standing or vice versa, the contraction force by the thigh elastic member 17 easily acts on the extension portion 30B (hip cover) of the rear body circumferential member 30, and the state where the wearer's hip is firmly covered is easily maintained. Therefore, it is possible to suppress the hip cover from being rolled up when the wearer's posture changes. Conversely, since the range (effective length) in which the expansion and contraction force of the thigh elastic member 17 acts on the front side in the front-rear direction is short, even if a force acts on the extension portion 30B (hip cover) when the wearer's posture changes, the force transmitted to the front side via the thigh elastic member 17 is not likely to become excessively large. Therefore, when the wearer moves the body, it is easily possible to suppress the front body circumferential member 20 from being pulled to the rear and slipping off.

[0060] In the absorbent article 1, the front end 17fe on the front side (one side) in the longitudinal direction of the portion where the expansion and contraction force of the thigh elastic member 17 acts is located on the rear side (the other side) of the front body circumferential elastic member 23dm that is located on the most rear side (the other side) in the longitudinal direction among the plurality of front body circumferential elastic members 23, 23,... arranged side by side at a predetermined interval in the longitudinal direction. Note that "on the rear side (the other side) of the front body circumferential elastic member 23dm that is located on the most rear side (the other side) in the longitudinal direction" means, for example, when the front body circumferential elastic member 23dm is a belt-like elastic member or a stretchable sheet, "on the rear side (the other side) of the rear end on the rear side (the other side) of the front body circumferential elastic member 23dm that is located on the most rear side (the other side) in the longitudinal direction".

[0061] In the absorbent article 1 of the present embodiment, in the longitudinal direction, the length g2 from the rear end 20be of the front body circumferential member 20 to the front end 17fe of the portion where the elastic force of the crotch elastic member 17 acts is longer than the length g1 from the front body circumferential elastic member 23dm provided at the rearmost side to the rear end 20be of the front body circumferential member 20 (g1 < g2). For example, when the wearer changes the posture from a sitting position to a standing position as described above, the force acting on the extension portion 30B (hip cover) of the rear body circumferential member 30 is transmitted forward through 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 body circumferential member 20 is long, it becomes difficult for the force to be transmitted from the crotch elastic member 17 to the front body circumferential member 20, and it is possible to suppress the front body circumferential member 20 from being pulled and displaced.

[0062] On the other hand, in the front body circumferential member 20, since the length g1 from the front body circumferential elastic member 23dm to the rear end 20be of the front body circumferential member 20 is short, it becomes easier for the lateral contraction force by the front body circumferential elastic member 23dm to act on the rear end 20be of the front body circumferential member 20. That is, the influence of the force acting by the front body circumferential elastic member 23dm becomes larger than the force acting by the crotch elastic member 17 on the rear end 20be of the front body circumferential member 20. Therefore, it becomes easier to resist the force by which the front body circumferential member 20 is pulled backward (the lower side in the vertical direction) by the crotch elastic member 17, and it is possible to suppress the front body circumferential member 20 from being displaced.

[0063] Also, in the front-rear direction, the length h2 from the front end 30fe of the rear-side body surrounding member 30 (extension portion 30B) to the rear end 10be of the absorbent body 10 is longer than the length h1 from the rear end 20be of the front-side body surrounding member 20 to the front end 30fe of the rear-side body surrounding member 30 (h1 < h2). That is, the length (h2) of the portion where the absorbent body 10 and the rear-side body surrounding member 30 overlap is longer than the length (h1) of the portion constituting the perimeter of the leg hole LH in the absorbent body 10. For example, when walking or the like while wearing the absorbent article 1, even if the portion of length h1 in the absorbent body 10 is pulled forward by the wearer moving the leg greatly forward, the portion of length h2 (the portion longer than h1) in the absorbent body 10 fits firmly to the buttocks, making it difficult for the absorbent body 10 to be displaced. Thereby, it becomes easier to maintain good fit at the buttocks.

