Absorbent article

Abstract

In an absorbent article (1), an absorbent core (21 to 23) includes: a skin side layer (21) which has a first thickness (t1) and in which the volume occupied by a superabsorbent polymer (SAP) is larger than the volume occupied by a liquid absorbent fiber (201); an intermediate layer (22) which has a second thickness (t2) and in which the volume occupied by the liquid absorbent fiber (201) is larger than the volume occupied by the superabsorbent polymer (SAP); and a non-skin side layer (23) which has a third thickness (t3) and in which the volume occupied by the superabsorbent polymer (SAP) is larger than the volume occupied by the liquid absorbent fiber (201), and the total water retention amount of the superabsorbent polymer present in the skin side layer (21) is different from the total water retention amount of the superabsorbent polymer present in the non-skin side layer (23).

Description

absorbent articles

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

[0002] Various improvements have been made to absorbent articles to achieve a thin and comfortable fit while maintaining absorption performance. For example, Patent Document 1 discloses an absorbent article including an absorbent core containing superabsorbent polymer particles and consisting of a first layer and a second layer, in which the first layer has a plurality of grooves including a plurality of main grooves extending in the longitudinal direction and penetrating in the thickness direction, and a plurality of bases, the main grooves and bases extending alternately in the lateral direction, and the second layer has a plurality of main groove corresponding portions at positions overlapping with the main grooves in the thickness direction and a plurality of base corresponding portions at positions overlapping with the bases in the thickness direction.

[0003] Furthermore, conventionally, there are absorbent articles such as disposable diapers that include a liquid-absorbing absorbent body. When worn, it is preferable that the absorbent article is not noticeable from the outside of clothing. Generally, among absorbent articles, the absorbent body (absorbent core) that absorbs excrement is particularly thick and rigid. It is known that the absorbent body is formed from a superabsorbent polymer, a liquid-absorbent fiber, or the like. For example, Patent Document 2 discloses an absorbent article having an absorbent body in which a superabsorbent polymer is arranged in a sheet form. A superabsorbent polymer has the characteristics of high liquid retention and allowing the absorbent body to be formed thin.

[0004] Japanese Patent No. 6320467 Japanese Patent Application Laid-Open No. 2023-122342

[0005] The present invention aims to solve at least one of the following problems. Regarding the first problem, the absorbent core described in Patent Document 1 repeatedly absorbs body fluid through an absorption cycle in which body fluid passes from multiple main groove-corresponding portions of the absorbent core to multiple main grooves, is drawn into adjacent base portions, and then, when the base portions are no longer able to retain the body fluid, is sucked up by the multiple base-corresponding portions. This results in excellent liquid diffusibility and suppression of liquid return. While excellent absorption performance, like the absorbent body described in Patent Document 1, can ensure absorbency, it is difficult to simultaneously achieve a thin absorbent core. For example, if an absorbent core contains pulp fibers and a superabsorbent polymer, reducing the proportion of pulp fibers and increasing the proportion of superabsorbent polymer in the absorbent core to improve absorbency can result in the superabsorbent polymer feeling more gritty to the touch, and the superabsorbent polymer may be more likely to crumble due to reduced entanglement with the pulp fibers. Conversely, if the ratio of superabsorbent polymer is reduced to suppress the gritty feeling and achieve a thinner design, it becomes difficult to ensure absorbency. Therefore, there is a need to realize an absorbent body that ensures absorbency while reducing the uncomfortable gritty feeling caused by superabsorbent polymer.

[0006] In the second problem, absorbent articles including an absorbent body (SAP sheet) made of a superabsorbent polymer have a thin absorbent body when first worn before absorbing bodily waste (liquid), making the absorbent article less noticeable from the outside of clothing. However, as bodily waste is absorbed, the superabsorbent polymer swells, increasing the rigidity of the absorbent body, and the absorbent article becomes thicker, making the absorbent article more noticeable from the outside of clothing and more likely to cause discomfort to the wearer. On the other hand, providing the absorbent body with liquid-absorbent fibers prevents excessive swelling of the absorbent body (superabsorbent polymer) and an excessive increase in the rigidity of the absorbent body due to absorption of bodily waste, but the absorbent body (absorbent article) becomes thicker before absorbing bodily waste, causing the absorbent article to become more noticeable from the outside of clothing. In other words, the problem of the present invention is that an improved absorbent article is desired.

[0007] The present invention has been made in consideration of the above-mentioned problems, and its first object is to provide an absorbent article that ensures good absorption performance while reducing the discomfort caused by the gritty feel of superabsorbent polymers.

[0008] The present invention has been made in view of the above-mentioned problems of the prior art, and a second object of the present invention is to provide an absorbent article that reduces the risk of the absorbent article being noticeable from the outside of clothing after absorbing bodily waste, that easily fits the wearer's body, and that easily reduces discomfort when worn. In other words, an object of the present invention is to provide an improved absorbent article.

[0009] The main invention for achieving the first object is an absorbent article having an absorbent core which, in an unfolded state, has a longitudinal direction, a width direction, and a thickness direction which are perpendicular to each other, and which contains liquid-absorbent fibers and a superabsorbent polymer, wherein the absorbent core has a skin-side layer having a first thickness and in which the volume occupied by the superabsorbent polymer is larger than the volume occupied by the liquid-absorbent fibers, an intermediate layer having a second thickness and in which the volume occupied by the liquid-absorbent fibers is larger than the volume occupied by the superabsorbent polymer, and a non-skin-side layer having a third thickness and in which the volume occupied by the superabsorbent polymer is larger than the volume occupied by the liquid-absorbent fibers, wherein the intermediate layer is located closer to the skin side in the thickness direction than the skin-side layer, and the non-skin-side layer is located closer to the skin side in the thickness direction than the intermediate layer, and the total water retention capacity of the superabsorbent polymer present in the skin-side layer is different from the total water retention capacity of the superabsorbent polymer present in the non-skin-side layer.

[0010] The main invention for achieving the second object is an absorbent article having a longitudinal direction, a width direction, and a thickness direction which are perpendicular to one another in an unfolded state, and comprising an absorbent core, wherein the absorbent core comprises cellulose fibers and a superabsorbent polymer, the absorbent core has a basis weight lower than that of its periphery and comprises a low basis weight portion along the longitudinal direction, and when the absorbent article is folded in half at a fold in the center in the longitudinal direction, the bottom area is 150 cm ２A weight having a weight of 5 kg is placed on the absorbent article for 24 hours, and then the weight is removed from the absorbent article, and the thickness of the folded portion at the center in the width direction is 6.5 mm or less. 40 ml of artificial urine is dropped three times over 5 seconds onto the skin side of the absorbent article in the unfolded and stretched state after the weight is removed, at a position 50 mm forward from the center in the longitudinal direction and at the center in the width direction. In this case, the absorbent article has a thickness of 6.5 mm or less at the center in the width direction. The present invention is an absorbent article characterized in that the thickness of the folded portion at the center in the width direction is 20.3 mm or less, and in a torsion test in which the center in the longitudinal direction of both end portions in the width direction of the absorbent article in the folded state is gripped and twisted around an imaginary axis along the width direction, and the center in the width direction of both end portions in the longitudinal direction of the absorbent article in the folded state is gripped and twisted around an imaginary axis along the longitudinal direction, the torque value of the absorbent article is 44.1 mN m or less. Other features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[0011] According to the main invention for achieving the first object, it is possible to provide an absorbent article that ensures good absorption performance while reducing the discomfort caused by the gritty feel of superabsorbent polymers.

[0012] According to the main invention for achieving the second objective, the risk of the absorbent article being noticeable from the outside of clothing after absorbing excrement can be reduced, and the absorbent article can be made to fit the wearer's body easily and reduce discomfort when worn.

[0013] 6A is a schematic perspective view of the diaper 1; FIG. 6B is a schematic cross-sectional view of the diaper 1 in an unfolded and stretched state, viewed from the skin side; FIG. 6C is a schematic cross-sectional view of the absorbent body 20 of this embodiment; FIG. 6D is a plan view of the absorbent cores 21-23 stacked together; FIG. 6A is a plan view of the skin side layer 21 and the intermediate layer 22, and FIG. 6B is a plan view of the non-skin side layer 23; FIG. 6C is a schematic plan view of the absorbent body 20, viewed from the skin side; FIG. 6D is a partially enlarged plan view showing the adhesive HMA that bonds the core wrap sheet 25 to the skin side upper layer 24 (skin side layer 21); FIG. 6E is a partial enlarged plan view of the adhesive HMA that bonds the core wrap sheet 25 to the skin side upper layer 24 (skin side layer 21). Images of the non-skin side of the core wrap sheet 25 in the inner region UR of the diaper 1 before use are taken; FIG. 10A and FIG. 10B are cross-sectional views of modified absorbent cores 21-24; and FIG. 10C are cross-sectional views of modified absorbent cores 21-23. 17A is a schematic cross-sectional view taken along the center line CL of FIG. 13. FIG. 17B is a plan view of absorbent cores 1021-1023 superimposed on one another. FIG. 17A is a plan view of the skin-side layer 1021 and the intermediate layer 1022, and FIG. 17B is a plan view of the non-skin-side layer 1023. FIG. 17B is a schematic plan view of the absorbent 1020 as viewed from the skin side. FIG. 17C is a diagram illustrating a state in which a weight W1000 is placed on the diaper 1000. FIG. 17D is a diagram illustrating the process for achieving an absorbing state. FIG. 17D is a diagram illustrating measurement of the fold F. FIG. 17E is an explanatory diagram for a "torsion test." FIG. 17F is a diagram illustrating measurement results for the diaper 1000 and products A, B, and C. FIG. 17F is a schematic cross-sectional view of the absorbent 1020 showing a modified skin-side layer 1021. FIG. 17F is a schematic cross-sectional view of a modified absorbent 1020.

[0014] At least the following matters will become clear from the description of this specification and the accompanying drawings. (Aspect 1) An absorbent article having an absorbent core which, in an unfolded state, has a longitudinal direction, a width direction, and a thickness direction which are orthogonal to one another, and which contains liquid-absorbent fibers and a superabsorbent polymer, wherein the absorbent core has a skin-side layer having a first thickness and in which a volume occupied by the superabsorbent polymer is larger than a volume occupied by the liquid-absorbent fibers, an intermediate layer having a second thickness and in which a volume occupied by the liquid-absorbent fibers is larger than a volume occupied by the superabsorbent polymer, and a non-skin-side layer having a third thickness and in which a volume occupied by the superabsorbent polymer is larger than a volume occupied by the liquid-absorbent fibers, wherein the intermediate layer is located closer to the skin side in the thickness direction than the skin-side layer, and the non-skin-side layer is located closer to the skin side in the thickness direction than the intermediate layer, and wherein the total water retention capacity of the superabsorbent polymer present in the skin-side layer is different from the total water retention capacity of the superabsorbent polymer present in the non-skin-side layer.

[0015] According to Aspect 1, the layer with a lower total water retention capacity can prevent the superabsorbent polymer from swelling and inhibiting liquid absorption, making it easier for excreted liquid to diffuse. Furthermore, the layer with a lower total water retention capacity has a smaller total volume of superabsorbent polymer after absorbing water, making it comfortable against the skin and less likely to have a gritty feel. The layer with a higher total water retention capacity can firmly absorb and retain excreted liquid, ensuring absorbency. Therefore, even after the absorbent core has absorbed excreted liquid, absorbency can be ensured while reducing any discomfort to the touch.

[0016] (Aspect 2) The absorbent article according to aspect 1, wherein the total water retention capacity of the superabsorbent polymer present in the non-skin side layer is greater than the total water retention capacity of the superabsorbent polymer present in the skin side layer.

[0017] According to Aspect 2, rewetting can be suppressed by retaining a certain amount of water in the skin-side layer and retaining more water in the non-skin-side layer. The skin-side layer is less likely to swell even after absorption, and the gritty feel of the superabsorbent polymer is less likely to be felt. Furthermore, because the skin-side layer retains less water, absorption is less likely to be inhibited by the superabsorbent polymer, and liquid can easily migrate to the intermediate layer and non-skin-side layer. Furthermore, excreted liquid temporarily stored in the intermediate layer, which has a high volumetric occupancy rate of liquid-absorbent fibers, is ultimately firmly absorbed and retained in the non-skin-side layer, which has a high total water retention capacity, ensuring absorbency.

[0018] (Aspect 3) An absorbent article having an absorbent core which, in an unfolded state, has a longitudinal direction, a width direction, and a thickness direction which are orthogonal to one another, and which contains liquid-absorbent fibers and a superabsorbent polymer, wherein the absorbent core has a skin-side layer having a first thickness, and in which a volume occupied by the superabsorbent polymer is larger than a volume occupied by the liquid-absorbent fibers, an intermediate layer having a second thickness, and in which a volume occupied by the liquid-absorbent fibers is larger than a volume occupied by the superabsorbent polymer, and a non-skin-side layer having a third thickness, and in which a volume occupied by the superabsorbent polymer is larger than a volume occupied by the liquid-absorbent fibers, the non-skin-side layer is located closer to the skin in the thickness direction than the intermediate layer, the non-skin-side layer is located closer to the skin in the thickness direction than the intermediate layer, the average value of the total area occupied by the superabsorbent polymer per unit area in a cross section along the thickness direction of the skin-side layer is different from the average value of the total area occupied by the superabsorbent polymer per unit area in a cross section along the thickness direction of the non-skin-side layer, and a skin-side upper layer is provided closer to the skin in the thickness direction than the skin-side layer, which is thinner than the first thickness and in which the volume occupied by the liquid-absorbent fiber is larger than the volume occupied by the superabsorbent polymer.

[0019] According to Aspect 3, a layer with a small average total area occupied by SAP per unit area is less likely to feel gritty to the touch. When such a layer is the skin-side layer, the wearer is less likely to feel uncomfortable to the touch of the SAP. When such a layer is the non-skin-side layer, the person changing the article is less likely to feel uncomfortable to the touch of the SAP. A layer with a large average total area occupied by SAP per unit area improves absorbency. When such a layer is the skin-side layer, the SAP can retain excreted liquid, thereby suppressing rewet. When such a layer is the non-skin-side layer, water retention is improved. Furthermore, the presence of an upper skin-side layer with a high volumetric ratio of liquid-absorbent fibers further reduces the wearer's perception of the unevenness of the superabsorbent polymer. Furthermore, the liquid-absorbent fibers in the upper skin-side layer prevent the superabsorbent polymer in the skin-side layer from rolling around within the layer, preventing a deterioration in the feel.

[0020] (Aspect 4) An absorbent article according to aspect 3, wherein the average value of the total area occupied by the superabsorbent polymer per unit area in a cross section along the thickness direction of the non-skin side layer is greater than the average value of the total area occupied by the superabsorbent polymer per unit area in a cross section along the thickness direction of the skin side layer.

[0021] According to Aspect 4, the average total area occupied by SAP per unit area of ​​the skin-side layer is small, so the wearer is less likely to feel uncomfortable due to the gritty feel of SAP. Furthermore, SAP swelling and inhibition of absorption can be prevented, improving the diffusibility of excreted fluid. Even in cases of repeated excretion, the non-skin-side layer, which has a larger average total area occupied by SAP, can absorb and retain more excreted fluid, thereby suppressing rewetting.

[0022] (Aspect 5) The absorbent article according to aspect 1 or aspect 2, further comprising a skin-side upper layer that is thinner than the first thickness and has a volume occupied by the liquid-absorbent fibers greater than the volume occupied by the superabsorbent polymer, on the skin side of the skin-side layer in the thickness direction.

[0023] According to Aspect 5, the presence of the thin skin-side upper layer reduces the gritty feel of the superabsorbent polymer. Although it is positioned closer to the skin than the skin-side layer, its thinness reduces rewetting, and the layer's high liquid-absorbent fiber content further improves the absorption of excreted liquid from the skin-side sheet material.

[0024] (Aspect 6) The absorbent article according to any one of Aspects 3 to 5, wherein the skin-side layer has a low basis weight region in which the absorbent core has a lower basis weight than the surrounding area, and the skin-side upper layer is arranged so as to overlap the low basis weight region of the skin-side layer in a planar view.

[0025] According to aspect 6, there is a risk that the superabsorbent polymer may shift and infiltrate into the low basis weight region from the periphery of the low basis weight region, but the presence of the skin-side upper layer covering the low basis weight region from the skin side makes it less likely that the superabsorbent polymer contained in the region outside the low basis weight region in the width and length directions will shift, making it easier to maintain the shape of the low basis weight region.

