Sheet member and absorbent article

Abstract

To provide a sheet member which reduces discomfort and adverse effects on the skin of a wearer. [Solution] A sheet member 25 for an absorbent article having a skin side layer 25a capable of contacting the wearer's skin, and a non-skin side layer 25b provided on the non-skin side of the skin side layer 25a, wherein the hydrophilicity of skin side fibers 25as which are the base fiber of the skin side layer 25a is higher than the hydrophilicity of non-skin side fibers 25bs which are the base fiber of the non-skin side layer 25b, the skin side layer 25a has a predetermined basis weight portion 25aP with 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 is characterized in that, when viewed in the thickness direction, it has 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.

Description

[Technical field]

[0001] The present invention relates to a sheet member. [Background technology]

[0002] A sheet member for an absorbent article comes into contact with the wearer's skin and absorbs moisture such as sweat from the wearer while wearing the product. For example, Patent Document 1 discloses a sweat-absorbing sheet formed of an inner layer made of hydrophobic fibers and an outer layer made of hydrophilic fibers. The sweat-absorbing sheet of Patent Document 1 transfers the sweat absorbed from the inner layer located on the skin side to the outer layer located on the non-skin side, preventing moisture from remaining on the skin side of the sweat-absorbing sheet. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2001-327534 A Summary of the Invention [Problem to be solved by the invention]

[0004] In general, hydrophobic fibers are inferior to hydrophilic fibers in terms of feel against the skin, and therefore, there is a demand for improving the feel against the skin of sweat-absorbent sheets that come into contact with the skin side. However, since hydrophilic fibers have the property of easily absorbing and retaining moisture, there has been a problem in that it is difficult to provide hydrophilic fibers on the skin side of a sweat-absorbent sheet.

[0005] The present invention has been made in consideration of the above-mentioned problems, and has an object to provide a sheet member that reduces discomfort and adverse effects on the wearer's skin. [Means for solving the problem]

[0006] The main invention for achieving the above object is a sheet member for absorbent articles having a skin side layer capable of contacting the skin of a wearer, and a non-skin side layer provided on the non-skin side of the skin side layer, wherein the hydrophilicity of the skin side fibers which are base fibers of the skin side layer is higher than the hydrophilicity of the non-skin side fibers which are base fibers of the non-skin side layer, the skin side layer has a predetermined basis weight section provided with the skin side fibers of a predetermined basis weight, and a low basis weight section in which the basis weight of the skin side fibers is lower than that of the predetermined basis weight section, and has a portion where the predetermined basis weight section and the non-skin side layer overlap, and a portion where the low basis weight section and the non-skin side layer overlap, when viewed in the thickness direction. The non-skin side fibers are thermoplastic fibers, the absorbent article has a joint portion at which both left and right side portions of a pair of waistband portions are welded together, the sheet member is used at a position overlapping at least a portion of the joint portion when viewed in the thickness direction, and the joint portion overlaps at least a portion of a portion where the low basis weight portion and the non-skin side layer overlap. The sheet member is characterized in that Other features of the present invention will become apparent from the following detailed description of the present invention and the accompanying drawings. Effect of the Invention

[0007] According to the present invention, it is possible to provide a sheet member that reduces discomfort and adverse effects on the wearer's skin. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic perspective view of a pants-type disposable diaper 1. [Diagram 2] FIG. 1 is a schematic plan view of a diaper 1 in an unfolded and extended state, as viewed from the wearer's skin side. [Diagram 3] FIG. 3 is a schematic cross-sectional view taken along line AA in FIG. [Figure 4] 2 is a schematic cross-sectional view of a seat portion 25. FIG. [Figure 5A] FIG. 2 is a diagram illustrating the sheet portion 25 as viewed from the skin side. [Figure 5B] FIG. 4B is an enlarged schematic diagram of a portion of FIG. 4A. [Figure 6] FIG. 3 is an enlarged schematic view of a portion X in FIG. [Figure 7] 13 is a first modified example of the arrangement of the seat portion 25 of the present invention. [Figure 8] 2 shows modified example 2 of the arrangement of the seat portion 25 of the present invention. [Figure 9] 3 shows modified example 3 of the arrangement of the seat portion 25 of the present invention. [Figure 10]4 shows modified example 4 of the arrangement of the seat portion 25 of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] At least the following points will become apparent from the description of this specification and the accompanying drawings. (Aspect 1) This sheet member is for an absorbent article, having a skin side layer that can come into contact with the wearer's skin, and a non-skin side layer that is provided on the non-skin side of the skin side layer, wherein 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, the skin side layer has a specified basis weight section provided with the skin side fiber of a specified basis weight, and a low basis weight section in which the basis weight of the skin side fiber is lower than that of the specified basis weight section, and is characterized in that, when viewed in the thickness direction, the sheet member has a portion where the specified basis weight section and the non-skin side layer overlap, and a portion where the low basis weight section and the non-skin side layer overlap.

[0010] According to the sheet member of aspect 1, the highly hydrophilic skin-side layer improves the water absorbency and feel of the sheet member, while the moisture absorbed by the skin-side layer is easily transferred from the low basis weight portion to the non-skin side of the sheet member, thereby reducing the risk of moisture absorbed by the sheet member continuing to come into contact with the wearer's skin and reducing discomfort and adverse effects on the wearer's skin.

[0011] (Aspect 2) The sheet member of aspect 1, characterized in having a portion where the skin side fibers and the non-skin side fibers are entangled.

[0012] According to the sheet member of aspect 2, the flexibility of the sheet member can be improved, and the feel of the absorbent article using the sheet member can be improved.

[0013] (Aspect 3) The sheet member according to aspect 1 or 2, wherein the skin side fiber is a cotton fiber.

[0014] According to the sheet member of aspect 3, the fiber shape of the skin side fiber of the skin side layer that can come into contact with the wearer's skin is rounded cotton fiber, which provides a good feel against the wearer's skin and reduces irritation to the wearer's skin when worn.

[0015] (Aspect 4) The sheet member is any of the sheet members of aspects 1 to 3, characterized in that it has a vertical direction and a horizontal direction perpendicular to the thickness direction, the predetermined basis weight portions and the low basis weight portions are alternately arranged in the vertical direction, and the predetermined basis weight portions and the low basis weight portions are alternately arranged in the horizontal direction.

[0016] According to the sheet member of aspect 4, the specified basis weight portion of the skin side layer improves water absorbency and feel, while the moisture absorbed by the skin side layer can be easily transferred from the low basis weight portion to the non-skin side layer, thereby reducing the risk of moisture absorbed by the sheet member continuing to come into contact with the wearer's skin and reducing discomfort and adverse effects on the wearer's skin.

[0017] (Aspect 5) The sheet member according to any one of aspects 1 to 4, wherein the density of the skin side fibers in the low basis weight portion is lower than the density of the skin side fibers in the predetermined basis weight portion.

[0018] According to the sheet member of aspect 5, the skin-side layer improves absorbency and feel, while the moisture absorbed by the skin-side layer is easily transferred from the low basis weight portion to the non-skin-side layer, thereby reducing the risk of moisture absorbed by the sheet member remaining in contact with the wearer's skin and reducing discomfort and adverse effects on the wearer's skin.

[0019] (Aspect 6) The sheet member of any one of aspects 1 to 5, wherein at least a part of the non-skin side fibers is present on the skin side of the skin side layer.

[0020] According to the sheet member of aspect 6, absorbed liquid can be easily transferred from the skin side layer to the non-skin side layer, thereby reducing the risk of moisture absorbed by the sheet member remaining in contact with the wearer's skin, thereby reducing discomfort and adverse effects on the wearer's skin.

[0021] (Aspect 7) The sheet member according to any one of Aspects 1 to 6, wherein the sheet member is not provided with an adhesive.

[0022] The sheet member of aspect 7 reduces the risk of the sheet member becoming hard and reduces the risk of moisture absorption being hindered by the adhesive, while suppressing irritation to the skin of a wearer of an absorbent article using this sheet member.

[0023] (Aspect 8) The sheet member according to any one of aspects 1 to 7, wherein the sheet member does not have a portion formed by compressing the sheet member in a thickness direction.

[0024] According to the sheet member of aspect 8, the risk of the sheet member becoming hard can be reduced, and irritation to the skin of a wearer of an absorbent article using this sheet member can be suppressed.

[0025] (Aspect 9) The sheet member according to any one of aspects 1 to 7, wherein the sheet member has the skin side layer and a sheet compressed portion obtained by compressing a part of the skin side layer in a thickness direction.

[0026] According to the sheet member of aspect 9, the risk of separation between the skin side layer and the non-skin side layer can be reduced.

[0027] (Aspect 10) The absorbent article is a sheet member of any of aspects 1 to 9, characterized in that the absorbent article has a hydrophilic member having fibers that are more hydrophilic than the non-skin-side fibers, and the sheet member is used in the absorbent article on the skin side in the thickness direction of the hydrophilic member and in a position overlapping the hydrophilic member when viewed in the thickness direction.

[0028] According to the sheet member of aspect 10, when the absorbent article is worn, moisture absorbed from the sheet member side can be easily transferred to the non-skin side, thereby reducing discomfort and adverse effects caused by moisture continuing to adhere to the wearer's skin.

[0029] (Aspect 11) The absorbent article has a non-hydrophilic member including fibers having a lower hydrophilicity than the non-skin side fibers, The sheet member of any of aspects 1 to 9 is characterized in that in the absorbent article, the sheet member is used on the skin side in the thickness direction of the non-hydrophilic member and in a position overlapping the non-hydrophilic member when viewed in the thickness direction.

[0030] According to the sheet member of the eleventh aspect, the non-hydrophilic member is provided on the non-skin side of the non-skin side layer, which makes it easier to prevent moisture absorbed from the sheet member side from migrating from the non-skin side layer to the non-hydrophilic member when the absorbent article is worn, thereby reducing the risk of the non-skin side of the absorbent article becoming sticky. In addition, since the low basis weight portion has a low basis weight of the skin side fibers, the low basis weight portion is thin and easily recessed to the non-skin side, which reduces the risk of moisture continuing to adhere to the wearer's skin. This makes it easier to reduce discomfort on both the skin side and the non-skin side of the absorbent article when worn.

[0031] (Aspect 11) The absorbent article is a sheet member of any of aspects 1 to 10, characterized in that the sheet member has a stretchable elastic member, and in the absorbent article in an unfolded and stretched state, when viewed in the thickness direction, the sheet member is used in a position that overlaps at least a portion of the stretchable member.

[0032] According to the sheet member of aspect 11, the feel of the absorbent article is improved by the sheet member, while wrinkles are formed in at least a portion of the sheet member, thereby improving the breathability of the sheet member and reducing stuffiness and irritation to the skin when the absorbent article is worn.

