TWI879973B - Underwear sanitary napkins - Google Patents

Abstract

The invention relates to an underpants type sanitary napkin (1) comprising an absorbent body (10) having an absorbent core (11) and a waist structure (20), wherein a plurality of elastic structures (50) which are stretchable in the vertical direction are arranged at predetermined intervals in the left-right direction on the non-skin side of the absorbent core (11), the elastic structure (50) comprising a first elastic structure (51) arranged on the outermost side and a second elastic structure (52) arranged adjacent to the inner side of the first elastic structure (51) on both sides in the left-right direction, and the absorbent body (10) comprises a high-density portion (40) in which the density of the absorbent core (11) is higher than that of the surrounding portion at least in the region between the first elastic structure (51) and the second elastic structure (52) in the left-right direction.

Description

Underwear sanitary napkins

The present invention relates to underwear type sanitary napkins.

In the past, there are known absorbent articles such as disposable diapers and sanitary napkins with absorbent bodies having liquid absorption properties. In such absorbent articles, elastic members with stretchability are arranged along the longitudinal direction of the absorbent body to improve the fit of the absorbent body when worn. For example, in patent document 1, a plurality of elastic members 17 for crotch are arranged along the longitudinal direction of the absorbent body 3, and the absorbent body 3 is lifted upward (towards the skin side of the wearer) by the contraction force of the elastic members 17 for crotch, thereby improving the fit in the crotch of the wearer. [Prior technical document] [Patent document]

[Patent Document 1] Japanese Patent Application Publication No. 2004-350809

[The problem the invention is trying to solve]

The absorbent article of Patent Document 1 can make the absorbent body close to the crotch of the wearer (excretory opening such as the vagina) in the area where the elastic member (elastic member 17 for crotch) is arranged, but it is difficult for the absorbent body to close to the skin of the wearer in the parts where the elastic member is not arranged on the left and right sides of the absorbent article. Therefore, there is a concern that the excretion fluid such as menstrual blood with high viscosity will be transmitted to the skin of the wearer (for example, the legs) and leak out on the side of the absorbent body (side leakage).

The present invention is made in view of the above-mentioned problems, and its purpose is to provide a panty-type sanitary napkin with high fit at the excretion opening and both sides in the left and right directions. [Technical means for solving the problem]

The main invention for achieving the above-mentioned purpose is a kind of underwear type sanitary napkin, which has mutually intersecting up-down direction, left-right direction and front-back direction, and has: an absorbent body, which is an absorbent core with liquid absorption; and a waist structure, which is overlapped with the non-skin side of the absorbent body, and the underwear type sanitary napkin is characterized in that: on the non-skin side of the absorbent body closer to the absorbent core, there is a predetermined interval in the left-right direction. A plurality of elastic members that stretch along the vertical direction, the elastic members having, on both sides of the horizontal direction, a first elastic member disposed on the outermost side and a second elastic member disposed adjacent to the inner side of the first elastic member, and the absorbent body having a high-density portion in which the density of the absorbent core is higher than that of the surrounding portion at least in the region between the first elastic member and the second elastic member in the horizontal direction. Other features of the present invention are apparent from the description of the present specification and the attached drawings. [Effects of the invention]

According to the present invention, a panty-type sanitary napkin having high fit at the excretion opening and both sides in the left and right directions can be provided.

Based on the descriptions in this manual and the attached drawings, at least the following matters should be understood.

A panty-type sanitary napkin has mutually intersecting up-down direction, left-right direction and front-back direction, and comprises: an absorbent body, which is an absorbent core having liquid absorption; and a waist structure, which is arranged to overlap with the non-skin side of the absorbent body. The panty-type sanitary napkin is characterized in that: on the non-skin side of the absorbent body closer to the absorbent core, a plurality of waist structures are arranged along the aforementioned left-right direction at predetermined intervals. An elastic member that stretches in the up-down direction, the elastic member having, on both sides in the left-right direction, a first elastic member arranged at the outermost side, and a second elastic member arranged adjacent to the inner side of the first elastic member, the absorbent body having a high-density portion in which the density of the absorbent core is higher than that of the surrounding portion at least in the area between the first elastic member and the second elastic member in the left-right direction.

According to such an underpants type sanitary napkin, the high-density portion is used as the starting point of the bend, and the left-right central portion where the second elastic member is disposed and the left-right side portions where the first elastic member is disposed are lifted toward the crotch of the wearer and closely adhere to the skin of the wearer. Therefore, the fit of the absorbent body is improved at the crotch of the wearer, at the excretion opening (vaginal opening) at the left-right central portion, and at the groin at the left-right side portions, so that excretion fluids such as menstrual blood are not easily leaked.

In addition, a panty-type sanitary napkin has mutually intersecting up-down direction, left-right direction and front-back direction, and comprises: an absorbent body, which is an absorbent core having liquid absorption; and a waist member, which is arranged to overlap with the non-skin side of the absorbent body, wherein the panty-type sanitary napkin is characterized in that: on the non-skin side of the absorbent body closer to the absorbent core, a plurality of elastic members that stretch along the up-down direction are arranged at predetermined intervals in the left-right direction, and the elastic members are arranged at predetermined intervals in the waist member. The two sides in the left-right direction respectively have: a first elastic member arranged on the outermost side, and a second elastic member arranged adjacent to the inner side of the first elastic member, and the absorbent body has a high-density portion where the density of the absorbent core is higher than the surrounding portion on the two sides in the left-right direction, and when viewed in the front-back direction, the region in the absorbent body where the first elastic member is arranged and the region where the second elastic member is arranged each form a convex shape toward the skin side of the wearer. According to such an underpants-type sanitary napkin, the central portion in the left-right direction where the second elastic member is arranged and the two side portions in the left-right direction where the first elastic member is arranged in the absorbent core are respectively lifted toward the crotch side of the wearer and deformed to convexly move upward. Therefore, the fit of the absorbent body is improved at the wearer's crotch, at the excretion opening (vaginal opening) in the middle of the left and right directions, and at the groin on both sides of the left and right directions, making it difficult for excretion fluids such as menstrual blood to leak.

In such an underwear-type sanitary napkin, it is desired that the length of the portion where the contraction force caused by the elastic member acts is longer at the rear side of the folding line when the underwear-type sanitary napkin is folded in the front-rear direction than at the front side of the folding line.

According to such an underpants-type sanitary napkin, the contraction force acting on the back side (dorsal side) behind the fold line is larger than the contraction force acting on the front side (abdomen side), so that the absorbent body can be more easily attached to the back side (buttocks side) of the wearer. This can effectively prevent menstrual blood discharged from the excretion opening from being transferred to the wearer's buttocks and moving obliquely to the back side to leak out of the underpants-type sanitary napkin.

In such an underwear-type sanitary napkin, a pair of leak-proof wall portions are provided on both sides of the aforementioned absorbent body in the aforementioned left-right direction, and the aforementioned leak-proof wall portion has a leak-proof wall elastic component that can stretch along the aforementioned up-down direction. At least at the posterior side of the aforementioned folding line, it is desirable that the length of the portion where the contraction force caused by the aforementioned elastic component acts is longer than the length of the portion where the contraction force caused by the aforementioned leak-proof wall elastic component acts.

According to such an underpants type sanitary napkin, since the contraction force of the elastic member acting on the back side (buttocks side) of the wearer is higher than the contraction force of the elastic member of the leak-proof wall, it is easy to make the absorbent core and the wearer's skin close to each other, and the leak-proof wall can be prevented from excessively standing up toward the wearer's skin side. Therefore, when the underpants type sanitary napkin is worn, the formation of a gap (space) between the wearer's buttocks and the absorbent core can be suppressed, and the excrement can be prevented from leaking.

In such an underwear-type sanitary napkin, the high-density portion has a rear convex portion extending from the outer side of the left-right direction toward the inner side, and from the lower side of the upper side of the upper-lower direction, at the upper end portion further rearward than the folding line. In the left-right direction, it is desirable that the first elastic component is located further outward than the outer end of the rear convex portion.

According to such an underpants type sanitary napkin, the three-dimensional deformation of the absorbent core is easily suppressed at the portion where the rear convex portion extending obliquely is provided. However, by pulling the two side portions of the rear convex portion by the first elastic member, the rear end region of the absorbent core is kept in a planar shape, and the absorbent core can be attached to the vicinity of the sacrum (buttocks) of the wearer.

In such an underwear-type sanitary napkin, the waist structure at least has a skin side sheet and a non-skin side sheet layered on the non-skin side of the skin side sheet, and has a sheet joint portion joining the skin side sheet and the non-skin side sheet. When viewed in the thickness direction, in an area where the absorbent body and the waist structure overlap, it is desirable that the total area of the sheet joint portions formed per unit area in an area closer to the inner side in the left-right direction than the high-density portion is smaller than the total area of the sheet joint portions formed per unit area in an area closer to the outer side in the left-right direction than the high-density portion.

According to such an underpants type sanitary napkin, the area ratio of the joint part is increased in the area more outward in the left-right direction than a pair of high-density parts, so that the stretch stress can be reduced and the width of the absorbent body in the left-right direction can be easily ensured. On the other hand, in the area more inward in the left-right direction than the high-density part, the stretch force of the waist structure can be effectively utilized by reducing the area ratio of the joint part, so that the absorbent body can be easily fitted with the groove of the wearer's buttocks. In this way, even if the wearer moves his legs, it is easy to maintain the good fit of the sanitary napkin, which can inhibit the leakage of menstrual blood through the skin.

