Absorbent article

Abstract

An absorbent article (1) comprises an absorbent body (10), a front waist section (20), and a back waist section (30). At least one of the front waist section (20) and the back waist section (30) has, on the side thereof closest to the skin, a sheet section (25) comprising a cotton layer (25a). At least a portion of the sheet section is positioned above the absorbent body (10) in the vertical direction. The absorbent article (1) further comprises: a joining section (50x) constituted of an upper-side arrangement region (25UP) belonging to the sheet section (25) and an adjacent sheet member adjacent to the upper-side arrangement region (25UP) on the non-skin side in the thickness direction, the upper-side arrangement region (25UP) and the adjacent sheet member being joined to each other by welding or adhesion; and a non-joining section (50z) in which the upper-side arrangement region (25UP) and the adjacent sheet member are not joined to each other by welding or adhesion.

Description

absorbent articles

[0001] The present invention relates to an absorbent article.

[0002] BACKGROUND ART Absorbent articles such as disposable diapers have been known which include a sheet for absorbing moisture such as sweat on the skin-contacting side of the waist portion. For example, Patent Document 1 discloses a disposable diaper in which a hydrophilic sheet having an inner hydrophilic sheet and an outer hydrophilic sheet is arranged on the waist flap (waist portion).

[0003] Japanese Patent Application Laid-Open No. 2010-246901

[0004] The disposable diaper described in Patent Document 1 transfers the wearer's sweat to an inner hydrophilic sheet and then quickly transfers it to an outer hydrophilic sheet, thereby promoting the diffusion of sweat and preventing skin problems such as eczema and heat rash. However, the waist area of ​​absorbent articles such as disposable diapers is a part that naturally experiences a lot of movement, making it prone to friction between the product and the wearer's skin, which could irritate the skin. Therefore, it is desirable to place cotton on a portion of the skin-contacting surface of the waist area of ​​the absorbent article that comes into contact with the skin, not only to absorb sweat but also to reduce skin irritation. However, placing cotton on the skin-contacting surface of the waist area can cause pilling and other problems due to friction, so a design is needed that can obtain the benefits of providing cotton on the skin-contacting surface while suppressing such pilling.

[0005] The present invention has been made in consideration of the above-mentioned problems, and its object is to provide an absorbent article that, when a cotton layer is placed on the side of the waist that faces the skin closest to the body, suppresses pilling while allowing the wearer to feel the comfortable feel of cotton against the skin.

[0006] The main invention for achieving the above object is an absorbent article having intersecting vertical and thickness directions, the absorbent article comprising an absorbent main body, a ventral waistband portion positioned on the ventral side of a wearer, and a dorsal waistband portion positioned on the dorsal side of the wearer, wherein a sheet portion including a cotton layer having a cotton fiber base and at least a portion of which is positioned above the absorbent main body in the vertical direction is provided on the side closest to the skin of at least one of the ventral waistband portion and the dorsal waistband portion, and wherein, when a region of the sheet portion positioned above the absorbent main body in the vertical direction is defined as an upper-positioning region, the absorbent article has a joint portion where the upper-positioning region and an adjacent sheet member adjacent to the upper-positioning region from the non-skin-facing side in the thickness direction are joined by welding or adhesive, and a non-joining portion where the upper-positioning region and the adjacent sheet member are not joined by welding or adhesive. Other features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[0007] According to the present invention, it is possible to provide an absorbent article that, when a cotton layer is arranged on the side of the waist that faces the skin closest to the body, can suppress pilling and provide the comfortable feel of cotton against the skin.

[0008] 1 is a schematic perspective view of the diaper 1 as seen from the ventral side. FIG. 2 is a schematic plan view of the diaper 1 in an unfolded and stretched state as seen from the wearer's skin side. FIG. 3 is a schematic cross-sectional view taken along line A-A in FIG. 2. FIG. 4 is a schematic cross-sectional view of the sheet portion 25. FIG. 5 is a plan view showing an adhesive bonding the sheet portion 25 to an adjacent sheet member adjacent to the sheet portion 25 from the non-skin-facing side. FIG. 6 is a diagram illustrating the vertical length of the bonding portion 50x in the upper arrangement region 25UP. FIG. 7 is an enlarged photograph of the sheet portion 25 as seen from the skin side. FIG. 8 is a diagram illustrating the low basis weight portion 25aL. FIG. 9 is an enlarged view of the ventral waist portion 20 of the diaper 1 shown in FIG. 2. FIG. 10A and FIG. 10B are diagrams illustrating another modified example of the sheet portion 25. FIG. 10C is a diagram illustrating a modified arrangement of the sheet portion 25. FIG. 10D is a diagram illustrating yet another modified example of the sheet portion 25.

[0009] The present specification and the accompanying drawings make at least the following clear: Aspect 1 is an absorbent article having a vertical direction and a thickness direction that intersect each other, the absorbent article having an absorbent main body, a ventral waistline portion located on the ventral side of a wearer, and a back waistline portion located on the back side of the wearer, wherein a sheet portion including a cotton layer having a cotton fiber base and at least a portion of which is located above the absorbent main body in the vertical direction is provided on the side closest to the skin of at least one of the ventral waistline portion and the back waistline portion, the sheet portion including a cotton layer having a cotton fiber base and at least a portion of which is located above the absorbent main body in the vertical direction, when a region of the sheet portion that is located above the absorbent main body in the vertical direction is defined as an upper arrangement region, the absorbent article has a joint portion where the upper arrangement region and an adjacent sheet member adjacent to the upper arrangement region from the non-skin-facing side in the thickness direction are joined by welding or adhesive, and a non-joined portion where the upper arrangement region and the adjacent sheet member are not joined by welding or adhesive.

[0010] According to Aspect 1, the non-jointed portions of the sheet portion that come into contact with the skin are easily deformed, and when movement occurs in the waistband portion, the non-jointed portions follow such movement, reducing friction with the skin and thereby suppressing pilling of the cotton fibers. At the same time, the presence of the jointed portions also prevents the cotton fibers from falling off. Furthermore, by continuously contacting the skin with the cotton layer while reducing friction with the skin, the user can experience the softness of the cotton while suppressing irritation to the skin.

[0011] Aspect 2 is the absorbent article according to aspect 1, wherein in the unfolded state and the stretched state, the total area of ​​the non-jointed portions is larger than the total area of ​​the joined portions when the upper arrangement region is viewed in a plan view.

[0012] According to aspect 2, the total area of ​​the non-jointed portions is larger, so that when movement occurs around the waist, more parts can follow the movement, thereby reducing friction with the skin and suppressing pilling of the cotton layer.

[0013] Aspect 3 is the absorbent article according to aspect 1 or 2, wherein the total length of the joined portions is greater than the total length of the non-joined portions in the up-down direction.

[0014] According to aspect 3, providing a large number of non-bonded portions can suppress pilling of the cotton layer, but on the other hand, there is a risk that the bond between the sheet portion and the adjacent sheet member may peel off. By making the total length of the bonded portions in the vertical direction longer than the total length of the non-bonded portions, it is possible to make the bond less likely to peel off.

[0015] Aspect 4 is an absorbent article described in any one of Aspects 1 to 3, wherein the sheet portion has a non-skin side layer located on the non-skin side of the cotton layer in the thickness direction, and the average fiber length of the non-skin side fibers that are the base fibers of the non-skin side layer is longer than the average fiber length of the cotton fibers.

[0016] According to Aspect 4, the cotton fibers are bonded to fibers with a long average fiber length, which improves the durability of the cotton layer and makes the cotton fibers less likely to fall off. Also, when bonding the sheet portion to an adjacent sheet member, the long average fiber length of the non-skin-side fibers located on the non-skin-side of the sheet portion makes the bond less likely to come apart, improving the sheet member's ability to conform to the adjacent sheet member.

[0017] Aspect 5 is an absorbent article according to any one of Aspects 1 to 4, wherein the sheet portion has a non-skin side layer located on the non-skin side of the cotton layer in the thickness direction, and the thermal conductivity of the cotton fiber is lower than the thermal conductivity of the non-skin side fiber, which is the base fiber of the non-skin side layer.

[0018] According to Aspect 5, the cotton fiber in contact with the wearer's skin has low thermal conductivity, so even if the cotton layer becomes wet with sweat or the like while wearing the garment, it is unlikely to immediately cool down. Furthermore, the non-skinside fiber in the non-skinside layer has a higher thermal conductivity than the cotton fiber, which facilitates heat exchange. Therefore, heat transferred to the non-skinside layer is released further away from the non-skinside layer, preventing heat from building up in the sheet portion.

[0019] Aspect 6 is an absorbent article according to any one of Aspects 1 to 5, wherein the sheet portion has a non-skin side layer located on the non-skin side of the cotton layer in the thickness direction, and the hydrophilicity of the cotton fiber that is the base fiber of the cotton layer is higher than the hydrophilicity of the non-skin side fiber that is the base fiber of the non-skin side layer.

[0020] According to aspect 6, by arranging a cotton layer having highly hydrophilic cotton fibers as the base fiber on the surface that comes into contact with the wearer's skin, water absorption is improved, and because the hydrophilicity of the non-skin-side fiber that is the base fiber of the non-skin-side layer is lower than that of the cotton fiber, when moisture such as sweat absorbed by the cotton fiber moves to the non-skin side, the non-skin-side layer does not retain excessive moisture and promotes evaporation, making it less likely to become stuffy.

[0021] Aspect 7 is the absorbent article according to any one of Aspects 1 to 6, wherein the proportion of the cotton fibers in the sheet portion is less than 50% by mass.

[0022] According to aspect 7, the inclusion of cotton fibers allows the user to feel a pleasant texture, and at the same time, the low mass ratio of cotton fibers suppresses pilling of the cotton layer.

[0023] Aspect 8 is an absorbent article according to any one of Aspects 1 to 7, wherein the cotton layer has a predetermined basis weight portion provided with the cotton fibers of a predetermined basis weight and a low basis weight portion in which the cotton fibers have a basis weight lower than that of the predetermined basis weight portion.

[0024] According to Aspect 8, by providing a low basis weight portion with a low basis weight, it is possible to suppress shedding of cotton fibers with a short average fiber length. Therefore, it is possible to achieve both a comfortable feel due to the cotton fibers provided in the predetermined basis weight portion and suppress shedding of cotton fibers.