[0033] (Aspect 12) The absorbent article is a sheet member of any of aspects 1 to 11, characterized in that it has a compression member having a portion compressed in the thickness direction, the sheet member is provided in the absorbent article on the skin side of the compression member, and when viewed in the thickness direction, the portion where the low basis weight portion and the non-skin side layer overlap has a portion that overlaps with the compressed portion of the compression member.

[0034] According to the sheet member of embodiment 12, the compressing member has a portion with a high density due to compression, and thus moisture can be easily transferred from the sheet member to the compressing member due to capillary action.

[0035] (Aspect 13) The sheet member according to any one of aspects 1 to 12, wherein the sheet member has a portion where the skin side fibers and the non-skin side fibers are melt-bonded to each other.

[0036] According to the sheet member of the thirteenth aspect, the risk of separation between the skin side layer and the non-skin side layer can be reduced.

[0037] (Aspect 14) The sheet member of any of aspects 1 to 13, wherein the non-skin side fibers are thermoplastic fibers, the absorbent article has an adjacent member that is arranged at a position overlapping the sheet member when viewed in the thickness direction, the absorbent article has a welded joint where the sheet member and the adjacent member are welded together in the thickness direction, and when the absorbent article is viewed in the thickness direction, the portion where the low basis weight portion and the non-skin side layer overlap overlaps at least a portion of the welded joint.

[0038] According to the sheet member of the fourteenth aspect, the risk of a decrease in the bonding strength of the welded joint can be reduced.

[0039] (Aspect 15) The sheet member of any of aspects 1 to 14 is characterized in that the non-skin side fibers are thermoplastic fibers, the absorbent article has a joint where both left and right side portions of a pair of waistband portions are welded together, the sheet member 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 and the non-skin side layer overlap.

[0040] According to the sheet member of the fifteenth aspect, it is possible to reduce the risk of a decrease in the joint strength of the joints at both left and right sides of the pair of waistband portions.

[0041] (Aspect 16) The sheet member of aspect 15 is characterized in that the pair of waistband portions 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.

[0042] According to the sheet member of embodiment 16, it is possible to facilitate the transfer of moisture absorbed by the skin side layer from the low basis weight portion to the non-skin side layer, while reducing the risk of a decrease in the bonding strength of the joints at both side portions in the left-right direction of the pair of waistband portions.

[0043] (Aspect 17) The sheet member of aspect 15 or 16 is characterized in that the joints are provided intermittently in the vertical direction, the sheet member has a vertical direction and a horizontal direction perpendicular to the thickness direction, and the area of ​​the region bounded by straight lines connecting the centers of four low basis weight sections adjacent to each other in the vertical direction and the horizontal direction is smaller than the maximum area of ​​the joints.

[0044] According to the sheet member of embodiment 17, it is easier to provide a wider area where the low basis weight portions and the joint overlap in the thickness direction than when the area defined by straight lines connecting the centers of four adjacent low basis weight portions 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.

[0045] (Aspect 18) The sheet member of aspect 15 or 16 is characterized in that the joints are provided intermittently in the vertical direction, the sheet member has a vertical direction and a horizontal direction perpendicular to the thickness direction, and the area of ​​the region bounded by straight lines connecting the centers of four low basis weight sections adjacent to each other in the vertical direction and the horizontal direction is greater than the minimum area of ​​the joints.

[0046] According to the sheet member of embodiment 18, the area where the low basis weight portion and the joint overlap 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 portions in the vertical and horizontal directions is made larger than the minimum area of ​​the joint, thereby reducing the risk of the joint strength becoming excessively strong and making it difficult to separate the ventral waist portion and the rear waist portion after use of the absorbent article.

[0047] (Aspect 19) The absorbent article has an absorbent body and a sheet member provided on the skin side of the absorbent body, the sheet member having a skin side layer that can come into contact with the wearer's skin and a non-skin side layer provided on the non-skin side of the skin side layer, 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, the skin side layer has a predetermined basis weight section having the skin side fiber of a predetermined basis weight and a low basis weight section in which the basis weight of the skin side fiber is lower than that of the predetermined basis weight section, and the absorbent article has, when viewed in the thickness direction, a portion where the predetermined basis weight section and the non-skin side layer overlap and a portion where the low basis weight section and the non-skin side layer overlap.

[0048] According to the absorbent article of aspect 19, the highly hydrophilic skin-side layer improves the absorbency and feel of the sheet member, while the moisture absorbed by the skin-side layer is easily transferred from the low basis weight portion to the non-skin side of the sheet member, thereby reducing the risk of moisture absorbed by the sheet member continuing to come into contact with the wearer's skin and reducing discomfort and adverse effects on the wearer's skin.

[0049] === Implementation form === Hereinafter, the sheet member for the absorbent article according to this embodiment will be described using a pants-type disposable diaper 1 for adults (hereinafter, simply referred to as "diaper 1") as an example of an absorbent article, and a sweat-absorbing sheet (sheet portion 25, 35) of the waist portion 20, 30 of the diaper 1 as an example of a sheet member. However, the absorbent article according to this embodiment is not limited to the above, and can be applied as, for example, pants-type disposable diapers for infants, shorts-type napkins, tape-type disposable diapers, etc. In addition, the sheet member may be any member that can contact the skin side of each absorbent article, regardless of the sweat-absorbing sheet.

[0050] <Basic configuration of pants-type disposable diaper 1> Fig. 1 is a schematic perspective view of a diaper 1 as viewed from the abdominal side. Fig. 2 is a schematic plan view of the diaper 1 in an unfolded and stretched state as viewed from the wearer's skin side. Fig. 3 is a schematic cross-sectional view taken along line AA in Fig. 2.

[0051] The "unfolded state" of the diaper 1 refers to a state in which the diaper 1 in the pants-type state shown in Fig. 1 is unfolded at side seams SS (described later) on both the left and right sides to separate the ventral waist portion 20 (described later) and the rear waist portion 30 (described later), and the diaper 1 is opened vertically, thereby unfolding the diaper 1 on a flat surface. 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 of the components constituting the diaper 1 (e.g., the absorbent body 10, the ventral waist portion 20, etc.) are stretched to the extent that they match or are close to the dimensions of the individual components.

[0052] In the pants-type state when worn as shown in FIG. 1, the diaper 1 has a vertical direction, a horizontal direction, and a front-rear direction that intersect with each other, 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 that corresponds to the wearer's crotch is the lower side. In the front-rear direction, the side that corresponds to the wearer's abdominal side is the front side, and the side that corresponds to the back side is the back side. In the unfolded and extended state shown in FIG. 2, the diaper 1 has three mutually orthogonal directions, namely, a longitudinal direction, a horizontal direction, and a thickness direction (directions penetrating the paper in FIG. 2). The longitudinal direction is along the above-mentioned vertical direction. One side of the longitudinal direction corresponds to the abdominal side (front side), and the other side corresponds to the back side (rear side). In addition, the diaper 1 has a thickness direction in which materials are layered as shown in FIG. 3, and the side in the thickness direction that contacts the wearer is the skin side, and the opposite side is the non-skin side.

[0053] The diaper 1 has an absorbent body 10 and an exterior body 18. The exterior body 18 has a pair of waist-lined sections 20, 30 and a crotch section 40 located between the crotch of a wearer. The exterior body 18 is bonded to the non-skin side of the absorbent body 10 with an adhesive or the like. Of the pair of waist-lined sections 20, 30, the one located on the ventral side (front side) of the wearer is also called the ventral waist-lined section 20, and the one located on the dorsal side (rear side) is also called the dorsal waist-lined section 30. The ventral waist-lined section 20 and the dorsal waist-lined section 30 are bonded to each other at both left and right sides by a pair of side joints SS. Examples of the bonding method using the side joints SS include heat welding, ultrasonic welding, and bonding using an adhesive.

[0054] As shown in FIG. 3, the absorbent body 10 has an absorbent core (absorbent body) 11, a liquid-permeable top sheet 12 arranged closer to the skin than the absorbent core 11, a liquid-impermeable back sheet 13 arranged 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 be covered with a liquid-permeable sheet such as tissue paper or 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 film that is liquid-impermeable and breathable, such as polyethylene or polypropylene. The exterior sheet 14 is formed of, for example, the same nonwoven fabric as the top sheet 12.

[0055] 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, a leakage prevention wall that can stand up against the skin side may be provided 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.

[0056] 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).

[0057] The inner layer sheet 21 is disposed from the ventral waist portion 20 through the crotch portion 40 to the back waist portion 30 (Fig. 3). The width (length in the left-right direction) of the inner layer sheet 21 in the ventral waist portion 20 and the back waist 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.

[0058] 2 and 3, the ventral outer layer sheet 22 is provided 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 encases one end (outer end) of the inner layer sheet 21 in the longitudinal direction. The outer end (upper end) of the ventral outer layer sheet 22 in the longitudinal direction may not be folded back.

[0059] 2 and 3, the back outer sheet 32 ​​is provided closer to the skin than the inner sheet 21, and the back outer sheet 32 ​​and the inner sheet 21 together form the back waist 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 ​​envelops 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.

[0060] 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.

[0061] 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 waist elastic members 23, 33 are arranged at intervals in the up-down 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 Figs. 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 stretch members such as rubber threads and elongated stretchable sheets.

[0062] In this embodiment, rear leg elastic members 34 are provided in the rear waistband portion 30 between the inner sheet 21 and the rear outer sheet 32. The rear leg elastic members 34 may be, for example, a plurality of rubber threads or a stretchable band-like elastic sheet. The rear leg elastic members 34 are joined and fixed in a stretched state with an adhesive such as a hot melt adhesive.

[0063] In this embodiment, sheet portions 25, 35 that easily absorb sweat of the wearer are provided in predetermined regions of the ventral waist portion 20 and the rear waist portion 30 that are closest to the skin (hatched areas in FIG. 2). The sheet portions 25, 35 are arranged closer to the skin than the absorbent main body 10 (absorbent core 11), and are strip-shaped sheet members that are shorter in vertical length than the inner layer sheet 21 and the ventral and rear outer layer sheets 22, 32, etc., and are arranged to cover the longitudinal ends of the absorbent main body 10. Details of the sheet portions 25, 35 will be described later.

[0064] The basic configuration of the diaper 1 has been described above, but the above-mentioned configuration of the diaper 1 is merely an example and is not limited thereto. For example, the diaper 1 of the present embodiment is configured to include an exterior body 18 having three parts, the ventral waist portion 20, the rear waist portion 30, and the crotch portion 40 connecting them, but the present invention is not limited thereto. For example, the diaper may have a configuration in which the ventral waist portion 20 and the rear waist portion 30 are formed of separate members and the non-skin side of the absorbent body 10 is exposed in the crotch portion, or the diaper may have an exterior member formed of a single member that is continuous from the ventral waist portion 20 to the rear waist portion 30.

