Absorbent article

Abstract

An absorbent article (1) comprises an absorbent body (10), a front waist section (20), and a back waist section (30), and further comprises a sheet section (25) disposed on the side closest to the skin of at least the front waist section (20) and the back waist section (30). The sheet section (25) and an adjacent sheet member adjacent to the sheet section (25) on the non-skin side are joined by adhesion or fusion. The sheet section (25) has a skin-side layer (25a) that comes into contact with the wearer's skin and a non-skin-side layer (25b) positioned on the non-skin side with respect to the skin-side layer (25a). The hydrophilicity of a skin-side fiber (25as), which is the base material fiber of the skin-side layer (25a), is higher than the hydrophilicity of the non-skin-side fiber (25bs), which is the base material fiber of the non-skin-side layer (25b).

Description

absorbent articles

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

[0002] Conventionally, 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 region. For example, Patent Document 1 discloses a wearing article which includes a front sweat-absorbent sheet and a rear sweat-absorbent sheet on the inner surfaces of the front and rear edge portions of the front and rear waist regions, each of which has an inner layer which contacts the wearer's skin and contains 70 to 98% by weight of hydrophobic fibers, and an outer layer which is on the side opposite to the inner layer and contains 50 to 100% by weight of hydrophilic fibers.

[0003] Japanese Patent Application Laid-Open No. 2001-327534

[0004] The wearing article described in Patent Document 1 transfers sweat from the front and back of the waist to the outer layer, and by placing mainly sweat-free hydrophobic fibers in contact with the skin, the waist area is prevented from becoming stuffy due to sweat, even when the sweat-absorbent sheet is tightly attached to the waist. However, in the case of absorbent articles in which a sheet material containing hydrophilic fibers is arranged, particularly when the outer layer (non-skin side) contains a large amount of hydrophilic fibers as in Patent Document 1, if the sheet material becomes wet with sweat or excrement, the adhesive strength between the sheet material and another sheet material adjacent to the non-skin side may decrease, and the sheet material may partially peel off. If the sheet material peels off, it will no longer be able to perform its original functions, such as absorbing sweat, and the wearing comfort may be impaired.

[0005] The present invention has been made in consideration of the above-mentioned problems, and its purpose is to provide an absorbent article in which, when a sheet portion having hydrophilic fibers is placed on the side of the waist that faces the skin, the sheet portion is unlikely to peel off from the absorbent article main body even when wet.

[0006] The main invention for achieving the above object is an absorbent article having an absorbent main body, a ventral waistband portion located on the ventral side of a wearer, and a dorsal waistband portion located on the dorsal side of the wearer, wherein the absorbent article further comprises a sheet portion located closest to the skin of at least one of the ventral waistband portion and the dorsal waistband portion, the sheet portion and an adjacent sheet member adjacent to the sheet portion from the non-skin-facing side being joined by adhesive or welding, the sheet portion having a skin-side layer that contacts the wearer's skin and a non-skin-side layer that is located on the non-skin-facing side of the skin-side layer, the skin-side fiber that is the base fiber of the skin-side layer having a higher hydrophilicity than the non-skin-side fiber that is the base fiber of the non-skin-side layer. 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, an absorbent article can be provided in which, when a sheet portion having hydrophilic fibers is placed on the side of the waist that faces the skin, the sheet portion is unlikely to peel off from the absorbent article main body even when wet.

[0008] 5 is a schematic perspective view of the diaper 1 as seen from the abdominal side. FIG. 6 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 schematic cross-sectional view of the sheet portion 25 to the folded-back portion 22r taken along line X in FIG. 5. FIG. 7 is an enlarged photograph of the sheet portion 25 as seen from the skin side. FIG. 8 is an enlarged photograph of the sheet portion 25 as seen from the non-skin side. FIG. 9 is a diagram showing a modified example of the sheet portion 25. FIG. 10A and FIG. 10B are diagrams illustrating another modified example of the sheet portion 25. FIG. 10B is a diagram showing a modified example of the arrangement of the sheet portion 25. FIG. 10C is a diagram showing yet another modified example of the sheet portion 25. FIG. 10D is a diagram showing yet another modified example of the sheet portion 25.

[0009] At least the following points become clear from the description of this specification and the accompanying drawings: Aspect 1 is an absorbent article having an absorbent main body, a ventral waistline portion located on the ventral side of a wearer, and a dorsal waistline portion located on the dorsal side of the wearer, the absorbent article further comprising a sheet portion located on the closest skin-facing side of at least one of the ventral waistline portion and the dorsal waistline portion, the sheet portion and an adjacent sheet member adjacent to the sheet portion from the non-skin-facing side being joined by adhesive or welding, the sheet portion having a skin-side layer that contacts the wearer's skin and a non-skin-side layer located on the non-skin-facing side of the skin-side layer, the hydrophilicity of the skin-side fiber that is the base fiber of the skin-side layer being higher than the hydrophilicity of the non-skin-side fiber that is the base fiber of the non-skin-side layer.

[0010] According to Aspect 1, the skin-side layer has high hydrophilicity of the skin-side fibers, so it easily absorbs sweat and excrement. On the other hand, the non-skin-side layer has a lower hydrophilicity than the skin-side fibers, which is the base fiber, so even if the sheet portion gets wet, it can maintain its adhesive strength with the adjacent sheet member and prevent peeling of the sheet portion. This allows the sheet portion to perform its intended function and prevents the sheet portion from peeling, which could impair the wearing comfort.

[0011] Aspect 2 is the absorbent article according to aspect 1, wherein the content of the skin side fibers in the sheet portion is 50% by mass or less.

[0012] According to aspect 2, if the mass proportion of highly hydrophilic skin-side fibers in the entire sheet portion becomes too high, there is a risk that the adhesive strength with adjacent sheet members will be weakened when the sheet portion becomes wet. However, this can be avoided by reducing the mass proportion of skin-side fibers in the entire sheet portion.

[0013] Aspect 3 is the absorbent article according to aspect 1 or 2, wherein at least a portion of the skin side fibers in the skin side layer are present on the same plane as the non-skin side surface of the non-skin side layer.

[0014] According to Aspect 3, moisture absorbed by the skin-side layer can be quickly transferred to the non-skin-side layer via the extending skin-side fibers. This allows excess moisture in the skin-side layer to be removed by the non-skin-side layer, and because the non-skin-side layer has a low proportion of skin-side fibers, it does not retain too much of the transferred moisture and can maintain adhesive strength with the adjacent sheet member. This prevents the sheet portion from peeling off unexpectedly, which could impair the wearing comfort.