In such an underwear type sanitary napkin, when viewed in the thickness direction, it is desirable that the total area of the aforementioned thin film joints formed per unit area in the area where the aforementioned absorbent body and the aforementioned waist structure overlap and in the area which is closer to the inner side in the aforementioned left-right direction than the aforementioned high-density part, and in the area which is further rearward than the folding line when the aforementioned underwear type sanitary napkin is folded in the aforementioned front-rear direction is smaller than the total area of the aforementioned thin film joints formed per unit area in the area which is closer to the front side than the aforementioned folding line.

According to such an underwear-type sanitary napkin, when worn, the rigidity of the front side of the waist structure is improved compared to the back side. As a result, when the wearer uses it in a sleeping position at night, even if the wearer turns over, the absorbent body can easily maintain its deformed shape on the front side (abdomen). On the other hand, by reducing the rigidity on the back side (dorsum) of the waist structure, the longitudinal (up and down) expansion and contraction of the elastic structure of the absorbent body is not easily hindered, so the absorbent body can easily follow the groove of the buttocks. In addition, since the waist structure is also easy to shrink in the left and right directions, it is easy to keep it in close contact with the buttocks even if the wearer turns over.

In such an underwear-type sanitary napkin, the absorbent body comprises: a liquid-impermeable back sheet arranged on the non-skin side relative to the absorbent core, and a side sheet laminated on the non-skin side of the back sheet, and having a back joint portion joining the back sheet and the side sheet, and a third elastic member arranged adjacent to the inner side of the second elastic member in the left-right direction, and it is desirable that the total area of the back joint portion formed per unit area in the region between the first elastic member and the second elastic member in the left-right direction is larger than the total area of the back joint portion formed per unit area in the region between the second elastic member and the third elastic member.

According to such an underpants type sanitary napkin, the bonding strength between the back sheet and the side sheet is improved in the area between the first elastic member and the second elastic member, and the rigidity of the absorbent body can be improved. Therefore, it is easy to form folding habits in the absorbent body (absorbent core) in this area, and when the absorbent core bulges and deforms, it is easy to maintain the shape. Thereby, it is easy to maintain the state of the absorbent body and the crotch of the wearer, which can improve the absorbency of menstrual blood and the like, and it is easy to suppress leakage.

In such an underwear type sanitary napkin, the waist structure includes: a front waist structure and a rear waist structure, and at both ends in the left and right directions, there are side joints for joining the front waist structure and the rear waist structure to each other, and it is desirable that the lower end of the side joint is located more forward than a folding line when the underwear type sanitary napkin is folded in the front-to-back direction, and the position of the lower end of the side joint is higher than the position of the upper end of the first elastic member.

According to such an underpants type sanitary napkin, when worn, even if the front waist structure is deformed in response to the movement of the wearer's body (abdomen), the influence of the deformation is not easily transmitted to the elastic structure of the absorbent body. Therefore, the position of the absorbent body is prevented from shifting in conjunction with the movement of the front waist structure, and the good fit of the absorbent body can be easily maintained.

In such an underwear type sanitary napkin, there is a main body joint portion joined to the aforementioned absorbent main body on the skin side of the aforementioned waistline, and in the aforementioned left and right directions, the spacing between a pair of aforementioned first elastic components is larger than 1/2 of the width of the aforementioned absorbent core and smaller than the width of the aforementioned main body joint portion.

According to such an underpants type sanitary napkin, by setting the interval of the first elastic member smaller than the width of the main body joint, the elastic force caused by the first elastic member is not easy to act on the starting point of the leakage-proof wall (the outer side end of the main body joint), and the leakage-proof wall is not easy to be blocked. In addition, by setting the interval of the first elastic member larger than 1/2 of the width of the absorbent core, the area of the central part of the absorbent core in the left-right direction is suppressed from being too narrow, and the convex deformation is not easy to occur and it is not easy to fit with the excretion opening.

In such an underpants-type sanitary napkin, it is desirable that the width of the main body joint portion at the upper end portion in the upper and lower directions is greater than the width of the main body joint portion at the lower end portion in the upper and lower directions.

According to such an underpants type sanitary napkin, the absorbent body is widely joined to the waist member at the upper end in the vertical direction, the absorbent body is not easily twisted or deformed, and the absorbent body is easily fitted to the wearer's body in a wide and flat manner. On the other hand, at the lower end in the vertical direction (under the crotch), the absorbent body is easily deformed because the portion where the absorbent body is joined to the waist member is narrow, and the side edges of the absorbent body are suppressed from being pressed toward the wearer's groin to cause discomfort.

In such an underpants-type sanitary napkin, it is desirable that the underpants-type sanitary napkin has a folding line when the underpants-type sanitary napkin is folded in the front-rear direction, and does not have a portion where the high-density portion overlaps with the folding line.

According to such an underpants-type sanitary napkin, since the high-density portion sandwiching the fold line is not continuous, when the underpants-type sanitary napkin is worn, the absorbent body can easily deform independently in each region of the abdomen and back. That is, the abdomen and back of the absorbent body can easily follow the movement of the wearer's body, and the fit can be further improved. Thereby, the leakage of menstrual blood can be easily suppressed.

In such an underpants type sanitary napkin, the high-density portion preferably has a reversed portion in which a portion of the region is reversed toward the opposite side of the vertical direction, and the reversed portion preferably has a portion intersecting with the first elastic member.

According to such an underpants type sanitary napkin, at the portion where the reverse portion and the first elastic member intersect, the contraction force of the first elastic member is less likely to act on the absorbent core due to the influence of the reverse portion. Therefore, by adjusting the arrangement of the reverse portion, the deformation of the absorbent core can be locally controlled. Thereby, the absorbent core can be easily made to fit along the body of the wearer.

In such an underwear-type sanitary napkin, the high-density portion is a dot-shaped embossed portion in which the absorbent core is compressed in the thickness direction. A plurality of the embossed portions are arranged at predetermined intervals in the up-down direction and the left-right direction. It is desired that the distance between two adjacent embossed portions in the up-down direction and the distance between two adjacent embossed portions in the left-right direction are narrower than the distance between two adjacent elastic members in the left-right direction.

According to such an underpants type sanitary napkin, by providing the embossed parts at a narrower interval than the interval of the elastic member of the absorbent body, when the wearer moves the legs or body while wearing the sanitary napkin, the force generated by the expansion and contraction of the elastic member of the absorbent body can be easily interfered by the plurality of embossed parts. As a result, the absorbent core is not easily twisted and can easily follow the minute movements of the wearer's body. Therefore, the fit during wearing can be further improved.

In such an underpants-type sanitary napkin, it is desirable that at least a portion of the embossed portion is disposed on the front and rear sides of the absorbent body in the longitudinal direction of the unfolded state, rather than the region where the contraction force caused by the elastic member acts.

According to such underwear type sanitary napkin, the embossed part is provided in the longitudinal direction of the absorbent core, in the area further outside the range of the elastic member of the absorbent body, so that the area can be kept in a flat state. Thereby, when the wearer wears it, the absorbent body can fit the wearer's lower abdomen (abdominal side) and sacrum (dorsal side) along the body shape, and the leakage of excrement can be easily suppressed.

In such an underwear type sanitary napkin, the waist structure at least comprises a skin side sheet and a non-skin side sheet laminated on the non-skin side of the skin side sheet, at least one of the skin side sheet and the non-skin side sheet is a stretchable sheet having stretchability in the left-right direction, and comprises a plurality of sheet joint portions for joining the skin side sheet and the non-skin side sheet, and it is desirable that a distance between two adjacent sheet joint portions in the left-right direction is narrower than a distance between two adjacent embossed portions in the left-right direction.

According to such an underpants type sanitary napkin, when the waist structure shrinks in the left-right direction during wearing, fine wrinkles are easily formed between the adjacent sheet joints. Moreover, such fine wrinkles are formed on the waist structure closer to the non-skin side than the absorbent body, and the absorbent core is not easily twisted, which improves the fit of the sanitary napkin.

In such an underpants type sanitary napkin, a main body joint portion joined to the absorbent main body is provided on the skin side of the waist portion, and it is desirable that the width of the main body joint portion is wider than the width of the absorbent core in the left-right direction.

According to such an underpants type sanitary napkin, the elasticity of the waist member in the left and right directions is easily transmitted to the entire left and right directions of the absorbent core. Therefore, the elasticity of the waist member can easily press the absorbent core toward the body side of the wearer, which can improve the fit.

===First Implementation Form=== An example of an absorbent article according to the first implementation form of the present invention is described with reference to an underwear type sanitary napkin 1 (hereinafter also simply referred to as sanitary napkin 1).

<Basic structure of sanitary napkin 1> Figure 1 is a schematic three-dimensional view of sanitary napkin 1 of this embodiment. Figure 2 is a top view of sanitary napkin 1 in an unfolded and stretched state as viewed from the skin side in the thickness direction. Figure 3 is a schematic cross-sectional view of Figure 2 taken along line A-A.

In addition, the "stretched state" of the sanitary napkin 1 refers to a state in which the sanitary napkin 1 as a whole (the product as a whole) is lengthened to a wrinkle-free state by stretching each elastic component of the sanitary napkin 1 (for example, the absorbent elastic component 50 and the skin side sheets 22, 23 described later). Specifically, it refers to a state in which the size of each component constituting the sanitary napkin 1 (for example, the non-skin side sheet 21 and the skin side sheets 22, 23 described later) is stretched to a size that is consistent with or close to the size of the component alone.