[0025] Aspect 9 is the absorbent article according to Aspect 8, having a left-right direction perpendicular to the up-down direction and the thickness direction, and at least one of the ventral waistline portion and the back waistline portion comprises an inner layer sheet, an outer layer sheet arranged closer to the skin than the inner layer sheet, and multiple waistline elastic members stretchable in the left-right direction and arranged at intervals in the up-down direction between the inner layer sheet and the outer layer sheet, and in the cotton layer, multiple low basis weight portions are provided at intervals in the up-down direction, and the minimum value of the center-to-center distance in the up-down direction between adjacent low basis weight portions in the up-down direction is smaller than the minimum value of the center-to-center distance in the up-down direction between adjacent waistline elastic members in the up-down direction.

[0026] According to aspect 9, by providing multiple low basis weight sections with small spacing between them in the vertical direction, it is possible to further suppress the shedding of cotton fibers with short average fiber lengths, and to further suppress irritation to the skin caused by shedding of fibers.

[0027] Aspect 10 is the absorbent article according to any one of Aspects 1 to 9, wherein the sheet portion is a sheet member disposed closer to the body than the inner layer sheet.

[0028] According to Aspect 10, since the waist elastic member is disposed between the inner sheet and the outer sheet, there is an area of ​​interference between the waist elastic member and the sheet portion (sheet member) including the cotton layer, which prevents the cotton layer on the skin side from stretching excessively, reduces friction between the cotton layer and the skin, and suppresses shedding and fluffing of cotton fibers.

[0029] In an eleventh aspect of the absorbent article according to any one of the first to tenth aspects, the sheet portion is positioned below and spaced apart from the upper end of at least one of the ventral waistband and the back waistband in the up-down direction, and when a region in the up-down direction from the upper end of the ventral waistband or the back waistband where the sheet portion is provided to the upper end of the sheet portion is defined as a non-positioning region, and a region in the up-down direction from the upper end to the lower end of the sheet portion of the ventral waistband or the back waistband where the sheet portion is provided is defined as a positioning region, a portion of the non-positioning region closest to the skin contains hydrophobic fibers, and the magnitude of the force required to stretch the non-positioning region of a unit width in the up-down direction by a unit length in the left-right direction is greater than the magnitude of the force required to stretch the positioning region of a unit width in the up-down direction by a unit length in the left-right direction.

[0030] According to aspect 11, the skin-facing side of the non-placement area, which has a strong grip, contains hydrophobic fibers, thereby suppressing stickiness and reducing discomfort to the wearer's body, and the placement area of ​​the sheet portion, which is prone to pilling when the grip is strong, has a weaker gripping force, thereby reducing friction with the skin and suppressing pilling of the cotton fibers.

[0031] Aspect 12 is the absorbent article according to any one of Aspects 1 to 11, wherein the length of the sheet portion in the vertical direction is half or less of the length of the ventral waistband portion or the dorsal waistband portion.

[0032] According to Aspect 12, the cotton layer of the sheet portion reduces friction on the skin, and by reducing the length of the cotton layer, pilling is suppressed. Therefore, the cotton layer provides a pleasant feel to the skin, reduces irritation to the skin, and prevents pilling.

[0033] Aspect 13 is an absorbent article according to any one of Aspects 1 to 12, in which at least one of the ventral waistband portion and the dorsal waistband portion has an inner layer sheet, an outer layer sheet positioned closer to the skin than the inner layer sheet, and a folded-back portion in which the upper end of the outer layer sheet in the vertical direction is folded back toward the skin, and the length of the sheet portion in the vertical direction is longer than the length of the folded-back portion.

[0034] According to aspect 13, by providing the sheet portion longer than the vertical length of the folded-back portion, it becomes easier to feel the pleasant feel of the cotton layer against the skin.

[0035] Aspect 14 is an absorbent article according to any one of Aspects 1 to 12, in which at least one of the ventral waistband portion and the dorsal waistband portion has an inner layer sheet, an outer layer sheet positioned closer to the skin than the inner layer sheet, and a folded-back portion in which the upper end of the outer layer sheet in the vertical direction is folded back toward the skin, and the length of the sheet portion in the vertical direction is shorter than the length of the folded-back portion.

[0036] According to aspect 14, by not disposing the sheet portion excessively long in the vertical direction, the possibility of pilling of the cotton layer is further reduced.

[0037] Aspect 15 is an absorbent article described in any one of aspects 1 to 14, wherein the sheet portion straddles the upper end of the absorbent main body in the vertical direction in at least one of the ventral waist portion and the dorsal waist portion.

[0038] According to aspect 15, the upper end of the absorbent body is a portion with relatively large irregularities, and by covering this upper end, friction on the skin can be suppressed, and irritation to the skin can be reduced.

[0039] Aspect 16 is the absorbent article according to any one of Aspects 1 to 15, in which no hook-and-loop fastener is provided between the sheet portion and the adjacent sheet member in the thickness direction. According to Aspect 16, providing a hook-and-loop fastener increases rigidity and makes it difficult to follow the movement of the adjacent sheet member, but not providing such a hook-and-loop fastener improves followability.

[0040] ===Embodiment=== Hereinafter, a pants-type disposable diaper 1 for adults (hereinafter simply referred to as "diaper 1") will be described as an example of an absorbent article according to this embodiment. However, the absorbent article according to this embodiment is not limited to the above and can also be applied, for example, to pants-type disposable diapers for infants, shorts-type napkins, tape-type disposable diapers, etc. <Basic Structure of Pants-Type Disposable Diaper 1> Fig. 1 is a schematic perspective view of the diaper 1 as seen from the ventral side. Fig. 2 is a schematic plan view of the diaper 1 in an unfolded and stretched state as seen from the skin side of the wearer. Fig. 3 is a schematic cross-sectional view taken along line A-A in Fig. 2.

[0041] The "unfolded state" of the diaper 1 refers to a state in which the diaper 1 is unfolded on a plane by separating the ventral waistband 20 (described later) and the dorsal waistband 30 (described later) from the pants-type diaper 1 in Fig. 1 at the side seams SS (described later) on both the left and right sides, and opening the diaper 1 vertically. The "stretched state" of the diaper 1 refers to a state in which the product (diaper 1) is stretched without wrinkles, specifically, a state in which the dimensions of each component (e.g., the absorbent main body 10, the ventral waistband 20, etc.) constituting the diaper 1 are stretched to the extent that they match or are close to the dimensions of the individual components.

[0042] When worn in a pants-like state as shown in FIG. 1 , the diaper 1 has intersecting vertical, horizontal, and front-to-back directions, and has a waist opening BH and a pair of leg openings LH. In the vertical direction, the waist opening BH side is the upper side, and the side facing the wearer's crotch is the lower side. In the front-to-back direction, the side facing the wearer's belly side is the front side, and the side facing the wearer's back side is the back side. In the unfolded and stretched state shown in FIG. 2 , the diaper 1 has three mutually intersecting directions: a longitudinal direction, a lateral direction, and a thickness direction (a direction passing through the paper in FIG. 2 ). The longitudinal direction is aligned with the above-mentioned vertical direction. One longitudinal side corresponds to the ventral side (front side), and the other longitudinal side corresponds to the back side (rear side). The diaper 1 also has a thickness direction in which materials are layered, as shown in FIG. 3 . The side in contact with the wearer in the thickness direction is the skin side, and the opposite side is the non-skin side.

[0043] The diaper 1 includes an absorbent body 10 and an outer casing 18. The outer casing 18 includes a pair of waistband sections 20, 30 and a crotch section 40 located between the wearer's legs. The outer casing 18 is joined to the non-skin side of the absorbent body 10 with an adhesive or the like. Of the pair of waistband sections 20, 30, the one located on the ventral side (front side) of the wearer is also referred to as the ventral waistband section 20, and the one located on the dorsal side (rear side) is also referred to as the dorsal waistband section 30. The ventral waistband section 20 and the dorsal waistband section 30 are joined on both lateral sides by a pair of side joining sections SS. Examples of joining methods using the side joining sections SS include thermal welding, ultrasonic welding, and adhesive joining.

[0044] As shown in FIG. 3 , the absorbent body 10 includes an absorbent core 11, a liquid-permeable top sheet 12 disposed closer to the skin than the absorbent core 11, a liquid-impermeable back sheet 13 disposed closer to the skin than the absorbent core 11, and an exterior sheet 14. The absorbent core 11 may be any material capable of absorbing and retaining excreted liquid, and may be, for example, a liquid-absorbent material such as pulp fiber or superabsorbent polymer (SAP) molded into a predetermined shape. The absorbent core 11 may also be covered with a liquid-permeable sheet such as tissue paper or a nonwoven fabric. The top sheet 12 is formed of, for example, a nonwoven fabric such as an air-through nonwoven fabric or a spunbond nonwoven fabric. The back sheet 13 is, for example, a liquid-impermeable and breathable film such as polyethylene or polypropylene. The exterior sheet 14 is formed of, for example, the same nonwoven fabric as the top sheet 12.

[0045] 2, a plurality of leg-hole elastic members 15 (e.g., rubber threads) that stretch along the longitudinal direction of the absorbent body 10 are provided on both lateral sides of the absorbent body 10. Furthermore, by providing, for example, an elastic member that stretches in the longitudinal direction on the inner side of the leg-hole elastic members 15 in the lateral direction, a leakage prevention wall that can stand up against the skin side may be provided.

[0046] As shown in FIGS. 2 and 3, the exterior body 18 has an inner layer sheet 21, a ventral side outer layer sheet 22 (outer layer sheet), and a dorsal side outer layer sheet 32 ​​(outer layer sheet).

[0047] The inner layer sheet 21 is disposed from the ventral waistline portion 20 through the crotch portion 40 to the back waistline portion 30 (FIG. 3). The width (length in the left-right direction) of the inner layer sheet 21 in the ventral waistline portion 20 and the back waistline portion 30 is greater than the width (length in the left-right direction) of the inner layer sheet 21 in the crotch portion 40 (FIG. 2). The inner layer sheet 21 may be an air-through nonwoven fabric, a spunbond nonwoven fabric, an SMS nonwoven fabric (spunbond-meltblown-spunbond nonwoven fabric), a waterproof film, or the like.