[0015] Aspect 4 is the absorbent article according to any one of Aspects 1 to 3, wherein the average fiber length of the skin side fibers in the skin side layer is shorter than the average fiber length of the non-skin side fibers in the non-skin side layer.

[0016] According to Aspect 4, the short average fiber length of the skin-side fibers in the skin-side layer allows them to easily penetrate into the gaps between the non-skin-side fibers in the non-skin-side layer, and moisture absorbed by the skin-side layer can be quickly transferred to the non-skin-side layer via the penetrated skin-side fibers. Furthermore, the longer average fiber length of the non-skin-side fibers in the non-skin-side layer increases the bonding strength with the adjacent sheet member. This prevents unexpected peeling of the sheet portion while removing excess moisture from the skin-side layer.

[0017] Aspect 5 is an absorbent article described in any of Aspects 1 to 4, in which when the welded portions are the areas where fibers are welded together in the skin-side layer and the non-skin-side layer, the total volume of the welded portions per unit volume of the non-skin-side layer is larger than the total volume of the welded portions per unit volume of the skin-side layer.

[0018] According to Aspect 5, the skin-side layer has few (or no) welded portions, so moisture can easily penetrate between the fibers and absorb moisture from the wearer's skin. On the other hand, the non-skin-side layer has welded portions, which ensures surface smoothness and makes it easier to maintain adhesive strength even when the sheet portion becomes wet. Furthermore, the presence of welded portions in the non-skin-side layer improves the strength of the sheet portion as a whole, making it less likely to peel from adjacent sheet members.

[0019] Aspect 6 is the absorbent article according to aspect 5, wherein the ratio of the total volume of the welded portions to the entire volume of the non-skin side layer is 5% or more and 25% or less.

[0020] According to Aspect 6, the presence of the welded portions in such a proportion ensures the smoothness of the surface of the non-skin side layer, which makes it easier to maintain adhesive strength even when the sheet portion is wet, and improves the strength of the sheet portion as a whole, thereby making it less likely to peel from the adjacent sheet member.

[0021] Aspect 7 is an absorbent article described in any one of Aspects 1 to 6, wherein the non-skin side layer has a non-skin side portion of the non-skin side layer located on the skin side in the thickness direction of the non-skin side layer 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 of the non-skin side portion of the non-skin side layer is higher than the fiber density of the non-skin side fibers of the non-skin side portion of the non-skin side layer.

[0022] According to aspect 7, the non-skin side portion of the non-skin side layer is the portion that adheres to the adjacent sheet member, and the higher fiber density of the non-skin side portion can increase the adhesive strength with the adjacent sheet member.

[0023] Aspect 8 is an absorbent article described in any of Aspects 1 to 6, wherein the non-skin side layer has a non-skin side portion of the non-skin side located on the skin side in the thickness direction of the non-skin side layer and a non-skin side portion of the non-skin side of the non-skin side layer, and the fiber density of the non-skin side fibers of the non-skin side portion of the non-skin side layer is higher than the fiber density of the non-skin side fibers of the non-skin side portion of the non-skin side layer.

[0024] According to aspect 8, 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 part of the non-skin side fiber with higher fiber density is placed adjacent to the skin side layer with higher hydrophilicity, and the moisture absorbed by the skin side fiber is drawn into the skin side portion of the non-skin side layer, reducing the moisture in the skin side layer and suppressing stickiness in the part that comes into contact with the skin.

[0025] Aspect 9 is an absorbent article described in any one of Aspects 1 to 8, wherein the non-skin side layer has a non-skin side portion of the non-skin side located on the skin side in the thickness direction of the non-skin side layer, and a non-skin side portion of the non-skin side of the non-skin side layer located on the non-skin side, and the hydrophilicity of the non-skin side fibers in the non-skin side portion of the non-skin side layer is higher than the hydrophilicity of the non-skin side fibers in the non-skin side portion of the non-skin side layer.

[0026] According to Aspect 9, the skin-side portion of the non-skin-side layer is the portion that contacts the skin-side fibers of the skin-side layer, and by increasing the hydrophilicity of the non-skin-side fibers in the skin-side portion of the non-skin-side layer, moisture is easily transferred from the skin-side fibers to the non-skin-side fibers. 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 evaporation is more likely to be promoted. Since moisture is less likely to accumulate in the non-skin-side portion of the non-skin-side layer, adhesion between the non-skin-side layer and the adjacent sheet member is more easily maintained.

[0027] Aspect 10 is an absorbent article according to any one of Aspects 1 to 9, wherein the skin-side fibers are cotton fibers, and the non-skin-side fibers are hydrophobic fibers containing at least one of polypropylene, polyethylene, and polyurethane, or fibers that have been hydrophilically treated with at least one of polypropylene, polyethylene, and polyurethane.

[0028] According to Aspect 10, the skin-side layer contains cotton fibers, which facilitates moisture absorption from the skin. The non-skin-side layer contains the hydrophobic fibers (or hydrophilically treated fibers), which prevents excess moisture from the skin-side layer from being excessively retained after it migrates to the non-skin-side layer, promoting evaporation to the non-skin side. This maintains the adhesive strength with the adjacent sheet member and prevents unexpected peeling of the sheet portion, which could impair the wearing comfort.

[0029] Aspect 11 is an absorbent article described in any one of Aspects 1 to 10, wherein the skin side layer has a predetermined basis weight portion having skin side fibers of a predetermined basis weight, and a low basis weight portion having skin side fibers with a lower basis weight than the predetermined basis weight portion.

[0030] According to aspect 11, the specified basis weight portion is a portion that is absorbent and feels good against the skin, and moisture such as sweat absorbed from the skin side is easily transferred from the low basis weight portion to the non-skin side, thereby preventing moisture from accumulating in the skin side layer and promoting evaporation.

[0031] Aspect 12 is an absorbent article described in Aspect 11, in which the non-skin side layer has a predetermined basis weight portion having non-skin side fibers of a predetermined basis weight, and a low basis weight portion in which the non-skin side fibers have a lower basis weight than the predetermined basis weight portion, and the low basis weight portion of the skin side layer and the low basis weight portion of the non-skin side layer have overlapping portions when viewed in the thickness direction of the absorbent article.