[0026] (Aspect 7) The absorbent article according to any one of Aspects 1 to 6, wherein the third thickness is greater than the first thickness.

[0027] According to Aspect 7, the thinner skin-side layer is thinner after water retention than the non-skin-side layer. This configuration makes it less likely that absorption will be hindered due to swelling of the superabsorbent polymer, and also makes it less likely that the gritty feel on the skin side caused by the superabsorbent polymer will worsen.

[0028] (Aspect 8) The absorbent article according to any one of Aspects 1 to 7, wherein the non-skin side layer has an average basis weight higher than the average basis weight of the skin side layer.

[0029] According to Aspect 8, the skin-side layer having a low average basis weight is less likely to swell after water retention, and therefore the skin-side layer is less likely to suffer from absorption inhibition due to swelling of the superabsorbent polymer, and the feel on the skin (gritty feeling) is also less likely to deteriorate.

[0030] (Aspect 9) An absorbent article according to any one of Aspects 1 to 8, wherein the skin-side layer has a different type of superabsorbent polymer from that of the non-skin-side layer, and the superabsorbent polymer contained in the skin-side layer has a slower liquid absorption rate, as measured by the vortex method, than the superabsorbent polymer contained in the non-skin-side layer.

[0031] According to Aspect 9, excreted liquid is more likely to migrate to the intermediate layer before it is absorbed by the superabsorbent polymer in the skin-side layer. This allows for efficient use of the absorbent core, improving absorption performance. By absorbing more liquid in the non-skin-side layer, rewetting of the skin-side layer can be suppressed.

[0032] (Aspect 10) The absorbent article according to any one of Aspects 1 to 9, wherein the skin side layer and the intermediate layer are laminated adjacent to each other in the thickness direction without an adhesive or a nonwoven fabric therebetween.

[0033] According to the tenth aspect, it is possible to prevent the adhesive or nonwoven fabric from interfering with the transfer of excreted fluid from the skin side layer to the intermediate layer, and the rate of absorption into the intermediate layer is increased.

[0034] (Aspect 11) The absorbent article according to any one of Aspects 1 to 9, wherein the intermediate layer and the non-skin side layer are laminated adjacent to each other in the thickness direction without an adhesive or nonwoven fabric therebetween.

[0035] According to Aspect 11, it is possible to prevent the adhesive or nonwoven fabric from interfering with the transfer of excreted fluid from the intermediate layer to the non-skin side layer, thereby increasing the rate of absorption into the non-skin side layer.

[0036] (Aspect 12) The absorbent article according to any one of Aspects 1 to 11, wherein at least one of the skin side layer, the intermediate layer, and the non-skin side layer has a low basis weight region in which the absorbent core has a basis weight lower than that of the surrounding area.

[0037] According to Aspect 12, excreted liquid is more easily transferred and diffused from the low basis weight region to the layer closer to the skin side, which makes it easier to draw excreted liquid deep into the absorbent core and improves absorbency.

[0038] (Aspect 13) An absorbent article according to any one of Aspects 1 to 12, wherein one of the skin-side layer, the intermediate layer, and the non-skin-side layer has a low basis weight region in which the absorbent core has a basis weight lower than that of the surrounding area, and at least one of the skin-side layer, the intermediate layer, and the non-skin-side layer other than the layer having the low basis weight region has another low basis weight region in which the absorbent core has a basis weight lower than that of the surrounding area, and when viewed in a plane of the absorbent core, the low basis weight region has a portion that overlaps with the other low basis weight region.

[0039] According to Aspect 13, the overlapping of the low basis weight regions creates a passageway for excreted liquid, facilitating the migration of excreted liquid from one layer with a low basis weight region to another layer with a low basis weight region. This facilitates the drawing of excreted liquid deep into the absorbent core. Furthermore, the low basis weight regions are less likely to experience absorption inhibition due to swelling of the superabsorbent polymer, promoting liquid permeation without impeding the drawing of liquid.

[0040] (Aspect 14) The absorbent article according to any one of Aspects 1 to 13, wherein, in the longitudinal central portion of the absorbent article, the non-skin side layer has a portion whose widthwise length is longer than the widthwise lengths of the skin side layer and the intermediate layer.

[0041] According to Aspect 14, the non-skinside layer absorbs the excreted fluid that is not fully absorbed by the skin-side layer and the intermediate layer, thereby preventing leakage. In addition, the number of layers is partially reduced, which reduces rigidity and improves wearability.

[0042] (Aspect 15) The absorbent article according to any one of Aspects 1 to 14, wherein the maximum lengths of the skin side layer and the intermediate layer in the width direction are longer than the maximum length of the non-skin side layer.

[0043] According to aspect 15, the skin-side layer and the intermediate layer have a wide width (long maximum length), so that excreted fluid is absorbed and diffused more effectively in the area closer to the skin than in the non-skin-side layer.

[0044] (Aspect 16) The absorbent article according to any one of Aspects 1 to 15, wherein the lengths of the skin side layer and the intermediate layer in the longitudinal direction are longer than the length of the non-skin side layer.

[0045] According to aspect 16, if the length of the non-skin side layer is longer, it becomes difficult for excretory fluid to migrate from the skin side beyond the skin side layer and intermediate layer, but by positioning the skin side layer and intermediate layer beyond the non-skin side layer in the longitudinal direction, excretory fluid can be effectively migrated along the entire longitudinal direction of the non-skin side layer.

[0046] (Aspect 17) The absorbent article according to any one of Aspects 1 to 16, wherein at least one of the skin side layer and the non-skin side layer has a plurality of compressed dots formed so as to compress the absorbent core in a dot-like manner in the thickness direction.

[0047] According to Aspect 17, the compressed points reduce clumps of the superabsorbent polymer, suppressing a gritty feel. Furthermore, by locally compressing the absorbent body, the flexibility is not lost and collapse of the absorbent body is prevented.

[0048] (Aspect 18) An absorbent article described in any of aspects 1 to 17, wherein a core wrap sheet is arranged on the skin side of the skin side layer in the thickness direction, and a strip-shaped adhesive is provided on the non-skin side surface of the core wrap sheet in the thickness direction, the average width of the strip-shaped adhesive is smaller than the average particle size of the superabsorbent polymer, and the minimum value of the distance between the intersections of the strip-shaped adhesive is smaller than the average particle size of the superabsorbent polymer when maximally swollen.

[0049] According to Aspect 18, when the SAP absorbs water (when the SAP swells to its maximum), the SAP particles are less likely to protrude from the mesh formed by the intersection of the numerous strip-shaped adhesives, thereby suppressing the movement of the SAP. As a result, even after the SAP particles swell, clumps of SAP are less likely to form, and the gritty feel can be reduced.

[0050] (Aspect 19) An absorbent article having an absorbent core which, in an unfolded state, has a longitudinal direction, a width direction, and a thickness direction which are perpendicular to one another and which contains a superabsorbent polymer, and a sheet material (core wrap sheet or nonwoven fabric) arranged on one side of the absorbent core in the thickness direction, wherein a strip of adhesive is provided on the other surface of the sheet material in the thickness direction, and the average width of the strip of adhesive is smaller than the average particle size of the superabsorbent polymer, and wherein an outer region is an area of ​​the other surface of the sheet material which is located outside the outermost edge of the absorbent core in the width direction, and an inner region is an area of ​​the other surface of the sheet material which is located inside the outermost edge of the absorbent core in the width direction, and the number of intersections of the strip of adhesive per unit area in the outer region is smaller than the number of intersections of the strip of adhesive per unit area in the inner region.

[0051] In the absorbent article of Aspect 19, because a strip-shaped adhesive is provided with a width narrower than the SAP particle diameter, the adhesive easily penetrates into the gaps between the SAP particles, fixing the SAP particles together and preventing them from losing their shape. Furthermore, in the sheet material, the adhesive coating density is reduced in the outer widthwise regions where no SAP particles are disposed so that the number of intersections between the adhesive is fewer than in the inner widthwise regions where the SAP particles are disposed, thereby preventing the adhesive from seeping out.

[0052] (Aspect 20) The absorbent article according to aspect 19, wherein the minimum distance between the intersections of the strip-shaped adhesives is smaller than the average particle size of the superabsorbent polymer when swollen.

[0053] According to the absorbent article of Aspect 20, even when the SAP particles swell due to the absorption of excrement during use, the SAP particles are less likely to protrude from the mesh of the strip-shaped adhesive, thereby making the absorbent core (non-skin side layer) less likely to collapse.

[0054] (Aspect 21) The absorbent article according to aspect 19 or 20, wherein the minimum distance between the intersections of the strip-shaped adhesives is smaller than the average particle size of the superabsorbent polymer when not swollen.

[0055] According to the absorbent article of Aspect 21, even before use, SAP particles are less likely to protrude from the mesh formed by the intersection of the numerous strip-shaped adhesives, which, for example, prevents the SAP from shifting position during distribution of the absorbent article, causing the absorbent core to collapse before use.

[0056] (Aspect 22) The absorbent article according to any one of aspects 19 to 21, wherein the thickness of the absorbent core is greater than 1.5 times the average particle size of the superabsorbent polymer.

[0057] According to the absorbent article of aspect 22, the absorbent core has at least 1.5 layers of SAP particles stacked therein, thereby improving water absorption and water retention compared to a single-layer absorbent core in which the SAP particles are arranged in a plane.

[0058] (Aspect 23) The absorbent article according to any one of aspects 19 to 22, wherein at least a portion of the strip-shaped adhesive is present at a central position in the thickness direction of the absorbent core.

[0059] According to the absorbent article of Aspect 23, the adhesive penetrates into the absorbent core, so that the SAP particles are less likely to become displaced from one another, and the absorbent core is less likely to collapse.

[0060] (Aspect 24) The absorbent article according to any one of aspects 19 to 23, wherein the adhesive for fixing the superabsorbent polymer to the sheet material has a residual stress of 2 KPa or more and 20 KPa or less.

[0061] According to the absorbent article of aspect 24, the adhesive that fixes the SAP particles has a resistance (residual stress) that is sufficient to prevent the SAP particles from falling off the sheet material (base sheet) even when external forces are applied, thereby increasing the probability that the fixation rate of the SAP particles will be 40% or more, and making the absorbent core less likely to collapse.

[0062] (Aspect 25) An absorbent article as described in any of Aspects 19 to 24, having an intermediate sheet on the other side of the absorbent core in the thickness direction, a strip of adhesive provided on one surface of the intermediate sheet in the thickness direction, and the average width of the strip of adhesive provided on the other surface of the sheet material being smaller than the average width of the strip of adhesive provided on the one surface of the intermediate sheet.

[0063] In the absorbent article of Aspect 25, the adhesive is not applied excessively to the skin-side (other side) surface of the sheet material, thereby preventing the adhesive from seeping out to the non-skin-side surface of the sheet material. On the other hand, if a larger amount of adhesive is applied to the non-skin-side (one side) surface of the intermediate sheet, a larger amount of adhesive is ejected toward the SAP particles, so the SAP particles are more firmly fixed to each other, preventing the absorbent core from losing its shape.

[0064] (Aspect 26) An absorbent article as described in any of Aspects 19 to 24, having an intermediate sheet on the other side of the absorbent core in the thickness direction, a strip of adhesive provided on one surface of the intermediate sheet in the thickness direction, and the average width of the strip of adhesive provided on the other surface of the sheet material being larger than the average width of the strip of adhesive provided on the one surface of the intermediate sheet.

[0065] In the absorbent article of Aspect 26, the amount of adhesive applied to the intermediate sheet is reduced, which makes it less likely that excreted liquid will be hindered from moving in the thickness direction of the intermediate sheet, thereby facilitating smooth transfer of excreted liquid and the like to the absorbent core provided on the non-skin side (one side) of the intermediate sheet in the thickness direction.

[0066] (Aspect 27) The absorbent article according to any one of aspects 19 to 26, wherein the absorbent core has a low basis weight region that is a region having a predetermined width in the width direction and has a basis weight lower than that of surrounding areas.

[0067] According to the absorbent article of Aspect 27, excrement is absorbed less easily in the low basis weight region than in other regions, and excrement is more likely to spread along the low basis weight region. Therefore, even if a force that compresses the absorbent core in the thickness direction is applied, for example, when the wearer assumes a seated position while wearing the absorbent article, excrement can be easily drawn into the absorbent core.

[0068] (Aspect 28) The absorbent article according to any one of aspects 19 to 27, wherein the average basis weight of the low basis weight region is greater than 0% and not more than 50% of the average basis weight of the region of the absorbent core other than the low basis weight region.

[0069] According to the absorbent article of Aspect 28, by setting the average basis weight in the low basis weight region to 50% or less of the average basis weight of the other regions, the difference in average basis weight becomes larger than when the average basis weight is greater than 50%, making it easier to move liquids such as excrement along the low basis weight region. Furthermore, if the average basis weight in the low basis weight region is greater than 0%, at least the entire low basis weight region is prevented from being configured as a slit, making it easier to ensure the strength of the low basis weight region.

[0070] (Aspect 29) The absorbent article according to any one of aspects 19 to 28, wherein the minimum distance between intersections of the strip-shaped adhesives is smaller than the width of the low basis weight region.

[0071] According to the absorbent article of Aspect 29, at least one intersection of adhesives is provided between both side edges of the low basis weight region, which makes it easier to fix the SAP particles in the low basis weight region, and also increases the likelihood that adhesive will be present at both side edges of the low basis weight region, thereby preventing the low basis weight region in the absorbent core from collapsing or being crushed.

[0072] (Aspect 30) The absorbent article according to any one of aspects 19 to 29, further comprising an intermediate sheet on the other side of the absorbent core in the thickness direction, and a portion in the low basis weight region where the sheet material and the intermediate sheet are joined in the thickness direction.

[0073] In the absorbent article of Aspect 30, if the sheet material and the intermediate sheet are joined at least partially in the area where the low basis weight region is provided, the SAP particles are prevented from migrating across the low basis weight region. That is, each of the absorbent cores divided by the low basis weight region is more likely to independently maintain its shape. Therefore, the absorbent core as a whole is less likely to lose its shape.

[0074] (Aspect 31) The absorbent article according to any one of aspects 19 to 30, comprising an absorbent body including the absorbent core and the sheet material, and having intermittent regions in which the superabsorbent polymer is not provided at the front and rear end portions in the longitudinal direction of the absorbent body.

[0075] In the absorbent article of Aspect 31, because SAP particles are not disposed in the intermittent regions, the sheet material is more likely to be directly bonded to a member (e.g., an intermediate sheet) disposed opposite the sheet material in the thickness direction, which makes it difficult for the SAP particles constituting the absorbent core to protrude to both ends in the front-rear direction, and the absorbent core is less likely to lose its shape.

[0076] (Aspect 32) The absorbent article according to any one of aspects 19 to 31, wherein the average basis weight of the superabsorbent polymer in front of a center position in the longitudinal direction of the absorbent body is smaller than the average basis weight of the superabsorbent polymer in rear of the center position in the longitudinal direction of the absorbent body.

[0077] According to the absorbent article of aspect 32, by increasing the average basis weight of the SAP particles in the longitudinal front region located near the wearer's excretory opening when worn, excretory fluids such as urine can be more quickly absorbed, thereby suppressing urine leakage on the abdominal side.

[0078] (Aspect 33) The absorbent article according to any one of aspects 19 to 31, wherein the average basis weight of the superabsorbent polymer in front of a center position in the longitudinal direction of the absorbent body is equal to or greater than the average basis weight of the superabsorbent polymer in back of the center position in the longitudinal direction of the absorbent body.

[0079] According to the absorbent article of aspect 33, when worn, by increasing the average basis weight of the SAP particles in the longitudinal rear region located on the back side (buttocks side) of the wearer, it is possible to prevent excretory fluids such as urine from flowing around the buttocks to the back side and leaking out from the upper end of the back side.

[0080] (Aspect 34) The absorbent article according to any one of Aspects 19 to 33, wherein a second absorbent layer (skin side layer) containing the superabsorbent polymer and liquid-absorbent fibers is laminated to the absorbent core (non-skin side layer) in the thickness direction.

[0081] According to the absorbent article of aspect 34, the absorbent core has a laminated structure of two or more layers (a non-skin-side layer and a skin-side layer), which improves water absorption and water retention capacity compared to an absorbent core consisting of only one layer.

[0082] (Aspect 35) The absorbent article according to any one of aspects 19 to 33, wherein the second absorbent layer (skin side layer) is disposed on the other side of the absorbent core (non-skin side layer).