[0048] 2 and 3, the ventral outer layer sheet 22 is located closer to the skin than the inner layer sheet 21, and the ventral outer layer sheet 22 and the inner layer sheet 21 together form the ventral waistline portion 20. The outer end (upper end) of the ventral outer layer sheet 22 in the longitudinal direction is folded back toward the skin. The folded-back portion 22r of the ventral outer layer sheet 22 encloses one end (outer end) of the inner layer sheet 21 in the longitudinal direction. However, the outer end (upper end) of the ventral outer layer sheet 22 in the longitudinal direction may not be folded back.

[0049] 2 and 3, the back outer sheet 32 ​​is disposed closer to the skin than the inner sheet 21, and the back outer sheet 32 ​​and the inner sheet 21 together form the back waistband portion 30. The outer end (upper end) of the back outer sheet 32 ​​in the longitudinal direction is folded back toward the skin. The folded-back portion 32r of the back outer sheet 32 ​​encloses the other end (outer end) of the inner sheet 21 in the longitudinal direction. The outer end (upper end) of the back outer sheet 32 ​​in the longitudinal direction may not be folded back.

[0050] The ventral outer layer sheet 22 and the dorsal outer layer sheet 32 ​​may be made of an air-through nonwoven fabric, a spunbond nonwoven fabric, an SMS nonwoven fabric (spunbond meltblown spunbond nonwoven fabric), or the like.

[0051] The ventral waist portion 20 and the back waist portion 30 each have waist elastic members 23, 33 that are stretchable in the left-right direction. The multiple waist elastic members 23, 33 are spaced apart in the vertical direction between the inner layer sheet 21 and the ventral outer layer sheet 22, and between the inner layer sheet 21 and the back outer layer sheet 32, and are fixed in a stretched state in the left-right direction (see Figures 2 and 3). Thus, the ventral waist portion 20 and the back waist portion 30 stretch in the left-right direction to fit the waist of the wearer. Examples of the waist elastic members 23, 33 include thread-like stretchable members such as rubber threads and elongated stretchable sheets.

[0052] In this embodiment, rear leg elastic members 34 are provided in the back waistband 30 between the inner sheet 21 and the back outer sheet 32. The rear leg elastic members 34 may be, for example, a plurality of rubber threads or a stretchable elastic sheet in the shape of a strip. The rear leg elastic members 34 are joined and fixed in a stretched state with an adhesive such as a hot melt adhesive.

[0053] In this embodiment, sheet portions 25, 35 that easily absorb the wearer's sweat are provided in predetermined regions of the ventral waistline portion 20 and the dorsal waistline portion 30 that are closest to the skin (shaded areas in Fig. 2 ). The sheet portions 25, 35 are arranged closer to the skin than the absorbent main body 10, are shorter in vertical length than the inner layer sheet 21 and the ventral and dorsal outer layer sheets 22, 32, etc., and are strip-shaped sheet members arranged to cover the longitudinal ends of the absorbent main body 10. Details of the sheet portions 25, 35 will be described later.

[0054] The above describes the basic configuration of the diaper 1, but the above configuration of the diaper 1 is merely an example and is not intended to be limiting. For example, the diaper 1 of this embodiment is configured with an outer body 18 having three sections: a ventral waist section 20, a dorsal waist section 30, and a crotch section 40 connecting them. However, the present invention is not limited to this. For example, the diaper may have a configuration in which the ventral waist section 20 and the dorsal waist section 30 are formed from separate members, and the non-skin side of the absorbent main body 10 is exposed in the crotch section. Alternatively, the diaper may have an outer body member formed from a single member that is continuous from the ventral waist section 20 to the dorsal waist section 30.

[0055] <Regarding seat portions 25, 35> The specific configurations of seat portions 25 and 35 according to this embodiment will be described below. Note that in this embodiment, the seat portion 25 provided in the ventral waistline portion 20 and the seat portion 35 provided in the dorsal waistline portion 30 have substantially the same configuration. Therefore, in the following description, content common to both seat portion 25 and seat portion 35 will be described only for seat portion 25 as a representative of both. Regarding seat portion 35, reference numerals of components corresponding to seat portion 25 will be indicated in parentheses as necessary, and a specific description will be omitted.

[0056] Fig. 4 is a schematic cross-sectional view of the sheet portion 25. As described above, the sheet portion 25 in this embodiment constitutes a part of the surface of the ventral waistline portion 20 that comes into contact with the wearer's skin (Fig. 3). As shown in Fig. 4, the sheet portion 25 has a skin-side layer 25a that is arranged to come into contact with the wearer's skin, and a non-skin-side layer 25b that is located on the non-skin side of the skin-side layer 25a in the thickness direction.

[0057] The skin-side layer 25a is a layer whose base fiber is cotton, a hydrophilic fiber (hereinafter, the skin-side layer 25a will also be referred to as the "cotton layer 25a"). The "base material" mentioned above refers to a material whose mass accounts for more than 50% of each layer (skin-side layer 25a, non-skin-side layer 25b). The non-skin-side fiber, which is the base fiber of the non-skin-side layer 25b, is a polyester fiber, polypropylene fiber, polyethylene fiber, or a composite fiber thereof whose surface has been hydrophilically treated. The fibers listed as the non-skin-side fibers above may also be fibers that have not been hydrophilically treated.

[0058] In the sheet member constituting the sheet portion 25 of this embodiment, the cotton fibers 25as, which are the base fibers of the cotton layer 25a, are entangled with the non-skin side fibers 25bs, which are the base fibers of the non-skin side layer 25b (FIG. 4). The cotton layer 25a and the non-skin side layer 25b can be integrated by entanglement using a known hydroentanglement method, such as a water jet.

[0059] As described above, the sheet member (sheet portion 25) is formed by intertwining the fibers of each layer, and in the cotton layer 25a of this embodiment, all fibers are cotton fibers except for the non-skin-side fibers 25bs that have penetrated into the cotton layer 25a. However, this is not limited thereto, and the cotton layer 25a may contain more than 50% by mass of cotton fibers, and preferably more than 80% by mass of cotton fibers.

[0060] In this embodiment, in the process of integrating the cotton layer 25a and the non-skin side layer 25b using the hydroentanglement method as described above, the hydrophilizing agent applied to the surface of the base fiber of the non-skin side layer 25b is partially removed by the water flow. Therefore, the non-skin side fibers bs of the non-skin side layer 25b in this embodiment include fibers from which the hydrophilizing agent has been completely removed and which have become hydrophobic fibers, fibers from which the hydrophilizing agent has been partially removed but which still retain some of the hydrophilizing agent, and fibers from which the hydrophilizing agent remains completely.

[0061] Therefore, in the sheet portion 25 of this embodiment, the hydrophilicity of the cotton fibers 25as, which are the base fibers of the cotton layer 25a, is higher than the hydrophilicity of the non-skinside fibers 25bs, which are the base fibers of the non-skinside layer 25b. The sheet portion 25 can be used to absorb sweat from the wearer. When the diaper 1 is worn, sweat on the wearer's skin is first absorbed by the cotton layer 25a, and the absorbed sweat then migrates to the non-skinside layer 25b. The cotton layer 25a, which is based on highly hydrophilic cotton fibers 25as, is disposed on the surface that contacts the wearer's skin to improve water absorption. Furthermore, the hydrophilicity of the non-skinside fibers 25bs of the non-skinside layer 25b is lower than that of the cotton fibers as. This allows the non-skinside layer 25b to evaporate moisture, such as sweat, absorbed by the cotton fibers as and migrate to the non-skin side, without excessively retaining moisture, thereby preventing the sheet portion 25 from becoming stuffy. By disposing such a sheet portion 25 (35) in the ventral waist portion 20 (dorsal waist portion 30), it is possible to suppress the occurrence of skin troubles such as eczema, heat rash, and rash.

[0062] The "hydrophilicity" of the above-mentioned fibers is evaluated based on the contact angle of the fibers, measured by the following method. Specifically, a smaller measured contact angle indicates higher hydrophilicity, and a larger contact angle indicates lower hydrophilicity. <Contact Angle Measurement Method> (1) First, cotton fibers and non-skin-side fibers are removed from predetermined locations of each layer. The removed fibers are cut to a fiber length of 10 mm, and five fibers of each type are prepared as samples. (2) The measurement device is an automatic micro-contact angle meter MCA-J manufactured by Kyowa Interface Science Co., Ltd., and the measurement environment is a room temperature of 22±2°C and a humidity of 65±2% RH. (3) The sample is placed on the measurement device, and 20 picoliters of distilled water (microdroplets) are dropped onto the fiber surface from the inkjet head installed in the device. The appearance of the microdroplets is recorded over time. (4) Images taken immediately after the microdroplets adhere to the fiber surface are analyzed, and the contact angle of the microdroplets with respect to the fiber surface is calculated. (5) The contact angle is measured at 20 different points for each fiber. The contact angle is measured for each of five samples, and the average value of the measured values ​​for a total of 100 points is used as the contact angle. If the layer (sheet) to be measured is joined to another member by adhesive, fusion, or the like, the adhesive strength of the joint is weakened by cooling means such as cold spray to the extent that it does not affect the contact angle of the fiber, and then the sample is removed.

[0063] Furthermore, when compared using the above-mentioned evaluation method with the non-skin-side fibers bs of the non-skin-side layer 25b, which are "fibers in which the hydrophilizing agent remains completely," the cotton fibers 25as of the cotton layer 25a have a higher degree of hydrophilicity.

[0064] 4, the cotton layer 25a and the non-skin side layer 25b are laminated in the thickness direction, and at least a portion of the cotton fibers 25as of the cotton layer 25a is present on the same plane as the non-skin side surface of the non-skin side layer 25b. That is, the cotton fibers 25as of the cotton layer 25a are entangled with the non-skin side fibers 25bs, and at least a portion of them extend into the non-skin side layer 25b, and some of the extending cotton fibers 25as are also present on the same plane as the non-skin side surface of the non-skin side layer 25b. The presence of the cotton fibers 25as in the non-skin side layer 25b allows moisture absorbed from the cotton layer 25a to quickly move to the non-skin side layer 25b through the cotton fibers 25as that have penetrated the non-skin side layer 25b, allowing moisture to escape from the non-skin side layer 25b, which has a relatively low hydrophilicity.