[0064] Also, when the absorbent article 1 is viewed in the thickness direction, at the central position in the left-right direction (second center line CC1), there is a portion where the front-side body surrounding elastic member 23 and the absorbent body 10 overlap. On the other hand, at the central position in the left-right direction (second center line CC1), the rear-side body surrounding elastic member 24 and the absorbent body 10 do not have an overlapping portion. With such a configuration, on the front side (ventral side), the front-side end portion 10F in the longitudinal direction of the absorbent body 10 is pressed against the skin side (abdomen) of the wearer by the contracting force of the front-side body surrounding elastic member 23 and is firmly held, so that it is difficult for the absorbent body 10 and the front-side body surrounding member 20 to slip off the wearer's body. On the other hand, on the rear side (dorsal side), it is difficult for the contracting force of the rear-side body surrounding elastic member 33 to act on the absorbent body 10. Therefore, the contracting force of the popliteal elastic member 17 acting on the rear side of the absorbent body 10 is hardly interfered with by the rear-side body surrounding elastic member 33, the absorbent body 10 easily fits into the groove and the peripheral portion of the buttocks, and back leakage of excreted liquid and the like is suppressed.

[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. FIGS. 5A and 5B are diagrams illustrating an example of a method for folding the absorbent article 1. FIG. 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, FIG. 5A shows the cross-sectional shape of the pant-type absorbent article 1 shown in FIG. 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 FIG. 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 ends 17fe of the crotch elastic members 17 are 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 fold line (second center line CL2f) along which the absorbent article 1 is folded in four and the crotch elastic members 17 do not intersect. 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 intermediate position (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 folding line (second center line CL2b) along which the absorbent article 1 is folded in four does not intersect with the crotch elastic members 17 on the rear side (the other side) in the front-to-rear direction, which prevents 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 in the longitudinal direction of the rear waistline member 30 (the lower end in the up-down direction of the extension portion 30B). In FIG. 4, the front end 42fe in the longitudinal direction of the rear main body joining portion 42 that joins 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 (extension 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. In addition, 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 up-down direction) in the longitudinal direction of the rear waistline member 30 (buttocks cover), 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 (lower end in the up-down direction) of the front waistline member 20. 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 front end 30fe and 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 rear end 41be and rear end 20be). Because the length of the dry edge (rear non-joined portion) is long on the rear side (back side), the lower end in the vertical direction of the rear waistline member 30 (buttocks cover) easily covers the crotch elastic member 17. On the other hand, because the length of the dry edge (front non-joined portion) is short on the front side (belly side), the lower end in the vertical direction of the front waistline member 20 is less likely 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. When the pants-type absorbent article 1 of this embodiment is subjected to a menstrual blood drop test in which artificial menstrual blood is dropped onto a central region R1 in the longitudinal and left-right directions 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 is in contact with 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, based on the applicant's research.

[0073] Unlike this embodiment, napkins whose central region R1 becomes thicker 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 position where the absorbent article 1 contacts the excretory opening and its surrounding area, allowing the stretchability of the crotch elastic members 17 to act more effectively 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] Here, the method of the "menstrual blood drop test" will be explained. (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, and fixed with the skin side facing up (see FIG. 2). (2) Next, a center position P1 (see FIG. 6) is determined, which is the intersection of a line that divides the absorbent core 11 in half at its maximum length in the longitudinal direction and a line that divides the absorbent core 11 in half at its maximum width in the left-right direction. A circular region R1 with a diameter of 8 cm and centered at the center position P1 is determined as the center R1 of the absorbent core 11 in the longitudinal and left-right directions. (3) Next, the thickness of the entire absorbent article 1 is measured at five points in the central region R1, and the average value of the thicknesses at those five points 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 center R1. 10 ml of artificial menstrual blood is dropped inside the jig 50, and after the artificial menstrual blood has permeated the absorbent main body, the jig 50 is removed and left for 1 hour. (5) After the artificial menstrual blood is 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 non-compressed 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 has the following structure. Example A uses pulp fiber (basis weight 145 g / m 2 ) does not contain SAP (super absorbent polymer), and Example B is pulp fiber (basis weight 145 g / m 2 ) with a total SAP weight of 1.3g and a basis weight of 20.4g / m 2 In Example C, pulp fibers (basis weight 145 g / m 2 ) with a total SAP weight of 1.95g and a basis weight of 30.6g / m 2 In Example D, pulp fibers (basis weight 145 g / m2 ) with a total SAP weight of 2.6g and a basis weight of 40.8g / m 2 Comparative Example A contains pulp fiber (basis weight 145 g / m 2 ) with a total SAP weight of 8.5g and a basis weight of 133.4g / m 2 The surface sheet 12 is made of a hydrophilic air-through nonwoven fabric (basis weight 25 g / m 2 ), and 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, it was found 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] FIG. 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. 2 The 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 drip 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 drip test was smaller than the thickness before the test. Therefore, it was found that the pressure applied in the thickness direction during the production 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 between the rear waistline member 30 and the absorbent main body 10 is ensured. 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 back sheet 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 in the direction perpendicular to the measurement direction (peel direction) is measured.