As shown in FIG1 , sanitary napkin 1 has mutually orthogonal "up-down direction", "left-right direction" and "front-back direction". Also, as shown in FIG3 , it has a "thickness direction" as the direction of stacking each component. In the up-down direction, when the wearer wears sanitary napkin 1, the side that will become the waist side of the wearer is the "upper side", and the side that will become the crotch side of the wearer is the "lower side". Also, in the front-back direction, when worn, the side that will become the abdominal side of the wearer is the "front side", and the side that will become the back side of the wearer is the "back side". In the thickness direction, when the wearer wears the sanitary napkin 1, the side in contact with the skin of the wearer is referred to as the "skin side", and the opposite side is referred to as the "non-skin side".

In the unfolded state shown in Fig. 2, the sanitary napkin 1 has a "longitudinal direction" and a "transverse direction" which are orthogonal to each other. The "longitudinal direction" is a direction along the up-down direction of the underwear type, and the "transverse direction" is a direction along the left-right direction of the underwear type.

The sanitary napkin 1 of this embodiment comprises: a liquid-absorbent main body 10 for absorbing liquid such as menstrual blood, and a waist structure 20, which is arranged on the non-skin side of the absorbent main body 10 and is arranged around the waist of the wearer when the sanitary napkin 1 is worn.

(Absorbent body 10) Figure 4 is a top view and a cross-sectional view of the absorbent body 10. As shown in Figure 2, the absorbent body 10 of this embodiment is roughly rectangular in the top view along the vertical direction of the sanitary napkin 1 in the longitudinal direction (i.e., the long side direction of the absorbent body 10). Moreover, as shown in Figures 3 and 4, the absorbent body 10 has: an absorbent core 11 along the longitudinal direction (vertical direction), a top sheet 12 arranged closer to the skin side than the absorbent core 11, a second sheet 13 arranged between the top sheet 12 and the absorbent core 11, a back sheet 14 arranged closer to the non-skin side than the absorbent core 11, and a side sheet 15 arranged on the non-skin side of the back sheet 14.

The absorbent core 11 is a member for absorbing and retaining liquids such as urine, and is formed of liquid absorbent fibers such as pulp fibers mixed with superabsorbent polymers (SAP). In addition, the absorbent core 11 may be covered with a liquid permeable sheet member (core wrap sheet) such as tissue paper or nonwoven fabric.

The top sheet 12 is a liquid-permeable sheet member that can contact the skin of the wearer when worn, and is formed of, for example, hydrophilic hot air nonwoven fabric, spunbond nonwoven fabric, etc. In this embodiment, as shown in the cross-sectional view of FIG. 4 , the left and right side ends of the top sheet 12 are folded from the skin side in the thickness direction toward the non-skin side at the left and right outer sides of the absorbent core 11, and are sandwiched between the absorbent core 11 and the back sheet 14.

The second sheet 13 is a sheet member having the same function and structure as the top sheet 12, i.e., the non-skin side of the laminated top sheet 12. In addition, in the absorbent body 10, the second sheet 13 may not be provided.

The back sheet 14 is a breathable and liquid-impermeable sheet member for preventing liquid such as menstrual blood absorbed by the absorbent core 11 from leaking to the outside, and is formed of, for example, a resin film.

The side sheet 15 is a sheet member laminated on the non-skin side of the back sheet 14, and is made of, for example, a soft nonwoven fabric such as a hot air nonwoven fabric. In the present embodiment, the side sheet 15 forms a pair of leak-proof wall portions 30, 30.

The leakage-proof wall portion 30 is a pair of so-called three-dimensional hems provided on both sides of the absorbent body 10 in the left-right direction. When the sanitary napkin 1 is worn, the leakage-proof wall portion 30 stands from both sides of the absorbent body 10 in the left-right direction toward the skin side of the wearer, thereby preventing excretion such as menstrual blood from leaking out of the absorbent body 10.

In this embodiment, as shown in the cross-sectional view of Fig. 4, the side sheet 15 extends toward both outer sides in the left-right direction (lateral direction) of the absorbent core 11, and is bent toward the skin side in the thickness direction at both ends in the left-right direction of the absorbent body 10, and the end 15t is arranged closer to the skin side than the absorbent core 11. The end 15t is joined to the skin side of the top sheet 12 by the front side joining portion 32f at the front side (abdomen side) end in the longitudinal direction, and is joined to the skin side of the top sheet 12 by the rear side joining portion 32b at the rear side (dorsal side) end in the longitudinal direction (refer to Fig. 4). In addition, the front side joining portion 32f and the rear side joining portion 32b are formed using a joining material such as a thermal adhesive.

Furthermore, at the end 15t, as shown in FIG4, the side sheets 15 are folded to form a state in which they are stacked in the thickness direction, and a leak-proof wall elastic member 31 is provided between the stacked side sheets 15, 15. The leak-proof wall elastic member 31 is provided in a state of being stretched in the longitudinal direction (vertical direction), and is fixed at both ends in the longitudinal direction by the front side joint 32f and the rear side joint 32b, so that stretchability in the longitudinal direction (vertical direction) is exhibited between the front side joint 32f and the rear side joint 32b. When the sanitary napkin 1 is worn, the end 15t of the leakage-proof wall portion 30 is contracted in the longitudinal direction (up and down direction) according to the elasticity of the leakage-proof wall elastic member 31, so that the free end side of the end 15t stands up toward the skin side of the wearer. The elongation ratio of the leakage-proof wall elastic member 31 provided in the leakage-proof wall portion 30 is preferably about 2.2 to 2.6 times. In addition, the elongation ratio is represented by the value of the length of the elastic member (leakage-proof wall elastic member 31) in the elongated state divided by the length of the elastic member (leakage-proof wall elastic member 31) in the natural state.

Furthermore, the absorbent body 10 is provided with a high-density portion 40 in which the density of the absorbent core 11 is higher than that of the surrounding portions. The high-density portion 40 is formed by pressing the components constituting the absorbent body 10 in the thickness direction. As shown in FIG. 4 , the high-density portion 40 of the present embodiment is formed by arranging a plurality of point-shaped pressing portions, and has a first high-density portion 41, a second high-density portion 42, and a third high-density portion 43, which are respectively formed in linear shapes. By providing such a high-density portion 40, the liquid-absorbent fibers of the absorbent core 11 are prevented from being scattered and deformed in shape. Furthermore, when the sanitary napkin 1 is worn, the high-density portion 40 becomes the starting point for bending, so that the absorbent core 11 can be easily deformed in three dimensions according to the body shape of the wearer, and can easily fit the body of the wearer.

In addition, the absorbent body 10 is provided with a plurality of absorbent elastic members 50 that are stretchable in the longitudinal direction (vertical direction). The absorbent elastic member 50 is formed of, for example, a filament rubber, and is arranged on the non-skin side (specifically, between the back sheet 14 and the side sheet 15) of the absorbent core 11 in a state of being stretched in the longitudinal direction (vertical direction). The sanitary napkin 1 of this embodiment is provided with five absorbent elastic members 50 at predetermined intervals in the left-right direction as shown in FIG. The stretch ratio of the absorbent elastic member 50 is ideally about 2.7 to 3.2 times. By setting the stretch ratio of the absorbent elastic member 50 to be higher than that of the leak-proof wall elastic member 31, the absorbent body 10 can be easily contracted from the non-skin side in the thickness direction, and the absorbent body 10 can be easily fitted to the body of the wearer when the sanitary napkin 1 is worn. That is, the absorbent body 10 can be easily fitted to the crotch of the wearer by the stretchability of the absorbent elastic member 50, so that excretions such as menstrual blood are not easily leaked.

In the following, the absorbent elastic member 50 disposed on the outermost sides on both sides in the left-right direction is referred to as the first elastic member 51, 51. Furthermore, the absorbent elastic member 50 disposed adjacent to the inner side of the first elastic member 51, 51 in the left-right direction is referred to as the second elastic member 52, 52. Furthermore, the absorbent elastic member 50 disposed on the inner side of the second elastic member 52 in the left-right direction is referred to as the third elastic member 53. In addition, the absorbent elastic member 50 only needs to have at least one pair of the first elastic members 51, 51 and one pair of the second elastic members 52, 52. That is, the third elastic member 53 may be provided in two or more pieces, or may be zero.

(Waistline member 20)

The waist structure 20 is composed of a plurality of sheet members, and in this embodiment, it has a non-skin side sheet 21 and skin side sheets 22 and 23 (see FIG. 3 ). In the following description, the part of the waist structure 20 that is closer to the front side (abdomen side) than the central position CL in the longitudinal direction is also referred to as the front waist structure 20f, and the part that is closer to the back side (dorsum side) than the central position CL is also referred to as the back waist structure 20b.

The non-skin side sheet 21 is a non-stretchable sheet member disposed on the non-skin side of the sanitary napkin 1, and is formed of, for example, spunbond non-woven fabric, SMS non-woven fabric, etc. In the present embodiment, the non-skin side sheet 21 has a shape that is narrowed inward in the left-right direction at the longitudinal center (including the center position CL) as shown in the top view of FIG. 2 .

The skin-side sheet 22 is a sheet member having stretchability and is laminated on the skin-side of the non-skin-side sheet 21 on the front side (ventral side) in the longitudinal direction. The skin-side sheet 22 is formed of, for example, a stretchable nonwoven fabric. The "stretchable nonwoven fabric" is a nonwoven fabric subjected to appropriate stretching treatment such as gear rolling, and the nonwoven fabric includes: stretchable stretchable fibers and stretchable fibers having lower contraction than the stretchable fibers. The skin side sheet 22 of this embodiment can use fibers of a polyurethane elastomer which is a type of elastic thermoplastic elastomer as the stretchable fibers, and can use fibers of polypropylene (PP) which is a type of polyolefin resin which is a type of inelastic thermoplastic resin as the elongated fibers.