[0065] Conversely, at least a portion of the non-skin side fibers 25bs of the non-skin side layer 25b extends into the cotton layer 25a, which makes it easier for absorbed liquid to move from the cotton layer 25a to the non-skin side layer 25b along the non-skin side fibers 25bs extending into the cotton layer 25a, thereby reducing the risk that the moisture absorbed by the sheet portion 25 will continue to come into contact with the wearer's skin.

[0066] The thickness of each of the cotton layer 25a and the non-skin side layer 25b is preferably, for example, about 0.3 mm to 0.4 mm for the cotton layer 25a, and about 0.1 mm for the non-skin side layer 25b.

[0067] FIG. 5 is a plan view showing an adhesive bonding the sheet portion 25 to an adjacent sheet member adjacent to the sheet portion 25 from the non-skin-facing side. In this embodiment, as shown in FIG. 5 , a joint 50x is provided, in which the sheet portion 25 and an adjacent sheet member adjacent to the sheet portion 25 from the non-skin-facing side in the thickness direction are bonded with hot melt adhesive. The "adjacent sheet member" in the ventral waistband portion 20 refers to the top sheet 12 in the region where the sheet portion 25 and the absorbent main body 10 overlap in the vertical direction (longitudinal direction), and to the folded-back portion 22r of the ventral outer layer sheet 22 in the region above the absorbent main body 10. In this embodiment, the joint 50x is formed by applying hot melt adhesive in a spiral pattern extending in the left-right direction and arranged in two vertical rows, but the number and application pattern are not limited thereto. For example, in addition to applying an adhesive such as a hot melt adhesive using a non-contact application method, the joint 50x may also be formed by thermal welding or ultrasonic welding.

[0068] 5, at least a portion of the sheet portion 25 is disposed above the absorbent main body 10 in the vertical direction. When the region of the sheet portion 25 disposed above the absorbent main body 10 is defined as the upper arrangement region 25UP (the portion indicated by the thick line in FIG. 5), the upper arrangement region 25UP and the folded-back portion 22r of the ventral-side outer layer sheet 22, which is an adjacent sheet member adjacent to the upper arrangement region 25UP from the non-skin-facing side in the thickness direction, are joined (adhered) by the above-mentioned joint 50x. Furthermore, the ventral-side waistline portion 20 has a non-joined portion 50z where the upper arrangement region 25UP and the folded-back portion 22r of the ventral-side outer layer sheet 22 (adjacent sheet member) are not joined by adhesive or the like.

[0069] The waist area of ​​a wearer is a region where a lot of movement occurs, and this region is prone to friction between the product (diaper 1) and the wearer's skin during wear. For this reason, it is desirable to place cotton in a portion of the waist area of ​​an absorbent article such as diaper 1 that comes into contact with the skin to reduce irritation to the skin. However, since placing cotton on the skin-facing side of the waist area can cause pilling due to contact with the skin, a design is needed that can reduce pilling while also providing a comfortable feel by placing cotton on the skin-facing side.

[0070] In this embodiment, the upper arrangement region 25UP of the sheet portion 25 is located above the absorbent main body 10 and has lower rigidity than the portion of the sheet portion 25 below the upper arrangement region 25UP, i.e., the portion that overlaps with the absorbent main body 10 in the thickness direction. Therefore, the upper arrangement region 25UP is a region prone to movement, and cotton fibers are prone to fluffing due to friction with the skin. In the upper arrangement region 25UP, the non-bonded portion 50z is not bonded to the adjacent member (folded portion 22r) on the non-skin side, and therefore is a portion that is prone to deformation. Even when movement occurs in the ventral waistline portion 20 (dorsal waistline portion 30), the non-bonded portion 50z easily follows such movement. The non-bonded portion 50z's ability to follow movement reduces friction with the skin, thereby suppressing fluffing of the cotton fibers 25as of the cotton layer 25a. Furthermore, although the sheet portion 25 has portions that are easily deformed due to the non-bonded portions 50z, the provision of the bonded portions 50x prevents the cotton fibers 25as from falling off. Furthermore, the cotton layer 25a continuously contacts the skin while reducing friction with the skin, allowing the wearer to feel the softness of the cotton while suppressing irritation to the skin.

[0071] Furthermore, when the upper arrangement region 25UP of the sheet 25 is viewed in plan ( FIG. 5 ), the total area of ​​the non-joined portions 50z is preferably larger than the total area of ​​the joined portions 50x. The larger total area of ​​the non-joined portions 50z—that is, the larger proportion of the upper arrangement region 25UP occupied by the non-joined portions 50z compared to the joined portions 50x—enables the upper arrangement region 25UP to more easily follow the movement of the wearer's waist. This configuration reduces friction between the wearer's skin and the sheet 25 and suppresses pilling of the cotton layer 25a.

[0072] FIG. 6 is a diagram illustrating the vertical length of the joint portion 50x in the upper placement region 25UP. As shown in FIG. 6, the length L1 of the joint portion 50x in the vertical direction of the upper placement region 25UP of the sheet portion 25 is longer than the length L2 of the non-joint portion 50z. The vertical length L1 of the joint portion 50x here refers to the length of the region where the hot melt adhesive is present when viewed in the vertical direction, and the length L2 of the non-joint portion 50z refers to the length of the region where the hot melt adhesive is not present when viewed in the vertical direction. Unlike the present embodiment, if the upper placement region 25UP has multiple application patterns that form the joint portion 50x spaced apart in the vertical direction, it is preferable that the total vertical length of the joint portions 50x be longer than the total length of the non-joint portions 50z.

[0073] If the upper arrangement region 25UP were to have many (longer in the vertical direction) non-bonded portions 50z where the upper arrangement region 25UP and the adjacent folded-back portion 22r of the ventral outer layer sheet 22 on the non-skin side are not bonded, pilling of the cotton layer 25a located closest to the skin can be suppressed, but on the other hand, there is a risk that the bond between the sheet portion 25 and the folded-back portion 22r will peel off. Therefore, by making the vertical length (or total length) of the bonded portions 50x longer than the length (or total length) of the non-bonded portions 50z, the bond of the sheet portion 25 can be made less likely to peel off.

[0074] The average fiber length of the non-skin-side fibers 25bs, which are the base fibers of the non-skin-side layer 25b, is longer than the average fiber length of the cotton fibers 25as, which are the base fibers of the cotton layer 25a. The short-average fiber length of the cotton fibers as is bonded to the long-average fiber length of the non-skin-side fibers 25bs at the bonded portions 50x improves the durability of the cotton layer 25a and makes the cotton fibers 25as less likely to fall off. Furthermore, at the bonded portions 50x that bond the sheet portion 25 to the folded-back portion 22r (adjacent sheet member), the long average fiber length of the non-skin-side fibers 25bs of the non-skin-side layer 25b of the sheet portion 25, makes the bond less likely to come apart, improving the conformability of the ventral outer layer sheet 22, which is located on the non-skin side of the sheet portion 25, to the folded-back portion 22r (adjacent sheet member).

[0075] The average fiber length refers to the length-weighted average fiber length measured using the central fiber length (Cont). The length-weighted average fiber length is measured as the L(l) value using a Kajaani FiberLab fiber properties (off-line) manufactured by Metso Automation. This is also the method recommended in JIS P 8226-2 (Pulp - Fiber length measurement method by engineering automatic analysis method, conforming to the non-polarized light method).

[0076] The thermal conductivity of the cotton fibers 25as of the cotton layer 25a, which contacts the wearer's skin, is lower than that of the non-skin-side fibers 25bs, which are the base fibers of the non-skin-side layer 25b. The cotton layer 25a, which uses the cotton fibers 25as, which have low thermal conductivity, as its base fibers, does not immediately cool down even if the cotton layer 25a becomes wet with sweat or the like while being worn. Furthermore, because the non-skin-side fibers 25bs of the non-skin-side layer 25b have a higher thermal conductivity than the cotton fibers 25as, heat exchange is promoted, and heat is released further away from the skin than the non-skin-side layer 25b, making it less likely for heat to build up in the sheet portion 25.

[0077] The thermal conductivity of the fibers can be measured, for example, in accordance with ISO 22007-2 using a hot disk thermophysical property measuring device (for example, TPS2500S manufactured by Hot Disk Corp.) Specifically, for example, a disk-shaped measurement sample having a sample size of Φ5 mm and a thickness of 2 mm is molded using each fiber, a sensor of the measurement device is sandwiched between the sample, and a constant current is passed through it to generate heat, and the thermal conductivity is calculated from the temperature rise.

[0078] The sheet portion 25 has cotton fibers 25as in the cotton layer 25a and non-skin-side fibers 25bs in the non-skin-side layer 25b, but the proportion of cotton fibers 25as may be less than 50% by mass in the entire sheet portion 25. Cotton fibers have a rounded fiber shape, and by using such cotton fibers 25as in the skin-side layer 25a (cotton layer) of the sheet portion 25 located closest to the skin of the ventral waistline portion 20, it is possible to realize a pleasant feel against the skin. At the same time, by reducing the mass proportion of cotton fibers 25as, it is possible to suppress pilling of the cotton layer 25a.

[0079] In order to compare the mass of each fiber in the entire sheet portion 25, it is necessary to separate the cotton fibers 25as from the non-skin side fibers 25bs.One method of separation is to immerse the sheet member that is the sheet portion 25 in water and agitate it for 24 hours, thereby separating the cotton fibers 25as from the non-skin side fibers 25bs.

[0080] Returning to Figure 2, the sheet portion 25 (35) of this embodiment vertically straddles the upper end 10e of the absorbent main body 10 in the vertical direction in the ventral waistline portion 20 (dorsal waistline portion 30). The upper end 10e of the absorbent main body 10 is a portion with relatively large unevenness, and by covering this upper end 10e from the skin side, friction with the skin during wear can be suppressed and irritation to the skin can be reduced. Note that in this embodiment, the sheet portions 25, 35 vertically straddle the upper end 10e of the absorbent main body 10 in both the ventral waistline portion 20 and the dorsal waistline portion 30, but this is not limited thereto, and it is sufficient that at least one of the ventral waistline portion 20 and the dorsal waistline portion 30 has such a configuration.