[0083] According to the absorbent article of Aspect 35, the second absorbent layer (skin-side layer) containing liquid-absorbent fibers that absorb water faster than the SAP particles is disposed on the skin-side (other side) in the thickness direction, so that excreted liquid is quickly drawn from the skin-side to the non-skin-side and is easily retained in the non-skin-side layer disposed on the non-skin-side. This improves the dryness of the skin-side layer, making it less likely for the wearer to experience discomfort or discomfort.

[0084] (Aspect 36) The absorbent article according to any one of aspects 19 to 34, wherein the second absorbent layer (skin side layer) is disposed on the one side of the absorbent core (non-skin side layer).

[0085] According to the absorbent article of Aspect 36, the absorbent core (skin-side layer) containing SAP particles, which have higher water retention than the liquid-absorbent fiber, is disposed on the non-skin side (one side) in the thickness direction, thereby increasing water retention on the skin side and making rewet less likely to occur, thereby making it less likely for the wearer to experience discomfort or an unpleasant feeling.

[0086] (Aspect 37) The absorbent article according to any one of aspects 19 to 36, wherein the sheet material is made of nonwoven fabric.

[0087] According to the absorbent article of Aspect 37, when an adhesive is applied or SAP particles are laminated while the nonwoven fabric is used as a base sheet and the base sheet is transported in the machine direction, the base sheet made of the nonwoven fabric is resistant to tearing, and therefore an absorbent body (absorbent core) with a stable shape can be formed. Furthermore, if the base sheet is transported while being sucked by a suction mechanism or the like, the SAP particles can be easily fixed on the base sheet.

[0088] (Aspect 38) An absorbent article according to any one of aspects 1 to 37, comprising an absorbent main body, the absorbent main body having an absorbent core including a skin-side layer, an intermediate layer, and a non-skin-side layer laminated at least in the thickness direction, the intermediate layer not including a nonwoven fabric.

[0089] According to Aspect 38, the skin-side layer and the intermediate layer of the absorbent core are laminated adjacently in the thickness direction without a nonwoven fabric in between, which prevents the adhesive or the nonwoven fabric from interfering with the transfer of excreted fluid from the skin-side layer to the intermediate layer, thereby increasing the rate of absorption by the intermediate layer.

[0090] (Aspect 39) The absorbent article according to any one of aspects 1 to 38, wherein the layer of the absorbent core closest to the skin does not contain a water-absorbent resin powder.

[0091] According to aspect 39, since the layer closest to the skin does not contain water-absorbent resin powder such as SAP, it is less likely to give a granular, gritty feeling to the wearer's skin, thereby reducing the discomfort felt when worn.

[0092] (Aspect 40) The absorbent article according to any one of aspects 1 to 39, wherein the superabsorbent polymer in the layer closest to the skin of the absorbent core has a liquid permeation rate under load of more than 10 seconds.

[0093] According to aspect 40, by making the liquid permeation rate under load in the layer closest to the skin exceed 10 seconds, the water retention of the absorbent core is improved compared to the opposite case, leading to prevention of leakage and also preventing the absorbent core from becoming thicker locally.

[0094] (Aspect 41) An absorbent article having a longitudinal direction, a width direction, and a thickness direction which are perpendicular to one another in an unfolded state, and including an absorbent core, wherein the absorbent core includes cellulose fibers and a superabsorbent polymer, the absorbent core has a basis weight lower than that of its periphery and includes a low basis weight portion along the longitudinal direction, and when the absorbent article is folded in half at a fold in the center in the longitudinal direction, the bottom area is 150 cm ２ A weight having a weight of 5 kg is placed on the absorbent article for 24 hours, and then the weight is removed from the absorbent article, and the thickness of the folded portion at the center in the width direction is 6.5 mm or less. 40 ml of artificial urine is dropped three times over 5 seconds onto the skin side of the absorbent article in the unfolded and stretched state after the weight is removed, at a position 50 mm forward from the center in the longitudinal direction and at the center in the width direction. In this case, the absorbent article has a thickness of 6.5 mm or less at the center in the width direction. The absorbent article is characterized in that the thickness of the widthwise center of the folded portion is 20.3 mm or less, and in a torsion test in which the center of the longitudinal direction at both widthwise end portions of the absorbent article in the folded state is grasped and twisted around an imaginary axis along the width direction, and the center of the widthwise direction at both lengthwise end portions of the absorbent article in the folded state is grasped and twisted around an imaginary axis along the longitudinal direction, the torque value of the absorbent article is 44.1 mN·m or less.

[0095] According to Aspect 41, even if the thickness of the folded portion in the folded state when the weight is removed is 6.5 mm or less, the absorbent article can easily improve the diffusion of body exudates along the longitudinal direction by including cellulose fibers with a relatively high absorption rate and a superabsorbent polymer with a relatively high liquid retention property, and by including a low basis weight portion along the longitudinal direction. Furthermore, by setting the thickness of the folded portion in the absorbent state to 20.3 mm or less, the risk of the absorbent article becoming excessively thick due to the absorption of body exudates during wear can be reduced compared to when the thickness in the absorbent state is greater than 20.3 mm, thereby reducing the risk of the absorbent article being noticeable from the outside of clothing after absorption. Furthermore, by setting the torsion test value of the absorbent article in the absorbed state to 44.1 mN·m or less, even after absorption of body exudates, the absorbent article can be made softer than when the torsion test value is greater than 44.1 mN·m, making the absorbent article more easily fit the wearer's body even after absorption of body exudates and reducing discomfort when worn.

[0096] (Aspect 42) The absorbent article of Aspect 41, wherein the absorbent core has a constricted portion constricted on the inside in the width direction in a crotch portion that is located between the crotch of a wearer when worn.

[0097] According to aspect 42, when worn, the absorbent article can be made to fit the shape of the wearer's body more easily, and even if the absorbent core expands to absorb excrement, the risk of it interfering with the movement of the wearer's legs can be reduced.

[0098] (Aspect 43) The absorbent article of aspect 41 or 42, wherein the superabsorbent polymer has a liquid absorption rate of 40 seconds or more as measured by the vortex method.

[0099] According to Aspect 43, when excrement is absorbed in the absorbent core, the excrement is more likely to diffuse within the absorbent core than if it were absorbed by the superabsorbent polymer when the liquid absorption rate of the superabsorbent polymer by the vortex method was faster than 40 seconds. This allows the superabsorbent polymer to locally absorb the excrement, reducing the risk of the absorbent core swelling locally, thereby reducing the risk of the absorbent article becoming excessively stiff and making it easier to soften the absorbent article after absorption. This reduces the risk of the absorbent article being noticeable from the outside of clothing even after absorbing excrement, and makes it less likely to hinder the wearer's leg movement.

[0100] (Aspect 44) The absorbent article of any one of Aspects 41 to 43, wherein the core wrap sheet provided on at least one of the skin side and non-skin side of the absorbent core is a hydrophilic nonwoven fabric.

[0101] According to aspect 44, the hydrophilic nonwoven fabric is thin and flexible, and has high drapeability after absorbing bodily waste. Therefore, when the absorbent article is worn, it easily fits the shape and movements of the wearer's body while maintaining a state in which it covers the absorbent core, thereby reducing the risk of the absorbent article being noticeable from the outside of the clothing.

[0102] (Aspect 45) A method for manufacturing a diaper-absorbing article comprising the steps of: (a) providing a skin-side core wrap sheet portion covering at least a portion of the skin-side side of the absorbent core; (b) providing a diaper-absorbing article having a skin-side core wrap sheet portion; (c) providing a diaper-absorbing article having a skin-side core wrap sheet portion covering at least a portion of the skin-side side of the absorbent core; (d) providing a diaper-absorbing article having a skin-side core wrap sheet portion covering at least a portion of the skin-side side of the absorbent core; (e) providing a diaper-absorbing article having a skin-side core wrap sheet portion covering at least a portion of the skin-side side of the absorbent core; (f) providing a diaper-absorbing article having a skin-side core wrap sheet portion covering at least a portion of the skin-side core wrap sheet portion; (g) providing a diaper-absorbing article having a skin-side core wrap sheet portion covering at least a portion of the skin-side core wrap sheet portion; (g) providing a diaper-absorbing article having a skin-side core wrap sheet portion covering at least a portion of the skin-side core wrap sheet portion; (f ... ２ Above, 90g / m ２ The basis weight of the superabsorbent polymer adhered to the skin-side core wrap sheet portion is 5 g / m or less. ２ Above, 160g / m ２ 45. The absorbent article of any one of Aspects 41 to 44, wherein:

[0103] According to Aspect 45, the absorbent article can have a function of absorbing bodily waste while having a thin absorbent core, thereby reducing the thickness of the absorbent article and reducing the risk of the absorbent article being noticeable from the outside of clothing while being worn. In addition, the absorbent article can be made soft, making it easier to fit the wearer's body and movements, and reducing the discomfort felt by the wearer.

[0104] (Aspect 46) An absorbent article according to any of Aspects 41 to 45, comprising a skin-side core wrap sheet portion covering at least a portion of the skin-facing side of the absorbent core, and a non-skin-side core wrap sheet portion covering at least a portion of the non-skin-facing side of the absorbent core, wherein the cellulose fibers and the superabsorbent polymer are adhered to the non-skin-side of the skin-side core wrap sheet portion, the cellulose fibers and the superabsorbent polymer are adhered to the skin-side of the non-skin-side core wrap sheet portion, the cellulose fibers not adhered to either the skin-side core wrap sheet portion or the non-skin-side core wrap sheet portion account for 5% or less by weight of the cellulose fibers, the density of the cellulose fibers adhered to the non-skin-side of the skin-side core wrap sheet portion is uniform, and the density of the superabsorbent polymer adhered to the non-skin-side of the skin-side core wrap sheet portion is uniform.

[0105] According to Aspect 46, the cellulose fibers bonded to the skin-side core wrap sheet portion and the non-skin-side core wrap sheet portion, and the cellulose fibers and the superabsorbent polymer bonded to the skin-side core wrap sheet portion at uniform densities, allow the thickness of the absorbent body to be reduced, thereby reducing the thickness of the absorbent article and reducing the risk of it being noticeable from the outside of clothing while being worn.In addition, while maintaining the function of absorbing excrement as an absorbent article, it is easy to fit to the wearer's body and movements, reducing the discomfort felt by the wearer.

[0106] (Aspect 47) An absorbent article according to any one of Aspects 41 to 46, characterized in that the absorbent core has a plurality of absorbent layers, the plurality of absorbent layers having a first absorbent layer and a second absorbent layer, the low basis weight portion having a first low basis weight portion provided in the first absorbent layer and a second low basis weight portion provided in the second absorbent layer, and having a portion where the first low basis weight portion and the second low basis weight portion overlap when viewed in the thickness direction.

[0107] According to aspect 47, the absorption function of the absorbent article is ensured by multiple absorbent layers, and the diffusion of excrement in the absorbent core can be improved by the first low basis weight section and the second low basis weight section, which have overlapping portions in the thickness direction, thereby reducing the risk of the absorbent article becoming thick in localized areas.

[0108] (Aspect 48) An absorbent article according to any one of Aspects 41 to 47, characterized in that the absorbent core has a plurality of absorbent layers, each of the plurality of absorbent layers having an SAP layer formed only of the superabsorbent polymer, the SAP layer being located furthest away from the skin among the plurality of absorbent layers, and an intermediate sheet being provided between the absorbent layer located closer to the skin than the SAP layer.

[0109] According to Aspect 48, by including an SAP layer, the absorbent article can be made thin while still retaining the appropriate function of absorbing bodily waste as an absorbent article.

[0110] (Aspect 49) The absorbent article of any one of Aspects 41 to 48, wherein the absorbent core has a plurality of absorbent layers, the plurality of absorbent layers having a first absorbent layer and a second absorbent layer, and on one side in the width direction, the side ends of the first absorbent layer and the second absorbent layer are located at different positions.

[0111] According to aspect 49, it becomes easier to reduce the torsional rigidity of the side end portions of the absorbent article, which makes it easier to reduce discomfort around the wearer's legs and the risk of restricting leg movement.

[0112] (Aspect 50) The absorbent article of any one of Aspects 41 to 49, wherein the absorbent core has a plurality of absorbent layers, the plurality of absorbent layers having a first absorbent layer and a second absorbent layer, and an end on one side of the longitudinal direction of the first absorbent layer and an end on one side of the longitudinal direction of the second absorbent layer are provided at different positions.

[0113] According to aspect 50, it is possible to reduce the torsional rigidity of one end of the absorbent core in the longitudinal direction while reducing the thickness of one end of the absorbent core in the absorbent article, which makes it easier to reduce the risk of the absorbent article being noticeable from the outside of clothing.

[0114] (Aspect 51) An absorbent article according to any one of aspects 41 to 50, characterized in that the absorbent core has a skin-side layer having a first thickness and in which the volume occupied by the superabsorbent polymer is larger than the volume occupied by the cellulose fibers, an intermediate layer having a second thickness and in which the volume occupied by the cellulose fibers is larger than the volume occupied by the superabsorbent polymer, and a non-skin-side layer having a third thickness and in which the volume occupied by the superabsorbent polymer is larger than the volume occupied by the cellulose fibers, wherein the intermediate layer is located on the non-skin side in the thickness direction of the skin-side layer, and the non-skin-side layer is located on the non-skin side in the thickness direction of the intermediate layer.

[0115] According to aspect 51, the absorbent core has the desired absorption function and flexibility, while reducing the risk of the absorbent core becoming excessively thick, making it easier to fit the wearer's body and movements, and reducing the risk of the absorbent article being noticeable from the outside of the clothing even after absorbing excrement.

[0116] (Aspect 52) ​​The absorbent article of Aspect 51, wherein the superabsorbent polymer contained in the skin-side layer has a liquid absorption rate measured by the vortex method that is slower than the superabsorbent polymer contained in the non-skin-side layer.

[0117] According to aspect 52, diffusion in the planar direction or toward the non-skin side is more easily promoted than absorption in the skin-side layer, and excrement is more easily diffused throughout the absorbent core, thereby reducing the risk of localized swelling of the absorbent core, thereby lowering the torsional rigidity of the absorbent article, making it easier to fit the wearer's body when worn, and reducing discomfort when worn. In addition, the risk of the absorbent article being noticeable from the outside of clothing after absorption can be reduced.

[0118] (Aspect 53) An absorbent article according to aspect 51 or 52, characterized in that the average value of the total area occupied by the superabsorbent polymer per unit area in a cross section along the thickness direction of the skin-side layer is greater than the average value of the total area occupied by the superabsorbent polymer per unit area in a cross section along the thickness direction of the non-skin-side layer.

[0119] According to aspect 53, the non-skin-side layer of the absorbent core is more likely to retain excrement than the skin-side layer, reducing the risk of localized swelling of the absorbent core and lowering the torsional rigidity of the absorbent article, which makes it easier to fit the wearer's body and reduces discomfort when worn. Also, it is easier to reduce the risk of the absorbent article being noticeable from the outside of clothing after absorption.

[0120] (Aspect 54) The absorbent article of any one of Aspects 51 to 53, wherein the total water retention capacity of the superabsorbent polymer present in the skin-side layer is less than the total water retention capacity of the superabsorbent polymer present in the non-skin-side layer.

[0121] According to aspect 54, since the non-skin-side layer of the absorbent core is more likely to retain excrement than the skin-side layer, the risk of localized swelling of the absorbent core can be reduced, which in turn reduces the torsional rigidity of the absorbent article, making it easier for the absorbent article to fit the wearer's body when worn, and reducing discomfort when worn. In addition, the risk of the absorbent article being noticeable from the outside of clothing after absorption can be reduced.

[0122] (Aspect 55) An absorbent article according to any one of aspects 41 to 54, characterized in that it has a skin-side core wrap sheet portion covering at least a portion of the skin-facing side of the absorbent core, a non-skin-side core wrap sheet portion covering at least a portion of the non-skin-facing side of the absorbent core, a top sheet provided on the skin side of the skin-side core wrap sheet portion, and a back sheet provided on the non-skin side of the non-skin-side core wrap sheet portion, and has a portion where the top sheet and the back sheet are adhered.

[0123] According to aspect 55, the number of members overlapped in the thickness direction can be reduced compared to when the topsheet is folded up to the non-skin side of the non-skin side core wrap sheet portion or when the backsheet is folded up to the skin side of the skin side core wrap sheet portion, which makes it easier to reduce the torsional rigidity of the absorbent article, makes it easier to fit the wearer's body when worn, and reduces discomfort when worn. Also, it is possible to reduce the risk of the absorbent article being noticeable from the outside of clothing.