[0032] According to aspect 12, in the overlapping area, the moisture absorbed by the skin-side layer is promoted to be drawn from the low basis weight portion of the skin-side layer to the low basis weight portion of the non-skin-side layer, and by more quickly removing moisture from the sheet portion, the adhesive strength can be maintained and peeling of the sheet portion can be prevented.

[0033] ===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.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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).

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] <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.

[0049] 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.

[0050] In this embodiment, the skin-side fiber, which is the base fiber of the skin-side layer 25a, is cotton fiber. The term "base material" as used herein refers to a material that accounts for more than 50% by mass 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, may be polyester fiber, polypropylene fiber, polyethylene fiber, polyurethane fiber, or a composite fiber thereof, whose surface has been hydrophilically treated. The fibers listed as the non-skin-side fibers may also be fibers that have not been hydrophilically treated.

[0051] In the sheet member constituting the sheet portion 25 of this embodiment, the skin side fibers 25as, which are the base fibers of the skin side 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 skin side layer 25a and the non-skin side layer 25b can be integrated by entanglement using, for example, a known hydroentangling method using a water jet.

[0052] As described above, the sheet member (sheet portion 25) is formed by intertwining the fibers of each layer, and in the skin side layer 25a of this embodiment, all fibers except for the non-skin side fibers 25bs that have penetrated into the skin side layer 25a are cotton fibers. However, the present invention is not limited to this, and the skin side layer 25a may contain more than 50% by mass of cotton fibers, and preferably more than 80% by mass of cotton fibers.

[0053] In this embodiment, in the process of integrating the skin side 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 25bs 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 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 completely remains.

[0054] Therefore, in the sheet portion 25 of this embodiment, the skin-side fibers 25as, which are the base fibers of the skin-side layer 25a, have a higher hydrophilicity than the non-skin-side fibers 25bs, which are the base fibers of the non-skin-side 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 skin-side layer 25a, and the absorbed sweat then migrates to the non-skin-side layer 25b. By arranging the skin-side layer 25a, which is based on the highly hydrophilic skin-side fibers 25as, on the surface that contacts the wearer's skin, water absorption is improved. Furthermore, because the non-skin-side fibers 25bs of the non-skin-side layer 25b have a lower hydrophilicity than the cotton fibers 25as, when moisture, such as sweat absorbed by the cotton fibers 25as, migrates to the non-skin-side layer 25b, the non-skin-side layer 25b does not retain excessive moisture and promotes evaporation, 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.

[0055] 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.

[0056] Furthermore, when compared using the above-mentioned evaluation method, the skin-side fibers 25as of the skin-side layer 25a have a higher degree of hydrophilicity than the non-skin-side fibers 25bs of the non-skin-side layer 25b, which are "fibers in which the hydrophilizing agent remains completely."

[0057] The thickness of each of the skin side layer 25a and the non-skin side layer 25b is preferably, for example, about 0.3 mm to 0.4 mm for the skin side layer 25a, and about 0.1 mm for the non-skin side layer 25b.

[0058] 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 schematic diagram showing a cross section from the sheet portion 25 to the folded-back portion 22r at position X in Fig. 5. In this embodiment, as shown in Fig. 5, a bonded portion 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 refers 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 bonded portion 50x is formed by applying hot melt adhesive in a spiral pattern extending along the left-right direction and arranged in two vertical rows, but the number and application pattern are not limited thereto. For example, the joints 50x may be provided by applying an adhesive such as a hot melt adhesive by a non-contact application method, or by thermal welding or ultrasonic welding.

[0059] The ventral waistline portion 20 also has a non-joined portion 50z where the sheet portion 25 and an adjacent sheet member (the top sheet 12 or the folded-back portion 22r of the ventral outer layer sheet 22) are not joined by adhesive or the like.

[0060] Thus, in the case of an absorbent article such as a diaper 1 in which a sheet portion 25 (sheet member) containing hydrophilic fibers such as cotton fibers is arranged on the skin-contacting surface, there are advantages such as improved sweat absorption and softness against the skin, but on the other hand, when the sheet member becomes wet with sweat or excrement, the adhesive strength between the sheet member and the absorbent article main body decreases, and there is a risk of the sheet member partially peeling off. If the sheet member partially peels off, there is a risk that the sheet member will not be able to perform its original function, which may impair the wearing comfort.

[0061] As described above, in the sheet portion 25 of this embodiment, the skin-side fibers 25as, which are the base fibers of the skin-side layer 25a of the sheet portion 25, have a higher hydrophilicity than the non-skin-side fibers 25bs, which are the base fibers of the non-skin-side layer 25b. This allows the skin-side layer 25a to easily absorb sweat and excrement. When the sheet portion 25 absorbs moisture such as sweat, the adhesive at the joints 50x that join the sheet portion 25 to the folded portion 22r of the ventral outer layer sheet 22 or the top sheet 12 may become wet, potentially reducing adhesive strength. However, because the non-skin-side fibers 25bs of the non-skin-side layer 25b have a lower hydrophilicity than the skin-side fibers 25as, the adhesive strength at the joints 50x can be maintained even when the sheet portion 25 becomes wet, preventing peeling of the sheet portion 25. This allows the sheet portion 25 to perform its intended function and prevents peeling of the sheet portion 25 from impairing the wearing comfort.

[0062] Furthermore, unlike the present embodiment, even when the sheet portion 25 and the folded-back portion 22r disposed on the non-skin side of the sheet portion 25 or the joint portion 50x with the top sheet 12 are joined by welding, it is conceivable that when the sheet portion 25 absorbs sweat or the like and becomes moist, the entanglement strength that entangles the fibers decreases, making the sheet portion 25 more likely to peel off. However, because the hydrophilicity of the non-skin side fibers 25bs is lower than that of the skin side fibers 25as, the non-skin side fibers 25bs are less likely to remain moist and therefore the entanglement strength is less likely to decrease, thereby preventing the sheet portion 25 from peeling off.