[0081] As described above, in the ventral-side waistline portion 20, the sheet portion 25 and the adjacent sheet member (the top sheet 12 and the folded-back portion 22r of the ventral-side outer layer sheet 22) adjacent to the sheet portion 25 from the non-skin-facing side in the thickness direction are joined by a joint 50x, but it is desirable that no hook-and-loop fastener or the like is provided between the sheet portion 25 and the adjacent sheet member in the thickness direction. In other words, it is preferable that the sheet portion 25 and the adjacent sheet member are not joined by a hook-and-loop fastener or the like. If a hook-and-loop fastener were provided between the sheet portion 25 and the adjacent sheet member, the sheet portion 25 would be highly rigid, making it difficult for the sheet portion 25 to follow the movement of the adjacent sheet member located on the non-skin side; however, not providing such a hook-and-loop fastener improves followability.

[0082] Fig. 7A shows an enlarged photograph of the sheet portion 25 as viewed from the skin side, and Fig. 7B is a diagram illustrating the low basis weight portions 25aL. Fig. 8 is an enlarged view of the ventral waistband portion 20 of the diaper 1 shown in Fig. 2. As shown in Fig. 4, the cotton layer 25a has a predetermined basis weight portion 25ap containing cotton fibers 25as of a predetermined basis weight and a low basis weight portion 25aL containing cotton fibers 25as with a lower basis weight than the predetermined basis weight portion 25ap. Here, basis weight refers to mass per unit area. Fig. 7A shows the cotton layer 25a as viewed from the skin side, with some of the low basis weight portions 25aL surrounded by white lines for clarity. In this embodiment, the low basis weight portions 25aL may also contain cotton fibers 25as with a basis weight of zero.

[0083] Specifically, in the low basis weight portion 25aL shown in Fig. 7A, the basis weight of the cotton fibers 25as is low or zero, so when viewed from the skin side, the non-skin-side fibers 25bs of the non-skin-side layer 25b located on the non-skin side of the cotton layer 25a are visible. The predetermined basis weight portion 25ap of the cotton layer 25a realizes a comfortable feel due to the cotton fibers 25as, while the low basis weight portion 25aL of the cotton layer 25a prevents the cotton fibers as, which have a short average fiber length, from falling out. In other words, it is possible to achieve both the comfort of the cotton fibers 25as and prevention of their falling out.

[0084] 7B is a schematic diagram of the low basis weight portion 25aL of the cotton layer 25a. As shown in FIGS. 7A and 7B, the cotton layer 25a has a plurality of low basis weight portions 25aL spaced apart in the vertical direction. In this embodiment, the low basis weight portions 25aL are shown as being generally diamond-shaped, but the shape, number, and arrangement of the low basis weight portions 25aL are not limited to the configuration of the low basis weight portions 25aL of this embodiment.

[0085] As shown in Fig. 8, the ventral waist portion 20 has a plurality of waist elastic members 23 that are stretchable in the left-right direction and are spaced apart in the vertical direction between the inner layer sheet 21 and the outer layer sheet 22. Returning to Fig. 7B, in the cotton layer 25a of the sheet portion 25, a low-basis weight portion is designated as 25aL1, and another low-basis weight portion vertically adjacent to the low-basis weight portion 25aL is designated as 25aL2. The vertical center-to-center distance between the low-basis weight portions 25aL1 and 25aL2 (the distance from the vertical center P1 of the low-basis weight portion 25aL1 to the vertical center P2 of the low-basis weight portion 25aL2) is designated as L3. As shown in Fig. 8, the vertical center-to-center distance between vertically adjacent waist elastic members 23 in the skin-side waist portion 20 (the distance from the vertical center of one waist elastic member 23 to the vertical center of the other waist elastic member 23) is designated as L7. In this embodiment, the minimum value of the vertical center-to-center distance (L3) between such vertically adjacent low basis weight portions 25aL is smaller than the minimum value of the vertical center-to-center distance (L7) between vertically adjacent waist elastic members 23. By providing multiple low basis weight portions 25aL so that the vertical spacing is small, it is possible to further suppress the shedding of cotton fibers 25as, which have a short average fiber length, and reduce irritation to the skin caused by shedding fibers.

[0086] 8 , the sheet portion 25 is disposed below and spaced from the upper end 20 e of the ventral waistline portion 20 in the up-down direction. The region from the upper end 20 e of the ventral waistline portion 20 to the upper end 25 e of the sheet portion 25 in the up-down direction is defined as a non-positioning region NT, and the region from the upper end 25 e to the lower end 25 d of the sheet portion 25 of the ventral waistline portion 20 in the up-down direction is defined as a positioning region 25H. The non-positioning region NT exerts a stronger tightening force when the diaper is worn than the positioning region 25H. Specifically, the magnitude of the force required to stretch the non-positioning region NT of a unit width in the up-down direction by a unit length in the left-right direction is greater than the magnitude of the force required to stretch the positioning region 25H of a unit width in the up-down direction by a unit length in the left-right direction.

[0087] The force required to stretch the non-positioning region NT of a unit width in the vertical direction by a unit length in the left-right direction and the force required to stretch the placement region 25H of a unit width in the vertical direction by a unit length in the left-right direction can be compared using a known method. For example, samples of the non-positioning region NT and the placement region 25H are cut out from the ventral waistband 20 (or the dorsal waistband 30) so that they have the same vertical length, and both ends of the sample corresponding to the left-right direction of the diaper 1 are clamped between the chucks of a tensile tester. The load obtained when the sample is stretched with the chucks spaced a unit length apart is measured. The load of each sample is then divided by the uniform vertical length (so-called unit width) and compared.

[0088] In this embodiment, the portion of the non-positioning region NT closest to the skin is the folded-back portion 22r of the ventral outer layer sheet 22, which contains hydrophobic fibers. Examples of hydrophobic fibers include polypropylene, polyester, and polyethylene-polypropylene composite fibers. The inclusion of hydrophobic fibers in the portion of the non-positioning region NT closest to the skin, which provides strong compression, reduces stickiness while wearing the diaper 1 and reduces discomfort to the wearer's body. Furthermore, by reducing the compression force in the positioning region 25H of the sheet portion 25, which is prone to pilling due to strong compression, friction with the skin is reduced and pilling of the cotton fibers 25as is prevented.

[0089] 8, the length L5 of the sheet portion 25 in the vertical direction is desirably equal to or less than half the length L4 of the side joint portion SS that joins the ventral waistline portion 20 and the back waistline portion 30. Also, the length L5 of the sheet portion 25 in the vertical direction is desirably equal to or less than half the length of the ventral waistline portion 20 (or the back waistline portion 30). In other words, the cotton layer 25a of the sheet portion 25 reduces friction on the skin, while the length of the cotton layer 25a is kept short, thereby suppressing pilling. This allows for both a pleasant feel due to the cotton layer 25a and prevention of pilling.

[0090] In this embodiment, the ventral waistline portion 20 (dorsal waistline portion 30) has a folded-back portion 22r (32r) formed by folding back the top end of the ventral outer sheet 22 (dorsal outer sheet 32) toward the skin, and the length L5 of the sheet portion 25 in the vertical direction is shorter than the length L6 of the folded-back portion 22r (32r) (FIG. 8). By not disposing the sheet portion 25 to be excessively long in the vertical direction, the possibility of pilling of the cotton layer 25a is further reduced.

[0091] However, the longitudinal length L5 of the sheet portion 25 is not limited to this. Conversely, the vertical length L5 of the sheet portion 25 may be longer than the vertical length L6 of the folded-back portion 22r (32r). By providing the sheet portion 25 longer than the vertical length L6 of the folded-back portion 22r (32r), the comfortable feel of the cotton layer 25a can be more easily felt.

[0092] In this embodiment, the sheet portion 25 is a sheet member disposed closer to the skin than the inner layer sheet 21. That is, for example, in the ventral waist portion 20, the waist elastic member 23 is disposed between the inner layer sheet 21 and the ventral outer layer sheet 22, which is disposed closer to the skin than the inner layer sheet 21, and therefore there is an interference area between the waist elastic member 23 and the sheet portion 25 (sheet member) including the cotton layer 25a. The interference area in the ventral waist portion 20 is the folded-back portion 22r of the inner layer sheet 21 and the ventral outer layer sheet 22, or the inner layer sheet 21 and the absorbent main body 10. The presence of such an interference area prevents the cotton layer 25a, which comes into contact with the skin, from being excessively stretched by the waist elastic member 23, thereby reducing friction between the cotton layer 25a and the skin and suppressing shedding and fluffing of cotton fibers 25as.

[0093] Fig. 9 is a diagram showing a modified example of the sheet portion 25. In this embodiment, the sheet portion 25 is provided as a sheet member separate from the inner layer sheet 21 and the ventral-side outer layer sheet 22 (dorsal-side outer layer sheet 32), but this is not limited to this. For example, in the modified example shown in Fig. 9, a separate sheet member is not provided as the sheet portion 25, and the upper end of the ventral-side outer layer sheet 22 (dorsal-side outer layer sheet 32) is not folded back toward the skin, so that the inner layer sheet 21 is located closest to the skin above the absorbent main body 10.

[0094] In this modification, the upper end of the inner layer sheet 21, which is a part of the inner layer sheet 21, functions as the sheet portion 25. That is, the entire inner layer sheet 21, or at least the portion of the inner layer sheet 21 that becomes the sheet portion 25, has a skin-side layer (cotton layer) 25a on the skin-side side and a non-skin-side layer 25b on the non-skin-side side of the skin-side layer 25a in the thickness direction. The sheet portion 25, which is a part of the inner layer sheet 21, and the ventral-side outer layer sheet 22 (adjacent sheet member) adjacent to the sheet portion 25 on the non-skin-side side in the thickness direction have a joint portion 50x (not shown) where they are joined by welding or adhesive, and a non-joined portion 50z (not shown) where the sheet portion 25 and the ventral-side outer layer sheet 22 (adjacent sheet member) are not joined by welding or adhesive. As in the present embodiment, this suppresses fluffing of the cotton fibers 25as due to the ease of deformation of the non-joined portion 50z, and suppresses shedding of the cotton fibers 25as by the joint portion 50x. Furthermore, the cotton layer 25a of the sheet portion 25 comes into contact with the skin, allowing the wearer to feel the softness of cotton.