The skin side sheet 22 is joined to the non-skin side sheet 21 by a plurality of scattered sheet joints 60 (see FIG. 6 ), thereby giving the front waist member 20f at least stretchability in the left-right direction. In this embodiment, the sheet joints 60 are formed by known joining means such as ultrasonic welding.

The skin side sheet 23 is a sheet member having stretchability which is layered on the skin side of the non-skin side sheet 21 at the rear side (dorsal side) in the longitudinal direction. The skin side sheet 23 has the same structure as the skin side sheet 22. That is, the skin side sheet 23 is formed of a stretchable nonwoven fabric and is joined to the non-skin side sheet 21 by a plurality of scattered sheet joints 60 (see FIG. 6 ). Thus, the rear waist member 20b is given stretchability in at least the left and right directions.

The sanitary napkin 1 is folded in half in the longitudinal direction (front-rear direction) with the central position CL (indicated by a dotted chain line in FIG. 2 ) of the absorbent body 10 in the longitudinal direction from the unfolded state shown in FIG. 2 . In the folded state, the transverse (left-right direction) ends 20fe, 20fe of the front waist member 20f and the transverse (left-right direction) ends 20be, 20be of the rear waist member 20b overlapped in the front-rear direction are joined by a well-known joining means such as sealing welding to form a side joint 20we. Thereby, the folded waist structure 20 (20f and 20b) is connected into a ring shape at the front side (abdomen side) and the back side (dorsum side), forming a waist opening 1a and a pair of leg openings 1b as shown in Figure 1, thereby forming an underwear-type sanitary napkin 1.

<About the fit of sanitary napkin 1> Next, the fit of sanitary napkin 1 when worn will be described. FIG. 5A is a diagram illustrating the fit of sanitary napkin 1 when worn as a comparative example. FIG. 5B is a diagram illustrating the fit of sanitary napkin 1 when worn according to the present embodiment.

The sanitary napkin of the comparative example shown in FIG5A is provided with an absorbent body 100. Although the structure of the absorbent body 100 of the comparative example is substantially the same as that of the absorbent body 10 of the present embodiment, the structure of the absorbent elastic member 50 is different from that of the absorbent body 10. That is, the absorbent body 100 of the comparative example is provided with three absorbent elastic members 50 in the region between a pair of high-density parts 40, 40 in the left-right direction, and an elastic member equivalent to the first elastic member 51 in the present embodiment is provided in the region further outward than the high-density parts 40, 40. In other words, in the absorbent body 100 of the comparative example, the elastic absorbent member 50 is provided in the central region in the left-right direction, but no elastic absorbent member 50 is provided in the regions on both sides in the left-right direction. In addition, in the absorbent body 100, the high-density portion 40 may not necessarily be provided.

When wearing sanitary napkins equipped with the comparative absorbent body 100, the absorbent core 11 is lifted toward the skin side of the wearer by the elastic member 50 of the absorbent body contracting in the area further inward in the left-right direction than the pair of high-density parts 40, 40 in the absorbent body 100 (the center part in the left-right direction). That is, as shown in FIG. 5A, the center part in the left-right direction of the absorbent core 11 is deformed and bulged toward the skin side of the wearer, and is closely attached to the excretion opening such as the vaginal opening. Therefore, menstrual blood and the like can be efficiently absorbed in the crotch area.

On the other hand, the absorbent body 100 of the comparative example does not have the absorbent elastic member 50 in the area further outward in the left-right direction than the pair of high-density parts 40, 40 (the left-right direction both sides), so the elastic absorbent member 50 does not act on the area, and the absorbent core 11 and the wearer's body are not easy to fit. That is, the absorbent core 11 is not easy to fit tightly in the area on both sides of the excretion port. Therefore, there is a concern that high-viscosity liquids such as menstrual blood may be transmitted to the wearer's legs and leak out laterally from the groin.

In contrast, in the sanitary napkin 1 of the present embodiment, the region (central region in the horizontal direction) of the absorbent body 10 that is closer to the inner side than the pair of high-density parts 40, 40 in the horizontal direction is as easy to fit the vaginal opening of the wearer as in the comparative example. That is, the second elastic member 52 (and the third elastic member 53) are contracted, and the central region in the horizontal direction of the absorbent core 11 is bent in a manner of lifting up toward the skin side of the wearer when viewed from the front side in the front-back direction as shown in FIG. 5B. That is, the region provided with the second elastic member 52 is deformed into a convex shape toward the skin side, and is easy to fit closely to the excretion opening such as the vaginal opening.

Furthermore, in the area (the two side parts in the left-right direction) that is further outside than the pair of high-density parts 40, 40 in the left-right direction, the two side parts in the left-right direction of the absorbent core 11 are bent and lifted toward the skin side of the wearer by the contraction of the first elastic members 51, 51. That is, the area provided with the first elastic members 51, 51 is deformed into a convex shape toward the skin side, so that it is easy to fit the vicinity of the wearer's groin. Therefore, even if the excrement such as menstrual blood is transmitted to the wearer's legs and flows in a lateral direction, the excrement is reliably absorbed by the absorbent core 11 in the groin, so that side leakage is not likely to occur.

In the absorbent body 10 of the present embodiment, the high-density portion 40 is disposed between the first elastic member 51 and the second elastic member 52 in the left-right direction. Therefore, when the absorbent elastic member 50 (51, 52) contracts, the high-density portion 40 becomes the starting point of bending, and the absorbent core 11 is easily deformed in three dimensions. That is, the area further inward in the left-right direction than the high-density portion 40 is easily deformed by the contraction of the second elastic member 52 toward the wearer's excretion port, and the area further outward in the left-right direction than the high-density portion 40 is easily deformed by the contraction of the first elastic member 51 toward the wearer's groin (see FIG. 5B ).

In this way, the sanitary napkin 1 is bent with the high-density portion 40 as the starting point, and the left-right central portion with the second elastic member 52 and the left-right side portions with the first elastic member 51 are respectively lifted toward the crotch of the wearer and closely adhered to the wearer's skin. Therefore, the fit of the wearer's crotch toward the excretion opening (vaginal opening) in the left-right central portion and the fit of the groin portion toward the left-right side portions are improved, so that excretion fluids such as menstrual blood are not easily leaked.

As shown in FIG. 4 , in the longitudinal direction of the sanitary napkin 1 (absorbent body 10), the length Lb50 of the portion where the contraction force due to the elastic member 50 of the absorbent body acts in the region further back than the central position CL is longer than the length Lf50 of the portion where the contraction force due to the elastic member 50 of the absorbent body acts in the region further forward than the central position CL (Lb50＞Lf50). That is, the magnitude of the contraction force acting further back (dorsal side) than the folding line (central position CL in the longitudinal direction) when the sanitary napkin 1 is folded forward and backward is greater than the magnitude of the contraction force acting further forward (abdominal side) than the folding line (central position CL). Therefore, when wearing sanitary napkin 1, absorbent body 10 is more easily attached to the back (buttocks) of the wearer. Thus, when the wearer sits or sleeps on his back, menstrual blood discharged from the excretion opening can be effectively prevented from passing to the buttocks of the wearer and moving obliquely to the rear to leak out of sanitary napkin 1.

Furthermore, at the longitudinal rear side closer to the central position CL, the length Lb50 of the portion where the contraction force caused by the elastic member 50 of the absorbent body acts is longer than the length Lb31 of the portion where the contraction force caused by the elastic member 31 of the leak-proof wall acts (Lb50＞Lb31). As described above, when wearing the sanitary napkin 1, the leak-proof wall portion 30 stands up toward the body side of the wearer due to the elasticity of the leak-proof wall portion 31, which easily suppresses the side leakage of the excrement. However, when the standing height of the leak-proof wall portion 30 is too high, a gap is formed between the absorbent core 11 and the wearer's skin, and there is a concern that the excrement is not easily absorbed by the absorbent core 11.

In contrast, in the present embodiment, Lb50>Lb31 is set to increase the contraction force of the absorbent elastic member 50 acting on the buttocks side. This makes it easier for the absorbent core 11 to fit closely to the wearer's skin, and can prevent the leakage-proof wall 30 from excessively rising toward the wearer's skin. Therefore, when the sanitary napkin 1 is worn, the formation of a gap (space) between the wearer's buttocks and the absorbent core 11 is prevented, and the absorbency of the excrement can be further improved. In addition, in the sanitary napkin 1 of the present embodiment, as mentioned above, because the elongation ratio of the absorbent elastic member 50 is set larger than the elongation ratio of the leakage-proof wall elastic member 31, the contraction force of the absorbent elastic member 50 becomes larger, and it is more difficult to form a gap (space).

Furthermore, the high-density portion 40 (third high-density portion 43) has a rear convex portion 43c (refer to FIG. 4 ) whose rear end portion is convex toward the rear side. When the sanitary napkin 1 is worn, the rear convex portion 43c is arranged at the upper end portion of the rear side (dorsal side) of the folding line, from the outer side to the inner side in the left-right direction, and from the lower side to the upper side in the up-down direction. In the area where the rear convex portion 43c is arranged, the three-dimensional deformation of the absorbent core 11 as described above is easily suppressed by the rear convex portion 43c extending obliquely, and the absorbent core 11 is easy to fit closely to the wearer's body while maintaining a planar shape. Since the area where the rear convex portion 43c is arranged is located along the sacrum of the wearer when the sanitary napkin 1 is worn, the absorbent core 11 can be flatly fitted to the vicinity of the sacrum of the wearer.