[0065] <About seat sections 25 and 35> The specific configurations of the sheet portions 25 and 35 according to this embodiment will be described below. In this embodiment, the sheet portion 25 provided in the ventral waist portion 20 and the sheet portion 35 provided in the dorsal waist portion 30 have almost the same configuration. Therefore, in the following description, regarding the contents common to both the sheet portion 25 and the sheet portion 35, only the sheet portion 25 will be described as a representative of both. Regarding the sheet portion 35, the reference numerals of the members corresponding to the sheet portion 25 will be shown in parentheses as necessary, and a specific description will be omitted.

[0066] Fig. 4 is a schematic cross-sectional view of the sheet portion 25. Fig. 5A is a diagram illustrating the sheet portion 25 as viewed from the skin side. Fig. 5B is an enlarged schematic diagram of a portion of Fig. 4A. As described above, in this embodiment, the sheet portion 25 constitutes a portion of the surface of the ventral waist 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 arranged to come into contact with the wearer's skin, and a non-skin side layer 25b located on the non-skin side in the thickness direction of the skin side layer 25a.

[0067] The skin side layer 25a is a layer whose base fiber is cotton fiber, which is a hydrophilic fiber. The above-mentioned "base material" means a material whose mass ratio in each layer (skin side layer 25a, non-skin side layer 25b) is more than 50%. 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, and the above-mentioned fibers may be either those whose fiber surface has been hydrophilized or those that have not been hydrophilized. In the following, the base material fiber of the skin side layer 25a is also referred to as "skin side fiber", and the base material fiber of the non-skin side layer 25b is also referred to as "non-skin side fiber".

[0068] In the sheet member constituting the sheet part 25 of this embodiment, the skin side fibers (cotton 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). As a method for integrating the skin side layer 25a and the non-skin side layer 25b by entangling them, for example, a known hydroentangling method using a water jet or the like can be used.

[0069] In this embodiment, the non-skin side fibers 25bs of the non-skin side layer 25b are themselves hydrophobic fibers, but the non-skin side fibers 25bs are coated with a hydrophilizing agent in advance and then entangled with the skin side fibers 25as by a water flow entanglement method to form a sheet. During this entanglement process, 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, fibers from which the hydrophilizing agent has been partially removed but still has some hydrophilizing agent remaining, and fibers from which the hydrophilizing agent still remains completely.

[0070] The sheet portion 25 can be provided on the skin side of the diaper 1, and the thickness direction of the sheet portion 25 is aligned with the thickness direction of the diaper 1. The longitudinal and lateral directions of the sheet portion 25 may or may not be aligned with the up-down and left-right directions, respectively, of the diaper 1. As long as the plane of the sheet portion 25 is aligned with the plane of the diaper 1, the sheet portion 25 can be used in any direction.

[0071] Since the sheet portion 25 is a member that contacts the wearer's skin when worn, it is preferable that it is pleasant to the touch. Therefore, it is preferable that the member constituting the sheet portion 25 is a fiber that is pleasant to the touch. For example, hydrophilic fibers such as cotton and rayon are known as fibers that are pleasant to the touch. On the other hand, the higher the hydrophilicity of the fiber, the easier it is for the fiber itself to absorb moisture and to continue to retain the absorbed moisture. Therefore, there is a risk that the sheet portion 25 will cause the diaper 1 to become steamy, or moisture will continue to adhere to the wearer's skin, causing discomfort to the wearer's skin, or causing adverse effects such as rough skin.

[0072] In contrast, the sheet member 25 used in the diaper 1 and capable of contacting the wearer's skin has a skin-side layer 25a and a non-skin-side layer 25b provided on the non-skin-side side of the skin-side layer 25a. The skin-side fibers 25as of the skin-side layer 25a have a higher hydrophilicity than the non-skin-side fibers 25bs of the non-skin-side layer 25b. 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. As shown in Figs. 4 and 5, when viewed in the thickness direction of the sheet member 25 (diaper 1), the sheet member 25 has 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 overlaps.

[0073] As described above, the more hydrophilic the fibers in the sheet portion 25 are, the more the water absorbency and the feel on the skin tend to improve. In particular, hydrophilic fibers such as cotton fibers and rayon fibers are soft and have a rounded shape, and therefore are highly hydrophilic fibers that are less irritating to the skin and have a good feel on the skin. Therefore, the skin side layer 25a including the skin side fibers 25as having a high hydrophilicity is provided closer to the skin than the non-skin side layer 25b having a lower hydrophilicity than the skin side fibers 25as, and the sheet portion 25 has a portion where the predetermined basis weight portion 25aP of the skin side layer 25a and the non-skin side layer 25b overlap when viewed in the thickness direction. When worn, the predetermined basis weight portion 25aP of the sheet portion 25 abuts against the wearer's skin, improving the water absorbency and feel of the sheet portion 25 (diaper 1) when worn. On the other hand, the sheet part 25 has a low basis weight part 25aL in which the basis weight of the skin side fiber is low, and has a part where the low basis weight part 25aL and the non-skin side layer 25b overlap when viewed in the thickness direction of the sheet part 25, so that when worn, the part where the predetermined basis weight part 25aP and the non-skin side layer 25b overlap when viewed in the thickness direction absorbs moisture such as sweat on the wearer's skin, and the moisture absorbed by the predetermined basis weight part 25aP is easily promoted to evaporate from the low basis weight part 25aL in which the basis weight of the skin side fiber 25as is low, and the moisture is easily promoted to move from the low basis weight part 25aL to the non-skin side layer 25b. Even if the skin side layer 25a absorbs moisture such as sweat when worn, the part of the skin side layer 25a that contacts the wearer's skin can be made small, so that the risk of the wearer's skin feeling sticky can be reduced even if the skin side fiber 25as of the skin side layer 25a absorbs moisture. This reduces the risk of the skin-side layer 25a retaining excessive moisture, thereby reducing the risk of the diaper 1 becoming damp and of adverse effects such as rough skin on the wearer. Thus, by providing the diaper 1 with such a sheet portion 25, discomfort and adverse effects on the skin of the wearer of the diaper 1 can be reduced.

[0074] The "low basis weight portion 25aL" may be a portion having a lower basis weight of the skin side fibers 25as than the predetermined basis weight portion 25aP, and may be a portion in which the skin side fibers 25as are provided in the low basis weight portion 25aL or a portion in which the skin side fibers 25as are not provided. In either case, the low basis weight portion 25aL is preferably a portion recessed toward the non-skin side from the predetermined basis weight portion 25aP. By recessing the low basis weight portion 25aL toward the non-skin side from the predetermined basis weight portion 25aP, when worn, the predetermined basis weight portion 25aP becomes a portion of the skin side layer 25a of the sheet portion 25 that is likely to come into contact with the wearer's skin, improving the feel against the wearer's skin, while the low basis weight portion 25aL becomes a portion that is unlikely to come into contact with the wearer's skin. This makes it easier for moisture such as sweat to move to the non-skin side layer 25b via the low basis weight section 25aL where the skin side fibers 25as are small, and even if the skin side layer 25a absorbs moisture such as sweat when worn, the portion of the skin side layer 25a that comes into contact with the wearer's skin is made smaller, thereby reducing the risk of the wearer's skin feeling sticky even if the skin side fibers 25as of the skin side layer 25a absorb moisture.

[0075] In the present embodiment, the low basis weight portion 25aL is a portion where the skin side fibers 25as are hardly provided, and where the basis weight of the skin side fibers 25as is 0 (zero), or, in other words, a portion where the skin side layer 25a is missing in the thickness direction. Therefore, when the sheet portion 25 is viewed from the skin side, the non-skin side layer 25b (non-skin side fibers 25bs) can be visually confirmed through the low basis weight portion 25aL. Note that since the skin side fibers 25as are soft fibers and have some fluidity, the portion where the basis weight of the skin side fibers 25as is 0 (zero) does not mean that the skin side fibers 25as are completely absent (zero), but may be a portion where about a few skin side fibers 25as are provided in the low basis weight portion 25aL.

[0076] With respect to the skin side layer 25a, the non-skin side layer 25b is preferably provided over substantially the entire area of ​​the sheet portion 25 when viewed in the thickness direction of the sheet portion 25. Therefore, when the basis weight of the skin side fiber 25as is 0 (zero), the portion where the low basis weight portion 25aL and the non-skin side layer 25b overlap is not blocked by the skin side fiber 25as when viewed from the skin side, so the non-skin side layer 25b can be directly seen. Note that the non-skin side layer 25b is formed by entanglement of fibers such as the non-skin side fiber 25bs, and therefore has gaps between the fibers. Since the gaps between the fibers are very small, it can be said that the non-skin side layer 25b is provided over the entire area of ​​the sheet portion 25. In other words, the non-skin side layer 25b is a layer that does not have any openings such as through holes that are intentionally provided.

[0077] In the present embodiment, when the low basis weight portion 25aL has a basis weight of 0 (zero), the specific basis weight portion 25aP of the skin side layer 25a of the sheet portion 25 is likely to come into contact with the wearer's skin, and the low basis weight portion 25aL is unlikely to come into contact with the wearer's skin, so that in the low basis weight portion 25aL, moisture such as sweat is less likely to be retained by the skin side fiber 25as and is more likely to be absorbed by the non-skin side layer 25b. This improves the feel of the specific basis weight portion 25aP against the wearer's skin, while facilitating the absorption of moisture by the non-skin side layer 25b, and thus reduces the risk of moisture being continuously retained by the skin side layer 25a.

[0078] The "hydrophilicity" of the above-mentioned fibers is evaluated based on the contact angle of the fibers measured by the following method. Specifically, the smaller the measured contact angle, the higher the hydrophilicity, and the larger the contact angle, the lower the hydrophilicity.

[0079] <Contact angle measurement method> (1) First, take out the cotton fibers and non-skin side fibers from a designated area of ​​each layer. Cut the taken fibers into 10 mm lengths and prepare five samples of each fiber. (2) The measurement device used is an automatic extremely small contact angle meter MCA-J manufactured by Kyowa Interface Science Co., Ltd. The measurement environment is a room temperature of 22±2°C and a humidity of 65±2% RH. (3) A sample is placed on the measuring device, and 20 picoliters of distilled water (microdroplets) are dropped onto the surface of the fiber from the inkjet head installed on the device, and the appearance of the microdroplets is recorded over time. (4) An image taken immediately after the microdroplets are deposited on the fiber surface is analyzed, and the contact angle of the microdroplets with respect to the fiber surface is calculated. (5) Measure the contact angle at 20 different points for each fiber. Measure the contact angle for each of the five samples, and use the average value of the measured values ​​at a total of 100 points as the contact angle. If the layer (sheet) to be measured is bonded to another member by adhesive, fusion, or the like, the adhesive strength of the bonded portion is weakened by a cooling means such as cold spray to the extent that does not affect the contact angle of the fiber before removal.