[0124] (Aspect 56) The density of the absorbent core is 0.2 g / cm ３ The absorbent article of any one of Aspects 41 to 55 is characterized in that:

[0125] According to aspect 56, the density of the absorbent core is 0.2 g / cm ３ Since the absorbent core is likely to diffuse excrement more readily than if it were smaller, the risk of localized swelling of the absorbent core can be reduced, which in turn reduces the torsional rigidity of the absorbent article, making it easier to fit the wearer's body when worn and reducing discomfort when worn. In addition, the risk of the absorbent article being noticeable from the outside of clothing after absorption can be reduced.

[0126] (Aspect 57) An absorbent article according to any one of aspects 41 to 56, comprising a skin-side core wrap sheet portion that covers at least a portion of the skin-facing side of the absorbent core, and a top sheet that is provided on the skin side of the skin-side core wrap sheet portion, wherein the density of the absorbent core is higher than the density of the top sheet.

[0127] According to Aspect 57, the absorbent core is less likely to expand after absorbing bodily waste than when the density of the absorbent core is lower than the density of the topsheet, which reduces the torsional rigidity of the absorbent article, making it easier to fit the wearer's body when worn and reducing discomfort when worn. It also reduces the risk that the absorbent article will be noticeable from the outside of clothing after absorption.

[0128] (Aspect 58) An absorbent article according to any one of Aspects 51 to 57, characterized in that the absorbent core has a plurality of absorbent layers including the skin-side layer, the intermediate layer, and the non-skin-side layer, and among the plurality of absorbent layers, one or more absorbent layers located non-skin-side relative to the absorbent layer located closest to the skin in the thickness direction do not contain nonwoven fabric.

[0129] According to aspect 58, the risk of the absorbent article becoming excessively thick due to the absorption of excrement is reduced, and the risk of the absorbent article being noticeable from the outside of clothing after absorption is reduced, while the absorbent article can be softened even after absorbing excrement, making it easier to fit the wearer's body and reducing discomfort when worn.

[0130] (Aspect 59) An absorbent article according to any one of aspects 51 to 58, characterized in that the absorbent core has a plurality of absorbent layers including the skin-side layer, the intermediate layer, and the non-skin-side layer, and among the plurality of absorbent layers, the absorbent layer located closest to the skin in the thickness direction does not contain absorbent resin powder.

[0131] According to aspect 59, the risk of the absorbent article increasing locally in thickness due to the absorption of excrement is reduced, and the risk of the absorbent article being noticeable from the outside of clothing after absorption is reduced, while the absorbent article can be softened even after absorbing excrement, making it easier to fit the wearer's body and reducing discomfort when worn.

[0132] (Aspect 60) The absorbent article of any one of Aspects 51 to 58, wherein the absorbent core has a plurality of absorbent layers including the skin-side layer, the intermediate layer, and the non-skin-side layer, and among the plurality of absorbent layers, the absorbent layer located closest to the skin in the thickness direction comprises the superabsorbent polymer, and the liquid permeation rate under load of the superabsorbent polymer of the absorbent layer located closest to the skin exceeds 10 seconds.

[0133] According to aspect 60, the risk of the absorbent article increasing locally in thickness due to the absorption of excrement is reduced, and the risk of the absorbent article being noticeable from the outside of the clothing after absorption is reduced, while the absorbent article can be softened even after absorbing excrement, making it easier to fit the wearer's body and reducing discomfort when worn.

[0134] First Embodiment An absorbent article according to the present invention will be described using a pants-type disposable diaper 1 for infants (hereinafter also referred to as "diaper 1") as an example. However, the absorbent article according to the present invention also includes tape-type disposable diapers, shorts-type napkins, absorbent pads, sanitary napkins, and other absorbent articles. Furthermore, the wearer of the absorbent article is not limited to infants, but may also be an adult, an animal, or other living being.

[0135] <Configuration of Diaper 1> Fig. 1 is a schematic perspective view of the diaper 1. Fig. 2 is a plan view of the diaper 1 in an unfolded and stretched state, as seen from the skin side. Fig. 3 is a schematic cross-sectional view taken along the center line CL in Fig. 2. The "stretched state" of the diaper 1 refers to a state in which the entire diaper 1 is stretched without wrinkles, specifically, a state in which the dimensions of each component constituting the diaper 1 (e.g., the absorbent main body 10 and waist-circumference sections 30, 40, etc., described below) are stretched to the extent that they match or are close to the dimensions of the individual components. The "unfolded state" of the diaper 1 refers to a state in which the diaper 1 is opened and unfolded in a plane by separating a pair of side seam sections 2 provided on both sides of the diaper 1.

[0136] The diaper 1 has a vertical direction, a width direction, and a front-to-rear direction that are perpendicular to each other, and has a waist opening BH and a pair of leg openings LH. The upper side in the vertical direction corresponds to the waist opening BH side, and the lower side corresponds to the crotch side. The front side in the front-to-rear direction corresponds to the wearer's abdomen side, and the rear side corresponds to the wearer's back side. The width direction is a direction along the stretch direction of the elastic threads 33, 43 of the front waist portion 30 and the rear waist portion 40. The vertical direction is a direction perpendicular to the stretch direction.

[0137] The diaper 1 is a so-called three-piece pants-type diaper having a liquid-absorbent main body 10 and a pair of waist-surrounding sections 30, 40. Of the pair of waist-surrounding sections, the one covering the wearer's abdominal region is also referred to as the front waist-surrounding section 30, and the other covering the wearer's dorsal region is also referred to as the rear waist-surrounding section 40.

[0138] In the unfolded state shown in Fig. 2, the diaper 1 has a longitudinal direction, a width direction, and a thickness direction, which are perpendicular to each other. The longitudinal direction is along the longitudinal direction of the absorbent main body 10 and along the vertical direction of the pants-type diaper 1. The thickness direction is the direction in which the materials constituting the diaper 1 are layered, as shown in Fig. 3. In the thickness direction, the side that contacts the wearer's skin is referred to as the skin side, and the opposite side is referred to as the non-skin side. In the unfolded state, the front waistband 30 and the rear waistband 40 are aligned parallel to each other with a gap in the longitudinal direction, with the absorbent main body 10 spanning between them, with each longitudinal end of the absorbent main body 10 bonded and fixed to the skin side of the nearest waistband 30, 40, resulting in a generally H-shaped external shape in a plan view. From this state, the absorbent main body 10 is folded in half along the longitudinal center line CL. In this folded state, the opposing front waistline portion 30 and rear waistline portion 40 are joined and connected at both widthwise sides to form a pair of side joint portions 2. The side joint portions 2 are formed by known joining means such as welding or adhesive.

[0139] The absorbent main body 10 has an absorbent body 20 (details will be described later), a liquid-permeable top sheet 12 arranged closer to the skin than the absorbent body 20, and a back sheet 13 arranged closer to the skin than the absorbent body 20. The back sheet 13 has a two-layer structure consisting of a liquid-impermeable sheet 13a and a hydrophobic exterior sheet 13b arranged on the far side of the liquid-impermeable sheet 13a. However, the absorbent main body 10 may also include sheet members other than these. For example, a second sheet (not shown) may be provided between the top sheet 12 and the absorbent body 20 in the thickness direction.

[0140] A pair of leakage preventing walls 15 is provided along the longitudinal direction of the absorbent main body 10 on both widthwise sides of the absorbent main body 10. In Figure 3, a part of the exterior sheet 13b extends outward from both ends of the absorber 20 in the widthwise direction and is folded toward the skin at multiple locations to form the pair of leakage preventing walls 15. A leakage preventing wall elastic member 16 such as rubber thread is attached to the tip of the leakage preventing wall 15 in a state stretched along the longitudinal direction of the absorbent main body 10, so that the leakage preventing wall 15 can stand up toward the skin. In addition, leg elastic members 17 such as rubber thread are attached to both widthwise sides of the absorbent main body 10 in a state stretched along the longitudinal direction of the absorbent main body 10.

[0141] The front waistline section 30 and the rear waistline section 40 each have a skin-side sheet 31, 41, a non-skin-side sheet 32, 42, and multiple waistline elastic members 33, 43 such as rubber threads. The multiple waistline elastic members 33, 43 are arranged vertically between the skin-side sheet 31, 41 and the non-skin-side sheet 32, 42 and are attached in a stretched state in the width direction. The stretchability of the waistline elastic members 33, 43 allows the front waistline section 30 and the rear waistline section 40 to fit the wearer's waist. In addition, a cover sheet 34, 44 may be provided to cover the upper end of the absorbent main body 10 from the skin side. The cover sheet 34, 44 can prevent the absorbent main body 10 from opening.

[0142] 2, the front waistline portion 30 and the rear waistline portion 40 have different planar shapes in the unfolded and stretched state. The front waistline portion 30 has a vertical length that is roughly the same as that of the side joint portion 2 and a rectangular shape that is long in the width direction. The rear waistline portion 40 has a rectangular portion that overlaps with the front waistline portion 30 and a generally trapezoidal portion 40E that extends downward from the rectangular portion 30. The extending portion 40E can cover the wearer's buttocks.

[0143] The basic configuration of the diaper 1 has been described above, but the above configuration is merely an example and is not intended to be limiting. For example, the front waistline portion 30 and the rear waistline portion 40 may be formed from a single continuous member, or an outer member may be provided in the crotch area connecting the front waistline portion 30 and the rear waistline portion 40. Furthermore, the elastic members such as the waistline elastic members 33, 43 may be sheet-like elastic members instead of rubber threads.

[0144] Regarding the absorbent body 20: Fig. 4 is a schematic cross-sectional view of the absorbent body 20 of this embodiment. Fig. 5 is a plan view of the absorbent cores 21 to 23 stacked together. Fig. 6A is a plan view of the skin side layer 21 and the intermediate layer 22, and Fig. 6B is a plan view of the non-skin side layer 23.

[0145] As shown in FIG. 4 , the absorbent body 20 has absorbent cores 21-23 between a core wrap sheet 25 on the skin side and a core wrap sheet 26 on the non-skin side. The absorbent cores 21-23 are components that absorb and retain excretory fluids such as urine, and include a liquid-absorbent fiber 201 and a super absorbent polymer. The liquid-absorbent fiber 201 and the super absorbent polymer (hereinafter also referred to as SAP) are not particularly limited as long as they are usable as absorbent cores for absorbent articles. For example, examples of the liquid-absorbent fiber 201 include wood pulp fibers, non-wood pulp fibers such as bagasse, kenaf, bamboo, hemp, and cotton, regenerated cellulose fibers such as rayon fibers, and semi-synthetic fibers such as acetate fibers. Examples of SAP include starch-based, cellulose-based, and synthetic polymer-based polymer absorbents. The core wrap sheets 25 and 26 are liquid-permeable sheet materials, examples of which include tissue and nonwoven fabric.

[0146] The absorbent cores 21-23 each include a skin-side layer 21, an intermediate layer 22, and a non-skin-side layer 23. The intermediate layer 22 is located closer to the skin side in the thickness direction than the skin-side layer 21, and the non-skin-side layer 23 is located closer to the skin side in the thickness direction than the intermediate layer 22. The skin-side layer 21 has a first thickness t1, and is a layer in which the volume occupied by SAP is larger than the volume occupied by the liquid-absorbent fibers 201. The intermediate layer 22 has a second thickness t2, and is a layer in which the volume occupied by the liquid-absorbent fibers 201 is larger than the volume occupied by SAP. The non-skin-side layer 23 has a third thickness t3, and is a layer in which the volume occupied by SAP is larger than the volume occupied by the liquid-absorbent fibers 201.

[0147] Furthermore, the absorbent body 20 of this embodiment further includes a skin-side upper layer 24, which is located closer to the skin in the thickness direction than the skin-side layer 21 and has a fourth thickness t4 that is thinner than the first thickness t1 of the skin-side layer 21. The skin-side upper layer 24 is a layer in which the volume occupied by the liquid-absorbent fiber 201 is greater than the volume occupied by the SAP. Specifically, the skin-side upper layer 24 of this embodiment is composed only of the liquid-absorbent fiber 201. That is, the skin-side upper layer 24, which is the layer closest to the skin among the multiple layers constituting the absorbent core, does not contain water-absorbent resin powder such as superabsorbent polymer (SAP). The absence of water-absorbent resin powder such as SAP in the layer closest to the skin reduces the granular, gritty feel on the wearer's skin and reduces discomfort during wear. However, the skin-side upper layer 24 is not necessarily provided in the absorbent body 20 of this embodiment.

[0148] 4, in this embodiment, the skin side layer 21 and the intermediate layer 22 are integrally formed, and therefore the volume occupancy of the SAP decreases and the volume occupancy of the liquid-absorbent fiber 201 increases from the skin side layer 21 toward the intermediate layer 22. Such an absorbent core can be manufactured, for example, by adjusting the order, amount, timing, etc. of feeding the SAP and the liquid-absorbent fiber 201 into a forming mold (recess) that corresponds to the shape of the absorbent core and is provided on the outer peripheral surface of a rotating drum.

[0149] In this embodiment, the skin side layer 21 and the intermediate layer 22 are laminated integrally, i.e., adjacent to each other in the thickness direction, without any adhesive or nonwoven fabric in between. This prevents the adhesive or nonwoven fabric from interfering with the transfer of excreted fluid from the skin side layer 21 to the intermediate layer 22, and increases the rate of absorption by the intermediate layer 22.

[0150] Furthermore, in this embodiment, the non-skin side layer 23 is not formed integrally with the intermediate layer 22, but is laminated adjacent to the intermediate layer 22 in the thickness direction via the non-woven fabric 27. The presence of the non-woven fabric 27 allows the excreted liquid to diffuse in the planar direction on the non-woven fabric 27 before transferring from the intermediate layer 22 to the non-skin side layer 23. Therefore, the excreted liquid diffused in the planar direction can transfer to the non-skin side layer 23, allowing the absorbent cores 21-23 to be effectively utilized in the planar direction.

[0151] The method for comparing the volumes occupied by the liquid absorbent fiber 201 and the SAP in each of the skin side layer 21, the intermediate layer 22, the non-skin side layer 23, and the skin side upper layer 24 will be described later.

[0152] In the case of an absorbent core containing SAP, as in the present embodiment, if the ratio of liquid-absorbent fibers in the absorbent core is reduced and the SAP ratio is increased in order to further improve absorbency, the gritty feel of the SAP may be felt more easily when touching the diaper, and the SAP layer may be more likely to break down due to reduced entanglement with the liquid-absorbent fibers. However, on the other hand, if the SAP ratio is reduced to suppress the gritty feel of the SAP, it becomes difficult to ensure absorbency. Therefore, it is necessary to ensure absorbency while reducing the uncomfortable gritty feel of the SAP.

[0153] The absorbent body 20 of this embodiment includes an absorbent core made up of a skin-side layer 21, an intermediate layer 22, a non-skin-side layer 23, and an upper skin-side layer 24. However, the total water retention capacity of the SAP present in the skin-side layer 21 is different from that of the SAP present in the non-skin-side layer 23. Specifically, the total water retention capacity of the SAP present in the non-skin-side layer 23 is greater than that of the SAP present in the skin-side layer 21. The skin-side layer 21, which has a lower total water retention capacity, can prevent SAP from swelling and inhibiting liquid absorption, allowing excreted liquid to diffuse easily. The excreted liquid that is quickly absorbed and diffused in the skin-side layer 21 quickly penetrates into the intermediate layer 22. Furthermore, since the intermediate layer 22 has a high volumetric ratio of liquid-absorbent fibers 201, the excreted liquid is temporarily stored in the intermediate layer 22 and then transferred to the layer with a higher total water retention capacity, i.e., the non-skin-side layer 23, which is the layer that ultimately retains water. Furthermore, since the total volume of SAP after absorption is small in the skin-side layer 21 with a low total water retention capacity, the wearer is less likely to feel uncomfortable with the gritty feel of SAP. Therefore, the non-skin-side layer 23 with a high total water retention capacity ensures absorbency, while reducing the uncomfortable feel even after the absorbent cores 21-24 have absorbed excrement.