[0063] Here, the adhesive strength of the joints in a wet state was compared using the following method. <Method for evaluating adhesive strength> 1) First, an outer layer spunbond nonwoven fabric was used as a sample of the member adjacent to the sheet portion 25 from the non-skin side. Multiple sheets of outer layer spunbond nonwoven fabric measuring 50 mm x 25 mm were prepared. 2) For evaluation, the above outer layer spunbond nonwoven fabric was bonded to each of the following three samples: a) Non-skin side layer 25b of the sheet member constituting sheet portion 25 (Example) b) Hydrophobic spunbond nonwoven fabric (100% synthetic fiber) (Comparative Example 1) c) Skin side layer 25a of the sheet member constituting sheet portion 25 (Comparative Example 2) Three sheets of each of the above a) to c) were prepared, each measuring 50 mm x 25 mm. Each sample was prepared by applying a hot melt adhesive to the outer layer spunbond nonwoven fabric and each of the sheets (or surfaces) a) to c) in the same pattern as the joint 50x. Three samples of each bonded sample (Example, Comparative Example 1, Comparative Example 2) were prepared. 3) Each sample was placed on the water surface with surfaces a) to c) facing downwards (i.e., with the outer layer spunbond nonwoven fabric facing away from the water surface) and left for 10 minutes. 4) Each sample was removed from the water surface and pulled in a tensile tester to peel the outer layer spunbond nonwoven fabric and each of the sheets a) to c) in a 180° direction, and the load value was measured. 5) The average of the measured load values ​​was taken as the adhesive strength (N).

[0064] The average values ​​obtained by the above-mentioned measurement method were highest in Comparative Example 1, followed by the Example and Comparative Example 2, with the average values ​​being 3.58 N for Comparative Example 1, 2.50 N for the Example and 0.73 N for Comparative Example 2. This indicates that the more cotton fibers there are on the bonding surface, the lower the adhesive strength becomes.

[0065] Therefore, in this embodiment, the non-skin side layer 25b, which has a small amount of cotton fibers, and the folded-back portion 22r of the ventral outer layer sheet 22 are joined at the joint 50x, so that even if the sheet portion 25 absorbs moisture, the adhesive strength of the joint 50x is not likely to decrease, and the sheet portion 25 is not likely to peel off.

[0066] Furthermore, the content of the skin side fibers 25as may be 50% by mass or less in the entire sheet portion 25. 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 to adjacent sheet members such as the top sheet 12 and the folded-back portion 22r of the ventral outer layer sheet 22 may be weakened when the sheet portion 25 becomes wet with sweat or the like. However, this can be avoided by reducing the mass proportion of the skin side fibers 25as in the entire sheet portion 25.

[0067] In order to compare the mass of each fiber in the entire sheet portion 25, it is necessary to separate the skin-side fibers 25as and 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 stir it for 24 hours, thereby separating the skin-side fibers 25as and the non-skin-side fibers 25bs.

[0068] 4 and 6, the skin side layer 25a and the non-skin side layer 25b are laminated in the thickness direction, and at least a portion of the skin side fibers 25as of the skin side layer 25a is present on the same plane as the non-skin side surface of the non-skin side layer 25b. That is, the skin side fibers 25as of the skin side 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 skin side fibers 25as are also present on the same plane as the non-skin side surface of the non-skin side layer 25b. In this way, the presence of the skin side fibers 25as in the non-skin side layer 25b allows moisture absorbed by the skin side layer 25a to be quickly transferred to the non-skin side layer 25b via the extending skin side fibers 25as. This allows excess moisture in the skin-side layer 25a to be removed to the non-skin-side layer 25b, while the non-skin-side layer 25b, having a low proportion of skin-side fibers 25bs, does not retain too much moisture that has migrated thereto, and is able to maintain adhesive strength with the folded-back portion 22r of the ventral-side outer layer sheet 22 adjacent to the non-skin-side side or the top sheet 12 (adjacent sheet member).This prevents the sheet portion 25 from peeling off unexpectedly, thereby preventing a loss of comfort when worn.

[0069] Conversely, at least a portion of the non-skin side fibers 25bs of the non-skin side layer 25b extend into the skin side layer 25a, and some of the non-skin side fibers 25bs are present on the same plane as the skin side surface of the skin side layer 25a. This makes it easier for absorbed liquid to migrate from the skin side layer 25a to the non-skin side layer 25b along the non-skin side fibers 25bs extending into the skin side layer 25a, and the migrated moisture is less likely to remain in the non-skin side layer 25b, which has low hydrophilicity, and this makes it easier for evaporation to be promoted.

[0070] Furthermore, the average fiber length of the skin-side fibers 25as in the skin-side layer 25a is shorter than the average fiber length of the non-skin-side fibers 25bs in the non-skin-side layer 25b. The short average fiber length of the skin-side fibers 25as in the skin-side layer 25a allows them to easily penetrate into the gaps between the non-skin-side fibers 25bs in the non-skin-side layer 25b, allowing moisture absorbed by the skin-side layer 25a to be rapidly transferred to the non-skin-side layer 25b via the penetrated skin-side fibers 25as. Furthermore, the longer average fiber length of the non-skin-side fibers 25bs in the non-skin-side layer 25b increases the bond strength to the folded-back portion 22r of the ventral outer layer sheet 22 adjacent to the non-skin side or the top sheet 12 (adjacent sheet component). This prevents unexpected peeling of the sheet portion 25 while removing excess moisture from the skin-side layer 25a.

[0071] 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).

[0072] Furthermore, in the sheet portion 25 of this embodiment, when the skin side layer 25a and the non-skin side layer 25b are formed by hydroentanglement, the kinetic energy of the water flow may be converted into thermal energy, causing the fibers to melt. In particular, in the non-skin side layer 25b, the fibers exemplified as base fibers are thermoplastic resin fibers, and thus hydroentanglement forms a welded portion (not shown) in which the fibers are partially welded together. Because the base fiber of the skin side layer 25a is cotton, the cotton fibers do not melt together due to the water flow. However, the non-skin side fibers 25bs that have entered the skin side layer 25a due to entanglement may melt, and a welded portion may be formed in which the skin side fibers 25as that are entangled with the melted non-skin side fibers 25bs are also entangled with the melted non-skin side fibers 25bs. As described above, the skinside layer 25a and the non-skinside layer 25b have welded portions where fibers are welded together. However, because the base fiber of the non-skinside layer 25b is a thermoplastic resin fiber, the total volume of the welded portions per unit volume of the non-skinside layer 25b is greater than the total volume of the welded portions per unit volume of the skinside layer 25a. Note that the "total volume of the welded portions per unit volume of the skinside layer 25a" also includes cases where the total volume of the welded portions is zero. Furthermore, the ratio of the total volume of the welded portions to the overall volume of the non-skinside layer 25b is preferably 5% to 25%. Because the skinside layer 25a has few (or no) welded portions, moisture easily penetrates between the fibers, absorbing moisture from the wearer's skin. Meanwhile, the non-skinside layer 25b has welded portions, ensuring a smooth surface and making it easier to maintain adhesive strength even when the sheet portion 25 becomes wet. In addition, the presence of the welded portion in the non-skin side layer 25b improves the strength of the sheet portion 25 as a whole, making it less likely to peel off from the folded portion 22r or top sheet 12 (adjacent sheet member) adjacent to the non-skin side.