[0080] It is preferable that the sheet portion 25 has a portion where the skin side fibers 25as and the non-skin side fibers 25bs are entangled. The sheet portion 25 is formed by entangling the fibers, which can improve the flexibility of the sheet portion 25 and the feel of the diaper 1 using this sheet 25. The skin side fibers 25as and the non-skin side fibers 25bs can be entangled by a well-known method such as by using a water flow or air.

[0081] Moreover, it is preferable that the sheet portion 25 is not provided with an adhesive. By not providing the sheet portion 25 with an adhesive, it is possible to reduce the risk of the sheet portion 25 becoming hard, and thus the risk of the diaper 1 using the sheet portion 25 becoming less soft to the touch. It is also possible to reduce the risk of the adhesive preventing the absorption of moisture, and thus the risk of moisture such as sweat remaining on the surface of the sheet portion 25, and thus the risk of discomfort or adverse effects on the wearer's skin. It is preferable that the sheet portion 25 itself is not provided with an adhesive, but an adhesive may be used to fix the sheet portion 25 to a member or the like adjacent to the sheet portion 25 in the diaper 1. The sheet portion 25 may be fixed to a predetermined position of the diaper 1 using an adhesive, and the adhesive used for this fixing may be impregnated into the sheet portion 25.

[0082] Similarly, it is preferable that sheet portion 25 does not have a portion where part of sheet portion 25 is compressed in the thickness direction. The compressed portion provided in sheet portion 25 reduces the risk of sheet portion 25 becoming hard, and reduces the risk of the diaper 1 using sheet portion 25 becoming soft to the touch. Note that the "portion compressed in the thickness direction" of sheet portion 25 refers to a portion where sheet portion 25 is locally compressed, and does not include sheet portion 25 where pressure is applied over the entire area when sheet portion 25 is formed.

[0083] The skin side fibers 25as in the skin side layer 25a of the sheet part 25 are preferably cotton fibers. Cotton fibers are soft, have a rounded fiber shape, and are highly absorbent. Therefore, by using cotton fibers for the skin side fibers 25as of the skin side layer 25a that contacts the wearer's skin, the fabric feels good against the wearer's skin and reduces irritation to the wearer's skin when worn.

[0084] The fibers forming the skin side layer 25a may contain fibers other than the skin side fibers 25as (e.g., hydrophobic fibers) as long as the weight ratio of the skin side fibers 25as, which are base fibers, is greater than 50%. Examples of the skin side fibers 25as include cellulose-based fibers such as cotton and rayon, and thermoplastic resin fibers that have been hydrophilized. The skin side fibers 25as, which are base fibers of the skin side layer 25a, may be one type of fiber or multiple types of fibers. In the present embodiment, the skin side fibers 25as are 100% cotton fibers, and the skin side layer 25a is formed almost exclusively of cotton fibers (skin side fibers 25as).

[0085] Since the sheet portion 25 is formed into a sheet shape by intertwining the fibers of the skin side layer 25a (skin side fibers 25as) and the fibers of the non-skin side layer 25b (non-skin side fibers 25bs), at least a part of the fibers of the non-skin side layer 25bs (non-skin side fibers 25bs) is disposed in the skin side layer 25a. It is preferable that at least a part of the skin side fibers 25as is present on the non-skin side surface of the non-skin side layer 25b. This can further strengthen the intertwining between the skin side layer 25a and the non-skin side layer 25b, and reduce the risk of separation between the skin side layer 25a and the non-skin side layer 25b.

[0086] The fibers forming the non-skin side layer 25b need only have a weight ratio of the non-skin side fibers 25bs, which are base fibers, greater than 50%, and may contain fibers other than the non-skin side fibers 25bs (e.g., hydrophilic fibers). Examples of the non-skin side fibers 25bs include thermoplastic resin fibers. The non-skin side fibers 25bs, which are base fibers of the non-skin side layer 25b, may be one type of fiber or multiple types of fibers. In the present embodiment, the non-skin side layer 25b is made of 100% composite fibers having a sheath-core structure of polypropylene (PP) and polyethylene (PE), and the non-skin side layer 25b is formed almost exclusively of composite fibers (non-skin side fibers 25bs) of PP and PE. Since the sheet portion 25 is formed into a sheet shape by intertwining the fibers of the skin side layer 25a (skin side fibers 25as) with the fibers of the non-skin side layer 25b (non-skin side fibers 25bs), at least a portion of the fibers of the skin side layer 25a (skin side fibers 25as) is arranged in the non-skin side layer 25b.

[0087] In addition, in the skin side layer 25a of the sheet portion 25, the basis weight of the skin side fibers 25as in the low basis weight portion 25aL is lower than the basis weight of the skin side fibers 25as in the specified basis weight portion 25aP, and it is more preferable that the basis weight of all fibers present in the low basis weight portion 25aL of the skin side layer 25a, not limited to the skin side fibers 25as, is lower than the basis weight of all fibers present in the specified basis weight portion 25aP.

[0088] It is also preferable that at least a part of the non-skin side fibers 25bs is present on the skin side of the skin side layer 25a. Since the non-skin side fibers 25bs have a lower liquid retention than the skin side fibers 25as, the non-skin side fibers 25bs present on the skin side of the skin side layer 25a are more likely to transfer moisture, such as sweat, toward the non-skin side layer 25b than the non-skin side fibers 25bs themselves would absorb. This reduces the risk that moisture absorbed by the sheet portion 25 will continue to come into contact with the wearer's skin, thereby reducing discomfort and adverse effects on the wearer's skin.

[0089] As described above, the skin side sheet 25 is formed into a sheet shape by entangling 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 thus has fibers in which the skin side fibers 25as and the non-skin side fibers 25bs are entangled with each other. Therefore, in the skin side layer 25a, the number of non-skin side fibers 25bs entangled with the skin side fibers 25as in the predetermined basis weight portion 25aP is preferably greater than the number of non-skin side fibers 25bs entangled with the skin side fibers 25as in the low basis weight portion 25aL. This makes it easier for the non-skin side fibers 25bs located in the predetermined basis weight portion 25aP to promote the movement of moisture from the skin side to the non-skin side of the predetermined basis weight portion 25aP. This reduces the risk that moisture absorbed by the sheet portion 25 will continue to contact the wearer's skin, and reduces discomfort and adverse effects on the wearer's skin.

[0090] In the sheet portion 25, the density of the skin-side fibers 25as of the low basis weight portion 25aL is preferably lower than the density of the skin-side fibers 25as of the predetermined basis weight portion 25aP. When worn, the portion where the predetermined basis weight portion 25aP and the non-skin-side layer 25b overlap in the thickness direction absorbs moisture such as sweat from the wearer's skin, and the moisture absorbed by the predetermined basis weight portion 25aP is easily promoted to evaporate from the low basis weight portion 25aL, which has a low basis weight of the skin-side fibers 25as, or to promote the movement of moisture from the low basis weight portion 25aL to the non-skin-side layer 25b. This reduces the risk of excessive moisture being retained in the skin-side layer 25a, thereby reducing the risk of the diaper 1 becoming steamy or having adverse effects such as rough skin. This reduces discomfort and adverse effects on the skin of the wearer of the diaper 1.

[0091] 5A and 5B, in the sheet portion 25, the predetermined basis weight portions 25aP and the low basis weight portions 25aL are alternately arranged in the up-down direction, and preferably the predetermined basis weight portions 25aP and the low basis weight portions 25aL are alternately arranged in the left-right direction. In the diaper 1 of this embodiment, the up-down direction of the diaper 1 is aligned with the vertical direction of the sheet portion 25, and the left-right direction of the diaper 1 is aligned with the horizontal direction of the sheet portion 25. In the sheet portion 25, the non-skin side layer 25b is provided over the entire area in the up-down and left-right directions, and the skin side layer 25a is provided in a staggered pattern closer to the skin than the non-skin side layer 25b. As a result, when worn, the overlapping portion of the predetermined basis weight portion 25aP and the non-skin side layer 25b in the thickness direction absorbs moisture such as sweat from the wearer's skin, and the moisture absorbed by the predetermined basis weight portion 25aP is easily promoted to evaporate from the low basis weight portion 25aL having a low basis weight of the skin side fiber 25as, and the moisture is easily promoted to move from the low basis weight portion 25aL to the non-skin side layer 25b. This reduces the risk of excessive moisture being retained in the skin side layer 25a, and reduces the risk of the diaper 1 becoming stuffy or having adverse effects such as rough skin. The predetermined basis weight portions 25aP and the low basis weight portions 25aL are alternately arranged in the vertical direction and in the horizontal direction, so that discomfort and adverse effects on the skin of the wearer of the diaper 1 can be reduced over a wide range of the sheet portion 25. The arrangement of the predetermined basis weight portions 25aP and the low basis weight portions 25aL in the sheet portion 25 is not limited to this. It is sufficient 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, and may be arranged, for example, in a lattice pattern or randomly.

[0092] In the above embodiment, the skin side layer 25a and the non-skin side layer 25b are integrated by intertwining the skin side fibers 25as and the non-skin side fibers 25bs of the sheet portion 25, but this is not limited to the above. For example, the sheet portion 25 may have a sheet compressed portion (not shown) in which parts of the skin side layer 25a and the non-skin side layer 25b are compressed in the thickness direction. In other words, the sheet portion 25 itself may be compressed. This can reduce the risk of separation between the skin side layer 25a and the non-skin side layer 25b.

[0093] Also, there may be a portion where only the skin side layer 25a or only the non-skin side layer 25b is compressed. For example, in the manufacturing process of the sheet portion 25, the non-skin side fibers 25bs may be compressed together in the thickness direction to form a layer, and then the non-skin side fibers 25bs and the skin side fibers 25as may be entangled to form the sheet portion 25.

[0094] Alternatively, the sheet portion 25 may have a portion (not shown) in which 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 are melt-bonded. In other words, the sheet portion 25 may have a portion in which the sheet portion 25 itself is melted. This can reduce the risk of separation between the skin side layer 25a and the non-skin side layer 25b.

[0095] The sheet portion 25 may further include a sheet compressed portion or a portion where the skin side fibers 25as and the non-skin side fibers 25bs are melt-bonded together in addition to the skin side fibers 25as and the non-skin side fibers 25bs being entangled.