[0095] 10A and 10B are diagrams illustrating another modified example of the sheet portion 25. In the modified example shown in Fig. 10A and 10B, no separate sheet member is provided as the sheet portion 25, and the folded-back portion 22r (32r) of the ventral outer layer sheet 22 (dorsal outer layer sheet 32) serves as the sheet portion 25 (35). In this modified example, at least the portion of the ventral outer layer sheet 22 (dorsal outer layer sheet 32) that will become the sheet portion 25 (35) has a skin-side layer (cotton layer) 25a on the skin side and a non-skin-side layer 25b on the non-skin side of the skin-side layer 25a in the thickness direction. Furthermore, the sheet portion 25 (35), which is part of the ventral outer layer sheet 22 (dorsal outer layer sheet 32), and the inner layer sheet 21 (adjacent sheet member) adjacent to the sheet portion 25 (35) on the non-skin-facing side in the thickness direction have a joint portion 50x (not shown) where the sheet portion 25 (35) is joined by welding or adhesive, and a non-joined portion 50z (not shown) where the sheet portion 25 (35) and the inner layer sheet 21 (adjacent sheet member) are not joined by welding or adhesive, thereby achieving the same effects as the above-described embodiment. Note that the folded-back portion 22 (32r) of the sheet portion 25 (35) in this modified example is a region of the ventral waistline 20 (dorsal waistline 30) that provides a strong grip. The presence of the cotton layer 25a on the skin-contacting surface of this region allows the wearer to feel the softness of the cotton more clearly. Furthermore, the non-joined portion 50z allows the sheet to more easily follow the movement of the waistline, thereby reducing friction with the skin and suppressing fluffing of the cotton fibers.

[0096] Fig. 11 is a diagram showing a modified arrangement of the sheet portion 25 (35). In the modified example shown in Fig. 11, the sheet portion 25 (35) is not provided to both ends in the left-right direction of the ventral waistline portion 20 (dorsal waistline portion 30), but is provided in the left-right central portion of the ventral waistline portion 20 (dorsal waistline portion 30) and so as to straddle the upper end 10e of the absorbent main body 10 in the vertical direction. Since the upper end 10e of the absorbent main body 10 is a portion where the unevenness is relatively large, by arranging the sheet portion 25 (35) so as to completely cover at least the upper end 10e, friction against the skin during wear can be suppressed and irritation to the skin can be reduced. Furthermore, in the upper arrangement region 25UP (35UP, both of which are indicated by thick lines in Figure 11) of the sheet portion 25 (35), which is arranged above the absorbent main body 10, the non-jointed portion 50z (not shown here) of this embodiment is provided, which makes it easier to follow the movement of the waist and suppresses pilling of the cotton fibers 25as of the cotton layer 25a.

[0097] FIG. 12 shows yet another modified example of the sheet portion 25 (35). In the modified example shown in FIG. 12, a sheet member that becomes the sheet portion 25 (35) is provided between the inner layer sheet 21 of the absorbent main body 10. The sheet member that becomes the sheet portion 25 is provided in the ventral waistline portion 20, between one end and the other end of the pair of side joints SS in the left-right direction, and in a region from the upper end to the lower end of the pair of side joints SS in the up-down direction. In the back waistline portion 30, the sheet member that becomes the sheet portion 35 is provided in the region from one end to the other end of the pair of side joints SS in the left-right direction, and in a region from the upper end to the vicinity of the lower end of the pair of side joints SS in the up-down direction. With this configuration, the cotton layer 25a is present on most of the skin-contacting surface of the ventral waistline portion 20 (back waistline portion 30) in the region other than the region where the absorbent main body 10 is disposed, improving the feel against the skin. Furthermore, since the sheet portion 25 (35) and the inner layer sheet 21 have a non-bonded portion 50z (not shown here) where they are not bonded by welding or adhesive, the sheet portion 25 (35) can more easily follow the movements of the wearer's waist and reduce friction with the skin, thereby suppressing pilling of cotton fibers even if the proportion of the cotton layer 25a in contact with the skin increases.

[0098] <Other Aspects of the Absorbent Article 1> In addition to the above-described aspects, the absorbent article 1 can have the following aspects.

[0099] (Other aspect 1) An absorbent article 1 having an absorbent main body 10, a ventral waistline portion 20 located on the ventral side of a wearer, and a dorsal waistline portion 30 located on the dorsal side of the wearer, wherein the absorbent article 1 has a sheet portion 25 (35) located on the side closest to the skin of at least one of the ventral waistline portion 20 and the dorsal waistline portion 30, the sheet portion 25 (35) and an adjacent sheet member adjacent to the sheet portion 25 (35) from the non-skin-facing side are joined by adhesion or welding, the sheet portion 25 (35) has a skin-side layer 25 a that abuts the wearer's skin, and a non-skin-side layer 25 b that is located on the non-skin-facing side of the skin-side layer, and the hydrophilicity of the skin-side fiber 25 as that is the base fiber of the skin-side layer 25 a is higher than the hydrophilicity of the non-skin-side fiber 25 bs that is the base fiber of the non-skin-side layer 25 b.

[0100] As a result, the skin-side layer 25a easily absorbs sweat and excrement because the skin-side fibers 25as have high hydrophilicity. On the other hand, the non-skin-side layer 25b, which is the base fiber of the non-skin-side fibers 25bs, has lower hydrophilicity than the skin-side fibers 25as. Therefore, even if the sheet portion 25 gets wet, the adhesive strength with the adjacent sheet member can be maintained, preventing peeling of the sheet portion 25. This allows the sheet portion 25 to perform its original function and prevents the sheet portion 25 from peeling, which could impair the wearing comfort.

[0101] (Other Aspect 2) The absorbent article 1 is characterized in that the content of skin side fibers 25as in the sheet portion 25 is 50% by mass or less.

[0102] If the mass proportion of the highly hydrophilic skin-side fibers 25as in the entire sheet portion 25 becomes too high, there is a risk that the adhesive strength with adjacent sheet members will be weakened when the sheet portion 25 becomes wet. However, this can be avoided by lowering the mass proportion of the skin-side fibers 25as in the entire sheet portion 25.

[0103] (Other Aspect 3) The absorbent article 1 is characterized in that at least a portion of the skin side fibers 25as of the skin side layer 25a is present on the same surface as the surface of the non-skin side 25bs of the non-skin side layer 25b.

[0104] This allows moisture absorbed by the skin-side layer 25a to be quickly transferred to the non-skin-side layer 25b along the extending skin-side fibers 25as. This allows excess moisture in the skin-side layer 25a to be removed by the non-skin-side layer 25b. Because the non-skin-side layer 25b has a low proportion of skin-side fibers 25as, it does not retain too much moisture and can maintain its adhesive strength with the adjacent sheet member. This prevents the sheet portion 25 from peeling off unexpectedly, thereby preventing a loss of comfort when wearing the garment.

[0105] (Other aspect 4) When the welded portions 50x are defined as the portions where fibers are welded together in the skin side layer 25a and the non-skin side layer 25b, the absorbent article 1 is characterized in that the total volume of the welded portions 50x per unit volume of the non-skin side layer 25b is larger than the total volume of the welded portions 50x per unit volume of the skin side layer 25a.

[0106] As a result, the skin-side layer 25a has few (or no) welded portions, allowing moisture to easily penetrate between the fibers and absorb moisture from the wearer's skin. On the other hand, the non-skin-side layer 25b has the welded portions 50x, ensuring a smooth surface and making it easier to maintain adhesive strength even when the sheet portion becomes wet. Furthermore, the presence of the welded portions 50x in the non-skin-side layer 25b improves the strength of the sheet portion 25 as a whole, making it less likely to peel from adjacent sheet members.

[0107] (Other Aspect 5) The absorbent article 1, wherein the ratio of the total volume of the welded portions 50x to the entire volume of the non-skin side layer 25b is 5% or more and 25% or less.

[0108] By having such a proportion of the welded portions 50x, the non-skin side layer 25b ensures a smooth surface, making it easier to maintain adhesive strength even when the sheet portion 25 becomes wet, and improving the strength of the entire sheet portion 25. This makes it less likely for the sheet portion 25 to separate from the adjacent sheet member.

[0109] (Other aspect 6) The non-skin side layer 25b has, in the thickness direction of the non-skin side layer 25b, a non-skin side portion of the non-skin side layer located on the skin side and a non-skin side portion of the non-skin side layer located on the non-skin side, and the fiber density of the non-skin side fibers 25bs of the non-skin side portion of the non-skin side layer is higher than the fiber density of the non-skin side fibers 25bs of the non-skin side portion of the non-skin side layer.

[0110] In this case, the non-skin side portion of the non-skin side layer is the portion that adheres to the adjacent sheet member, and since the fiber density of the non-skin side portion of the non-skin side layer 25b is higher, the adhesive strength with the adjacent sheet member can be increased.

[0111] (Other aspect 7) The non-skin side layer 25b has, in the thickness direction of the non-skin side layer 25b, a non-skin side portion of the non-skin side layer located on the skin side, and a non-skin side portion of the non-skin side layer located on the non-skin side, and the fiber density of the non-skin side fibers 25bs of the non-skin side portion of the non-skin side layer is higher than the fiber density of the non-skin side fibers 25bs of the non-skin side portion of the non-skin side layer.

[0112] In this way, higher fiber density makes it easier to absorb liquid, and when the fiber density of the skin side portion of the non-skin side layer is high, the high fiber density portion of the non-skin side fibers 25bs is positioned adjacent to the skin side layer 25a, which has a high hydrophilicity, and the moisture absorbed by the skin side fibers 25as is drawn into the skin side portion of the non-skin side layer, reducing the moisture in the skin side layer 25a and suppressing stickiness in the portion that comes into contact with the skin.