[0073] 6, the non-skin side layer 25b has a non-skin side portion 25bA of the non-skin side layer located on the skin side and a non-skin side portion 25bB of the non-skin side layer located on the non-skin side in the thickness direction of the non-skin side layer 25b. The sheet member constituting the sheet portion 25 of this embodiment is formed by hydroentangling the skin side fibers 25as of the skin side layer 25a and the non-skin side fibers 25bs of the non-skin side layer 25b, and during hydroentangling, water is applied from both the skin side of the skin side layer 25a and the non-skin side of the non-skin side of the non-skin side layer 25b. That is, since the water flow is applied to the non-skin side layer 25b from the non-skin side portion 25bB side, when the non-skin side fibers 25bs of the non-skin side portion 25bA of the non-skin side layer are compared with the non-skin side fibers 25bs of the non-skin side portion 25bB, the fiber density of the non-skin side fibers 25bs of the non-skin side portion 25bA 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 25bB of the non-skin side layer. Since a higher fiber density facilitates liquid absorption, as in this embodiment, by arranging the high fiber density portion of the non-skin side fibers 25bs (non-skin side portion 25bA of the non-skin side layer) adjacent to the highly hydrophilic skin side layer 25a, moisture absorbed by the skin side fibers 25as is quickly absorbed into the non-skin side portion 25bA of the non-skin side layer, reducing moisture in the skin side layer 25a and suppressing stickiness at the portion in contact with the skin.

[0074] Furthermore, the fiber densities of the non-skin side layer skin side portion 25bA and the non-skin side layer non-skin side portion 25bB are not limited to this, and conversely, the fiber density of the non-skin side fibers 25bs of the non-skin side layer non-skin side portion 25bB may be higher than the fiber density of the non-skin side fibers 25bs of the non-skin side layer skin side portion 25bA. The non-skin side layer non-skin side portion 25bB is the portion that adheres to the folded-back portion 22r of the ventral outer layer sheet 22 adjacent to the non-skin side or the top sheet 12 (adjacent sheet member), and the higher fiber density of the non-skin side fibers 25bs of the non-skin side layer non-skin side portion 25bB can increase the adhesive strength with the adjacent sheet member.

[0075] Similarly, when the sheet member (sheet portion 25) is produced by hydroentanglement, the water flow is applied to the non-skin side layer 25b from the non-skin side portion 25bB side of the non-skin side layer, and the hydrophilizing agent adhering to the fiber surface of the non-skin side fibers 25bs on the non-skin side portion 25bB side of the non-skin side layer is more easily removed by the water flow than the non-skin side fibers 25bs on the non-skin side portion 25bA side of the non-skin side layer. Therefore, the hydrophilicity of the non-skin side fibers 25bs on the non-skin side portion 25bA of the non-skin side layer is higher than that of the non-skin side fibers 25bs on the non-skin side portion 25bB of the non-skin side layer. The hydrophilicity can be compared in the same manner as described above using the hydrophilicity evaluation method.

[0076] The non-skin side layer skin side portion 25bA is the portion of the skin side layer 25a that abuts the skin side fibers 25as, and by increasing the hydrophilicity of the non-skin side fibers 25bs in the non-skin side layer skin side portion 25bA, moisture is more easily transferred 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 layer non-skin side portion 25bB, which has low hydrophilicity, and evaporation is more easily promoted. Since moisture is less likely to accumulate in the non-skin side layer non-skin side portion 25bB, adhesion between the non-skin side layer 25b and the adjacent folded-back portion 22r or top sheet 12 (adjacent sheet member) on the non-skin side is more easily maintained.

[0077] As described above, in this embodiment, the skin-side fibers 25as are cotton fibers, and the non-skin-side fibers 25bs are fibers that have been hydrophilically treated with at least one of polypropylene, polyethylene, and polyurethane, or may be hydrophobic fibers containing one of polypropylene, polyethylene, and polyurethane. The inclusion of cotton fibers in the skin-side layer 25a facilitates moisture absorption from the skin. Furthermore, the non-skin-side fibers 25bs of the non-skin-side layer 25b have a lower hydrophilicity than the skin-side fibers 25as. Therefore, after moisture from the skin-side layer 25a migrates to the non-skin-side layer 25b, the moisture is not excessively retained, and the moisture is more likely to evaporate toward the non-skin side. This allows the non-skin-side layer 25b to maintain its adhesive strength with the folded-back portion 22r or the top sheet 12 (adjacent sheet member) adjacent to the non-skin side, preventing unintended peeling of the sheet portion 25 and resulting in a loss of comfort when worn.

[0078] FIG. 7 shows an enlarged photograph of the sheet portion 25 as viewed from the skin side. FIG. 8 shows an enlarged photograph of the sheet portion 25 as viewed from the non-skin side. As shown in FIG. 4, the skin-side layer 25a has a predetermined basis weight portion 25ap having skin-side fibers 25as of a predetermined basis weight and a low basis weight portion 25aL having a lower basis weight of the skin-side fibers 25as than the predetermined basis weight portion 25ap. Here, basis weight refers to mass per unit area. FIG. 7 shows the skin-side layer 25a as viewed from the skin side, and for ease of understanding, some of the low basis weight portions 25aL are surrounded by white lines (the low basis weight portions 25aL are the areas inside the white lines). Note that the low basis weight portions 25aL in this embodiment also include cases where the basis weight of the skin-side fibers 25as is zero. Specifically, in the low basis weight portion 25aL shown in Figure 7, the basis weight of the skin side 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 skin side layer 25a can be seen.

[0079] The predetermined basis weight portion 25ap of the skin-side layer 25a is a portion that has good absorbency and a pleasant feel against the skin. In addition, in the skin-side layer 25a, moisture such as sweat absorbed from the skin side is easily transferred from the low basis weight portion 25aL to the non-skin side, which prevents moisture from being accumulated in the skin-side layer 25a and promotes evaporation.