[0154] Furthermore, the skin-side layer 21 has a lower total water retention capacity than the non-skin-side layer 23, but has a high volume occupancy rate of SAP, and therefore has adequate water retention. Therefore, when excreted liquid from the intermediate layer 22 or the non-skin-side layer 23 attempts to return to the skin side, the SAP in the skin-side layer 21 absorbs and retains the excreted liquid, thereby preventing the excreted liquid from rewetting.

[0155] The total water retention capacity of the SAP present in the skin-side layer 21 and the non-skin-side layer 23 can be measured by the following measurement method. First, 0.9% saline (enough to fully immerse the sample) is prepared in a water bath. Next, test pieces are prepared. One absorbent body 20 is cut into 50 mm pieces in the longitudinal direction to form the test pieces. Note that when the absorbent body 20 is cut into 50 mm pieces, the longitudinal length of the last test piece does not have to be less than 50 mm. First, to measure the total water retention capacity of the SAP present in the skin-side layer 21, each test piece is separated as follows: (Layer Separation Method 1) 1) Peel off the core wrap sheet 26 from the non-skin-facing side. 2) Peel off the non-skin-side layer 23. 3) Peel off the nonwoven fabric 27. 4) Peel off the layer of liquid-absorbent fiber 201 (corresponding to the intermediate layer 22) of the remaining sheet. 5) The sum of steps 1) to 4) above is designated as X1. 6) The remainder of X1 is designated X2 (X2 essentially includes the skin-side layer 21, the skin-side upper layer 24, and the core wrap sheet 25). For the next test piece, another absorbent body 20 is prepared, and similarly cut into 50 mm pieces in the longitudinal direction. To measure the total water retention capacity of the SAP present in the non-skin-side layer 23, each cut test piece is separated as follows. (Layer separation method 2) 1) Peel off the core wrap sheet 25 from the skin-facing side. 2) Of the remaining sheet, do not peel off the layer of liquid-absorbent fiber 201 (corresponding to the middle layer 22) (this removes the skin-side upper layer 24, the skin-side layer 21, and the middle layer 22). 3) Peel off the nonwoven fabric 27. 4) The above 1) to 3) are designated X4. 5) The remainder of X4 is designated X3 (X3 essentially includes the non-skin-side layer 23 and the core wrap sheet 26).

[0156] Next, samples X1 to X4 are each placed in a mesh plastic bag, sealed, and the weight (A) before water absorption is measured. After measurement, each sample X1 to X4 is immersed in physiological saline for 30 minutes. After 30 minutes, each sample is removed from the water tank, and with the core wrap sheet side of each sample facing downwards, an acrylic plate (320 x 545 mm, thickness 3 to 5 mm, weight 400 to 600 g) and a 5 kg weight are placed on top, and left for 20 minutes. After 20 minutes, the weight and acrylic plate are removed, and the weight (B) of each sample is measured. Weight (B) - weight (A) is the amount of water absorption.

[0157] After weight measurement, each sample is dehydrated using a centrifuge at 75 G for 90 seconds. After dehydration, the weight (C) of each removed sample is measured. Weight (C) - weight (A) is the water retention capacity. Note that dehydration using a centrifuge can remove water adhering to the liquid-absorbent fiber 201, core wrap sheet, and nonwoven fabric, and only the amount of water chemically retained by the SAP is determined. Therefore, the water retention capacity calculated by "weight (C) - weight (A)" above is the water retention capacity of the SAP present in each sample. Therefore, the water retention capacity of sample X2 is the water retention capacity of the SAP present in the skin-side layer 21, and the water retention capacity of sample X3 is the water retention capacity of the SAP present in the non-skin-side layer 23. In this embodiment, in order to compare the "total water retention capacity" of the SAP present in the skin-side layer 21 with the "total water retention capacity" of the SAP present in the non-skin-side layer 23, measurements were carried out on each test piece cut into 50 mm pieces as described above, and the sum of the water retention capacity of X2 of each test piece is the "total water retention capacity of the SAP present in the skin-side layer 21," and the sum of the water retention capacity of X3 of each test piece is the "total water retention capacity of the SAP present in the non-skin-side layer 23."

[0158] As an example, the water retention capacity of the above-mentioned X2 (one sample) was 25.4 g, and the water retention capacity of the above-mentioned X3 (one sample) was 41.1 g. In other words, when comparing the water retention capacities of test pieces with a longitudinal length of 50 mm, the water retention capacity of the SAP present in the non-skinside layer 23 was clearly greater. Therefore, it can be seen that in the diaper 1 of this embodiment, the total water retention capacity of the SAP present in the non-skinside layer 23 is greater than the total water retention capacity of the SAP present in the skinside layer 21.

[0159] The comparison of the volumes occupied by the liquid-absorbent fiber 201 and the SAP in each of the skin-side layer 21, the middle layer 22, the non-skin-side layer 23, and the skin-side upper layer 24 can be confirmed by the following method. For example, with the diaper 1 in its natural, dry state, in which no external force is acting, the diaper 1 (absorbent body 20) is cut widthwise at any position in the longitudinal direction of the absorbent body 20, specifically at a position where the four layers 21 to 24 are stacked and away from the product folding position. Next, the cut surface is magnified (e.g., 30 to 100 times) and photographed using an optical microscope (e.g., Keyence Corporation's Digital Microscope VHX-7000 or equivalent). The liquid-absorbent fiber 201 and the SAP are identified in the photographed cross-sectional image. Then, in the cross-sectional image, it is confirmed that the following layers are stacked in this order from the skin side in the thickness direction: a skin-side upper layer 24 in which the area occupied by the liquid-absorbent fibers 201 is larger than the area occupied by the SAP, a skin-side layer 21 in which the area occupied by the SAP is larger than the area occupied by the liquid-absorbent fibers 201, a middle layer 22 in which the area occupied by the liquid-absorbent fibers 201 is larger than the area occupied by the SAP, and a non-skin-side layer 23 in which the area occupied by the SAP is larger than the area occupied by the liquid-absorbent fibers 201. If the above is confirmed, the four layers 21 to 24 of this embodiment are defined. Cross-sectional images are prepared at multiple locations (e.g., 10 locations) along the longitudinal direction of the absorbent body 20 in which such four layers 21 to 24 can be confirmed, and if the area occupied by SAP in any of the cross-sectional images is larger than the area occupied by the liquid-absorbent fiber 201, then that layer is a layer in which "the volume occupied by SAP is larger than the volume occupied by the liquid-absorbent fiber," and if the area occupied by the liquid-absorbent fiber 201 in any of the cross-sectional images is larger than the area occupied by SAP, then that layer is a layer in which "the volume occupied by the liquid-absorbent fiber is larger than the volume occupied by SAP."

[0160] In addition, a comparison of the volumes occupied by the liquid-absorbent fibers 201 and the SAP in each layer can also be made by visualizing the liquid-absorbent fibers 201 and the SAP using X-ray microtomography (X-ray CT), for example, by the method described below: ScienceDirect, Carbohydrate Polymers 254, Mathias A. Hobisch et al., February 15, 2021, "How cellulose nanofibrils and cellulose microparticles impact paper strength - A visualization approach", Section "3.6. X-ray microtomography", https: / / www.sciencedirect.com / science / article / pii / S0144861720315794.

[0161] Furthermore, in this embodiment, the average value of the total area occupied by SAP per unit area in a cross section taken along the thickness direction of the skin-side layer 21 is different from the average value of the total area occupied by SAP per unit area in a cross section taken along the thickness direction of the non-skin-side layer 23. Specifically, the average value of the total area occupied by SAP per unit area in a cross section taken along the thickness direction of the non-skin-side layer 23 is greater than the average value of the total area occupied by SAP per unit area in a cross section taken along the thickness direction of the skin-side layer 21. A layer with a small average value of the total area occupied by SAP per unit area is less likely to produce a gritty feeling of SAP when touched. By using such a layer as the skin-side layer 21, the wearer is less likely to feel an uncomfortable sensation of SAP to the touch. Furthermore, a skin-side layer 21 with a small average value of the total area occupied by SAP per unit area can prevent SAP from swelling and inhibiting absorption, thereby improving the diffusibility of excreted fluid. A layer with a large average total area occupied by SAP per unit area has improved absorbency, and such a layer, the non-skin side layer 23, can absorb and retain more excreted liquid even in repeated excretion, thereby suppressing rewetting.

[0162] Furthermore, a skin-side upper layer 24 is provided on the skin side of the skin-side layer 21 in the thickness direction. The skin-side upper layer 24 has a fourth thickness t4 that is thinner than the first thickness t1 of the skin-side layer 21 and in which the volume occupied by the liquid-absorbent fibers 201 is larger than the volume occupied by the SAP. The skin-side upper layer 24, which has a high volumetric ratio of the liquid-absorbent fibers 201, is located closer to the skin than the skin-side layer 21, thereby further reducing the wearer's perception of the unevenness of the SAP. Furthermore, because the skin-side upper layer 24 contains a large amount of the liquid-absorbent fibers 201, it further improves the ability to draw excreted liquid from sheets (such as a top sheet) placed closer to the skin. Furthermore, the liquid-absorbent fibers 201 contained in the skin-side upper layer 24 make it difficult for the SAP of the skin-side layer 21 to roll within the layer, preventing a deterioration in the tactile feel. The skin-side upper layer 24 is arranged closer to the skin than the skin-side layer 21, but is thinner than the first thickness t1 of the skin-side layer 21, so that it can draw in excreted liquid without excessively retaining the excreted liquid, thereby reducing rewetting.

[0163] The "average value of the total area occupied by SAP per unit area in a cross section along the thickness direction of the skin-side layer 21 (non-skin-side layer 23)" can be determined as follows, for example, using the volume comparison method described above. The absorbent body 20 is cut at 10 locations along the width direction at any position in the longitudinal direction of the absorbent body 20, specifically, at a location where the skin-side layer 21 and the non-skin-side layer 23 are laminated and away from the product folding position. The cut surfaces are photographed under magnification using the optical microscope described above, and the "total area occupied by SAP per unit area" of the skin-side layer 21 and the "total area occupied by SAP per unit area" of the non-skin-side layer 23 are determined for each of the cut surfaces, and their average value is defined as the "average value of the total area occupied by SAP per unit area."

[0164] As described above, the skin-side layer 21 has a first thickness t1, the intermediate layer 22 has a second thickness t2, and the non-skin-side layer 23 has a third thickness t3 (see FIG. 4 ). The first thickness t1 to the third thickness t3 refer to average thicknesses. In this embodiment, the third thickness t3 of the non-skin-side layer 23 is thicker than the first thickness t1 of the skin-side layer 21. Specifically, the third thickness t3 of the non-skin-side layer 23 is preferably 0.38 mm to 0.58 mm for the S-size diaper 1 and 0.58 mm to 0.69 mm for the XXL-size diaper 1. The first thickness t1 of the skin-side layer 21 is preferably 0.3 mm to 0.48 mm for the S-size diaper 1 and 0.45 mm to 0.65 mm for the XXL-size diaper 1. The skin-side layer 21, which is thinner than the non-skin-side layer 23, also becomes thinner after moisture retention. That is, even after water retention, the SAP is less likely to swell, thereby inhibiting absorption, and the feel (grittiness) of the skin side of the diaper 1 is less likely to deteriorate. The average thickness of the absorbent body 20 is preferably 2.0 to 2.5 mm.

[0165] The average thickness t2 of the intermediate layer 22 is preferably 0.5 mm or greater. More preferably, it is 0.9 mm to 1.1 mm for an S-size diaper 1 and 1.28 mm to 1.61 mm for an XXL-size diaper 1. This allows for more excreted liquid to be absorbed between the liquid-absorbent fibers 201 of the intermediate layer 22 than when the average thickness of the intermediate layer 22 is less than 0.5 mm, for example, compared to when the intermediate layer 22 is a nonwoven fabric (sheet member) formed of pulp fibers or the like. This allows for quick and temporary absorption of excreted liquid in the intermediate layer 22, and after diffusing the excreted liquid in the intermediate layer 22, it quickly transfers the excreted liquid to the non-skinside layer 23, ensuring absorbency. However, because an excessively thick intermediate layer 22 can cause stiffness, the average thickness (second thickness t2) of the intermediate layer 22 is preferably 2.5 mm or less.

[0166] The thicknesses (t1 to t3) of the layers 21 to 23 can be measured using known methods. For example, with the diaper 1 in a natural, dry state without external forces, the diaper 1 (absorbent body 20) is cut widthwise at any longitudinal position in the portion of the diaper 1 where the absorbent body 20 is located, specifically, at a location where the three layers 21 to 23 are stacked and away from the product folding position. To prevent damage to the absorbent body 20 components, the diaper 1 is cut at a predetermined location and then measured. Next, using an optical microscope (e.g., Keyence Corporation's VHX-7000 Digital Microscope or equivalent), the cut surface is placed upright and magnified (e.g., 30 to 100 times) and photographed. The focus of the magnified photograph is on the liquid-absorbent fibers 201. In the captured cross-sectional image, the layer in which the liquid-absorbent fiber 201 is visible is determined to be the intermediate layer 22, and the portions of the absorbent core closer to the skin or closer to the skin are determined to be the skin-side layer 21 and the non-skin-side layer 23, respectively. Furthermore, measurement positions (e.g., five positions) are determined in the width direction of the cross-sectional image, and the thickness of each of the layers 21 to 23 at each measurement position is obtained. Preferably, cross-sectional images are captured at multiple positions in the longitudinal direction of the absorbent body 20 to obtain the thickness of each of the layers 21 to 23. The average values ​​of the obtained thicknesses are calculated for each of the layers 21 to 23, and are designated as the average thickness t1 (first thickness t1) of the skin-side layer 21, the average thickness t2 (second thickness t2) of the intermediate layer 22, and the average thickness t3 (third thickness t3) of the non-skin-side layer 23. Note that when measuring the thickness, portions other than the low basis weight regions 211, 221, and 231 are measured. Furthermore, when the absorbent layer is bonded to adjacent sheet portions (core wrap sheets 25, 26, nonwoven fabric 27) via adjacent adhesive, such as the skin-side upper layer 24, the skin-side layer 21, and the middle layer 22, it is difficult to identify the part where the material (liquid absorbent fiber, SAP) that constitutes each absorbent layer is actually bonded and fixed to the adjacent sheet portion with adhesive.Therefore, when it can be determined that adhesive exists between the absorbent layer and the adjacent sheet portion, the distance between adjacent sheet portions in the thickness direction is measured as the "thickness of the absorbent layer."

[0167] Using the above-mentioned method, five samples were prepared by cutting the longitudinal end of the absorbent body 20 and then cutting the absorbent body 20 so that the longitudinal length was 10 mm from that point.The average thicknesses measured were as follows: for the S size, the first thickness t1 was 0.41 mm, the second thickness t2 was 0.99 mm, and the third thickness t3 was 0.47 mm; and for the XXL size, the first thickness t1 was 0.56 mm, the second thickness t2 was 1.47 mm, and the third thickness t3 was 0.63 mm.

[0168] In this embodiment, the average basis weight of the non-skinside layer 23 is higher than the average basis weight of the skinside layer 21. A suitable average basis weight of the non-skinside layer 23 is 50 g / m ２ ~350g / m ２ Specifically, when the diaper 1 is a size S, the average basis weight of the non-skinside layer 23 is 173 g / m ２ The average basis weight of the skin side layer 21 is preferably about 82 g / m ２ When the diaper 1 is an XXL size, the average basis weight of the non-skinside layer 23 is about 300 g / m ２ The average basis weight of the skin side layer 21 is preferably about 171 g / m ２ The skin-side layer 21 having a low average basis weight is less likely to swell after retaining water, and therefore the skin-side layer 21 is less likely to suffer from absorption inhibition due to swelling of the SAP. As a result, the feel of the skin side (gritty feeling of the SAP) is less likely to deteriorate.

[0169] In addition, at least one of the skin side layer 21, the intermediate layer 22, and the non-skin side layer 23 has a basis weight of the absorbent core (i.e., the total basis weight of the liquid-absorbent fiber 201 and the SAP: g / m) that is smaller than that of the surrounding area. ２ 4, in the absorbent body 20 of this embodiment, the skin side layer 21 and the intermediate layer 22 have low basis weight regions 211, 221, and similarly, the non-skin side layer 23 also has a low basis weight region 231.