Furthermore, first elastic members 51, 51 are arranged outside the outer end of the rear convex portion 43c in the left-right direction. As a result, the first elastic member 51 pulls the two side portions of the rear convex portion 43c, and the rear end region of the absorbent core 11 is kept in a flat shape, so that the two side portions of the absorbent core 11 can fit the wearer's buttocks along the two sides of the sacrum. Therefore, leakage of menstrual blood and the like in the buttocks can be more easily suppressed.

Fig. 6A to Fig. 6C are diagrams for explaining the sheet joint 60 for joining the non-skin side sheet 21 and the skin side sheets 22, 23 of the waist structure 20. Fig. 6A shows the types and configurations of the sheet joint 60 of the waist structure 20 formed in the unfolded and stretched state. In the present embodiment, the non-skin side sheet 21 and the skin side sheets 22, 23 are joined to each other by two types of sheet joints 60. Specifically, in the area B shown by the oblique lines, the non-skin side sheet 21 and the skin side sheets 22, 23 are joined in a state of being stacked in the thickness direction by the plurality of first sheet joints 61 shown in Fig. 6B. Then, in the waist structure 20, the area C and the area D outside the area B are joined by a plurality of second sheet joints 62 shown in FIG. 6C in a state where the non-skin side sheet 21 and the skin side sheets 22, 23 are stacked in the thickness direction.

As described above, each sheet joint 60 (61, 62) is formed by a joining method such as ultrasonic welding. By distributing such fine sheet joints 60 throughout the waist structure 20, the waist structure 20 can maintain good flexibility and elasticity, and can also ensure sufficient strength.

Then, in the present embodiment, the total area of the first sheet joints 61 per unit area formed in the region B (the area ratio of the first sheet joints 61) is preferably larger than the total area of the second sheet joints 62 per unit area formed in the regions C and D (the area ratio of the second sheet joints 62). That is, the rigidity of the waist member 20 is preferably higher in the region B than in the regions C and D.

The region C shown in FIG6A is located on the inner side of the pair of high-density parts 40, 40 in the left-right direction when the absorbent body 10 is overlapped and installed on the waist structure 20, when viewed in the thickness direction. This region is a region where the absorbent core 11 is convexly deformed toward the skin side of the wearer as described in FIG5B. Therefore, in comparison with region B, in region C, by reducing the rigidity of the waist structure 20, the elasticity of the waist structure 20 is not easily hindered, and when the sanitary napkin 1 is worn, the absorbent body 10 and the crotch of the wearer can be easily maintained in a state of fitting. On the other hand, in region B, which is located on the outer side of the pair of high-density parts 40, 40 in the left-right direction, the rigidity is likely to become higher than that of region C. Therefore, the rigidity of the absorbent body 10 is easily maintained as a whole in the region B, and when the sanitary napkin 1 is worn, the absorbent body 10 is compressed in the left-right direction (so-called shrinkage) to prevent the fit from deteriorating. In addition, the region C has low rigidity and is easier to stretch than the region B, so it is easy to keep the absorbent body 10 and the buttocks groove in a fit state even when the body is moving, such as turning over. In this way, it is possible to prevent menstrual blood from leaking along the skin in the gap between the buttocks.

Furthermore, in the sanitary napkin 1, the region C is provided near the rear side in the longitudinal direction. In other words, the area of the region C which is further rearward than the central position CL in the longitudinal direction is larger than the area of the region C which is further forward than the central position CL (refer to FIG. 6A ). That is, the rigidity of the waist structure 20 in the rear side (dorsal side) in the longitudinal direction is lower than that in the front side (abdominal side). Therefore, when the sanitary napkin 1 is worn, the rear side (dorsal side) region of the waist structure 20 becomes easily deformed. With such a structure, when the wearer uses it in a sleeping position at night, even if the wearer turns over, etc., the front side can easily maintain the shape once deformed. In addition, by reducing the rigidity of the rear side, the elastic absorbent member 50 in the longitudinal direction (up and down direction) is not easily blocked, so the absorbent body 10 is easy to follow the groove of the wearer's buttocks. Furthermore, since the rear side (back side) of the waist member 20 is also easy to shrink in the left and right direction, it is easy to keep the fit to the buttocks even if turning over.

Fig. 7 is a diagram for explaining the back joint portion 70 for joining the back sheet 14 and the side sheet 15 in the absorbent body 10. As shown in Fig. 4, the back sheet 14 and the side sheet 15 are stacked in the thickness direction on the non-skin side of the absorbent core 11. Then, the back sheet 14 and the side sheet 15 are joined to each other via the back joint portion 70 with the absorbent elastic member 50 in a stretched state sandwiched therebetween. The back joint portion 70 is formed by arranging a plurality of joint materials such as a hot melt adhesive applied in a thin strip shape in the longitudinal direction (up and down direction) at predetermined intervals in the left and right direction as shown in Fig. 7.

As shown in FIG7 , in the left-right direction, two strip-shaped back bonding portions 70, 70 are arranged between the first elastic member 51 and the second elastic member 52, and one strip-shaped back bonding portion 70 is arranged between the second elastic member 52 and the third elastic member 53. That is, in the present embodiment, the area of the back bonding portion 70 per unit area in the region between the first elastic member 51 and the second elastic member 52 is larger than the area of the back bonding portion 70 per unit area in the region between the second elastic member 52 and the third elastic member 53. According to such a structure, at least the area between the first elastic member 51 and the second elastic member 52 is more firmly joined to the back sheet 14 and the side sheet 15 than the area between the second elastic member 52 and the third elastic member 53, so that the rigidity of the absorbent body 10 is increased.

As described above, the high-density portion 40 is provided in the area between the first elastic member 51 and the second elastic member 52 in the left-right direction, and becomes the starting point of bending when the absorbent body 10 is deformed three-dimensionally when the sanitary napkin 1 is worn. Therefore, by improving the rigidity of the absorbent body 10 in this area, the absorbent body 10 (absorbent core 11) is easy to form folding habits, and when the absorbent core 11 is deformed by convexity as shown in FIG. 5B, it is easy to maintain the shape. Thereby, it is easy to maintain the state of the absorbent body 10 and the crotch of the wearer, which can improve the absorbency of menstrual blood and the like, and it is easy to suppress leakage.

Furthermore, in the sanitary napkin 1, as shown in FIG. 2, the position of the lower end 20web of the side joint 20we (the two ends 20fe) formed in the front waist member 20f is higher than the position of the upper end 50fu in the front side of the absorbent elastic member 50 in the vertical direction. That is, in the vertical direction, the side joint 20we (the two ends 20fe) of the front waist member 20f and the absorbent elastic member 50 do not overlap. Therefore, when the wearer takes a forward bending posture or moves his feet forward while wearing the sanitary napkin 1, even if the front waist member 20f is deformed according to the movement of the wearer's body (abdomen), the influence caused by the deformation is not easily transmitted to the absorbent elastic member 50. Therefore, when the wearer moves, the position of the absorbent body 10 is prevented from shifting in conjunction with the movement of the front waist member 20f, and the good fit of the absorbent body 10 can be easily maintained. Thereby, leakage of menstrual blood and the like can be more easily suppressed.

Fig. 8 is a diagram for explaining the main body joint 80 for attaching and joining the absorbent main body 10 to the waist member 20. In the sanitary napkin 1, the non-skin side of the absorbent main body 10 (non-skin side of the side sheet 15) and the skin side of the waist member 20 are joined to each other via the main body joint 80 indicated by the shaded portion in Fig. 8. The main body joint 80 is formed by a joining material such as a thermal adhesive.

In the sanitary napkin 1 of this embodiment, the width of the main body joint 80 in the left-right direction is larger at the two ends in the longitudinal direction (the upper ends in the up-down direction) than in the central part in the longitudinal direction (the crotch part). That is, the main body joint 80 has a portion with a width W70a in the left-right direction at the front and rear ends in the longitudinal direction (the front upper end and the rear upper end in the underwear-shaped state), and has a portion with a width W70b narrower than W70a between the front and rear ends in the longitudinal direction (the lower end in the underwear-shaped state) (W70a＞W70b). According to such a structure, the absorbent body 10 is widely joined relative to the waist structure 20 at the two ends in the longitudinal direction, and the absorbent body 10 becomes less likely to be twisted or deformed. Therefore, the absorbent body 10 can easily fit in a wide plane on the abdomen and buttocks of the wearer. On the other hand, the absorbent body 10 can be easily deformed by the amount because the central part (crotch part) in the longitudinal direction is narrow relative to the part where the waist structure 20 joins the absorbent body 10. Therefore, the rigidity of the absorbent body 10 near the crotch of the wearer will not be excessively increased, making the absorbent body 10 easy to deform, and at the same time, the concern that the edges of the two sides of the absorbent body 10 will be pressed against the groin of the wearer and cause discomfort when the sanitary napkin 1 is worn can be suppressed. In this way, the absorbent body 10 as a whole can easily fit the wearer's body (abdomen, crotch, buttocks), and the leakage of menstrual blood and the like can be easily suppressed.

Furthermore, the interval W51 between the pair of first elastic members 51, 51 in the left-right direction is narrower than the widths W70a, W70b of the body joint 80 in the left-right direction (W51<W70). Since the side sheets 15 constituting the leakage-proof wall 30 are joined to the waist member 20 via the body joint 80, when the leakage-proof wall 30 stands up toward the skin, the side sheets 15 can be folded toward the skin with the two ends of the body joint 80 in the left-right direction as boundaries. That is, the two ends of the body joint 80 in the left-right direction serve as the positions of the standing starting points when the leakage-proof wall 30 stands up toward the skin. Therefore, by setting W51<W70, the contraction force of the first elastic members 51, 51 is unlikely to act on the rising starting point of the leakage preventing wall portion 30, and the deformation (rising) of the leakage preventing wall portion 30 is unlikely to be hindered.