[0096] Also, it is preferable that the diaper 1 has a hydrophilic member having fibers having a higher hydrophilicity than the non-skin-side fibers 25bs of the non-skin-side layer 25b of the sheet portion 25, and it is more preferable that the sheet portion 25 is used in the diaper 1 on the skin side in the thickness direction of the hydrophilic member and at a position overlapping the hydrophilic member when viewed in the thickness direction of the diaper 1. Specifically, in this embodiment, as shown in FIG. 3, the diaper 1 has a top sheet 12 having fibers having a higher hydrophilicity than the non-skin-side fibers 25bs of the non-skin-side layer 25b of the sheet portion 25, and the top sheet 12 corresponds to the hydrophilic member. The fibers of the top sheet 12 or the top sheet 2 itself are subjected to a hydrophilic treatment by a well-known method, so that the fibers of the top sheet 12 are more hydrophilic than the non-skin-side fibers 25bs of the non-skin-side layer 25b of the sheet portion 25. And, in the diaper 1, the sheet portion 25 is used in the diaper 1 on the skin side of the top sheet 12 and at a position overlapping the top sheet when viewed in the thickness direction of the diaper 1. This allows moisture such as sweat absorbed from the sheet portion 25 side to be easily transferred to the non-skin side when the diaper 1 is worn, thereby reducing discomfort and adverse effects on the wearer's skin caused by moisture continuing to adhere to the skin. The hydrophilic member in the diaper 1 is not limited to the top sheet 12, but may be any member that has fibers with a higher hydrophilicity than the non-skin side fibers 25bs of the non-skin side layer 25b of the sheet portion 25 and overlaps with the sheet portion 25 in the thickness direction, and the absorber 11, the inner layer sheet 21, etc. may be hydrophilic members. The hydrophilicity of the non-skin side fibers 25bs and the fibers of the top sheet 12 can be compared using the above-mentioned method for measuring hydrophilicity.

[0097] On the other hand, the diaper 1 may have a non-hydrophilic member comprising fibers having a lower hydrophilicity than the non-skin-side fibers 25bs of the non-skin-side layer 25b of the sheet portion 25, and the sheet portion 25 may be provided on the skin side of the non-hydrophilic member in the thickness direction of the diaper 1 and at a position overlapping the non-hydrophilic member when viewed in the thickness direction of the diaper 1. For example, in the diaper 1, the top sheet 12 provided on the non-skin side of the non-skin-side layer 25bs may comprise fibers having a lower hydrophilicity than the non-skin-side fibers 25bs of the non-skin-side layer 25b and is provided at a position overlapping the sheet portion 25 when viewed in the thickness direction. The top sheet 12 of this embodiment is subjected to a hydrophilization treatment, but the top sheet 12 as a non-hydrophilic member may comprise fibers having a lower hydrophilicity that have not been subjected to a hydrophilization treatment. By providing the non-hydrophilic member on the non-skin side of the non-skin side layer 25b, when the diaper 1 is worn, the moisture absorbed by the sheet portion 25 is prevented from migrating from the non-skin side layer 25b toward the non-hydrophilic member, and the non-skin side layer 25b is more likely to retain moisture. Therefore, the possibility that the moisture absorbed from the sheet portion 25 side will penetrate to the non-skin side of the diaper 1 and make the non-skin side of the diaper 1 sticky can be reduced. In addition, since the low basis weight portion 25aL has a low basis weight of the skin side fiber 25as, the low basis weight portion 25aL is thinner than the predetermined basis weight portion 25aP and is more likely to sink toward the non-skin side than the predetermined basis weight portion 25aP. Therefore, the possibility that moisture will continue to adhere to the wearer's skin can be reduced in the portion overlapping the low basis weight portion 25aL in the thickness direction. Therefore, the discomfort on both the skin side and the non-skin side of the diaper 1 when worn can be reduced.

[0098] It is also preferable that the diaper 1 has a stretchable elastic member, and the sheet portion 25 is provided at a position overlapping at least a part of the stretchable member when the diaper 1 is in an unfolded and stretched state, as viewed in the thickness direction. As shown in FIG. 3, the diaper 1 of this embodiment has a waist elastic member 23 that is stretchable in the left-right direction, and the sheet portion 25 is used at a position overlapping at least a part of the waist elastic member 23 when the diaper 1 is in an unfolded and stretched state, as viewed in the thickness direction. Wrinkles can be formed in the abdominal waist portion 20 and the sheet portion 25 by contraction of the waist elastic member 23. Therefore, the sheet portion 25 improves the feel of the diaper 1 against the skin, while the wrinkles formed in at least a part of the sheet portion 25 improve the breathability of the sheet portion 25, thereby reducing stuffiness and irritation to the skin of the wearer when the diaper 1 is worn.

[0099] As described above, the ventral waistline portion 20 and the back waistline portion 30 are joined at a pair of side joints (joints) SS on both sides in the left-right direction. FIG. 6 is an enlarged schematic view of a portion X in FIG. 2. In this embodiment, the inner layer sheet 21 and the ventral outer layer sheet 22 of the ventral waistline portion 20 are formed of nonwoven fabrics made of thermoplastic resin fibers, so that the side joints SS are composed of a plurality of joints 70 joined by welding. In FIG. 6, the joints 70 are indicated by a diagonal line slanting downward to the left. In such a case, it is preferable that the non-skin side fibers 25bs of the sheet portion 25 are made of thermoplastic fibers. Then, as shown in FIG. 2 and FIG. 6, the sheet portion 25 is provided at a position overlapping at least a part of the side joints SS when the diaper 1 (sheet portion 25) is viewed in the thickness direction, and it is preferable that the side joints SS overlap at least a part of the part overlapping the low basis weight portion 25aL and the non-skin side layer 25b. This reduces the risk of a decrease in the joining strength of the side joints SS on both sides of the pair of waistbands 20, 30 in the left-right direction.

[0100] Specifically, when the garment is in a pants-type configuration, the side joint SS is formed by stacking, from front to back in the fore-and-aft direction, the ventral outer sheet 22, the inner layer sheet 21, (the folded-back portion 22r, the folded-back portion 32r), the inner layer sheet 21, and the dorsal outer sheet 32 ​​in that order, and a welded joint 70 is formed by applying ultrasound, pressure, heat, etc. (see Figures 2 and 3). In the diaper 1, sheet portions 25, 35 are provided on the side closest to the skin of the waist portions 20, 30 and closer to the skin than the absorbent body 10 (absorbent body 11). The sheet portions 25, 35 are provided between the inner layer sheet 21 of the ventral waist portion 20 and the inner layer sheet 21 of the dorsal waist portion 30. The sheet portions 25, 35 are overlapped with the ventral outer layer sheet 22, the inner layer sheet 21 of the ventral waist portion 20, the inner layer sheet 21 of the dorsal waist portion 30, and the dorsal outer layer sheet 32, and are welded together to form a joint 70 with a portion where all of these sheets overlap when viewed in the thickness direction, thereby forming a side joint SS.

[0101] The skin-side layer 25a of the sheet portion 25 preferably uses highly hydrophilic fibers such as cotton fibers or rayon fibers as the skin-side fibers 25as, but such fibers are difficult to melt even when ultrasonic waves or heat are applied, and therefore tend to hinder welding and may reduce the bonding strength of the side joint portion SS. However, even if the sheet portion 25 of this embodiment is provided at a position overlapping the side joint portion SS in the thickness direction, the sheet portion 25 has a predetermined basis weight portion 25aP and a low basis weight portion 25aL, and the side joint portion SS overlaps at least a part of the portion where the low basis weight portion 25aL overlaps with the non-skin-side layer 25b in the thickness direction of the diaper 1. As a result, the low basis weight portion 25aL has a small amount of skin side fibers 25as, and the thermoplastic fibers, which are the non-skin side fibers 25bs of the non-skin side layer 25b, are easily fused with the fibers of the inner layer sheet 21, etc., thereby reducing the risk of the sheet portion 25 interfering with melt-bonding and reducing the decrease in bonding strength at the side bonding portion SS. In particular, in this embodiment, the basis weight of the skin side fibers 25as of the low basis weight portion 25aL is 0 (zero), so that in the low basis weight portion 25aL, the inner layer sheet 21, etc. and the non-skin side fibers 25bs of the non-skin side layer 25b of the sheet portion 25 can be melt-bonded without the skin side fibers 25as therebetween. This further reduces the risk of the bond strength at the side bonding portion SS being reduced.

[0102] Furthermore, as shown in FIG. 6, when the side joints SS of a pair of waist portions of the diaper 1 have a plurality of intermittent joints 70 in the vertical direction, it is preferable that the distance L70 between the centers 70c of adjacent joints 70 in the vertical direction is longer than the distance L3 between the centers P of the low basis weight portions 25aL (L70>L3). This makes it easier for moisture absorbed from the skin side layer 25a of the sheet portion 25 to move from the low basis weight portion 25aL to the non-skin side layer 25b, reducing the discomfort and adverse effects on the wearer caused by moisture continuing to come into contact with the skin, while making it easier to provide a wider overlapping portion between the joint 70 and the low basis weight portion 25aL when viewed in the thickness direction of the diaper 1 than when the distance L70 between the centers 70c of the joints 70 in the vertical direction is shorter than the distance L3 between the centers P of the low basis weight portions 25aL, thereby reducing the risk of a decrease in the bond strength of the side joints SS (joints 70) on both left-right sides of the pair of waist portions 20, 30.

[0103] In addition, when the side joints SS of the pair of waistbands of the diaper 1 have a plurality of joints 70 spaced apart in the up-down direction, it is preferable that the area of ​​the region Z defined by the straight lines (imaginary lines in FIG. 6) connecting the centers P of the four low basis weight portions 25aL adjacent to each other in the up-down direction (vertical direction) and left-right direction (horizontal direction) is larger than the minimum area of ​​the joints 70. This makes it easier to widen the overlapping region of the low basis weight portions 25aL and the joints 70 in the thickness direction than when the area of ​​the region Z is larger than the minimum area of ​​the joints 70. This reduces the risk that the overlapping region becomes too wide, which results in an excessively strong joint strength of the side joints SS (joints 70), making it difficult to separate the diaper 1 into the ventral waistband portion 20 and the back waistband portion 30 after use.

[0104] On the other hand, when the side joints SS of a pair of waistband portions of the diaper 1 have a plurality of joints 70 spaced apart in the up-down direction, the area of ​​a region Z defined by straight lines (imaginary lines in FIG. 6) connecting the centers P of four low basis weight portions 25aL adjacent to each other in the up-down (vertical) and left-right (horizontal) directions may be smaller than the maximum area of ​​the joints 70. This makes it easier to provide a wider region where the low basis weight portions 25aL and the joints 70 overlap when viewed in the thickness direction of the diaper 1 than when the area of ​​the region Z is larger than the maximum area of ​​the joints 70, and makes it easier to increase the joint strength at the side joints SS (joints 70).

[0105] <Regarding the arrangement of the sheet portion 25 in the diaper 1> 7 to 10 show modified examples of the arrangement of the sheet member of the present invention. In each of the modified examples, the sheet portion 25 is a sheet member having the above-mentioned characteristics.