[0170] Therefore, when the wearer excretes in the diaper 1 and the absorbent body 20 receives the excreted liquid, the excreted liquid is quickly drawn from the low basis weight region 211 into the interior of the absorbent body 20 (intermediate layer 22). The liquid-absorbent fiber 201 has a faster liquid absorption rate than SAP. Because the volume occupancy of the liquid-absorbent fiber 201 is high in the intermediate layer 22, the excreted liquid that migrates from the low basis weight region 211 to the intermediate layer 22 is quickly and temporarily absorbed by the intermediate layer 22. Thereafter, the excreted liquid absorbed between the fibers of the liquid-absorbent fiber 201 in the intermediate layer 22 gradually migrates to the non-skinside layer 23 due to gravity. Furthermore, because the intermediate layer 22 also has a low basis weight region 221, excreted liquid is more likely to migrate from the low basis weight region 221 to the non-skinside layer 23, and more likely to migrate from the low basis weight region 231 of the non-skinside layer 23 to a deeper portion of the non-skinside layer 23. Therefore, excreted liquid is easily drawn deep into the absorbent core, improving absorbency. In addition, since the volume occupancy of SAP in the non-skin side layer 23 is high, excreted liquid is firmly absorbed and retained by the SAP in the non-skin side layer 23.

[0171] Furthermore, the low basis weight region 211 of the skin side layer 21 is preferably a slit penetrating the skin side layer 21 in the thickness direction. In this case, excreted liquid falls into the low basis weight region 211, and therefore the migration speed of excreted liquid from the skin side layer 21 to the intermediate layer 22 increases.

[0172] Although not shown, the liquid-absorbent fiber 201 or SAP may be present in the low basis weight region 211 of the skin side layer 21. Alternatively, the low basis weight region 211 may be a region in which a part of the skin side layer 21 is recessed in the thickness direction.

[0173] Similarly, the low basis weight region 231 of the non-skin side layer 23 may be a slit penetrating in the thickness direction, or the low basis weight region 231 may contain liquid absorbent fibers 201 or SAP, or the low basis weight region 231 may be partially recessed in thickness.

[0174] 6A are integrally formed and have the same planar shape. The skin side layer 21 and the intermediate layer 22 have constricted portions 212, 222 constricted inward in the width direction at the longitudinal center (FIG. 5). The skin side layer 21 and the intermediate layer 22 are divided into thirds along their maximum longitudinal length, and the central region is defined as the longitudinal center, where at least a portion of the constricted portions 212, 222 is located.

[0175] 6B has three longitudinally elongated rectangular divided regions 23a-23c. The three divided regions 23a-23c are spaced apart in the width direction. Two regions between the three divided regions 23a-23c form low basis weight regions 231 (slits) of the non-skin side layer 23. The two low basis weight regions 231 are symmetrically arranged in the width direction across a center line CL2 of the non-skin side layer 23.

[0176] When the skin-side layer 21 and the intermediate layer 22 have the constricted portions 212, 222 as described above, the non-skin-side layer 23 has a portion in the longitudinal center of the diaper 1 whose widthwise length L1 is longer than the widthwise lengths of the skin-side layer 21 and the intermediate layer 22, as shown in Figure 5. The widthwise length L1 of the non-skin-side layer 23 here refers to the length from the widthwise end 23ae of the divided region 23a of the non-skin-side layer 23 to the widthwise end 23ce of the divided region 23c. Having a portion of the non-skin-side layer 23 that is longer than the widthwise lengths of the skin-side layer 21 and the intermediate layer 22 allows the non-skin-side layer 23 to absorb excrement that is not fully absorbed by the skin-side layer 21 and the intermediate layer 22, thereby preventing leakage. Furthermore, the number of layers is reduced in the longer widthwise portions of the non-skin-side layer 23, resulting in reduced rigidity. Here, by providing a region with reduced rigidity within the range where the constricted portions 212, 222 exist, the fit of the crotch area is improved when worn.

[0177] 5, the maximum widthwise length L2 of the skin-side layer 21 and the intermediate layer 22 is preferably longer than the maximum width L3 (and similarly, L1) of the non-skin-side layer 23. In the longitudinal central portion of the diaper 1, the skin-side layer 21 and the intermediate layer 22 have a portion where their width (widthwise length) is narrower than the width (L1) of the non-skin-side layer 23, resulting in less SAP on the skin-side side of the crotch area, resulting in a more comfortable feel against the skin. Furthermore, in portions other than the longitudinal central portion, the maximum width L2 of the skin-side layer 21 and the intermediate layer 22 is longer than the maximum length L3 of the non-skin-side layer 23, allowing for more effective absorption and diffusion of excretory fluid in areas closer to the skin than the non-skin-side layer 23.

[0178] 5, in this embodiment, the length L4 of the skin side layer 21 and the intermediate layer 22 in the longitudinal direction is longer than the length L5 of the non-skin side layer 23. If the length of the non-skin side layer 23 in the longitudinal direction were longer, excreted fluid would be less likely to migrate from the skin side beyond the skin side layer 21 and the intermediate layer 22. However, by arranging the skin side layer 21 and the intermediate layer 22 beyond the non-skin side layer 23 in the longitudinal direction, excreted fluid can be effectively migrated along the entire length of the non-skin side layer 23.

[0179] 5, in a plan view of the absorbent cores 21-23, it is preferable that the low basis weight region 211 of the skin-side layer 21, the low basis weight region 221 of the intermediate layer, and the low basis weight region 231 of the non-skin-side layer have overlapping portions. The skin-side layer 21 and the intermediate layer 22 of this embodiment each have two low basis weight regions 211, 221. The two low basis weight regions 211, 221 of the skin-side layer 21 and the intermediate layer 22 each overlap with two low basis weight regions 231 of the non-skin-side layer 23.

[0180] This makes it easier for excreted liquid that has flowed into the low basis weight region 211 of the skin-side layer 21 and the low basis weight region 221 of the intermediate layer 22 to flow directly into the low basis weight region 231 of the non-skin-side layer 23. This allows excreted liquid to be more quickly drawn deep into the absorbent cores 21 to 23. Furthermore, in the low basis weight regions 211 to 231, absorption is less likely to be hindered by swelling of the SAP, improving the absorption rate.

[0181] In this embodiment, low basis weight regions are provided in all of the skin side layer 21, intermediate layer 22, and non-skin side layer 23, but the present invention is not limited to this, and when one of the skin side layer 21, intermediate layer 22, and non-skin side layer 23 has a low basis weight region, at least one of the layers other than the layer having that low basis weight region may further have a low basis weight region (corresponding to another low basis weight region), and may have a portion where the low basis weight region overlaps with another low basis weight region in a plan view of the absorbent cores 21 to 23. This similarly forms a passage for excreted liquid, and excreted liquid can easily migrate from a layer having a low basis weight region to a layer having another low basis weight region.

[0182] Furthermore, the shape, size, number, and position of the low basis weight regions 211-231 in each layer are not particularly limited. For example, each layer may have one low basis weight region 211-231, which may be located on the center line CL2 in the width direction of the absorbent cores 21-23. The low basis weight regions 21-23 in each layer 21-23 may completely overlap, or multiple low basis weight regions 221-231 may be arranged spaced apart in the longitudinal direction.

[0183] As described above, the skin-side layer 21 has a low-basis weight region 211 in which the absorbent core has a lower basis weight than the surrounding area, and the skin-side upper layer 24, which is disposed closer to the skin than the skin-side layer 21, is disposed so as to overlap the low-basis weight region 211 of the skin-side layer 21 in a planar view, although not shown. The skin-side upper layer 24 is laminated so as to cover at least the shape of the skin-side layer 21 shown in Fig. 5, and in the constricted portion 212, the skin-side upper layer 24 is also laminated on portions outer than both ends of the constricted portion 212 in the width direction. There is a risk that SAP may shift from the periphery of the low-basis weight region 211 and infiltrate into the low-basis weight region 211, but the presence of the skin-side upper layer 24 covering the low-basis weight region 211 from the skin side makes it less likely that the SAP contained in regions outer than the low-basis weight region 211 in the width direction and length direction shift, making it easier to maintain the shape of the low-basis weight region 211.

[0184] The skin-side layer 21 may also contain a different type of SAP from that contained in the non-skin-side layer 23. For example, it is desirable that the SAP contained in the skin-side layer 21 has a liquid absorption rate, as measured by the vortex method, slower than that of the SAP contained in the non-skin-side layer 23.

[0185] This allows the excreted liquid to diffuse in the planar direction and migrate to the intermediate layer 22 before it is absorbed by the SAP in the skin-side layer 21. As a result, the absorbent cores 21 to 23 can be used more effectively, improving absorption performance. Furthermore, by absorbing more excreted liquid in the non-skin-side layer 23, rewetting of the skin-side layer 21 can be suppressed.

[0186] The liquid absorption rate of SAP using the vortex method can be measured by a known method. For example, 50.0 ml (±0.5 ml) of saline solution with a concentration of 0.900% (±0.009%) and a temperature of 25°C (±2°C) is placed in a 100 ml beaker. The beaker is then placed on a magnetic stirrer and a stir bar is inserted into the beaker. The stir bar is then rotated at 600 rpm (±30 rpm) to ensure that the saline solution in the beaker forms a stable vortex. A stopwatch is then started from the moment 2.00 g (±0.02 g) of the SAP to be measured, removed from the diaper 1, is placed in the beaker, and the time from when the vortex disappears and the liquid level becomes horizontal is measured. The longer this time, the slower the liquid absorption rate.

[0187] Furthermore, when the absorbent body 20 of this embodiment does not include the above-described skin-side upper layer 24, i.e., when the skin-side layer 21 is the layer closest to the skin of the absorbent core, it is preferable that the liquid permeation rate under load of the SAP included in this skin-side layer exceeds 10 seconds. If the liquid permeation rate of the excreted liquid is excessively fast when the skin-side layer 21 receives excreted liquid, the excreted liquid will migrate to the intermediate layer 22 without sufficiently diffusing in the width or length directions of the skin-side layer 21, which may result in a deterioration in the water retention performance of the absorbent core as a whole. Furthermore, if the SAP swells only in the portion that receives the excreted liquid, the absorbent core may become locally thick. In contrast, by setting the liquid permeation rate under load in the skin-side layer to exceed 10 seconds, the water retention of the absorbent core is improved, leading to leakage prevention, and local thickening of the absorbent core can be suppressed, compared to the opposite case.

[0188] The liquid permeation rate under load of the SAP in the layer closest to the skin of the absorbent core can be measured, for example, by the method described in JP 2019-41876 A. Specifically, 0.32±0.005 g of superabsorbent polymer (SAP) was immersed in 100 mL of physiological saline (0.9% by mass sodium chloride solution) in a 100 mL glass beaker and left for 60 minutes. A separate cylindrical filtration tube was prepared, equipped with a wire mesh (150 μm mesh, Sansho Hanbai Biocolumn Sintered Stainless Steel Filter 30SUS) and a capillary tube (4 mm inner diameter, 8 cm length) with a stopcock (2 mm inner diameter) at the bottom end of the opening of a vertically standing cylinder (25.4 mm inner diameter). With the stopcock closed, the entire contents of the beaker, including the swollen test sample, were poured into the cylindrical tube. Next, a 2 mm diameter cylindrical rod equipped with a 25 mm diameter wire mesh at the tip with 150 μm mesh openings is inserted into the cylindrical filtration tube so that the wire mesh and the test sample come into contact, and a weight is placed on the test sample so that a load of 2.0 kPa is applied. After leaving it in this state for 1 minute, the stopcock is opened to allow the liquid to flow, and the time T1 (seconds) until the liquid level in the cylindrical filtration tube reaches the 40 mL scale line from the 60 mL scale line (i.e., 20 mL of liquid passes through) is measured. Using the measured time T1 (seconds), the liquid passage rate under load at 2.0 kPa is calculated using the formula: Liquid passage rate under load (seconds) = T1 - T0. Note that in this formula, T0 (seconds) is the time required for 20 mL of saline to pass through the wire mesh without the test sample in the cylindrical filtration tube. The measurement is carried out at a temperature of 23±2° C. and a relative humidity of 50±5%, and the superabsorbent polymer (SAP) is kept in the same environment for 24 hours or more before the measurement.

[0189] FIG. 7 is a schematic plan view of the absorbent body 20 as viewed from the skin side. As shown in FIG. 7 , in this embodiment, the skin side layer 21 has a plurality of compressed dots 50 formed by compressing the skin side layer 21 (absorbent core 21) in a dotted pattern in the thickness direction. These "compressed dots 50" result in the absorbent core 21 being compressed in the thickness direction by embossing. The compression increases the fiber density of the absorbent core 21 compared to uncompressed portions. In this embodiment, the compressed dots 50 are formed as a collection of dots (circles), but the compressed dots 50 may also be formed as lines (straight lines, curves), for example. Alternatively, the compressed dots or lines may be formed discretely within a predetermined region. Furthermore, the compressed dots 50 are arranged in a pattern that appears as a dotted grid pattern (a so-called quilting pattern) as a whole, as shown in FIG. 7 , but other patterns may also be used.

[0190] Such compressed dots 50 reduce clumps of SAP during compression, suppressing the gritty feel of SAP. Furthermore, localized compression prevents collapse of the absorbent body 20 without impairing the flexibility of the absorbent cores 21-24. Note that the invention is not limited to providing multiple compressed dots 50 on the skin side layer 21, as long as at least one of the skin side layer 21 and the non-skin side layer 23 has compressed dots 50.

[0191] 8 is a partially enlarged plan view showing the adhesive HMA that bonds the core wrap sheet 25 and the skin-side upper layer 24 (skin-side layer 21). A strip of adhesive HMA is provided on the non-skin-side surface of the core wrap sheet 25 in the thickness direction. Furthermore, on the skin side of the skin-side upper layer 24 (skin-side layer 21), the outer edge region in the width direction is designated as the outer edge region TR, and the region inside the outer edge region TR is designated as the inner region UR. The total adhesive area per unit area in the inner region UR is greater than the total adhesive area per unit area in the outer edge region TR. Because the skin-side upper layer 24 is thinner than the skin-side layer 21, the strip of adhesive HMA applied to the non-skin-side surface of the core wrap sheet 25 penetrates the skin-side layer 21. In the inner region UR, where the adhesive HMA is more abundant, the adhesive HMA facilitates fixation of the SAP contained in the skin-side layer 21. Such fixation makes it difficult for the SAP to move, thereby preventing the SAP from being exposed to the skin-facing surface of the absorbent body 20. Furthermore, such a configuration makes it difficult for SAP clumps to form even when the SAP swells, reducing the uncomfortable feeling of touch.

[0192] Furthermore, the average width of the strip-shaped adhesive HMA applied to the non-skin-side surface of the core wrap sheet 25 is smaller than the average particle size of the SAP particles, allowing the adhesive to easily penetrate between the SAP particles. Specifically, the average strip width is 0.016 to 0.018 mm, while the average particle size of the SAP particles is 0.3 to 0.4 mm (see Figure 9). Figure 9 shows an image of the non-skin-side surface of the core wrap sheet 25 in the inner region UR of a diaper 1 before use. That is, Figure 9 shows the state before the SAP particles absorb liquids such as excrement and swell. In this state, the minimum inter-intersection distance of the strip-shaped adhesive is smaller than the particle size (average particle size) of the SAP particles. For example, the inter-intersection distance d i of a certain strip-shaped adhesive shown in Figure 9 is clearly smaller than the diameter D sap of a certain SAP. Furthermore, during use of the diaper 1, the SAP particles absorb liquids such as excrement and swell, resulting in a particle size (average particle size) of the SAP particles that is even larger than the diameter Dsap shown in Figure 9. In other words, the minimum distance between the intersections of the strip-shaped adhesive is smaller than the particle size (average particle size) of the SAP particles at maximum swelling. This makes it difficult for the SAP particles to protrude from the mesh formed by the intersections of the numerous strip-shaped adhesives upon water absorption (maximum SAP swelling), thereby suppressing the movement of the SAP. This makes it difficult for the SAP particles to form clumps even after maximum swelling, thereby reducing the gritty feel when touched.