Moreover, the interval W51 between the pair of first elastic members 51, 51 in the left-right direction becomes wider than 1/2 of the width W11 of the absorbent core 11 (W51>W11/2). Assuming that the interval W51 between the first elastic members 51, 51 is less than 1/2 of the width W11 of the absorbent core 11, the area of the central portion in the left-right direction of the absorbent core 11 becomes narrower and the area of the side portions becomes wider. At this time, the absorbent core 11 is not easy to form a convex shape as shown in FIG. 5B, and the central portion of the absorbent core 11 in the left-right direction is not easy to fit with the excretion port. Moreover, even if the first elastic member 51 is contracted, the side portions in the left-right direction of the absorbent core 11 cannot be fully lifted, and the absorbent core 11 is not easy to fit with the wearer's groin. In contrast, by setting the interval W51 between the first elastic components 51, 51 to be larger than 1/2 of the width W11 of the absorbent core 11, the absorbent core 11 can be properly convexed and deformed, making it easier to achieve good fit.

Furthermore, the high-density portion 40 of the present embodiment does not overlap with the folding line (central position CL in the longitudinal direction) when the sanitary napkin 1 is folded in the front-to-back direction. In FIG. 4 , in the longitudinal direction, the central position CL is arranged between the second high-density portion 42 and the third high-density portion 43. That is, the high-density portion 40 is arranged in a manner that does not have a portion overlapping with the central position CL (folding line) in the longitudinal direction. Since the high-density portion 40 sandwiching the folding line is not continuous in the longitudinal direction, when the sanitary napkin 1 is worn, the movement of the abdomen and the movement of the back are not easy to be linked, and the absorbent body 10 is easy to deform independently in each area. Therefore, the abdomen and the back of the absorbent body 10 are easy to follow the movement of the wearer's body, respectively, and the fit can be further improved. Thereby, leakage of menstrual blood etc. can be easily suppressed.

Furthermore, the high-density portion 40 of the sanitary napkin 1 has reversing portions 42r1 and 42r2 that are reversed toward opposite sides in the longitudinal direction. In FIG. 4 , the second high-density portion 42 has a reversing portion 42r1 that is reversed toward the rear side at the front side end portion in the longitudinal direction, and a reversing portion 42r2 that is reversed toward the front side at the rear side end portion in the longitudinal direction. Moreover, the reversing portions 42r1 and 42r2 are configured in a manner that spans the first elastic member 51 in the left-right direction. That is, the reversing portions 42r1 and 42r2 have portions that intersect with the first elastic member 51. In the portion where the reversing portions 42r1 and 42r2 intersect with the first elastic member 51, the contraction force caused by the first elastic member 51 is not easy to act on the absorbent core 11 due to the influence of the reversing portions 42r1 and 42r2. Therefore, by adjusting the arrangement of the inverted parts 42r1 and 42r2, the deformation of the absorbent core 11 can be controlled locally. For example, as shown in FIG. 4, the contraction force of the first elastic member 51 is weakened between the inverted parts 42r1 and 42r2, and the absorbent core 11 is more likely to maintain a flat shape in this area than in other areas. In this way, the absorbent core 11 can be easily fitted along the plane of the wearer's abdomen.

<Modification> In the above-mentioned embodiment, the high-density portion 40 is formed into a linear first high-density portion 41, a second high-density portion 42, and a third high-density portion 43 with a hinge shape by arranging a plurality of dot-shaped pressed portions, but the high-density portion 40 is not limited to such a linear arrangement. For example, the high-density portion 40 may be replaced with the above-mentioned first density portion 41 by providing a plurality of embossed portions 45 (see FIG. 9 described later) on the entire absorbent core 11.

The embossed portion 45 is different from the high-density portions 41 to 43. The density of the absorbent core 11 is made higher than that of the surrounding portions by pressing only the absorbent core 11 in the absorbent body 10 in the thickness direction, and is formed during the manufacturing process of the absorbent core 11. By arranging a plurality of such embossed portions 45 at predetermined intervals in the longitudinal and transverse directions, it is easy to maintain the absorbent core 11 in a thin plate shape, and it is not easy to be deformed even if the wearer moves his body when wearing the sanitary napkin 1.

In this modification, an embossed portion 45 as a high-density portion 40 is provided in the region between the first elastic member 51 and the second elastic member 52 in the left-right direction. Thus, when the absorbent elastic member 50 (51, 52) contracts, the embossed portion 45 (high-density portion 40) becomes the starting point of bending, and as shown in FIG. 5B , the absorbent core 11 is easily deformed in three dimensions. That is, in the absorbent body 10 (absorbent core 11), the left-right central portion where the second elastic member 52 is arranged and the left-right side portions where the first elastic member 51 is arranged are respectively deformed by bulging toward the crotch of the wearer, and closely adhere to the skin of the wearer. Thereby, the fit of the crotch portion of the wearer to the wearer's excretory opening (vaginal opening) and groin is improved, and leakage of excreta such as menstrual blood is less likely to occur.

===Second embodiment=== In the second embodiment, an underpants-type sanitary napkin 1 having an absorbent body 10 having a different structure from that of the first embodiment is described. The absorbent body 10 of the second embodiment has a plurality of embossed portions 45 provided on the absorbent core 11. The structure other than this is substantially the same as that of the underpants-type sanitary napkin 1 of the first embodiment. FIG. 9 is a top view and a cross-sectional view of the absorbent body 10 in the second embodiment. FIG. 10 is a diagram showing an enlarged view of area E of FIG. 9 .

The embossed portion 45 is formed by pressing the absorbent core 11 in the thickness direction as described above. That is, the portion of the absorbent body 10 (absorbent core 11) where the embossed portion 45 is formed becomes a high-density portion 40 having a higher density than the surrounding portion. In the second embodiment, as shown in FIG. 9 and FIG. 10, the dot-shaped embossed portion 45 is dispersed in the entire absorbent core 11 at predetermined intervals in the longitudinal direction (up and down direction) and the transverse direction (left and right direction) in the unfolded state. By distributing a plurality of embossed portions 45 in this way, the water-retaining fibers such as pulp fibers constituting the absorbent core 11 are not easily dispersed in a concentrated state, so the shape of the absorbent core 11 is not easily collapsed, and it is easy to maintain good water absorption.

In the absorbent core 11 of the second embodiment, the embossed portions 45 are regularly arranged. In FIG. 10 , the distance between two embossed portions 45, 45 adjacent to each other in the longitudinal direction (vertical direction) is p45v, and the distance between two embossed portions 45, 45 adjacent to each other in the transverse direction (left-right direction) is p45s. Moreover, these distances p45v and p45s are narrower than the interval d50 (d50A, d50B) in the transverse direction (left-right direction) of the absorbent elastic member 50 (51-53) (p45v, p45s＜d50).

When such sanitary napkin 1 is worn, as shown in FIG. 5B , the high-density portion 40 disposed between the first elastic member 51 and the second elastic member 52 becomes the starting point of bending, so that the absorbent core 11 is deformed and bulged toward the excretion opening and groin of the wearer to improve the fit. Then, by providing a plurality of embossed portions 45 on the entire absorbent core 11, it is easy to maintain the shape of the absorbent body 10 (absorbent core 11) after the deformation. Furthermore, by providing the embossed portions 45 at a narrower interval than the interval of the absorbent elastic member 50, when the wearer moves his legs or body while wearing the sanitary napkin 1, it is easy for the plurality of embossed portions 45 to interfere with the force generated by the expansion and contraction of the absorbent elastic member 50. Thereby, the absorbent core 11 can easily follow the fine movement of the wearer's body while suppressing the twist of the absorbent core 11. Therefore, the fit of the sanitary napkin 1 when worn can be further improved.

Furthermore, in the longitudinal direction (vertical direction) of the unfolded absorbent body 10, at least a portion of the embossed portion 45 is arranged outside the region where the contraction force of the absorbent elastic member 50 acts. That is, in the longitudinal direction of FIG. 9 , at least a portion of the embossed portion 45 is arranged in a region further forward than the end 50fu in the front side of the absorbent elastic member 50. Similarly, in the longitudinal direction, at least a portion of the embossed portion 45 is arranged in a region further rearward than the end 50bu in the rear side of the absorbent elastic member 50.

Assuming that the contraction force caused by the elastic member 50 of the absorbent body acts as a whole in the longitudinal direction of the absorbent core 11, the absorbent body 10 is likely to bulge out and deform in the lower abdomen (abdomen) and the vicinity of the sacrum (dors) of the wearer's body, which are relatively flat. At this time, a gap is likely to be generated between the wearer's body and the absorbent body 10, which will become a major factor in the leakage of excretion fluid such as menstrual blood. In contrast, in the longitudinal direction of the absorbent core 11, the range of the elastic action of the elastic member 50 of the absorbent body (the so-called effective length range) is limited, and the high-density portion 40 (embossed portion 45) is provided in the area further outward than this, so that the area can be kept in a flat state. Thus, when the sanitary napkin 1 is worn, the absorbent body 10 can easily fit the wearer's lower abdomen (abdominal side) and sacrum (dorsal side) along the body shape to prevent leakage of excrement.

Furthermore, although the waist structure 20 of the sanitary napkin 1 is provided with a plurality of sheet joints 60 (see FIG. 6 ) that join the non-skin side sheet 21 and the skin side sheets 22 and 23, it is desirable that the interval between two adjacent sheet joints 60, 60 in the left-right direction (lateral direction) is narrower than the interval p45s in the left-right direction (lateral direction) of the embossed portion 45. At this time, when the sanitary napkin 1 is worn, when the waist structure 20 shrinks in the left-right direction, fine irregularities (wrinkles on the surface of the waist structure 20) are easily formed between the adjacent sheet joints 60, 60. Therefore, by forming fine wrinkles on the waist structure 20 on the non-skin side of the absorbent body 10, the absorbent body 10 (absorbent core 11) is less likely to be twisted, and the fit of the sanitary napkin 1 can be improved.