[0106] (Variation 1) 7A and 7B are diagrams illustrating a first modified example of the arrangement of the sheet portion 25 of the present invention. In the first modified example, no separate sheet member is provided as the sheet portion 25, and the folded-back portion 22r (32r) of the ventral outer layer sheet 22 (dorsal outer layer sheet 32) is used 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 becomes the sheet portion 25 (35) has a skin-side layer (cotton layer) 25a on the skin side and a non-skin-side layer 25b on the non-skin side in the thickness direction of the skin-side layer 25a. Furthermore, by having a joint portion (not shown) where 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 in the thickness direction are joined by welding or adhesive, and by having a non-joint portion (not shown) where the sheet portion 25 (35) and the inner layer sheet 21 (adjacent sheet member) are not joined by welding or adhesive, it is possible to obtain the same effect as in the present embodiment described above. The folded-back portion 22 (32r) of the sheet portion 25 (35) of this modification is a portion of the ventral waist portion 20 (dorsal waist portion 30) that is tightly fastened, and the presence of the skin-side layer 25a on the skin-contacting surface of such a portion allows the wearer to feel the softness of the skin-side fiber 25as such as cotton fiber more, and the non-jointed portion makes it easier to follow the movement of the waist, thereby reducing friction with the skin and suppressing fluffing of the skin-side fiber 25as such as cotton fiber. In the first modification, the sheet portion 25 (35) is replaced with the folded-back portion 22r (32r), but this is not limited thereto. Regardless of whether the diaper 1 has the folded-back portion 22r (32r) or not, the sheet portion 25 (35) may be disposed at the position shown in FIG. 7.

[0107] (Variation 2) Fig. 8 is a diagram illustrating a modified example 2 of the arrangement of the sheet portion 25 of the present invention. In the modified example 2 shown in Fig. 8, the sheet portion 25 (35) is not provided to both ends in the left-right direction of the ventral waist portion 20 (back waist portion 30), but is provided in the left-right central portion of the ventral waist portion 20 (back waist 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 with relatively large irregularities, by arranging the sheet portion 25 (35) so as to cover at least the entire upper end 10e, friction against the skin during wearing can be suppressed and irritation to the skin can be reduced.

[0108] (Variation 3) FIG. 9 is a diagram for explaining a third modification of the arrangement of the sheet portion 25 of the present invention. In the third modification shown in FIG. 9, a sheet member that becomes the sheet portion 25 (35) is provided between the inner layer sheet 21 of the absorbent 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 vertical direction. In the back waistline portion 30, the sheet member that becomes the sheet portion 35 is provided 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 vicinity of the lower end of the pair of side joints SS in the vertical direction. With this configuration, the skin side layer 25a is present in most of the skin contact surface in the region of the ventral waistline portion 20 (back waistline portion 30) other than the region where the absorbent body 10 is arranged, improving the feel against the skin. Furthermore, by providing a non-jointed portion between the sheet portion 25 (35) and the inner layer sheet 21 that is not joined by welding or adhesive, the sheet portion 25 (35) can easily follow the movement of the wearer's waist and reduce friction with the skin, thereby suppressing fluffing of the skin side fibers 25as such as cotton fibers even if the proportion of the skin side layer 25a that contacts the skin increases. Note that in the waist portions 20, 30, instead of the inner layer sheets 21, 31, the sheet portions 25, 35 may be disposed as the sheets located closest to the skin of the waist portions 20, 30.

[0109] Furthermore, when the non-skin side fibers 25bs are thermoplastic fibers, the diaper 1 may have an adjacent member provided at a position overlapping the sheet portion 25 in the thickness direction, the diaper 1 may have a welded joint portion where the sheet portion 25 and the adjacent member are welded in the thickness direction, and the diaper 1 may have at least a part of the welded joint portion overlapping the portion where the low basis weight portion 25aL and the non-skin side layer 25b overlap in the thickness direction of the diaper 1. For example, in the first to third modifications shown in Figs. 7 to 9, when the inner layer sheet 21 (or the ventral side outer layer sheet 22) at a position where the sheet portion 25 of the ventral side waist portion 20 overlaps in the thickness direction is the adjacent member, the sheet portion 25 and the inner layer sheet 21 (or the ventral side outer layer sheet 22) may have a welded joint portion (not shown) where the sheet portion 25 and the inner layer sheet 21 (or the ventral side outer layer sheet 22) are welded in the thickness direction. In such a case, it is preferable that, when viewed in the thickness direction, at least a part of the welded joint overlaps with the overlapping portion of the low basis weight portion 25aL and the non-skin side layer 25b of the sheet portion 25. This reduces the risk of a decrease in the bonding strength of the welded joint that welds the sheet portion 25 and the inner sheet 21 (or the outer sheet 22).

[0110] In the above-mentioned embodiment and modified examples 1 to 3, the sheet portion 25 is provided in the ventral waist portion 20 and the sheet portion 35 is provided in the back waist portion 30, but this is not limited to the above. Each diaper 1 may be configured so that the sheet portion 25 is provided only in the ventral waist portion 20 and the sheet portion 35 is not provided in the back waist portion 30, or the sheet portion 35 is provided only in the back waist portion 30 and the sheet portion 25 is not provided in the ventral waist portion 20.

[0111] (Variation 4) Fig. 10 is a diagram illustrating modified example 4 of the arrangement of the sheet portion 25 of the present invention. In modified example 4 shown in Fig. 10, a sheet portion 25 is provided as the top sheet 12 of the absorbent main body 10. Since the top sheet 12 is a member of the absorbent main body 10 that contacts the wearer's skin, by providing the sheet portion 25 as the top sheet 12, it is possible to improve the feel on 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.

[0112] The diaper 1 of the modified example shown in FIG. 10 may have a compression member having a portion (not shown) compressed in the thickness direction. Examples of the compression member include the absorbent core 11. The diaper 1 may have a sheet portion 25 (top sheet 12) provided on the skin side of the compression member (absorbent core 11), and a portion overlapping the low basis weight portion 25aL and the non-skin side layer 25b in the thickness direction may have a portion overlapping the compressed portion of the compression member (absorbent core 11). Generally, the compressed portion is a portion having a high fiber density, and therefore is a portion that is likely to absorb moisture due to capillary action. Therefore, when the compression member (absorbent core 11) has a portion with a high density due to compression, moisture is easily transferred from the sheet portion 25 (top sheet 12) to the compression member located on the non-skin side of the sheet portion 25.

[0113] <Other Aspects of the Absorbent Article 1> In addition to the above-mentioned aspects, the absorbent article 1 can be embodied in the following ways.

[0114] (Other aspect 1) The absorbent article 1 may have a vertical direction and a thickness direction that intersect with each other, and includes an absorbent main body 10, a ventral waist portion 20 located on the ventral side of a wearer, and a back waist portion 30 located on the back side of the wearer, and a sheet portion 25 (35) including a cotton layer (skin side layer) 25a based on cotton fibers (skin side fibers) 25as is provided on the skin-facing side of at least one of the ventral waist portion 20 and the back waist portion 30, and at least a portion of the sheet portion 25 (35) is located above the absorbent main body 10 in the vertical direction, and when a region of the sheet portion 25 (35) that is located above the absorbent main body 10 in the vertical direction is defined as an upper arrangement region, the absorbent article 1 may be characterized in that 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 have a joint portion joined by welding or adhesive between them, and a non-joint portion between the upper arrangement region and the adjacent sheet member that is not joined by welding or adhesive between them. According to this embodiment, the non-jointed portion of the sheet portion that contacts the skin is a portion that is easily deformed, and when the waist portion moves, the non-jointed portion follows the movement and reduces friction with the skin, thereby suppressing fluffing of the cotton fibers 25as. At the same time, the presence of the jointed portion also prevents the cotton fibers 25as from falling off. Furthermore, the cotton layer 25a continuously contacts the skin while reducing friction with the skin, allowing the user to feel the softness of cotton while suppressing irritation to the skin.

[0115] (Other aspects 2) In the unfolded and stretched states, the absorbent article 1 may have a total area of ​​non-jointed portions larger than the total area of ​​joined portions when the upper arrangement region is viewed in a plan view. According to this embodiment, the total area of ​​the non-jointed portions is larger, so that when movement occurs around the waist, more parts can follow the movement, thereby reducing friction with the skin and suppressing pilling of the cotton layer 25a.

[0116] (Other Aspect 3) The absorbent article 1 may be such that the total length of the joined portions is longer than the total length of the non-jointed portions in the up-down direction. According to this embodiment, the provision of a large number of non-jointed parts can suppress pilling of the cotton layer 25a, but on the other hand, there is a risk that the joint between the sheet part 25 (35) and the adjacent sheet member may peel off. By making the total length of the joint parts in the vertical direction longer than the total length of the non-jointed parts, the joint can be made less likely to peel off.

[0117] (Other Aspect 4) The sheet portion may be an absorbent article 1 having a non-skin side layer 25b located on the non-skin side in the thickness direction of the cotton layer 25a, and the average fiber length of the non-skin side fibers 25bs, which are the base fiber of the non-skin side layer 25b, is longer than the average fiber length of the cotton fibers 25as. According to this embodiment, the cotton fibers 25as are bonded to fibers with a long average fiber length, which improves the durability of the cotton layer 25a and makes the cotton fibers 25as less likely to fall off. Also, in the bonding between the sheet portion 25(35) and an adjacent sheet member, the non-skin side fibers 25bs located on the non-skin side of the sheet portion 25(35) have a long average fiber length, which makes the bonding less likely to come off and improves the conformability to the adjacent sheet member.

[0118] (Other Aspect 5) The sheet portion 25 (35) may be an absorbent article 1 having 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 25b. According to this embodiment, since the thermal conductivity of the cotton fiber 25as that contacts the wearer's skin is low, even if the cotton layer 25a becomes wet with sweat or the like while being worn, the cotton layer 25a is unlikely to become cold immediately. Also, since the non-skin side fiber 25bs in the non-skin side layer 25b has a higher thermal conductivity than the cotton fiber 25as, heat exchange is likely to be promoted. Therefore, the heat transferred to the non-skin side layer 25b is released further away from the non-skin side than the non-skin side layer 25b, making it difficult for heat to build up in the sheet portion 25.

[0119] (Other Aspect 6) The sheet portion 25 (35) may be an absorbent article 1 having a non-skin side layer 25b located on the non-skin side in the thickness direction of the cotton layer 25a, and the hydrophilicity of the cotton fiber 25as, which is the base fiber of the cotton layer 25a, is higher than the hydrophilicity of the non-skin side fiber 25bs, which is the base fiber of the non-skin side layer 25b. According to this embodiment, by arranging cotton layer 25a, which has highly hydrophilic cotton fiber 25as as its base fiber, on the surface that comes into contact with the wearer's skin, water absorbency is improved, and since non-skin side fiber 25bs, which is the base fiber of non-skin side layer 25b, has a lower hydrophilicity than cotton fiber 25as, when moisture such as sweat absorbed by cotton fiber 25as moves to the non-skin side, non-skin side layer 25b does not retain excessive moisture and promotes evaporation, making it less likely to become stuffy.