[0193] The average particle size of SAP can be measured using an electromagnetic sieve shaker (e.g., AS-200 model manufactured by Retsch) as follows. The electromagnetic sieve shaker has sieves No. 1 to No. 7 with different mesh sizes (e.g., mesh sizes: 850, 600, 500, 355, 300, 250, and 150 μm) and a tray. First, the weights of the sieves No. 1 to No. 7 and the tray are measured and designated as measurement value A. Next, from bottom to top, the tray and sieves with mesh sizes of 150, 250, 300, 355, 500, 600, and 850 μm are stacked and set in the shaker. Next, 50 g of SAP is placed on the top sieve with an 850 μm mesh size, and the sieve is covered and secured with a pressure pad. Next, the shaker is set to a 1.35 mm amplitude (the amplitude adjustment dial is 45 for the AS-200 model), continuous operation, and an operation time of 30 minutes. Shaking is then initiated, and a 30-minute shaking test is performed. After the shaking test is completed, the weight of the SAP remaining on each of the first to seventh sieves, the sieves, and the tray are measured and recorded as measurement value B. From these data, the SAP particle size distribution = (B - A) / (total weight of SAP remaining on each sieve and tray) x 100 (%) is calculated. For example, if the shaking test results for a certain sample show that the distribution of SAP remaining on the fourth sieve (355 μm mesh) is 48.3%, then the distribution of SAP particles in the 355-500 μm range is 48.3%. From these data, the average SAP particle size can be determined. Alternatively, SAP particle size may be calculated from magnified microscope images without using such a shaking test.

[0194] 10A, 10B, and 11 are cross-sectional views of modified examples of the absorbent cores 21 to 24. As shown in the modified example of Fig. 10A, the liquid-absorbent fibers 201 do not have to be disposed in the low basis weight region 221 of the intermediate layer 22. Preferably, the low basis weight region 221 of the intermediate layer 22 is a slit. In this way, excreted liquid is not temporarily absorbed by the liquid-absorbent fibers 201 in the low basis weight region 221 of the intermediate layer 22, and therefore excreted liquid can be quickly drawn deeper into the non-skin side layer 23.

[0195] 10B , the intermediate layer 21 and the non-skin side layer 23 may be laminated adjacent to each other in the thickness direction without an adhesive or nonwoven fabric (nonwoven fabric 27 in this embodiment). This prevents the adhesive or nonwoven fabric from interfering with the transfer of excreted fluid from the intermediate layer 21 to the non-skin side layer 23, and increases the rate of absorption by the non-skin side layer 23.

[0196] 11, the intermediate layer 22 and the non-skinside layer 23 are integrally formed, with a nonwoven fabric 27 provided closer to the skin than the intermediate layer 22. In this modification, the total water retention capacity of the SAP present in the skinside layer 21 is configured to be greater than the total water retention capacity of the SAP present in the non-skinside layer 23. This configuration makes it difficult for the non-skinside layer 23 to swell even after absorbing excrement, reducing the discomfort felt by the gritty texture of the SAP when changing the diaper 1. Furthermore, the skinside layer 21, which has a high total water retention capacity, can firmly absorb and retain excrement, ensuring absorbency.

[0197] 11 , in contrast to the present embodiment, the average value of the total area occupied by SAP per unit area in a cross section taken along the thickness direction of the skin-side layer 21 is larger than the average value of the total area occupied by SAP per unit area in a cross section taken along the thickness direction of the non-skin-side layer 23. When the skin-side layer 21 is the layer with a larger average value of the total area occupied by SAP per unit area, the SAP can retain excreted liquid and suppress rewetting. When the non-skin-side layer 23 is the layer with a smaller average value of the total area occupied by SAP per unit area, a person changing the diaper 1 is less likely to feel an uncomfortable sensation from the feel of the SAP.

[0198] 11 , the liquid-absorbent fibers 201 do not have to be disposed in the low basis weight region 231 of the non-skin side layer 23. Preferably, the low basis weight region 231 of the non-skin side layer 23 is a slit. This prevents excreted liquid from being temporarily absorbed by the liquid-absorbent fibers 201 in the low basis weight region 231 of the non-skin side layer 23, allowing the excreted liquid to be quickly drawn deeper into the non-skin side layer 23.

[0199] 11, the skin side layer 21 and the intermediate layer 22 may be laminated adjacent to each other in the thickness direction without the interposition of the nonwoven fabric 27 or adhesive. This prevents the adhesive or nonwoven fabric from interfering with the transfer of excreted fluid from the skin side layer 21 to the intermediate layer 22, and increases the rate of absorption by the intermediate layer 22.

[0200] Furthermore, the intermediate layer 22 is not limited to being formed integrally with either one of the skin side layer 21 and the non-skin side layer 23, but may be formed integrally with both. Alternatively, the three layers 21 to 23 may be formed individually and then laminated. In this case, a nonwoven fabric or an adhesive may or may not be provided between the skin side layer 21 and the intermediate layer 22, and between the intermediate layer 22 and the non-skin side layer 23, respectively.

[0201] Furthermore, the superabsorbent polymer (SAP) used in this embodiment is preferably spherical rather than crushed. By uniformly stacking spherical SAP, which has a uniform shape and a smaller surface area than crushed SAP, the absorbent body 20 can be made thinner, and the absorbent body 20 is less likely to become hard when made thinner.

[0202] Furthermore, in the absorbent body 20 of the diaper 1, the core wrap sheets 25, 26 covering the absorbent core (SAP particles) are preferably formed from a hydrophilic SMS (spunbond-meltblown-spunbond) nonwoven fabric, spunlace nonwoven fabric, or the like. Nonwoven fabrics are generally stronger and more tear-resistant than tissues and the like, making them suitable as base sheets for forming the absorbent body 20. For example, during the manufacture of the absorbent body 20 of the diaper 1, when adhesive is applied or SAP particles are laminated while the nonwoven fabric is conveyed in the conveyance direction as the base sheet, the tear-resistant nonwoven fabric base sheet allows for the formation of an absorbent body (absorbent core) with a stable shape. Furthermore, conveying the base sheet while suctioning it with a suction mechanism or the like can facilitate the fixation of the SAP particles on the base sheet. Furthermore, when the nonwoven fabric is an SMS nonwoven fabric, the material is thinner than other nonwoven fabrics, thereby improving the flexibility of the absorbent body 20. Furthermore, when the nonwoven fabric is a spunlace nonwoven fabric, the gritty feel of the SAP can be reduced and the absorption rate can be improved because spunlace nonwoven fabric is a bulky and highly absorbent material.

[0203] Furthermore, in the absorbent cores 21-23, it is preferable that a layer having a high volume occupancy of SAP that does not contain the liquid-absorbent fiber 201 is present as the skin-side layer 21 or the non-skin-side layer 23. In this embodiment, the non-skin-side layer 23 is a layer that does not contain the liquid-absorbent fiber 201. Such a layer that does not contain the liquid-absorbent fiber 201 is more susceptible to liquid transfer than a layer that does contain the liquid-absorbent fiber 201. The presence of the non-skin-side layer 23 having a high volume occupancy of SAP that does not contain the liquid-absorbent fiber 201 improves absorbency. Furthermore, in the absorbent body 20 shown in the modified example of FIG. 11 , a layer having a high volume occupancy of SAP that does not contain the liquid-absorbent fiber 201 is present as the skin-side layer 21. In such a case, rewet can be suppressed by the skin-side layer 21 firmly absorbing the liquid.

[0204] The skin-side layer 21 of this embodiment contains the liquid-absorbent fiber 201 and has a high volume occupancy of SAP, but the volume occupancy of SAP is preferably 80% or less. In the area where the skin-side layer 21 and the intermediate layer 22 are adjacent to each other, the SAP particles and the liquid-absorbent fiber 201 are entangled, making the SAP less likely to crumble. As described above, the preferred average basis weight of the non-skin-side layer 23, which does not contain the liquid-absorbent fiber 201, is 50 g / m ２ ~350g / m ２ The non-skin-side layer 23, which does not contain the liquid-absorbent fibers 201, is uniformly layered with little overlap in the thickness direction, reducing the gritty feel of the SAP while ensuring absorbency. This configuration allows the SAP to be distributed in one product (absorbent body 20) without being concentrated in one place, and ensures absorbency while reducing the gritty feeling.

[0205] ===Other=== The above embodiments are intended to facilitate understanding of the present invention and are not intended to limit the present invention. The present invention may be modified or improved without departing from the spirit thereof, and it goes without saying that the present invention includes equivalents thereof.

[0206] In the above-described embodiment, the non-skinside layer 23 illustrated in Fig. 5 has a shorter longitudinal length than the skinside layer 21 and the intermediate layer 22, but this is not limited thereto and the longitudinal lengths may be the same. Conversely, the longitudinal length of the back side (rear side) of the non-skinside layer 23 may be even shorter than the length in this embodiment. In this case, material can be reduced, and the rigidity of the back-side absorbent core is reduced, increasing its flexibility. Furthermore, because the back side region is also away from the wearer's urinary excretion opening, even if the longitudinal length of the non-skinside layer 23 is short, the problem of excreted fluid leakage is unlikely to occur.

[0207] In the above-described embodiment, three layers, namely, the skin-side layer 21, the intermediate layer 22, and the non-skin-side layer 23, are laminated over substantially the entire absorbent cores 21-23. However, this is not limiting, and the three layers (21-23) may be laminated anywhere. Preferably, the three layers (21-23) are laminated at or near the position where the wearer's urinary orifice contacts when the diaper 1 is worn. Similarly, the low-basis-weight regions 211, 221 of the skin-side layer 21 and the intermediate layer 22 and the low-basis-weight region 231 of the non-skin-side layer 23 may also be located at or near the position where the wearer's urinary orifice contacts. This allows the excreted liquid to be quickly drawn to the innermost part of the absorbent cores 21-23 at positions that directly receive a large amount of excreted liquid during excretion.

[0208] In the above-described embodiment, the skin side layer 21 and the intermediate layer 22 are integrally formed, but this is not limiting, and the skin side layer 21 and the intermediate layer 22 do not have to be integrally formed. For example, an adhesive or a nonwoven fabric may be disposed between the skin side layer 21 and the intermediate layer 22. The adhesive can further fix the SAP contained in the skin side layer 21, and the nonwoven fabric can further diffuse excreted liquid in the planar direction on the nonwoven fabric.

[0209] In addition, an adhesive is applied to the skin side of the core wrap sheet 26 (sheet material) in this embodiment to secure the SAP particles, and the residual stress of the applied adhesive is preferably 2 KPa or more and 20 KPa or less. The adhesive that secures the SAP particles is required to have a resistance (residual stress) that prevents the SAP particles from falling off the core wrap sheet 26 (base sheet) even when external forces associated with the swelling of the SAP particles are applied. If the residual stress of the adhesive is 2 KPa or more and 20 KPa or less, there is a high probability that the SAP fixation rate will be 40% or more, making it possible to make the non-skin side layer 23 less likely to collapse.

[0210] Here, the SAP fixation rate indicates the proportion of SAP that does not fall off when the absorbent sheet to be measured is immersed in physiological saline (0.9% by mass saline) being stirred at a specified rotation speed, and can be an indicator of the fixation of the absorbed and swollen SAP to the base sheet, with a larger value for the SAP fixation rate indicating a higher fixation of the SAP to the base sheet in the absorbent sheet and less likely to cause SAP to fall off, not only before use but also after absorbing liquid. The SAP fixation rate is measured according to the following procedures 1 to 5.

[0211] (Procedure 1) Prepare a measurement sample from an absorbent sheet having a square shape in plan view, measuring 5 cm square. The edges of the measurement sample are grasped and the measurement sample is temporarily suspended vertically, and then the weight of the measurement sample (initial sample weight) is measured. (Procedure 2) The entire measurement sample is immersed in physiological saline, and 30 minutes after the start of immersion, the measurement sample is removed from the physiological saline. (Procedure 3) A cylindrical stirring bar with a diameter of 35 mm and an axial length of 12 mm and 300 ml of physiological saline are placed in a 300 ml beaker, and the stirring bar is rotated at a rotation speed of 60 ± 5 rpm using a magnetic stirrer to stir the physiological saline. The measurement sample that has undergone procedure 2 above is added to the stirred physiological saline, and 30 seconds after addition, the measurement sample is removed from the physiological saline. (Step 4) The wet measurement sample that has undergone Step 3 is left to stand for 12 hours in a thermostatic bath whose temperature is set to 105°C, and then the weight of the dry measurement sample (sample weight after stirring treatment) is measured. (Step 5) The total weight of the components other than the water-absorbent polymer is subtracted from each of the initial sample weight and the sample weight after stirring treatment to calculate the initial water-absorbent polymer weight (W0) and the water-absorbent polymer weight after stirring treatment (W1), respectively. Then, the water-absorbent polymer fixation rate of the measurement sample (absorbent sheet) is calculated using the following formula: Water-absorbent polymer fixation rate (%) = (W1 / W0) x 100

[0212] In step 1, the reason for grasping the end of the measurement sample (an absorbent sheet having a square shape in a plan view, 5 cm square) and temporarily suspending it vertically is to remove any unfixed matter, such as a water-absorbent polymer that is not fixed on the base sheet (for example, a water-absorbent polymer that is not fixed with an adhesive or the like but is simply sprinkled from above the base sheet). In suspending the measurement sample, the end of the measurement sample is simply grasped and suspended approximately vertically for approximately 3 to 5 seconds, without striking or violently shaking the suspended measurement sample. Furthermore, when suspending the measurement sample, first, the end of the measurement sample is grasped using tweezers or the like and suspended for 3 to 5 seconds, and then the end opposite to the end grasped during suspension is grasped and suspended for 3 to 5 seconds. Furthermore, in the above-mentioned procedure 1, if it is not possible to prepare an absorbent sheet of 5 cm square as the measurement sample (for example, if the size of the measurement sample is less than 5 cm square due to the small size of the absorbent sheet), multiple small measurement samples of less than 5 cm square are collected from the sheet to be evaluated, and the total area of ​​one side of these multiple measurement samples is 25 cm2. Then, for each of the multiple measurement samples, the water-absorbent polymer fixation rate is measured according to the above-mentioned procedures 1 to 5, and the average value of the multiple water-absorbent polymer fixation rates thus obtained is defined as the water-absorbent polymer fixation rate of the absorbent sheet.

[0213] Examples of measuring equipment used in step 3 include the following: Magnetic stirrer: HI-304N (reverse stirrer, manufactured by HANNA Co., Ltd.) Stirrer: Star head NALGENE (6600-0035) [35φ×12 mm] Beaker: 300 ml [78φ×103 mm]

[0214] The residual stress of an adhesive is measured by the following method. <Method for Measuring Residual Stress of an Adhesive> Using a rotational rheometer (manufactured by Anton Paar, model "Physica MCR301"), the adhesive to be measured is placed between a receiving plate that is circular in plan view and supports the measurement sample from below, and a pressing plate that is also circular in plan view and is placed above the receiving plate to face the receiving plate. In this state, the adhesive has a circular shape in plan view, a thickness of 1.5 mm, a diameter of 12 mm, and a temperature of 30°C. Then, from this state, the pressing plate is rotated to apply a 30% strain to the adhesive. 20 minutes after applying the strain to the adhesive, the shear stress of the adhesive is measured, and this measured value is taken as the residual stress of the adhesive.

[0215] In measuring the residual stress, if the adhesive to be measured is unused (i.e., if it is not applied to a substrate sheet and is not a component of an absorbent sheet), the unused adhesive is used as is for measurement. On the other hand, if the adhesive to be measured is a component of an absorbent sheet, the adhesive is extracted from the absorbent sheet by the solvent extraction method described below, and the extracted adhesive is used for measurement.

[0216] <Solvent extraction method for adhesive> First, an absorbent sheet containing an adhesive is mixed with a solvent capable of dissolving the adhesive in a container such as a beaker to obtain an adhesive solution in which the adhesive is dissolved in the solvent. Next, the adhesive solution is collected from the container, and the adhesive solution is dried under reduced pressure using a rotary evaporator, for example, to remove the solvent from the adhesive solution to obtain an adhesive. The adhesive thus obtained is used as the measurement target for the measurement of the residual stress. The solvent used to dissolve the adhesive may be selected appropriately depending on the type of adhesive, etc. When the adhesive to be measured is, for example, a hot melt adhesive, examples of solvents used to dissolve the adhesive include toluene, methyl ethyl ketone, and heptane.

[0217] Second Embodiment An absorbent article according to the present invention will be described using a pants-type disposable diaper 1000 for infants (hereinafter also referred to as "diaper 1000") as an example. However, the absorbent article according to the present invention also includes tape-type disposable diapers, shorts-type napkins, absorbent pads, sanitary napkins, and other absorbent articles. Furthermore, the wearer of the absorbent article is not limited to infants, but may also be an adult, an animal, or other living being.