[0085] Next, the sample is set in a tensile tester so that the components constituting the sample (the rear waistband member 30 and the absorbent main body 10, or the back sheet 13 and the sheet member 14) are peeled along the measurement direction, with a predetermined direction (left-right or longitudinal direction) of the absorbent article 1 as the measurement direction. That is, the end of the rear waistband member 30 or the back sheet 13 in the measurement direction is clamped by one chuck, and the 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) 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 × 25 mm) (N / 25 mm), and the resulting value is compared as the bonding 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 make up 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 prevented.

[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 edge 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 a predetermined direction (lateral or longitudinal direction) of the absorbent article 1 as the measurement direction. That is, the edge of the skin-side sheet 31 or the backsheet 13 in the measurement direction is clamped by one chuck, and the edge of the non-skin-side sheet 32 or the sheet member 14 in the measurement direction is clamped by the other chuck. Then, separate the chucks at a constant speed (e.g., 100 mm / min) until the components that make up the sample are completely peeled (separated). Observe the load applied during that period and obtain the maximum value (N). Then, convert the maximum measured value (N) for each sample from the measured width (W0) of each sample to a width of 25 mm (measurement value / W0 x 25 mm) (N / 25 mm) and compare this value as the bonding strength.

[0089] ===Other=== The above-described 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 babies or adults, may require a 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 also preferably applied to a shorts-type napkin because it can effectively prevent leakage of menstrual blood from the viewpoint of suppressing leakage.

[0091] In the above-described embodiment, it has been explained that there is a rear non-bonded portion (dry edge) where no adhesive is provided between the lower end (front end 42fe in the longitudinal direction in Figure 4) of the rear main body joint 42 and the lower end (front end 30fe in the longitudinal direction in Figure 4) of the rear waistline member 30 (30B). 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, it is preferable that the length in the up-down direction (front-rear direction) of the rear non-joined portion is 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 length at the 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 main body 10 are less likely to roll up or rub when held by the rear waistband member 30, thereby reducing discomfort. [Explanation of symbols]

[0093] 1. Pants-type absorbent article, 2 side joints, 3 Leakage prevention wall section, 10. Absorbent body; 10F end (front), 10B end (rear), 10fe end (front side), 10be end (rear side), 11 absorbent core, 12 surface sheet, 13 back sheet, 14 sheet member, 15 core wrap sheet, 16 Leak-proof wall elastic member, 17 crotch elastic member, 17fe end (front side), 17be end (rear side), 18 Elastic member around the legs, 20 front waistband member, 20be end (rear side), 21 skin side sheet, 22 non-skin side sheet, 23 front waist elastic member, 23dm front waist elastic member, 30 rear waistband member, 30fe end (front side), 30A Waist side, 30B Extension (buttocks cover), 31 skin side sheet, 32 non-skin side sheet, 33 rear waist elastic member, 35 rear extension elastic member, 41 Front body joint; 41fe end (front), 41be end (rear), 42 Rear body joint, 42fe end (front), 42be end (rear), 50 jigs, BH waist opening, LH leg opening, CL1: First center line (longitudinal direction), CL2: Second center line (longitudinal direction)