Furthermore, in the sanitary napkin 1, it is desirable that the width W80 of the body joint portion 80 joining the absorbent body 10 and the waist structure 20 in the left-right direction is larger than the width W11 of the absorbent core 11 in the left-right direction (refer to FIG. 9 ). According to such a structure, the stretchability of the waist structure 20 in the left-right direction (lateral direction) is easily transmitted to the entire left-right direction (lateral direction) of the absorbent core 11. Therefore, the absorbent core 11 can be easily pressed toward the wearer's body side by the stretchability of the waist structure 20, which can improve the fit. In addition, the width W80 of the body joint portion 80 in the left-right direction is narrower than the width of the absorbent body 10 in the left-right direction. This can prevent the heat-sealing agent or the like forming the main body joint 80 from seeping out to the outer side in the left-right direction of the absorbent main body 10 and adhering to the body or clothes of the wearer.

Furthermore, it is desirable that at least a portion of the embossed portion 45 provided in the absorbent core 11 is arranged further outward in the left-right direction than the left and right pair of second high-density portions 42 (41, 43) which are the starting points of the bending when the absorbent core 11 is deformed to convexly as shown in FIG. 5B (see FIG. 9 ). In the absorbent core 11, the region further outward in the left-right direction than the pair of high-density portions 42 (41, 43) is a region that is easily compressed inward in the left-right direction by being clamped between the legs of the wearer when the sanitary napkin 1 is worn. Therefore, by providing the embossed portion 45 in such an area, the rigidity is improved, and when the absorbent core 11 is further compressed in the left-right direction after being deformed into a convex shape, the width of the absorbent core 11 can be prevented from narrowing, or from twisting or bending between the legs of the wearer. In this way, the fit of the sanitary napkin 1 is improved, and the side leakage of the excrement can be easily prevented.

===Others=== The above implementation forms are for facilitating the understanding of the present invention, and are not intended to limit the interpretation of the present invention. The present invention can be changed and improved without departing from its purpose, and it goes without saying that the present invention also includes its equivalents.

Although the above-mentioned embodiment is described with respect to sanitary napkin 1 as an example of underwear type absorbent article, the present invention can also be applied to light incontinence shorts for adults.

In the above-mentioned embodiment, the skin-side sheets 22 and 23 constituting the waist structure 20 are provided with stretchability in the left-right direction by using stretchable sheets such as stretchable nonwoven fabric, but other stretchable members may be provided in the waist structure 20. For example, as shown in FIG2 , waist elastic members 25 such as thread rubber may be provided at the upper ends of the front waist structure 20f and the rear waist structure 20b so as to be stretchable in the left-right direction. By providing such waist elastic members 25, the fit in the waist opening 1b is further improved, and the positional displacement of the waist structure 20 can be suppressed when the sanitary napkin 1 is worn.

Furthermore, when the waist elastic member 25 is provided in the waist member 20, at least a portion of the waist elastic member 25 may be arranged to overlap with the skin-side sheets 22, 23. In this way, the elasticity of the waist elastic member 25 in the left-right direction is linked with the elasticity of the skin-side sheets 22, 23 in the left-right direction, and the fit of the sanitary napkin 1 in the waist of the wearer can be further improved.

1: Sanitary napkin (underwear type sanitary napkin, absorbent article) 1a: Waist opening 1b: Leg opening 10: Absorbent body 11: Absorbent core 12: Top sheet 13: Second sheet 14: Back sheet 15: Side sheet 15t: End 20: Waist structure 20f: Front waist structure 20fe: End 20b: Back waist structure 20be: End 20we: Side joint 21: Non-skin side sheet 22: Skin side sheet 23: Skin side sheet 25: Waist elastic structure 30: Leakage-proof wall 31: Leakage-proof wall elastic member 32f: Front side joint 32b: Rear side joint 40: High density part 41: 1st high density part 42: 2nd high density part 42r1: Reversal part 42r2: Reversal part 43: 3rd high density part 43c: Rear side convex part 45: Embossed part 50: Absorbent elastic member 51: 1st elastic member 52: 2nd elastic member 53: 3rd elastic member 60: Sheet joint 61: 1st sheet joint 62: 2nd sheet joint 70: Back side joint 80: Body joint 100: Absorbent body (comparative example) CL: Center position (fold line) 50fu: upper end 20web: lower end

[Fig. 1] is a schematic three-dimensional view of sanitary napkin 1. [Fig. 2] is a top view of sanitary napkin 1 in an unfolded and stretched state viewed from the skin side in the thickness direction. [Fig. 3] is a schematic diagram of the A-A section of Fig. 2. [Fig. 4] is a top view and a cross-sectional view of the absorbent body 10. [Fig. 5] Fig. 5A is a diagram for explaining the fit when wearing a conventional sanitary napkin as a comparative example. Fig. 5B is a diagram for explaining the fit when wearing sanitary napkin 1 of the present embodiment. [Fig. 6] Figs. 6A to 6C are diagrams for explaining the sheet joint 60 of the non-skin side sheet 21 and the skin side sheets 22 and 23 of the waist structure 20. [Fig. 7] is a diagram for explaining the back joint 70 for joining the back sheet 14 and the side sheet 15 in the absorbent body 10. [Fig. 8] is a diagram for explaining the body joint 80 for attaching and joining the absorbent body 10 to the waist member 20. [Fig. 9] is a top view and a cross-sectional view of the absorbent body 10 in the second embodiment. [Fig. 10] is a diagram showing an enlarged view of the area E of Fig. 9.

1: sanitary napkin (underwear type sanitary napkin, absorbent article) 10: absorbent body 11: absorbent core 20: waist member 20fe: end 20we: side joint 20f: front waist member 20b: back waist member 20be: end 51: first elastic member 52: second elastic member 25: waist elastic member CL: center position (fold line) 40: high density part 50fu: upper end 20web: lower end

Claims (17)