[0113] (Other aspect 8) The absorbent article 1 is characterized in that the non-skin side layer 25b has a non-skin side layer skin side portion located on the skin side and a non-skin side layer non-skin side portion located on the non-skin side in the thickness direction of the non-skin side layer 25b, and the hydrophilicity of the non-skin side fibers 25bs in the non-skin side layer skin side portion is higher than the hydrophilicity of the non-skin side fibers 25bs in the non-skin side layer non-skin side portion.

[0114] In this case, the skin-side portion of the non-skin-side layer is the portion that abuts the skin-side fibers 25as of the skin-side layer 25a, and increasing the hydrophilicity of the non-skin-side fibers 25bs in the skin-side portion of the non-skin-side layer facilitates the transfer of moisture from the skin-side fibers 25as to the non-skin-side fibers 25bs. The transferred moisture is less likely to remain in the non-skin-side portion of the non-skin-side layer, which has low hydrophilicity, and is therefore more likely to evaporate. Since moisture is less likely to accumulate in the non-skin-side portion of the non-skin-side layer, it is easier to maintain adhesion between the non-skin-side layer 25b and the adjacent sheet member.

[0115] (Other Aspect 9) The absorbent article 1, wherein the skin-side fibers 25as are cotton fibers, and the non-skin-side fibers 25bs are hydrophobic fibers containing at least one of polypropylene, polyethylene, and polyurethane, or fibers that have been hydrophilically treated from at least one of polypropylene, polyethylene, and polyurethane.

[0116] The skin-side layer 25a, containing cotton fibers, easily absorbs moisture from the skin. The non-skin-side layer 25b, containing the hydrophobic fibers (or hydrophilically treated fibers), allows excess moisture from the skin-side layer 25a to be removed without retaining it after it migrates to the non-skin-side layer 25b, maintaining adhesive strength with the adjacent sheet member. This prevents the sheet portion 25 from peeling off unexpectedly, which could impair the comfort of wearing the garment.

[0117] (Other aspect 10) The non-skin side layer 25b has a predetermined basis weight portion having non-skin side fibers 25bs of a predetermined basis weight, and a low basis weight portion in which the basis weight of the non-skin side fibers 25bs is lower than that of the predetermined basis weight portion, and the low basis weight portion 25aL of the skin side layer 25a and the low basis weight portion of the non-skin side layer 25b have an overlapping portion when viewed in the thickness direction of the absorbent article 1.

[0118] This promotes the absorption of moisture in the skin side layer 25 a from the low basis weight portion 25 aL of the skin side layer 25 a to the low basis weight portion of the non-skin side layer 25 b in the overlapping area, thereby more quickly removing moisture from the sheet portion 25, maintaining adhesive strength and preventing peeling of the sheet portion 25.

[0119] (Other Aspect 11) A sheet member 25 for an absorbent article having a skin-side layer 25a that can come into contact with the skin of a wearer, and a non-skin-side layer 25b that is provided on the non-skin-side side of the skin-side layer 25a, wherein the hydrophilicity of skin-side fibers 25as that are base fibers of the skin-side layer 25a is higher than the hydrophilicity of non-skin-side fibers 25bs that are base fibers of the non-skin-side layer 25b, the skin-side layer 25a has a predetermined basis weight portion 25ap that has skin-side fibers 25as of a predetermined basis weight, and a low basis weight portion 25aL in which the basis weight of the skin-side fibers 25as is lower than that of the predetermined basis weight portion 25ap, and the sheet member 25 has, when viewed in the thickness direction, a portion where the predetermined basis weight portion 25ap and the non-skin-side layer 25b overlap, and a portion where the low basis weight portion 25aL and the non-skin-side layer 25b overlap.

[0120] In this way, the highly hydrophilic skin-side layer 25a improves the absorbency and feel of the sheet member 25, while also facilitating the transfer of moisture absorbed by the skin-side layer 25a from the low basis weight portion 25aL to the non-skin side of the sheet member 25, thereby reducing the risk of moisture absorbed by the sheet member 25 remaining in contact with the wearer's skin and reducing discomfort and adverse effects on the wearer's skin.

[0121] (Other Aspect 12) A sheet member 25 characterized by having a portion where the skin side fibers 25as and the non-skin side fibers 25bs are entangled.

[0122] This improves the flexibility of the sheet member 25, and makes it possible to improve the feel of the absorbent article 1 using the sheet member 25 against the skin.

[0123] (Other Aspect 13) The sheet member 25 is characterized in that the skin side fibers 25as are cotton fibers.

[0124] In this way, since the fiber shape of the skin side fiber 25as of the skin side layer 25a that can come into contact with the wearer's skin is rounded cotton fiber, it feels good against the wearer's skin and can reduce irritation to the wearer's skin when worn.

[0125] (Other Aspect 14) The sheet member 25 has a vertical direction and a horizontal direction perpendicular to the thickness direction, and is characterized in that the predetermined basis weight portions 25ap and the low basis weight portions 25aL are alternately arranged in the vertical direction, and the predetermined basis weight portions 25ap and the low basis weight portions 25aL are alternately arranged in the horizontal direction.

[0126] This improves absorbency and feel by the specified basis weight portion 25ap of the skin-side layer 25a, while facilitating the transfer of moisture absorbed by the skin-side layer 25a from the low basis weight portion 25aL to the non-skin-side layer 25b, thereby reducing the risk of moisture absorbed by the sheet member 25 remaining in contact with the wearer's skin and reducing discomfort and adverse effects on the wearer's skin.

[0127] (Other Aspect 15) A sheet member 25 characterized in that the density of the skin side fibers 25as in the low basis weight portion 25aL is lower than the density of the skin side fibers 25as in the predetermined basis weight portion 25ap.

[0128] This improves the absorbency and feel of the skin-side layer 25a, while also facilitating the transfer of moisture absorbed by the skin-side layer 25a from the low basis weight portion 25aL to the non-skin-side layer 25b, thereby reducing the risk of moisture absorbed by the sheet member 25 remaining in contact with the wearer's skin and reducing discomfort and adverse effects on the wearer's skin.

[0129] (Other Aspect 16) A sheet member 25 characterized in that at least a portion of the non-skin side fibers 25bs are present on the skin side surface of the skin side layer 25a.

[0130] This allows the absorbed liquid to be easily transferred from the skin-side layer 25a to the non-skin-side layer 25b, thereby reducing the risk that the moisture absorbed by the sheet member 25 will continue to come into contact with the wearer's skin, and reducing discomfort and adverse effects on the wearer's skin.

[0131] (Other Aspect 17) The sheet member 25 is characterized in that the sheet member 25 is not provided with an adhesive.

[0132] This reduces the risk of the sheet member 25 becoming hard and the risk of the adhesive interfering with moisture absorption, while also suppressing irritation to the skin of the wearer of the absorbent article 1 using this sheet member 25.

[0133] (Other Aspect 18) The sheet member 25 is characterized in that the sheet member 25 does not have a portion where the sheet member 25 is compressed in the thickness direction.

[0134] This reduces the risk of the sheet member 25 becoming hard, and makes it possible to suppress irritation to the skin of a wearer of the absorbent article 1 using this sheet member 25.

[0135] (Other Aspect 19) The sheet member 25 is characterized in that the sheet member 25 has a skin side layer 25a and a sheet compressed portion obtained by compressing a part of the skin side layer 25a in the thickness direction.

[0136] This reduces the risk of separation between the skin side layer 25a and the non-skin side layer 25b.

[0137] (Other aspect 20) The absorbent article 1 has a hydrophilic member that is more hydrophilic than the sheet member 25, and the sheet member 25 is used in the absorbent article 1 on the skin side in the thickness direction of the hydrophilic member and in a position that overlaps with the hydrophilic member when viewed in the thickness direction.

[0138] This makes it easier for the moisture absorbed from the sheet member 25 side to move to the non-skin side when the absorbent article 1 is worn, thereby reducing the discomfort and adverse effects caused by moisture continuing to adhere to the wearer's skin.

[0139] (Other aspect 21) The absorbent article 1 has a stretchable stretchable member, and the sheet member 25 is used in a position overlapping at least a part of the stretchable member when viewed in the thickness direction of the absorbent article 1 in an unfolded and stretched state.

[0140] In this way, the sheet member 25 improves the feel of the absorbent article 1 against the skin, and by forming wrinkles in at least a part of the sheet member 25, the breathability of the sheet member 25 is improved, thereby reducing stuffiness and irritation to the skin when the absorbent article 1 is worn.

[0141] (Other aspect 22) The absorbent article 1 has a compressing member having a portion compressed in the thickness direction, and the absorbent article 1 has a sheet member 25 provided on the skin side of the compressing member, and the sheet member 25 is characterized in that, when viewed in the thickness direction, the portion where the low basis weight portion 25aL and the non-skin side layer 25b overlap has a portion that overlaps the compressed portion of the compressing member.

[0142] In this case, the compressed member has a portion with a high density due to compression, and thus moisture can be easily transferred from the sheet member 25 to the compressed member by capillary action.

[0143] (Other Aspect 23) The sheet member 25 is characterized in that it has a portion where the skin side fibers 25as and the non-skin side fibers 25bs are melt-bonded.

[0144] This reduces the risk of separation between the skin side layer 25a and the non-skin side layer 25b.

[0145] (Other aspect 24) The non-skin side fiber 25bs is a thermoplastic fiber, and the absorbent article 1 has an adjacent member that is arranged at a position that overlaps the sheet member 25 when viewed in the thickness direction, and the absorbent article has a welded joint where the sheet member 25 and the adjacent member are welded and joined in the thickness direction, and the sheet member 25 is characterized in that when the absorbent article 1 is viewed in the thickness direction, the portion where the low basis weight portion 25aL and the non-skin side layer 25b overlaps at least a part of the welded joint.

[0146] This reduces the risk of the bond strength of the welded joint decreasing.

[0147] (Other aspect 25) The non-skin side fiber 25bs is a thermoplastic fiber, the absorbent article 1 has a joint where both left and right side portions of a pair of waistband portions 20, 30 are welded and joined, and a sheet member 25 is used in a position overlapping at least a portion of the joint when viewed in the thickness direction, and the joint overlaps at least a portion of the portion where the low basis weight portion 25aL and the non-skin side layer 25b overlap.

[0148] This reduces the risk of a decrease in the joining strength of the joints at both left and right sides of the pair of waistband portions 20, 30.