Claims

1. having an up-down direction, a left-right direction, and a front-rear direction which intersect with one another, The absorbent body has a front waistband member and a rear waistband member, 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 left-right direction, The absorbent body has a crotch elastic member that stretches along the longitudinal direction of the absorbent body, the rear waistband member has an extension portion that extends downward in the vertical direction beyond a lower end of the side joint portion, In the longitudinal direction when in the deployed and extended 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 length from the central position to a rear end of a portion where the stretch force of the crotch elastic member is acting is longer than a length from the central position to a front end of a portion where the stretch force of the crotch elastic member is acting, the length from the front end to the rear end of the rear body joint is longer than the length from the front end to the rear end of the front body joint, A pants-type absorbent article, characterized in that 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. The pants-type absorbent article according to claim 1, In the longitudinal direction when in the deployed and extended state, A pants-type absorbent article characterized in that the length from the front end of the extension portion to the rear end of the part where the stretchable force of the crotch elastic member acts is longer than the length from the front end of the part where the stretchable force of the crotch elastic member acts to the front end of the extension portion.

3. The pants-type absorbent article according to claim 1 or 2, The front waistband member has a plurality of front waistband elastic members that stretch in the left-right direction, In the longitudinal direction when in the deployed and extended state, The length from the rearmost front waist elastic member to the rear end of the front waist elastic member is A pants-type absorbent article, characterized in that the length from the rear end of the front waistband member to the front end of the portion where the stretchable force of the crotch elastic member acts is longer.

4. The pants-type absorbent article according to claim 1 or 2, In the longitudinal direction when in the deployed and extended state, A pants-type absorbent article characterized in that 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. The pants-type absorbent article according to claim 1 or 2, 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, A pants-type absorbent article characterized in that, when viewed in the thickness direction, at the center position in the left-right direction, the front waist elastic member and the absorbent main body have an overlapping portion, and the rear waist elastic member and the absorbent main body do not have an overlapping portion.

6. The pants-type absorbent article according to claim 1 or 2, In the longitudinal direction when in the deployed and extended state, The pants-type absorbent article is characterized in that the crotch elastic members do not extend across an intermediate position between the central position and the front end of the front waistband member.

7. The pants-type absorbent article according to claim 1 or 2, In the longitudinal direction when in the deployed and extended state, The pants-type absorbent article, wherein the crotch elastic members do not extend across an intermediate position between the central position and the rear end of the rear waistband member.

8. The pants-type absorbent article according to claim 1 or 2, a rear non-joined portion where no adhesive is provided between a lower end of the rear main body joint portion and a lower end of the rear waistband member in the up-down direction; In the longitudinal direction when in the deployed and extended state, The pants-type absorbent article is characterized in that the crotch elastic members straddle the rear non-joined portion.

9. The pants-type absorbent article according to claim 8, a front non-joined portion where no adhesive is provided between a lower end of the front main body joint portion and a lower end of the front waistband member in the up-down direction; A pants-type absorbent article, wherein the length of the rear non-joined portion in the up-down direction is longer than the length of the front non-joined portion in the up-down direction.

10. The pants-type absorbent article according to claim 1 or 2, The absorbent body includes an absorbent core containing water-retaining fibers, In the expanded and extended state, When a menstrual blood drop test was conducted in which artificial menstrual blood was dropped onto the center portion of the absorbent core in the longitudinal direction and the left-right direction, The thickness of the central portion of the pants-type absorbent article after the menstrual blood drop test is A pants-type absorbent article, characterized in that the thickness of the central portion of the pants-type absorbent article is smaller than the thickness of the central portion of the pants-type absorbent article before the menstrual blood drop test.

11. The pants-type absorbent article according to claim 1 or 2, 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, A pants-type absorbent article, characterized in that 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. The pants-type absorbent article according to claim 1 or 2, 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 disposed on a non-skin side of the skin side sheet, A pants-type absorbent article, characterized in that 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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