A kind of underwear type sanitary napkin has mutually intersecting up-down direction, left-right direction and front-back direction, and has: an absorbent body, which is an absorbent core with liquid absorption; and a waist structure, which is arranged to overlap with the non-skin side of the absorbent body. The underwear type sanitary napkin is characterized by: On the non-skin side of the absorbent core of the absorbent body, a plurality of elastic structures that stretch along the up-down direction are arranged at predetermined intervals in the left-right direction, The elastic structure has: a first elastic structure arranged on the outermost side, and a second elastic structure arranged adjacent to the inner side of the first elastic structure on both sides of the left-right direction, The absorbent body has a high-density portion in which the density of the absorbent core is higher than that of the surrounding portion at least in the region between the first elastic member and the second elastic member in the left-right direction. The waist structure has at least a skin-side sheet and a non-skin-side sheet stacked on the non-skin-side of the skin-side sheet. It has a sheet joint portion for joining the skin-side sheet and the non-skin-side sheet. When viewed in the thickness direction, in the region where the absorbent body and the waist structure overlap, The total area of the thin sheet joints formed per unit area in the region closer to the inside of the high-density portion in the left-right direction is smaller than the total area of the thin sheet joints formed per unit area in the region closer to the outside of the high-density portion in the left-right direction. A kind of underwear type sanitary napkin has mutually intersecting up-down direction, left-right direction and front-back direction, and has: an absorbent body, which is an absorbent core with liquid absorption; and a waist structure, which is arranged to overlap with the non-skin side of the absorbent body. The underwear type sanitary napkin is characterized by: On the non-skin side of the absorbent core of the absorbent body, a plurality of elastic structures that stretch along the up-down direction are arranged at predetermined intervals in the left-right direction, The elastic structure has: a first elastic structure arranged on the outermost side, and a second elastic structure arranged adjacent to the inner side of the first elastic structure on both sides of the left-right direction, The absorbent body has a high-density portion on both sides in the left-right direction where the density of the absorbent core is higher than that of the surrounding portion. When viewed in the front-back direction, the region in the absorbent body where the first elastic member is disposed and the region where the second elastic member is disposed each form a convex shape toward the skin side of the wearer. The waist structure has at least a skin-side sheet and a non-skin-side sheet laminated on the non-skin side of the skin-side sheet. It has a sheet joint portion for joining the skin-side sheet and the non-skin-side sheet. When viewed in the thickness direction, in the region where the absorbent body and the waist structure overlap, The total area of the thin sheet joints formed per unit area in the region closer to the inside of the high-density portion in the left-right direction is smaller than the total area of the thin sheet joints formed per unit area in the region closer to the outside of the high-density portion in the left-right direction. The underpants sanitary napkin of claim 1 or 2, wherein, there is a folding line when the underpants sanitary napkin is folded in the front-rear direction, the length of the portion where the contraction force caused by the elastic member acts further back than the folding line is longer than the length of the portion where the contraction force caused by the elastic member acts further forward than the folding line. As in claim 3, the underwear type sanitary napkin, wherein, a pair of leak-proof wall portions are provided on both sides of the absorbent body in the left-right direction, the leak-proof wall portion has a leak-proof wall elastic member that stretches along the up-down direction, at least further back than the fold line, the length of the portion where the contraction force caused by the elastic member acts is longer than the length of the portion where the contraction force caused by the elastic member of the leak-proof wall acts. As in claim 3, the underwear-type sanitary napkin, wherein, the high-density portion has a rear convex portion extending from the outer side in the left-right direction toward the inner side and from the lower side in the upper-lower direction toward the upper side at the upper end portion of the fold line, in the left-right direction, the first elastic member is located further outward than the outer end of the rear convex portion. The underwear type sanitary napkin of claim 1 or 2, wherein, when viewed in the thickness direction, in the region where the absorbent body and the waist structure overlap and in the region closer to the inside in the left-right direction than the high-density portion, the total area of the thin sheet joints formed per unit area in the region closer to the rear than the folding line when the underwear type sanitary napkin is folded in the front-back direction is smaller than the total area of the thin sheet joints formed per unit area in the region closer to the front than the folding line. An underpants-type sanitary napkin as claimed in claim 1 or 2, wherein: the absorbent body comprises: a liquid-impermeable back sheet arranged on the non-skin side relative to the absorbent core, and a side sheet laminated on the non-skin side of the back sheet, and a back joint portion joining the back sheet and the side sheet, a third elastic member arranged adjacent to the inner side of the second elastic member in the left-right direction, and a total area of the back joint portion formed per unit area in the region between the first elastic member and the second elastic member in the left-right direction is larger than the total area of the back joint portion formed per unit area in the region between the second elastic member and the third elastic member. The underpants sanitary napkin of claim 1 or 2, wherein, the waist structure comprises: a front waist structure and a rear waist structure, at both ends in the left-right direction, there are side joints for joining the front waist structure and the rear waist structure to each other, more forward than the folding line when the underpants sanitary napkin is folded in the front-back direction, the lower end of the side joint is higher than the upper end of the first elastic structure. A kind of underwear type sanitary napkin has mutually intersecting up-down direction, left-right direction and front-back direction, and has: an absorbent body, which is an absorbent core with liquid absorption; and a waist structure, which is arranged to overlap with the non-skin side of the absorbent body. The underwear type sanitary napkin is characterized by: On the non-skin side of the absorbent core of the absorbent body, a plurality of elastic structures that stretch along the up-down direction are arranged at predetermined intervals in the left-right direction, The elastic structure has: a first elastic structure arranged on the outermost side, and a second elastic structure arranged adjacent to the inner side of the first elastic structure on both sides of the left-right direction, The absorbent body has a high-density portion where the density of the absorbent core is higher than that of the surrounding portion at least in the region between the first elastic member and the second elastic member in the left-right direction, and has a body joint portion for joining the absorbent body on the skin side of the waist member, and the interval between a pair of the first elastic members in the left-right direction is larger than 1/2 of the width of the absorbent core and smaller than the width of the body joint portion, and the width of the body joint portion in the upper end portion in the upper-lower direction is larger than the width of the body joint portion in the lower end portion in the upper-lower direction. A kind of underwear type sanitary napkin has mutually intersecting up-down direction, left-right direction and front-back direction, and has: an absorbent body, which is an absorbent core with liquid absorption; and a waist structure, which is arranged to overlap with the non-skin side of the absorbent body. The underwear type sanitary napkin is characterized by: On the non-skin side of the absorbent core of the absorbent body, a plurality of elastic structures that stretch along the up-down direction are arranged at predetermined intervals in the left-right direction, The elastic structure has: a first elastic structure arranged on the outermost side, and a second elastic structure arranged adjacent to the inner side of the first elastic structure on both sides of the left-right direction, The absorbent body has a high-density portion on both sides of the left-right direction where the density of the absorbent core is higher than that of the surrounding portion. When viewed in the front-back direction, the region in the absorbent body where the first elastic member is disposed and the region where the second elastic member is disposed each form a convex shape toward the skin side of the wearer. On the skin side of the waist member, there is a body joint portion for joining the absorbent body. In the left-right direction, the interval between a pair of the first elastic members is larger than 1/2 of the width of the absorbent core and smaller than the width of the body joint portion. The width of the body joint portion in the upper end portion in the upper-lower direction is larger than the width of the body joint portion in the lower end portion in the upper-lower direction. An underpants sanitary napkin as claimed in any one of claim items 1, 2, 9, and 10, wherein, it has a folding line when the underpants sanitary napkin is folded in the front-rear direction, and does not have a portion where the high-density portion overlaps with the folding line. A kind of underwear type sanitary napkin has mutually intersecting up-down direction, left-right direction and front-back direction, and has: an absorbent body, which is an absorbent core with liquid absorption; and a waist structure, which is arranged to overlap with the non-skin side of the absorbent body. The underwear type sanitary napkin is characterized by: On the non-skin side of the absorbent core of the absorbent body, a plurality of elastic structures that stretch along the up-down direction are arranged at predetermined intervals in the left-right direction, The elastic structure has: a first elastic structure arranged on the outermost side, and a second elastic structure arranged adjacent to the inner side of the first elastic structure on both sides of the left-right direction, The absorbent body has a high-density portion in which the density of the absorbent core is higher than that of the surrounding portion at least in the region between the first elastic member and the second elastic member in the left-right direction. The high-density portion has a reversal portion in which a portion of the region is reversed toward the opposite side of the up-down direction. The reversal portion has a portion intersecting with the first elastic member. A kind of underwear type sanitary napkin has mutually intersecting up-down direction, left-right direction and front-back direction, and has: an absorbent body, which is an absorbent core with liquid absorption; and a waist structure, which is arranged to overlap with the non-skin side of the absorbent body. The underwear type sanitary napkin is characterized by: On the non-skin side of the absorbent core of the absorbent body, a plurality of elastic structures that stretch along the up-down direction are arranged at predetermined intervals in the left-right direction, The elastic structure has: a first elastic structure arranged on the outermost side, and a second elastic structure arranged adjacent to the inner side of the first elastic structure on both sides of the left-right direction, The absorbent body has a high-density portion on both sides of the left-right direction where the density of the absorbent core is higher than that of the surrounding portion. When viewed in the front-back direction, the region in which the first elastic member is disposed and the region in which the second elastic member is disposed in the absorbent body each form a convex shape toward the skin side of the wearer. The high-density portion has a reversing portion that reverses a portion of the region toward the opposite side of the up-down direction. The reversing portion has a portion that intersects with the first elastic member. A kind of underwear type sanitary napkin has mutually intersecting up-down direction, left-right direction and front-back direction, and has: an absorbent body, which is an absorbent core with liquid absorption; and a waist structure, which is arranged to overlap with the non-skin side of the absorbent body. The underwear type sanitary napkin is characterized by: On the non-skin side of the absorbent core of the absorbent body, a plurality of elastic structures that stretch along the up-down direction are arranged at predetermined intervals in the left-right direction, The elastic structure has: a first elastic structure arranged on the outermost side, and a second elastic structure arranged adjacent to the inner side of the first elastic structure on both sides of the left-right direction, The absorbent body has a high-density portion in which the density of the absorbent core is higher than that of the surrounding portion at least in the region between the first elastic member and the second elastic member in the left-right direction. The high-density portion is a dot-shaped embossed portion that compresses the absorbent core in the thickness direction. A plurality of embossed portions are provided at predetermined intervals in the vertical direction and the left-right direction. The distance between the two adjacent embossed portions in the vertical direction and the distance between the two adjacent embossed portions in the left-right direction are both narrower than the distance between the two adjacent elastic members in the left-right direction. In the longitudinal direction of the absorbent body in the unfolded state, at least a portion of the embossed portion is arranged at the front and rear sides of the region where the contraction force caused by the elastic member acts. A kind of underwear type sanitary napkin has mutually intersecting up-down direction, left-right direction and front-back direction, and has: an absorbent body, which is an absorbent core with liquid absorption; and a waist structure, which is arranged to overlap with the non-skin side of the absorbent body. The underwear type sanitary napkin is characterized by: On the non-skin side of the absorbent core of the absorbent body, a plurality of elastic structures that stretch along the up-down direction are arranged at predetermined intervals in the left-right direction, The elastic structure has: a first elastic structure arranged on the outermost side, and a second elastic structure arranged adjacent to the inner side of the first elastic structure on both sides of the left-right direction, The absorbent body has a high-density portion on both sides in the left-right direction where the density of the absorbent core is higher than that of the surrounding portion. When viewed in the front-back direction, the region in the absorbent body where the first elastic member is disposed and the region where the second elastic member is disposed each form a convex shape toward the skin side of the wearer. The high-density portion is a dot-shaped embossed portion in which the absorbent core is compressed in the thickness direction. The embossed portion is provided in plurality at predetermined intervals in the up-down direction and the left-right direction. The distance between two adjacent embossed portions in the up-down direction and the distance between two adjacent embossed portions in the left-right direction are both narrower than the distance between two adjacent elastic members in the left-right direction. In the longitudinal direction of the absorbent body in the unfolded state, at least a portion of the embossed portion is arranged further forward and rearward than the region where the contraction force caused by the elastic member acts. An underpants sanitary napkin as claimed in any one of claims 1, 2, 9, 10, 12, 13, 14, and 15, wherein: the waist structure comprises at least a skin-side sheet and a non-skin-side sheet laminated on the non-skin-side of the skin-side sheet, at least one of the skin-side sheet and the non-skin-side sheet is a stretchable sheet having stretchability in the left-right direction, there are a plurality of sheet joints for joining the skin-side sheet and the non-skin-side sheet, the interval between two adjacent sheet joints in the left-right direction is narrower than the interval between two adjacent embossed portions in the left-right direction. An underpants-type sanitary napkin as claimed in any one of claims 1, 2, 9, 10, 12, 13, 14, and 15, wherein, the waist structure has a body joint portion joined to the absorbent body on the skin side, and the width of the body joint portion in the left-right direction is wider than the width of the absorbent core.

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