[0120] (Other Aspect 7) The absorbent article 1 may be one in which the proportion of cotton fibers 25as in the sheet portion 25 (35) is less than 50% by mass. According to this embodiment, the inclusion of the cotton fibers 25as allows the user to feel a good texture, and at the same time, the low mass ratio of the cotton fibers 25as suppresses pilling of the cotton layer 25a.

[0121] (Other Aspect 8) The cotton layer 25a may be an absorbent article 1 having a predetermined basis weight portion 25aP having cotton fibers 25as of a predetermined basis weight, and a low basis weight portion 25aL having a lower basis weight of the cotton fibers 25as than the predetermined basis weight portion 25aP. According to this embodiment, by having the low basis weight portion 25aL, it is possible to suppress the shedding of the cotton fibers 25as having a short average fiber length. Therefore, it is possible to achieve both the realization of a comfortable feel by the cotton fibers 25as provided in the specific basis weight portion 25aP and the suppression of the shedding of the cotton fibers 25as.

[0122] (Other Aspect 9) The absorbent article 1 may have a left-right direction perpendicular to the top-bottom and thickness directions, and at least one of the ventral waist portion 20 and the back waist 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 waist elastic members 23, 33 that are stretchable in the left-right direction and arranged at intervals in the top-bottom direction between the inner layer sheet 21 and the outer layer sheet 22, 32, and the waist elastic members 23, 33 are stretchable in the left-right direction and arranged at intervals in the top-bottom direction, and in the cotton layer 25a, a plurality of low basis weight portions 25aL are provided at intervals in the top-bottom direction, and the minimum value of the distance between the centers P of vertically adjacent low basis weight portions 25aL is smaller than the minimum value of the distance between the centers P of vertically adjacent waist elastic members 23, 33. According to this embodiment, by providing multiple low basis weight portions 25aL with small vertical spacing, it is possible to further prevent the cotton fibers 25as, which have a short average fiber length, from falling out, and to further prevent irritation to the skin caused by fallen fibers.

[0123] (Other Aspect 10) The sheet portion 25 ( 35 ) may be the absorbent article 1 which is a sheet member arranged closer to the skin than the inner sheet 21 . According to this embodiment, the waist elastic members 23, 33 are disposed between the inner sheet 21 and the outer sheets 22, 32, so that there is an interference area between the waist elastic members 23, 33 and the sheet portion (sheet member) including the cotton layer 25a. This makes it possible to prevent the cotton layer 25a on the skin side from stretching excessively, reducing friction between the cotton layer 25a and the skin and suppressing the falling off and fluffing of the cotton fibers 25as.

[0124] (Other aspects 11) The sheet portion 25 (35) is positioned below and spaced from the upper end in the vertical direction of at least one of the ventral waist portion 20 and the rear waist portion 30. When the region in the vertical direction from the upper end of the ventral waist portion 20 or the rear waist portion 30 where the sheet portion 25 is provided to the upper end of the sheet portion 25 is defined as a non-positioning region, and the region in the vertical direction from the upper end to the lower end of the sheet portion 25 of the ventral waist portion 20 or the rear waist portion 30 where the sheet portion is provided is defined as a positioning region, the part of the non-positioning region closest to the skin contains hydrophobic fibers, and the magnitude of the force required to stretch the non-positioning region of a unit width in the vertical direction by a unit length in the horizontal direction may be greater than the magnitude of the force required to stretch the positioning region of a unit width in the vertical direction by a unit length in the horizontal direction. According to this embodiment, the skin-facing side of the non-placement area, which has a strong grip, contains hydrophobic fibers, thereby suppressing stickiness and reducing discomfort to the wearer's body, and the placement area of ​​the sheet portion, which is prone to pilling when the grip is strong, has a weaker gripping force, thereby reducing friction with the skin and suppressing pilling of the cotton fibers.

[0125] (Other aspects 12) The absorbent article 1 may have a length of the sheet portion 25 (35) that is half or less of the length of the ventral waist portion 20 or the dorsal waist portion 30 in the vertical direction. According to this embodiment, the cotton layer 25a of the sheet portion 25 reduces friction on the skin, while the length of the cotton layer 25a is reduced, thereby suppressing fluffing. Therefore, the cotton layer 25a provides a pleasant feel to the skin, reduces irritation to the skin, and prevents fluffing.

[0126] (Other Aspect 13) At least one of the ventral waist portion 20 and the dorsal waist portion 30 may have an inner layer sheet 21, an outer layer sheet 22 (32) arranged on the non-skin side of the inner layer sheet 21, and a folded-back portion 22r (32r) in which the upper end of the outer layer sheet 22 in the vertical direction is folded back toward the skin side, and the absorbent article 1 may have a length of the sheet portion 25 that is longer in the vertical direction than the length of the folded-back portion 22r. According to this embodiment, by providing the sheet portion longer than the vertical length of the folded-back portion 22r, it becomes easier to feel the pleasant texture of the cotton layer 25a against the skin.

[0127] (Other Aspect 14) At least one of the ventral waist portion 20 and the dorsal waist portion 30 may have an inner layer sheet 21, an outer layer sheet 22 (32) arranged on the non-skin side of the inner layer sheet 21, and a folded-back portion 22r (32r) in which the upper end of the outer layer sheet 22 in the vertical direction is folded back toward the skin side, and the absorbent article 1 may have a length of the sheet portion 25 that is shorter in the vertical direction than the length of the folded-back portion 22r. According to this embodiment, the sheet portion 25 is not disposed to be excessively long in the vertical direction, so that the possibility of pilling of the cotton layer 25a is further reduced.

[0128] (Other Aspect 15) The sheet portion 25 may be in the absorbent article 1 so as to vertically straddle 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 rear waistline portion 30 . According to this embodiment, the upper end of the absorbent body 10 is a portion with relatively large projections and recesses, and by covering this upper end, friction with the skin can be suppressed, and irritation to the skin can be reduced.

[0129] (Other Aspect 16) The absorbent article 1 may be one in which no hook-and-loop fastener is provided between the sheet portion 25 (35) and the adjacent sheet member in the thickness direction. According to this embodiment, 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.

[0130] (Other Aspects 17) The absorbent article 1 may have an absorbent main body 10, a ventral waist portion 20 located on the ventral side of a wearer, and a back waist portion 30 located on the back side of the wearer, and has a sheet portion 25 (35) arranged on the skin-facing side of at least one of the ventral waist portion 20 and the back waist portion 30, the sheet portion 25 (35) and an adjacent sheet member adjacent to the sheet portion 25 (35) from the non-skin-facing side are joined by adhesion or welding, the sheet portion 25 (35) has a skin-side layer 25a that abuts the wearer's skin, and a non-skin-side layer 25b that is located on the non-skin-facing side of the skin-side layer, and the hydrophilicity of the skin-side fiber 25as, which is the base fiber of the skin-side layer 25a, is higher than the hydrophilicity of the non-skin-side fiber 25bs, which is the base fiber of the non-skin-side layer 25b. According to this embodiment, the skin side layer 25a easily absorbs sweat and excreted fluids because the skin side fibers 25as have a high hydrophilicity. On the other hand, the non-skin side layer 25b has a lower hydrophilicity of the non-skin side fibers 25bs, which are the base fiber, than the skin side fibers 25as. Therefore, even if the sheet portion 25 gets wet, the adhesive strength with the adjacent sheet member can be maintained, and the sheet portion 25 is prevented from peeling off. This allows the sheet portion 25 to perform its original function, and prevents the sheet portion 25 from peeling off, which would impair the fit.

[0131] (Other Aspects 18) The absorbent article 1 may be characterized in that the content of skin side fibers 25as in the sheet portion 25 is 50% by mass or less. According to this embodiment, if the mass proportion of highly hydrophilic skin-side fibers 25as in the entire sheet portion 25 becomes too high, there is a risk that the adhesive strength with adjacent sheet components will be weakened when the sheet portion 25 becomes wet; however, this can be avoided by lowering the mass proportion of the skin-side fibers 25as in the entire sheet portion 25.

[0132] (Other Aspects 19) The absorbent article 1 may be characterized in that at least a part of the skin side fibers 25as in the skin side layer 25a is present in the same plane as the non-skin side surface of the non-skin side layer 25b. According to this embodiment, moisture absorbed by the skin side layer 25a can be transferred quickly to the non-skin side layer 25b through the extending skin side fibers 25as. As a result, excess moisture in the skin side layer 25a can be removed to the non-skin side layer 25b, and since the non-skin side layer 25b has a low ratio of skin side fibers 25as, it does not retain too much of the transferred moisture and can maintain its adhesive strength with the adjacent sheet member. This prevents the sheet part 25 from peeling off unexpectedly, which could impair the wearing comfort.

[0133] (Other Aspects 20) The absorbent article 1 may be characterized in that, when the welded portions are the areas where fibers are welded to each other in the skin side layer 25a and the non-skin side layer 25b, the total volume of the welded portions per unit volume of the non-skin side layer 25b is larger than the total volume of the welded portions per unit volume of the skin side layer 25a. The "fibers" of the skin side layer 25a and the non-skin side layer 25b refer to the skin side fibers 25as, the non-skin side fibers 25bs, and other fibers contained in the skin side layer 25a and the non-skin side layer 25b. For example, the welded portion in the skin side layer 25a may be a portion where the thermoplastic fibers in the skin side layer 25a and the non-skin side fibers 25bs, which are thermoplastic fibers in the non-skin side layer 25b, are welded together when the skin side layer 25a contains thermoplastic fibers other than cotton fibers (skin side fibers) 25as, and no welded portion exists when the skin side layer 25a is formed only from cotton fibers (skin side fibers) 25as. According to this embodiment, the skin side layer 25a has few (or no) welded parts, so moisture easily penetrates between the fibers and absorbs moisture from the wearer's skin. On the other hand, the non-skin side layer 25b has welded parts, which ensures the smoothness of the surface, and makes it easier to maintain the adhesive strength even when the sheet part gets wet. In addition, the presence of welded parts in the non-skin side layer 25b improves the strength of the sheet part 25 as a whole, making it difficult for the sheet part to peel off from the adjacent sheet member.

[0134] (Other Aspects 21) The absorbent article 1 may be characterized in that the ratio of the total volume of the welded parts to the entire volume of the non-skin side layer 25b is 5% or more and 25% or less. According to this embodiment, the presence of the welded parts at such a ratio ensures the smoothness of the surface of the non-skin side layer 25b, and makes it easier to maintain the adhesive strength even when the sheet part 25 gets wet, and also improves the strength of the entire sheet part 25. As a result, the adhesion to the adjacent sheet member becomes less likely to peel off.