[0080] Similarly, the non-skinside layer 25b has a predetermined basis weight portion 25bp with non-skinside fibers 25bs of a predetermined basis weight and a low basis weight portion 25bL in which the non-skinside fibers 25bs have a basis weight lower than that of the predetermined basis weight portion 25bp ( FIG. 4 ). Fig. 8 shows the non-skinside layer 25b as viewed from the non-skinside side. Similarly, for clarity, Fig. 8 also shows some of the low basis weight portions 25bL enclosed by white lines (the low basis weight portions 25bL are the areas inside the white lines). Note that the low basis weight portions 25bL in this embodiment also include cases in which the basis weight of the non-skinside fibers 25bs is zero. As shown in Figs. 4, 7, and 8, the low basis weight portions 25aL of the skinside layer 25a and the low basis weight portions 25bL of the non-skinside layer 25b overlap in the thickness direction of the diaper 1. The overlapping portion promotes the drawing of moisture absorbed by the skin-side layer 25a from the low basis weight portion 25aL of the skin-side layer 25a to the low basis weight portion 25bL of the non-skin-side layer 25b, allowing moisture to be more quickly removed from the sheet portion 25. This maintains the adhesive strength between the sheet portion 25 and the folded-back portion 22r or the top sheet 12 (adjacent sheet member) adjacent to the sheet portion 25 from the non-skin side, preventing peeling of the sheet portion 25.

[0081] 7 and 8 schematically show the low basis weight portions 25aL of the skin side layer 25a and the low basis weight portions 25bL of the non-skin side layer 25b. As shown in Fig. 7 and 8, the skin side layer 25a and the non-skin side layer 25b each have a plurality of low basis weight portions 25aL, 25bL spaced apart in the vertical direction. In this embodiment, the low basis weight portions 25aL, 25bL are shown as being generally diamond-shaped, but the shape, number, and arrangement of the low basis weight portions 25aL, 25bL are not limited to the configuration of the low basis weight portions 25aL, 25bL of this embodiment.

[0082] 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.

[0083] 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 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, is joined to 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 by a joint 50x (not shown here) formed by welding or bonding. In this modification, the non-skin-side fibers 25bs of the non-skin-side layer 25b are less hydrophilic than the skin-side fibers 25as of the skin-side layer 25a. Therefore, even if the sheet portion 25 of the inner layer sheet 21 becomes wet with sweat or the like during wear, the non-skin-side layer 25b does not continue to retain moisture, and the adhesive strength at the joint 50x can be maintained. This prevents the sheet portion 25 from peeling off from the ventral outer layer sheet 22.

[0084] 10A and 10B are diagrams illustrating another modified example of the sheet portion 25. In the modified example shown in FIGS. 10A and 10B, a separate sheet member is not 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 forms the sheet portion 25 (35) has a skin-side 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 (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) from the non-skin-side side in the thickness direction have a joint portion 50x (not shown here) joined by welding or adhesive. As a result, even if the sheet portion 25 (35) of the folded portion 22r (32r) becomes wet with sweat or the like, the non-skin side fibers 25bs of the non-skin side layer 25b are less hydrophilic than the skin side fibers 25as of the skin side layer 25a, so the non-skin side layer 25b does not continue to retain moisture and the adhesive strength at the joint 50x can be maintained, thereby preventing the sheet portion 25 from peeling off from the inner sheet 21.

[0085] 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.

[0086] FIG. 12 shows 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 skin-side layer 25a is present on most of the skin-contacting surface of the ventral waistline portion 20 (back waistline portion 30) in a region other than the region where the absorbent main body 10 is disposed, thereby improving the feel against the skin. Furthermore, even if the sheet member (sheet portion 25) is arranged on most of the skin-contacting surface of the ventral waist portion 20 (dorsal waist portion 30) in this manner, the hydrophilicity of the non-skin-side fibers 25bs of the non-skin-side layer 25b is lower than that of the skin-side fibers 25as of the skin-side layer 25a. Therefore, even after the sheet member (sheet portion 25) becomes wet with sweat or the like, the non-skin-side layer 25b does not continue to retain moisture, and the bonding strength between the sheet member and the adjacent sheet member on the non-skin side can be maintained.

[0087] Fig. 13 is a diagram illustrating yet another modified example of the arrangement of the sheet portion 25. In the modified example shown in Fig. 13, the sheet portion 25 is provided as the top sheet 12 of the absorbent main body 10. The top sheet 12 is the component of the absorbent main body 10 that comes into contact with the wearer's skin, and therefore, by providing the sheet portion 25 as the top sheet 12, it is possible to improve the feel against the skin by the skin-side fibers 25as of the skin-side layer 25a, while reducing discomfort to the wearer's skin and adverse effects on the wearer's skin.

[0088] <Other Aspects of the Absorbent Article 1> In addition to the above-described aspects, the absorbent article 1 can have the following aspects.

[0089] (Other aspect 1) An absorbent article 1 having mutually intersecting vertical and thickness directions, the absorbent article 1 comprising 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 a sheet portion 25 including a cotton layer 25a based on cotton fibers is provided on the side closest to the skin of at least one of the ventral waistline portion 20 and the dorsal waistline portion 30, and at least a portion of the sheet portion 25 is located above the absorbent main body 10 in the vertical direction, and when a region of the sheet portion 25 located above the absorbent main body 10 in the vertical direction is defined as an upper arrangement region, the absorbent article 1 has a joint portion 50x 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 50z where the upper arrangement region and the adjacent sheet member are not joined by welding or adhesive.

[0090] As a result, the non-jointed portions 50z of the sheet portion 25 that come into contact with the skin are easily deformed, and when movement occurs in the waistband portions 20, 30, the non-jointed portions 50z follow such movement, reducing friction with the skin and thereby suppressing pilling of the cotton fibers. At the same time, the presence of the joined portions 50x 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.

[0091] (Other Aspect 2) The absorbent article 1 is characterized in that, in the unfolded state and the stretched state, the total area of ​​the non-jointed portions 50z is larger than the total area of ​​the joined portions 50x when the upper arrangement region is viewed from above.

[0092] In this way, since the total area of ​​the non-jointed portions 50z is larger, there are more portions that can follow the movement when movement occurs around the waist, thereby reducing friction with the skin and suppressing pilling of the cotton layer 25a.

[0093] (Other Aspect 3) The absorbent article 1 is characterized in that the total length of the joined portions 50x is longer than the total length of the non-joined portions 50z in the up-down direction.