[0149] (Other Aspect 26) A sheet member characterized in that the pair of waistband portions 20, 30 have a plurality of intermittent joints in the vertical direction, and the distance between the centers of adjacent joints in the vertical direction is longer than the distance between the centers of the low basis weight portions 25aL.

[0150] This makes it easier for moisture absorbed by the skin-side layer 25a to move from the low basis weight portion 25aL to the non-skin-side layer 25b, while reducing the risk of a decrease in the bonding strength of the joints at both left and right sides of the pair of waistband portions 20, 30.

[0151] (Other aspect 27) The joints are provided intermittently in the vertical direction, the sheet member 25 has a vertical direction and a horizontal direction perpendicular to the thickness direction, and the area of ​​the region defined by straight lines connecting the centers of four low basis weight sections 25aL adjacent to each other in the vertical direction and horizontal direction is smaller than the maximum area of ​​the joints.

[0152] In this way, it becomes easier to provide a wider area where the low basis weight sections 25aL and the joint overlap in the thickness direction than when the area defined by the straight lines connecting the centers of four adjacent low basis weight sections 25aL in the vertical and horizontal directions is made larger than the maximum area of ​​the joint, making it easier to increase the bonding strength at the joint.

[0153] (Other aspect 28) The joints are provided intermittently in the vertical direction, the sheet member 25 has a vertical direction and a horizontal direction perpendicular to the thickness direction, and the area of ​​the region defined by straight lines connecting the centers of four low basis weight sections 25aL adjacent to each other in the vertical direction and horizontal direction is larger than the minimum area of ​​the joints.

[0154] In this way, the area where the low basis weight sections 25aL and the joint overlap when viewed in the thickness direction is wider than when the area of ​​the region defined by straight lines connecting the centers of four adjacent low basis weight sections 25aL in the vertical and horizontal directions is made larger than the maximum area of ​​the joint, thereby reducing the risk of the joint strength becoming excessively strong and making it difficult to separate the ventral waist section 20 and the dorsal waist section 30 after use of the absorbent article 1.

[0155] (Other Aspect 29) An absorbent article 1 having an absorbent body 10 and a sheet member 25 provided on the skin side of the absorbent body 10, wherein the sheet member 25 has a skin-side layer 25a that can come into contact with the wearer's skin and a non-skin-side layer 25b that is provided on the non-skin side of the skin-side layer 25a, wherein the skin-side fibers 25as that are base fibers of the skin-side layer 25a have a higher hydrophilicity than the non-skin-side fibers 25bs that are base fibers of the non-skin-side layer 25b, and the skin-side layer 25a has a predetermined basis weight portion 25ap that has skin-side fibers 25as of a predetermined basis weight and a low basis weight portion 25aL in which the skin-side fibers 25as have a lower basis weight than the predetermined basis weight portion 25ap, and wherein the absorbent article has, when viewed in the thickness direction, a portion where the predetermined basis weight portion 25ap and the non-skin-side layer 25b overlap and a portion where the low basis weight portion 25aL and the non-skin-side layer 25b overlap.

[0156] In this way, the highly hydrophilic skin-side layer 25a improves the absorbency and feel of the sheet member 25, while also facilitating the transfer of moisture absorbed by the skin-side layer 25a from the low basis weight portion 25aL to the non-skin side of the sheet member 25, thereby reducing the risk of moisture absorbed by the sheet member 25 remaining in contact with the wearer's skin and reducing discomfort and adverse effects on the wearer's skin.

[0157] ===Other=== The above embodiments are intended to facilitate understanding of the present invention and are not intended to limit the present invention. The present invention may be modified or improved without departing from the spirit thereof, and it goes without saying that the present invention includes equivalents thereof.

[0158] In the above-described embodiment and modified example, the seat portion 25 (35) is provided on both the ventral waist portion 20 and the dorsal waist portion 30, but this is not limited to this, and the seat portion 25 (35) may be provided on only one of the ventral waist portion 20 and the dorsal waist portion 30.

[0159] REFERENCE SIGNS LIST 1 pants-type disposable diaper (absorbent article) 10 absorbent body, 10e upper end 11 absorbent core 12 top sheet 13 back sheet 14 outer sheet 15 leg-hole elastic member 18 outer body 20 ventral waist portion 20e upper end 21 inner layer sheet 22 ventral outer layer sheet, 22r folded-back portion 23 waist-hole elastic member 25 sheet portion 25a cotton layer (skin-side layer) 25aL low basis weight portion, 25aL1 low basis weight portion, 25aL2 low basis weight portion 25ap predetermined basis weight portion 25as cotton fiber 25b non-skin-side layer, 25bs non-skin-side fiber 25H arrangement region 25UP upper arrangement region 30 back waist portion 32 back outer layer sheet, 32r folded-back portion 33 waist elastic member 34 rear leg elastic member 35 seat portion 40 crotch portion 50x joint portion 50z non-joined portion

Claims

1. An absorbent article having mutually intersecting vertical and thickness directions, comprising an absorbent main body, a ventral waist portion located on the ventral side of a wearer, and a rear waist portion located on the rear side of the wearer, wherein a sheet portion including a cotton layer based on cotton fibers and at least a portion of which is located above the absorbent main body in the vertical direction is provided on the side closest to the skin of at least one of the ventral waist portion and the rear waist portion, and wherein when a region of the sheet portion which is located above the absorbent main body in the vertical direction is defined as an upper arrangement region, the absorbent article has a joint portion where the upper arrangement region and an adjacent sheet member adjacent to the upper arrangement region from the non-skin-facing side in the thickness direction are joined by welding or adhesive, and a non-joint portion where the upper arrangement region and the adjacent sheet member are not joined by welding or adhesive.

2. An absorbent article as described in claim 1, characterized in that, in the unfolded and extended states, the total area of ​​the non-jointed portions when the upper arrangement region is viewed in a plane is greater than the total area of ​​the joined portions.

3. An absorbent article according to claim 2, characterized in that the total length of the joined portions in the vertical direction is longer than the total length of the non-jointed portions.

4. An absorbent article as described in claim 1 or 2, characterized in that the sheet portion has a non-skin side layer located on the non-skin side of the cotton layer in the thickness direction, and the average fiber length of the non-skin side fibers which are the base fiber of the non-skin side layer is longer than the average fiber length of the cotton fibers.

5. An absorbent article as claimed in claim 1 or 2, characterized in that the sheet portion has a non-skin side layer located on the non-skin side of the cotton layer in the thickness direction, and the thermal conductivity of the cotton fibre is lower than the thermal conductivity of the non-skin side fibre which is the base fibre of the non-skin side layer.

6. An absorbent article as claimed in claim 1 or 2, characterized in that the sheet portion has a non-skin side layer located on the non-skin side of the cotton layer in the thickness direction, and the hydrophilicity of the cotton fibre which is the base fibre of the cotton layer is higher than the hydrophilicity of the non-skin side fibre which is the base fibre of the non-skin side layer.

7. An absorbent article according to claim 1 or 2, characterized in that the ratio of said cotton fibers in said sheet portion is less than 50% by mass.

8. An absorbent article according to claim 1 or 2, characterized in that the cotton layer has a predetermined basis weight portion provided with cotton fibers of a predetermined basis weight, and a low basis weight portion in which the cotton fibers have a lower basis weight than the predetermined basis weight portion.

9. An absorbent article as described in claim 8, having a left-right direction perpendicular to the up-down direction and the thickness direction, at least one of the ventral waist portion and the dorsal waist portion having an inner layer sheet, an outer layer sheet arranged closer to the skin than the inner layer sheet, and waist elastic members stretchable in the left-right direction and arranged at intervals in the up-down direction between the inner layer sheet and the outer layer sheet, wherein a plurality of the low basis weight sections are provided in the cotton layer at intervals in the up-down direction, and the minimum value of the center-to-center distance in the up-down direction between adjacent low basis weight sections in the up-down direction is smaller than the minimum value of the center-to-center distance in the up-down direction between adjacent waist elastic members in the up-down direction.

10. An absorbent article according to claim 9, characterized in that the sheet portion is a sheet member disposed closer to the skin than the inner layer sheet.

11. An absorbent article as described in claim 9, wherein the sheet portion is arranged below and spaced from the upper end of at least one of the ventral waist portion and the rear waist portion in the vertical direction, and when a region in the vertical direction from the upper end of the ventral waist portion or the rear waist portion where the sheet portion is provided to the upper end of the sheet portion is defined as a non-positioning region, and a region in the vertical direction from the upper end to the lower end of the sheet portion of the ventral waist portion or the rear waist portion where the sheet portion is provided is defined as a positioning region, a portion of the non-positioning region closest to the skin contains hydrophobic fibers, and the magnitude of the force required to stretch the non-positioning region of a unit width in the vertical direction by a unit length in the left-right direction is greater than the magnitude of the force required to stretch the positioning region of a unit width in the vertical direction by a unit length in the left-right direction.

12. An absorbent article as claimed in claim 1 or 2, characterized in that the length of the sheet portion in the vertical direction is half or less of the length of the ventral waist portion or the dorsal waist portion.

13. An absorbent article as described in claim 1 or 2, wherein at least one of the ventral waist portion and the dorsal waist portion has an inner layer sheet, an outer layer sheet arranged on the non-skin side of the inner layer sheet, and a folded-back portion in which the upper end of the outer layer sheet in the vertical direction is folded back towards the skin side, and the length of the sheet portion in the vertical direction is longer than the length of the folded-back portion.

14. An absorbent article as described in claim 1 or 2, wherein at least one of the ventral waist portion and the dorsal waist portion has an inner layer sheet, an outer layer sheet arranged on the non-skin side of the inner layer sheet, and a folded-back portion in which the upper end of the outer layer sheet in the vertical direction is folded back towards the skin side, and the length of the sheet portion in the vertical direction is shorter than the length of the folded-back portion.

15. An absorbent article as described in claim 1 or 2, characterized in that the sheet portion straddles the upper end of the absorbent main body in the vertical direction in at least one of the ventral waist portion and the dorsal waist portion.

16. An absorbent article according to claim 1 or 2, characterized in that no hook-and-loop fastener is provided between said sheet portion and said adjacent sheet member in said thickness direction.

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