[0135] (Other Aspects 22) The non-skin side layer 25b may be an absorbent article 1 characterized in that it has, in the thickness direction of the non-skin side layer 25b, 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, and the fiber density of the non-skin side fibers 25bs of the non-skin side portion of the non-skin side layer is higher than the fiber density of the non-skin side fibers 25bs of the non-skin side layer skin side portion. According to this embodiment, the non-skin side portion of the non-skin side layer is the portion that adheres to the adjacent sheet member, and the fiber density of the non-skin side portion 25bB of the non-skin side layer 25b is higher, thereby increasing the adhesive strength with the adjacent sheet member.

[0136] (Other Aspects 23) The non-skin side layer 25b may be an absorbent article 1 characterized in that it has, in the thickness direction of the non-skin side layer 25b, 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, and the fiber density of the non-skin side fibers 25bs of the non-skin side layer skin side portion is higher than the fiber density of the non-skin side fibers 25bs of the non-skin side layer non-skin side portion. According to this embodiment, the higher the fiber density, the easier it is to absorb liquid, and when the fiber density of the skin side portion of the non-skin side layer is high, the high fiber density portion of the non-skin side fibers 25bs is positioned adjacent to the skin side layer 25a, which has a high hydrophilicity, and the moisture absorbed by the skin side fibers 25as is drawn into the skin side portion of the non-skin side layer, reducing the moisture in the skin side layer 25a and suppressing a sticky feeling in the portion that comes into contact with the skin.

[0137] (Other Aspects 24) The absorbent article 1 may be characterized in that the non-skin side layer 25b has a non-skin side layer skin side portion located on the skin side and a non-skin side layer non-skin side portion located on the non-skin side in the thickness direction of the non-skin side layer 25b, and the hydrophilicity of the non-skin side fibers 25bs in the non-skin side layer skin side portion is higher than the hydrophilicity of the non-skin side fibers 25bs in the non-skin side layer non-skin side portion. According to this embodiment, the skin side portion of the non-skin side layer is a portion of the skin side layer 25a that abuts against the skin side fibers 25as, and by increasing the hydrophilicity of the non-skin side fibers 25bs in the skin side portion of the non-skin side layer, moisture is 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 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, it is easier to maintain adhesion between the non-skin side layer 25b and the adjacent sheet member.

[0138] (Other Aspects 25) The absorbent article 1 may be characterized in that the skin side fibers 25as are cotton fibers, and the non-skin side fibers 25bs are hydrophobic fibers containing at least one of polypropylene, polyethylene, and polyurethane, or fibers that have been hydrophilically treated from at least one of polypropylene, polyethylene, and polyurethane. According to this embodiment, the skin side layer 25a contains cotton fiber, which makes it easier to absorb moisture from the skin. The non-skin side layer 25b contains the hydrophobic fiber (or hydrophilized fiber) and can remove excess moisture from the skin side layer 25a without retaining it after it migrates to the non-skin side layer 25b, thereby maintaining the adhesive strength with the adjacent sheet member. This prevents the sheet part 25 from peeling off unexpectedly, which would impair the fit.

[0139] (Other Aspects 26) The non-skin side layer 25b may have a predetermined basis weight portion having non-skin side fibers 25bs of a predetermined basis weight, and a low basis weight portion having a lower basis weight of the non-skin side fibers 25bs than the predetermined basis weight portion 25, and the low basis weight portion 25aL of the skin side layer 25a and the low basis weight portion of the non-skin side layer 25b may have an overlapping portion when viewed in the thickness direction of the absorbent article 1. According to this embodiment, in the overlapping portion, the moisture absorbed by the skin side layer 25a is promoted to be drawn from the low basis weight portion 25aL of the skin side layer 25a to the low basis weight portion of the non-skin side layer 25b. Therefore, by more quickly removing the moisture from the sheet portion 25, the adhesive strength can be maintained and peeling of the sheet portion 25 can be prevented.

[0140] ===Other=== The above-mentioned embodiment is for the purpose of facilitating understanding of the present invention, and is not intended to limit the present invention. The present invention can be modified and improved without departing from the spirit of the present invention, and it goes without saying that the present invention includes equivalents thereof. [Explanation of symbols]

[0141] 1 Diapers (pants-type disposable diapers, absorbent articles) 10 absorbent body, 10e top 11 Absorbent core (absorbent body) 12 Top sheet 13 Back Seat 14 Exterior sheet 15 Elastic member around the legs 18 Exterior body 20 Ventral waist 20e top end 21 Inner layer sheet 22 ventral outer sheet, 22r folded part 23 Waist elastic member 25 Seat section 25a Skin side layer (cotton layer) 25aL low basis weight part, 25aP Specified basis weight part 25as Skin side fiber (cotton fiber) 25b Non-skin side layer, 25bs Non-skin side fiber 30 Back waist circumference 32 Dorsal outer layer sheet, 32r folded part 33 Waist elastic member 34 Rear leg elastic member 35 Seat section 40 Inseam SS Side joint (joint)

Claims

1. A sheet member for an absorbent article, comprising: a skin-side layer capable of contacting the skin of a wearer; and a non-skin-side layer provided on a side away from the skin-side layer, the hydrophilicity of the skin side fiber, which is the base fiber of the skin side layer, is higher than the hydrophilicity of the non-skin side fiber, which is the base fiber of the non-skin side layer; the skin side layer has a predetermined basis weight portion having the skin side fibers of a predetermined basis weight, and a low basis weight portion having a basis weight of the skin side fibers lower than that of the predetermined basis weight portion, When viewed in the thickness direction, the predetermined basis weight portion and the non-skin side layer overlap each other, and the low basis weight portion and the non-skin side layer overlap each other. the non-skin side fiber is a thermoplastic fiber, The absorbent article has a joint portion where both left and right side portions of a pair of waistband portions are welded and joined, When viewed in the thickness direction, The sheet member is used in a position overlapping at least a portion of the joint, The joint portion overlaps at least a part of the portion where the low basis weight portion and the non-skin side layer overlap. A sheet member characterized in that:

2. The sheet member according to claim 1, A sheet member comprising a portion in which the skin side fibers and the non-skin side fibers are entangled.

3. The sheet member according to claim 1 or 2, The sheet member, wherein the skin side fibers are cotton fibers.

4. The sheet member according to claim 1 or 2, The sheet member has a longitudinal direction and a transverse direction perpendicular to the thickness direction, the predetermined basis weight portions and the low basis weight portions are alternately arranged in the longitudinal direction, A sheet member, characterized in that the predetermined basis weight portions and the low basis weight portions are alternately arranged in the lateral direction.

5. The sheet member according to claim 1 or 2, A sheet member, characterized in that the density of the skin side fibers in the low basis weight portion is lower than the density of the skin side fibers in the predetermined basis weight portion.

6. The sheet member according to claim 1 or 2, A sheet member, characterized in that at least a portion of the non-skin side fibers are present on the skin side of the skin side layer.

7. The sheet member according to claim 1 or 2, The sheet member is characterized in that no adhesive is provided on the sheet member.

8. The sheet member according to claim 1 or 2, The sheet member is characterized in that the sheet member does not have a portion formed by compressing a part of the sheet member in a thickness direction.

9. The sheet member according to claim 1 or 2, The sheet member has a sheet compression portion in which the skin side layer and a part of the skin side layer are compressed in a thickness direction.

10. The sheet member according to claim 1 or 2, The absorbent article has a hydrophilic member including fibers having a higher hydrophilicity than the non-skin side fibers, In the absorbent article, the sheet member is used on the skin side in the thickness direction of the hydrophilic member and at a position overlapping the hydrophilic member when viewed in the thickness direction.

11. The sheet member according to claim 1 or 2, The absorbent article has a non-hydrophilic member including fibers having a lower hydrophilicity than the non-skin side fibers, The sheet member is characterized in that, in the absorbent article, the sheet member is used on the skin side in the thickness direction of the non-hydrophilic member and at a position overlapping the non-hydrophilic member when viewed in the thickness direction.

12. The sheet member according to claim 1 or 2, The absorbent article has a stretchable member, The sheet member is characterized in that, in the absorbent article in an unfolded and stretched state, the sheet member is used at a position overlapping at least a portion of the elastic member when viewed in the thickness direction.

13. The sheet member according to claim 1 or 2, The absorbent article has a compression member having a portion compressed in a thickness direction, In the absorbent article, The sheet member is provided on the skin side of the compressing member, A sheet member characterized in that, when viewed in the thickness direction, an overlapping portion of the low basis weight portion and the non-skin side layer has a portion overlapping a compressed portion of the compressing member.

14. The sheet member according to claim 1 or 2, The sheet member has a portion where the skin side fibers and the non-skin side fibers are melt-bonded.

15. The sheet member according to claim 1 or 2, the non-skin side fiber is a thermoplastic fiber, The absorbent article has an adjacent member provided at a position overlapping the sheet member when viewed in the thickness direction, The absorbent article includes a welded joint portion in which the sheet member and the adjacent member are welded in the thickness direction, A sheet member characterized in that, when the absorbent article is viewed in the thickness direction, an overlapping portion of the low basis weight portion and the non-skin side layer overlaps at least a portion of the welded joint.

16. The sheet member according to claim 1 or 2, The pair of waistband portions have a plurality of intermittent joints in the up-down direction, A sheet member, characterized in that 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.

17. The sheet member according to claim 1 or 2, The joints are provided intermittently in the vertical direction, The sheet member has a longitudinal direction and a transverse direction perpendicular to the thickness direction, A sheet member, characterized in that an area of ​​a region defined by straight lines connecting centers of four low basis weight portions adjacent to each other in the longitudinal direction and the lateral direction is smaller than a maximum area of ​​the joint portion.

18. The sheet member according to claim 1 or 2, The joints are provided intermittently in the vertical direction, The sheet member has a longitudinal direction and a transverse direction perpendicular to the thickness direction, A sheet member, characterized in that an area of ​​a region defined by straight lines connecting centers of four low basis weight portions adjacent to each other in the longitudinal direction and the lateral direction is larger than the minimum area of ​​the joint portion.

19. An absorber; A sheet member provided on the skin side of the absorbent body; An absorbent article having the sheet member has a skin side layer capable of contacting the skin of a wearer, and a non-skin side layer provided on the non-skin side of the skin side layer, the hydrophilicity of the skin side fiber, which is the base fiber of the skin side layer, is higher than the hydrophilicity of the non-skin side fiber, which is the base fiber of the non-skin side layer; the skin side layer has a predetermined basis weight portion having the skin side fibers of a predetermined basis weight, and a low basis weight portion having a basis weight of the skin side fibers lower than that of the predetermined basis weight portion, When viewed in the thickness direction, the predetermined basis weight portion and the non-skin side layer overlap each other, and the low basis weight portion and the non-skin side layer overlap each other. the non-skin side fiber is a thermoplastic fiber, The pair of waistbands have joints at both left and right sides welded together, When viewed in the thickness direction, The sheet member is used in a position overlapping at least a portion of the joint, The joint portion overlaps at least a part of the portion where the low basis weight portion and the non-skin side layer overlap. An absorbent article characterized by:

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