[0094] In this case, providing a large number of non-bonded portions 50z can suppress pilling of the cotton layer 25a, but on the other hand, there is a risk that the bond between the sheet portion 25 and the adjacent sheet member may peel off. By making the total length of the bonded portions 50x in the vertical direction longer than the total length of the non-bonded portions 50z, it is possible to make the bond less likely to peel off.

[0095] (Other aspect 4) The absorbent article 1 is characterized in that the sheet portion 25 has a non-skin side layer 25b located on the non-skin side in the thickness direction of the cotton layer 25a, and the thermal conductivity of the cotton fiber 25as is lower than the thermal conductivity of the non-skin side fiber 25bs, which is the base fiber of the non-skin side layer.

[0096] As a result, because the cotton fibers 25as that come into contact with the wearer's skin have low thermal conductivity, the cotton layer 25a is less likely to cool down immediately even if it becomes wet with sweat or the like while being worn. Furthermore, because the non-skin-side fibers 25bs in the non-skin-side layer 25b have a higher thermal conductivity than the cotton fibers 25as, heat exchange is easily promoted. Therefore, heat transferred to the non-skin-side layer 25b is released further away from the non-skin-side layer 25b, preventing heat from building up in the sheet portion 25.

[0097] (Other Aspect 5) The absorbent article 1, wherein the ratio of cotton fibers 25as in the sheet portion 25 is less than 50% by mass.

[0098] In this way, the inclusion of the cotton fibers 25as allows the user to feel a pleasant texture, and at the same time, the low mass ratio of the cotton fibers 25as suppresses fluffing of the cotton layer.

[0099] (Other aspect 6) An absorbent article 1 having a left-right direction perpendicular to the up-down direction and the thickness direction, and at least one of the ventral waistline portion 20 and the back waistline portion 30 has an inner layer sheet 21, an outer layer sheet 22 (32) arranged closer to the skin than the inner layer sheet 21, and a plurality of left-right stretchable waistline elastic members 23 (33) arranged at intervals in the up-down direction between the inner layer sheet 21 and the outer layer sheet 22 (32), and wherein the cotton layer 25a has a plurality of low basis weight portions 25aL arranged 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 25aL 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 23 (33).

[0100] By providing multiple low basis weight portions 25aL with small spacing between them in the vertical direction, the falling out of cotton fibers 25as, which have a short average fiber length, can be further suppressed, and irritation to the skin caused by fallen fibers can be further suppressed.

[0101] (Other Aspect 7) The absorbent article 1 is characterized in that the sheet portion 25 is a sheet member disposed closer to the skin than the inner layer sheet 21 .

[0102] In this case, since the waist elastic member 23 (33) is disposed between the inner layer sheet 21 and the outer layer sheet 22 (32), there is an area of ​​interference between the waist elastic member 23 (33) and the sheet portion 25 (sheet member) including the cotton layer 25a. This prevents the cotton layer 25a on the skin-facing side from stretching excessively, reducing friction between the cotton layer 25a and the skin and suppressing shedding and fluffing of the cotton fibers 25as.

[0103] (Other Aspect 8) The sheet portion 25 is arranged below and spaced from the upper end of at least one of the ventral waistline portion 20 and the back waistline portion 30 in the vertical direction, and when a region in the vertical direction from the upper end of the ventral waistline portion 20 or the back waistline portion 30 where the sheet portion 25 is provided to the upper end of the sheet portion 25 is defined as a non-arrangement region, and a region in the vertical direction from the upper end to the lower end of the sheet portion 25 of the ventral waistline portion 20 or the back waistline portion 30 where the sheet portion 25 is provided is defined as a arrangement region, a portion of the non-arrangement region closest to the skin contains hydrophobic fibers, and the magnitude of the force required to stretch the non-arrangement region of a unit width in the vertical direction by a unit length in the horizontal direction is greater than the magnitude of the force required to stretch the arrangement region of a unit width in the vertical direction by a unit length in the horizontal direction.

[0104] In this way, the skin-facing side of the non-placement area, which has a strong grip, contains hydrophobic fibers, which suppress stickiness and reduce discomfort to the wearer's body, and the placement area of ​​the sheet part, which is prone to pilling when the grip is strong, has a weaker gripping force, which reduces friction with the skin and prevents the cotton fibers from pilling.

[0105] (Other Aspect 9) The absorbent article 1 is characterized in that the length of the sheet portion 25 in the vertical direction is equal to or less than half the length of the ventral waistline portion 20 or the dorsal waistline portion 30 .

[0106] This reduces friction on the skin with the cotton layer 25a of the sheet portion 25, while suppressing pilling by reducing the length of the cotton layer 25a. Therefore, the cotton layer 25a provides a pleasant feel to the skin, reduces irritation to the skin, and prevents pilling.

[0107] (Other aspect 10) An absorbent article 1, wherein at least one of the ventral waistline portion 20 and the dorsal waistline portion 30 has an inner layer sheet 21, an outer layer sheet 22 (32) arranged closer to the skin than the inner layer sheet 21, and a folded-back portion 22r (32r) formed by folding back the upper end of the outer layer sheet 22 (32) in the vertical direction toward the skin, and wherein the length of the sheet portion 25 in the vertical direction is longer than the length of the folded-back portion 22r (32r).

[0108] By providing the sheet portion 25 longer than the vertical length of the folded portion 22r (32r), the comfortable feel of the cotton layer 25a can be easily felt.

[0109] (Other aspect 11) An absorbent article 1, wherein at least one of the ventral waistline portion 20 and the dorsal waistline portion 30 has an inner layer sheet 21, an outer layer sheet 22 (32) arranged closer to the skin than the inner layer sheet 21, and a folded-back portion 22r (32r) formed by folding back the upper end of the outer layer sheet 22 (32) in the vertical direction toward the skin, and wherein the length of the sheet portion 25 in the vertical direction is shorter than the length of the folded-back portion 22r (32r).

[0110] In this way, by not disposing the sheet portion 25 excessively long in the vertical direction, the possibility of fluffing of the cotton layer 25a is further reduced.

[0111] (Other Aspect 12) The absorbent article 1 is characterized in that the sheet portion 25 vertically straddles the upper end of the absorbent main body 10 in the vertical direction in at least one of the ventral waistline portion 20 and the dorsal waistline portion 30.

[0112] In this case, the upper end of the absorbent body 10 is a portion with relatively large irregularities, and by covering this upper end, friction with the skin can be suppressed, and irritation to the skin can be reduced.

[0113] (Other Aspect 13) The absorbent article 1 is characterized in that no hook-and-loop fastener is provided between the sheet portion 25 and the adjacent sheet member in the thickness direction.

[0114] If a hook-and-loop fastener is provided, the rigidity increases and it becomes difficult to follow the movement of the adjacent sheet member, but by not providing such a hook-and-loop fastener, the followability is improved.

[0115] (Other Aspect 14) 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.

[0116] 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.

[0117] (Other Aspect 15) A sheet member 25 characterized by having a portion where the skin side fibers 25as and the non-skin side fibers 25bs are entangled.

[0118] 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.

[0119] (Other Aspect 16) The sheet member 25, wherein the skin side fibers 25as are cotton fibers.

[0120] 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.

[0121] (Other Aspect 17) 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.

[0122] 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.

[0123] (Other Aspect 17) 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.

[0124] 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.

[0125] (Other Aspect 18) 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.

[0126] This makes it easier to transfer absorbed liquid from the skin-side layer 25a to the non-skin-side layer 25b, reducing the risk that the moisture absorbed by the sheet member 25 will continue to come into contact with the wearer's skin, thereby reducing discomfort and adverse effects on the wearer's skin.

[0127] (Other Aspect 19) The sheet member 25 is characterized in that the sheet member 25 is not provided with an adhesive.

[0128] 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.

[0129] (Other Aspect 20) 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.

[0130] 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.

[0131] (Other Aspect 21) 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.

[0132] This reduces the risk of separation between the skin side layer 25a and the non-skin side layer 25b.

[0133] (Other aspect 22) 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 the hydrophilic member when viewed in the thickness direction.

[0134] 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.

[0135] (Other aspect 23) 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.

[0136] 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.

[0137] (Other aspect 24) 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.

[0138] 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.

[0139] (Other Aspect 25) 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.

[0140] This reduces the risk of separation between the skin side layer 25a and the non-skin side layer 25b.

[0141] (Other aspect 26) 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.

[0142] This reduces the risk of the bond strength of the welded joint decreasing.

[0143] (Other aspect 27) 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.

[0144] This reduces the risk of a decrease in the joining strength of the joints at both sides of the pair of waistband portions 20, 30 in the left-right direction.

[0145] (Other Aspect 28) 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.

[0146] 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.

[0147] (Other aspect 29) 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.

[0148] 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.

[0149] (Other aspect 30) 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 portions 25aL adjacent to each other in the vertical direction and horizontal direction is larger than the minimum area of ​​the joints.

[0150] 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.

[0151] (Other aspect 31) 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.

[0152] 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.

[0153] ===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.

[0154] 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.

[0155] 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 21 inner layer sheet 22 ventral outer layer sheet, 22r folded-back portion 23 waist-hole elastic member 25 sheet portion 25a skin-side layer (cotton layer) 25aL low basis weight portion 25ap predetermined basis weight portion 25as cotton fiber 25b non-skin-side layer, 25bA non-skin-side layer skin-side portion 25bB non-skin-side layer non-skin-side portion 25bL low basis weight portion 25bp predetermined basis weight portion 25bs non-skin-side fiber 30 back waist portion 32 back outer layer sheet, 32r Folded 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 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 the absorbent article has a sheet portion located on the closest skin-facing side of at least one of the ventral waist portion and the rear waist portion, the sheet portion and an adjacent sheet member adjacent to the sheet portion from the non-skin-facing side are joined by adhesion or welding, the sheet portion has a skin-side layer that abuts the wearer's skin, and a non-skin-side layer that is located on the non-skin-facing side of the skin-side layer, and the hydrophilicity of the skin-side fiber that is the base fiber of the skin-side layer is higher than the hydrophilicity of the non-skin-side fiber that is the base fiber of the non-skin-side layer.

2. An absorbent article as described in claim 1, characterized in that the content of said skin side fibers in said sheet portion is 50 mass % or less.

3. An absorbent article according to claim 1 or 2, characterized in that at least a portion of the skin side fibers in the skin side layer are present on the same plane as the non-skin side surface of the non-skin side layer.

4. An absorbent article according to claim 1 or 2, characterized in that the average fiber length of the skin side fibers in the skin side layer is shorter than the average fiber length of the non-skin side fibers in the non-skin side layer.

5. An absorbent article as claimed in claim 1 or 2, characterized in that when the welded portions are the areas in the skin side layer and the non-skin side layer where fibers are welded to each other, the total volume of the welded portions per unit volume of the non-skin side layer is greater than the total volume of the welded portions per unit volume of the skin side layer.

6. An absorbent article according to claim 5, characterized in that the ratio of the total volume of said welded parts to the total volume of said non-skin side layer is 5% or more and 25% or less.

7. An absorbent article as described in claim 1 or 2, characterized in that the non-skin side layer 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, and the fiber density of the non-skin side fibers of the non-skin side portion of the non-skin side layer is higher than the fiber density of the non-skin side fibers of the non-skin side layer skin side portion.

8. An absorbent article as described in claim 1 or 2, characterized in that the non-skin side layer has, in the thickness direction of the non-skin side layer, 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 of the non-skin side portion of the non-skin side layer is higher than the fiber density of the non-skin side fibers of the non-skin side portion of the non-skin side layer.

9. An absorbent article as described in claim 1 or 2, characterized in that the non-skin side layer 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, and the hydrophilicity of the non-skin side fibers in the non-skin side layer skin side portion is higher than the hydrophilicity of the non-skin side fibers in the non-skin side portion of the non-skin side layer.

10. An absorbent article as claimed in claim 1 or 2, characterized in that the skin side fibers are cotton fibers, and the non-skin side fibers are hydrophobic fibers containing at least one of polypropylene, polyethylene and polyurethane, or fibers that have been hydrophilically treated to be at least one of polypropylene, polyethylene and polyurethane.

11. An absorbent article as claimed in claim 1 or 2, characterized in that the skin side layer has a specified basis weight section provided with skin side fibers of a specified basis weight, and a low basis weight section in which the basis weight of the skin side fibers is lower than that of the specified basis weight section.

12. An absorbent article as described in claim 11, wherein the non-skin side layer has a specified basis weight section having non-skin side fibers of a specified basis weight, and a low basis weight section having a basis weight of the non-skin side fibers lower than that of the specified basis weight section, and the low basis weight section of the skin side layer and the low basis weight section of the non-skin side layer have overlapping portions when viewed in the thickness direction of the absorbent article.

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