[0218] <Configuration of the diaper 1000> Fig. 12 is a schematic perspective view of the diaper 1000. Fig. 13 is a plan view of the diaper 1000 in an unfolded and stretched state, as viewed from the skin side. Fig. 14 is a schematic cross-sectional view taken along the center line CL of Fig. 13. The "stretched state" of the diaper 1000 refers to a state in which the entire diaper 1000 is stretched without wrinkles, specifically, a state in which the dimensions of each component constituting the diaper 1000 (e.g., the absorbent main body 1010 and waist-circumference sections 1030, 1040, etc., described below) are stretched to the extent that they match or are close to the dimensions of the individual components. The "unfolded state" of the diaper 1000 refers to a state in which the diaper 1000 is opened and unfolded in a flat plane by separating a pair of side joining sections 2000 provided on both sides of the diaper 1000.

[0219] The diaper 1000 has a vertical direction, a width direction, and a front-to-rear direction that are perpendicular to each other, and has a waist opening BH and a pair of leg openings LH. The upper side in the vertical direction corresponds to the waist opening BH side, and the lower side corresponds to the crotch side. The front side in the front-to-rear direction corresponds to the wearer's abdomen side, and the rear side corresponds to the wearer's back side. The width direction is the direction along the stretch direction of the elastic threads 1033, 1043 of the front waist portion 1030 and the rear waist portion 1040, and is also referred to as the left-to-right direction. The vertical direction is the direction along the orthogonal direction that is perpendicular to the stretch direction.

[0220] The diaper 1000 is a so-called three-piece pants-type diaper having a liquid-absorbent main body 1010 and a pair of waist-surrounding sections 1030 and 1040. Of the pair of waist-surrounding sections, the one covering the wearer's abdominal region is also referred to as the front waist-surrounding section 1030, and the one covering the wearer's dorsal region is also referred to as the rear waist-surrounding section 1040.

[0221] In the unfolded state shown in Fig. 13, the diaper 1000 has a longitudinal direction, a width direction, and a thickness direction which are perpendicular to one another. The longitudinal direction is along the longitudinal direction of the absorbent main body 1010 and along the vertical direction of the pants-type diaper 1000. Line CC in Fig. 13 etc. is the center line in the width direction, and line CL is the center line in the longitudinal direction. The thickness direction is the direction in which the materials constituting the diaper 1000 are layered, as shown in Fig. 14. In the thickness direction, the side that comes into contact with the wearer's skin is referred to as the skin side, and the opposite side is referred to as the non-skin side. In the unfolded state, the front waistline portion 1030 and the rear waistline portion 1040 are aligned parallel to each other with a gap in the longitudinal direction, and the absorbent main body 1010 is suspended between them, with each longitudinal end of the absorbent main body 1010 joined and fixed to the skin side of the nearest waistline portion 1030, 1040, respectively, resulting in an external shape that is generally H-shaped in plan view. From this state, the absorbent main body 1010 is folded in half at a fold F along the longitudinal centerline CL. In this folded state (hereinafter also referred to as the "folded in half state"), the opposing front waistline portion 1030 and rear waistline portion 1040 are joined and connected at both widthwise sides to form a pair of side joining portions 2000. The side joining portions 2000 are formed by known joining methods such as welding or adhesive bonding.

[0222] The absorbent main body 1010 has an absorbent body 1020 (described in detail below), a liquid-permeable top sheet (surface sheet) 1012 arranged closer to the skin than the absorbent body 1020, and a back sheet (back surface sheet) 1013 arranged closer to the skin than the absorbent body 1020. The back sheet 1013 has a two-layer structure consisting of a liquid-impermeable sheet 1013a and a hydrophobic exterior sheet 1013b arranged on the far side of the liquid-impermeable sheet 1013a. However, the absorbent main body 1010 may also include sheet members other than these. For example, a second sheet (not shown) may be provided between the top sheet 1012 and the absorbent body 1020 in the thickness direction.

[0223] The absorbent main body 1010 is provided with a pair of leakage prevention walls 3000 on both sides in the width direction along the longitudinal direction of the absorbent main body 1010. In FIG. 14 , a leakage prevention wall elastic member 1016 such as rubber thread is attached between the folded side sheets 1015 in a stretched state along the longitudinal direction of the absorbent main body 1010. This allows the leakage prevention walls 3000 to stand up against the skin side. However, this is not limited to the above. The pair of leakage prevention walls may be formed by folding a portion of the outer sheet 1013b against the skin side at multiple locations while extending outward beyond both ends of the absorber 1020, or the diaper 1000 may not include the leakage prevention walls 3000. The absorbent main body 1010 also has a pair of leg gathers LG on both sides in the width direction. The leg gathers LG are provided with a plurality of leg gather elastic members 1017 such as rubber thread that stretch along the longitudinal direction (up-down direction). In Fig. 14, the end of the exterior sheet 1013b extending outward in the width direction from the absorbent main body 1010 is folded back onto the liquid-impermeable sheet 1013a. Between the folded-back portions of the exterior sheet 1013b, leg gather elastic members 1017 are attached in a stretched state along the longitudinal direction.

[0224] The front waistline portion 1030 and the rear waistline portion 1040 each include a skin-side sheet 1031, 1041, a non-skin-side sheet 1032, 1042, and multiple waistline elastic members 1033, 1043 such as rubber threads. The multiple waistline elastic members 1033, 1043 are arranged vertically between the skin-side sheet 1031, 1041 and the non-skin-side sheet 1031, 1041, and are attached in a stretched state in the width direction. The stretchability of the waistline elastic members 1033, 1043 allows the front waistline portion 1030 and the rear waistline portion 1040 to fit the wearer's waist. Cover sheets 1034, 1044 may also be provided to cover the upper end of the absorbent main body 1010 from the skin side. The cover sheets 1034, 1044 can prevent the absorbent main body 1010 from opening.

[0225] 13, the front waistline portion 1030 and the rear waistline portion 1040 have different planar shapes in the unfolded and stretched state. The front waistline portion 1030 has a vertical length that is roughly the same as that of the side joint portion 2000 and a rectangular shape that is long in the width direction. The rear waistline portion 1040 has a rectangular portion that overlaps with the front waistline portion 1030 and a generally trapezoidal portion 1040E that extends downward from the rectangular portion 1030. The extending portion 1040E can cover the wearer's buttocks.

[0226] The basic configuration of the diaper 1000 has been described above, but the above configuration is merely an example and is not intended to be limiting. For example, the front waistline portion 1030 and the rear waistline portion 1040 may be formed from a single continuous member, or an outer member may be provided in the crotch area connecting the front waistline portion 1030 and the rear waistline portion 1040. Furthermore, the elastic members such as the waistline elastic members 1033, 1043 may be sheet-like elastic members instead of rubber threads.

[0227] Regarding the absorbent body 1020: Fig. 15 is a schematic cross-sectional view of the absorbent body 1020 of this embodiment. Fig. 15 is a diagram illustrating a cross-section at the center CL in the longitudinal direction of the absorbent body 1020. Fig. 16 is a plan view of absorbent cores 1021 to 1023 stacked one on top of the other. Fig. 17A is a plan view of the skin side layer 1021 and the intermediate layer 1022, and Fig. 17B is a plan view of the non-skin side layer 1023.

[0228] As shown in FIG. 15, the absorbent body 1020 has an absorbent core 1020A between a skin-side core wrap sheet (skin-side core wrap sheet portion) 1025 and a non-skin-side core wrap sheet (non-skin-side core wrap sheet portion) 1026.

[0229] The absorbent core 1020A includes a liquid-absorbent fiber 10201 and a super-absorbent polymer. The liquid-absorbent fiber 10201 and the super-absorbent polymer (hereinafter also referred to as "SAP") are not particularly limited as long as they are usable as absorbent cores for absorbent articles. For example, the liquid-absorbent fiber 10201 may be a fiber containing cellulose fiber, such as wood pulp fiber, non-wood pulp fiber such as bagasse, kenaf, bamboo, hemp, or cotton, regenerated cellulose fiber such as rayon fiber, or semi-synthetic fiber such as acetate fiber. The liquid-absorbent fiber 10201 of this embodiment is formed from 100% cellulose fiber made from wood pulp fiber. Examples of SAP include starch-based, cellulose-based, and synthetic polymer-based polymer absorbents. The absorbent core 1020A includes an absorbent core 1021, an absorbent core 1022, and an absorbent core 1023.

[0230] The core wrap sheets 1025, 1026 are liquid-permeable sheet materials, such as tissue and nonwoven fabric. However, it is preferable that at least one of the core wrap sheets 1025, 1026 is a hydrophilic nonwoven fabric. Hydrophilic nonwoven fabrics are thin and flexible materials that exhibit high drapeability after absorbing excrement (liquid). Therefore, when the diaper 1000 is worn, it flexibly moves and conforms to the wearer's body movements and shape while maintaining a state in which the absorbent core 1020A is covered on either the skin side or the non-skin side, making it easier to fit. This also helps reduce the risk of the diaper 1000 being noticeable from the outside of clothing even after absorbing excrement.

[0231] The absorbent core 1020A has a skin-side layer (absorbent core) 1021, an intermediate layer (absorbent core) 1022, and a non-skin-side layer (absorbent core) 1023. The intermediate layer 1022 is located closer to the skin in the thickness direction than the skin-side layer 1021, and the non-skin-side layer 1023 is located closer to the skin in the thickness direction than the intermediate layer 1022. The skin-side layer 1021 has a first thickness t101 and is a layer in which the volume occupied by SAP is larger than the volume occupied by liquid-absorbent fibers 10201. The intermediate layer 1022 is a layer (pulp layer) in which the volume occupied by liquid-absorbent fibers 10201 is larger than the volume occupied by SAP. The non-skin side layer 1023 is a layer (SAP layer) having a third thickness t103 and in which the volume occupied by SAP is larger than the volume occupied by the liquid-absorbent fibers 10201.

[0232] Furthermore, the absorbent core 1020A of the absorbent body 1020 of this embodiment further includes a skin-side upper layer (absorbent core) 1024, which is located closer to the skin in the thickness direction than the skin-side layer 1021 and has a fourth thickness t104 that is thinner than the first thickness t101 of the skin-side layer 1021. The skin-side upper layer 1024 is a layer in which the volume occupied by the liquid-absorbent fiber 10201 is larger than the volume occupied by the SAP. Specifically, the skin-side upper layer 1024 of this embodiment is composed only of the liquid-absorbent fiber 10201.

[0233] 15 , in this embodiment, the skin side layer 1021 and the intermediate layer 1022 are integrally formed, and therefore the volume occupancy of SAP decreases and the volume occupancy of liquid-absorbent fiber 10201 increases from the skin side layer 1021 toward the intermediate layer 1022. Such an absorbent core can be manufactured, for example, by adjusting the order, amount, timing, etc. of feeding the SAP and liquid-absorbent fiber 10201 into a mold (recess) that corresponds to the shape of the absorbent core and is provided on the outer circumferential surface of a rotating drum.

[0234] In this embodiment, the skin side layer 1021 and the intermediate layer 1022 are laminated integrally, i.e., adjacent to each other in the thickness direction, without any adhesive or nonwoven fabric in between. This prevents the adhesive or nonwoven fabric from interfering with the transfer of excreted fluid from the skin side layer 1021 to the intermediate layer 1022, and increases the rate of absorption by the intermediate layer 1022.

[0235] Furthermore, in this embodiment, the non-skin side layer 1023 is not formed integrally with the intermediate layer 1022, but is laminated adjacent to the intermediate layer 1022 in the thickness direction via a nonwoven fabric 1027 (hereinafter also referred to as the "intermediate sheet 1027"). The presence of the nonwoven fabric 1027 allows excreted liquid to diffuse in the planar direction on the nonwoven fabric 1027 before transferring from the intermediate layer 1022 to the non-skin side layer 1023. Therefore, the excreted liquid diffused in the planar direction can transfer to the non-skin side layer 1023, allowing the absorbent core 1020A to be effectively utilized in the planar direction.

[0236] The skin side layer 1021 and the intermediate layer 1022 shown in Fig. 17A are integrally formed and have the same planar shape. The skin side layer 1021 and the intermediate layer 1022 have narrowed portions 10212, 10222 narrowed inward in the width direction at the center in the longitudinal direction (Fig. 16). Note that the center region when the skin side layer and the intermediate layer 1022 are divided into thirds at the maximum length in the longitudinal direction is defined as the center in the longitudinal direction, and at least a portion of the narrowed portions 10212, 10222 may be located there.

[0237] 17B has three rectangular divided regions 1023a to 1023c that are long in the longitudinal direction. The three divided regions 1023a to 1023c are arranged side by side at intervals in the width direction. Two regions between these three divided regions 1023a to 1023c form low basis weight regions 1231 (slits) of the non-skin side layer 1023. The two low basis weight regions 1231 are arranged symmetrically in the width direction across the center line C-C of the non-skin side layer 1023 in the width direction.

[0238] FIG. 18 is a schematic plan view of the absorbent body 1020 as viewed from the skin side. As shown in FIG. 18 , in this embodiment, the skin side layer 1021 has a plurality of compressed dots 1050 formed by compressing the skin side layer 1021 (absorbent core 1021) in a dotted pattern in the thickness direction. The "compressed dots 1050" are portions of the absorbent core 1021 that are compressed in the thickness direction by embossing. By compressing, the fiber density of the absorbent core 1021 is increased compared to uncompressed portions. In this embodiment, the compressed dots 1050 are formed by a collection of dots (circles); however, the compressed dots 1050 may also be formed by lines (straight lines, curves), for example. Alternatively, the compressed dots or lines may be formed discretely within a predetermined region. 18, the compressed dots 1050 are arranged in a dotted grid pattern (a so-called quilting pattern) as a whole, but other patterns may be used. Such compressed dots 1050 reduce SAP clumps during compression, suppressing the gritty feel of the SAP. Furthermore, localized compression prevents collapse of the absorbent body 1020 without impairing the flexibility of the absorbent cores 1021-1024. The compressed dots 1050 are not limited to being provided in the skin-side layer 1021, but may also be provided in the intermediate layer 1022 or non-skin-side layer 1023.

[0239] The diaper 1000 has an absorbent core 1020A containing cellulose fibers and a superabsorbent polymer, and includes low basis weight regions (low basis weight portions) 10211, 10221, and 10231. The low basis weight regions (low basis weight portions) 10211, 10221, and 10231 are portions that have a lower basis weight than the surrounding areas and are aligned along the longitudinal direction. When the diaper 1000 is folded in half at a fold F at the center CL in the longitudinal direction, the bottom area is 150 cm. ２After placing a 5 kg weight on the diaper 1000 for 24 hours, the thickness of the diaper 1000 at the center (center C-C) in the width direction of the folded portion F is 6.5 mm or less when the weight is removed. Furthermore, 40 ml of artificial urine is dripped three times over 5 seconds onto the skin-side surface of the diaper 1000 in an unfolded and stretched state without the weight, at a position 50 mm forward of the center CL in the longitudinal direction and at the center C-C in the width direction (the "drop position Pt" described below), to bring the diaper 1000 into an absorbed state in which the artificial urine has been absorbed. In this absorbed state, the thickness of the diaper 1000 at the center C-C in the width direction of the folded portion F is 20.3 mm or less. Furthermore, in a torsion test in which the diaper 1000 is folded in half and twisted around an imaginary axis along the width direction by gripping the longitudinal center of both widthwise ends and the diaper 1000 is folded in half and twisted around an imaginary axis along the width direction by gripping the longitudinal center of both widthwise ends and the diaper 1000 is folded in half and twisted around an imaginary axis along the length direction, the torque value of the diaper 1000 is 44.1 mN m or less. The state in which the weight is placed and each measurement method will be described later.

[0240] The absorbent body 1020 (absorbent core 1020A) is a component in the diaper 1000 that absorbs excrement such as urine and retains the absorbed excrement. Therefore, the absorbent body 1020 is required to have a desired absorption function, while also being a component in the diaper 1000 that has high rigidity.

[0241] In absorbent articles such as disposable diapers, the absorbent body (absorbent core) is a particularly thick portion. It has been known that superabsorbent polymers or liquid-absorbent fibers are used for absorbent cores. For example, absorbent articles including an absorbent body (SAP sheet) made of superabsorbent polymers have a thin absorbent body at the beginning of wear before absorbing bodily waste (liquid), making the absorbent article less noticeable from the outside of clothing. However, once the superabsorbent polymer absorbs bodily waste, the superabsorbent polymer swells, thickening the absorbent core and making the absorbent article more noticeable from the outside of clothing. Furthermore, when the superabsorbent polymer swells, the rigidity of the absorbent core increases, which can easily cause discomfort to the wearer. On the other hand, absorbent articles that have liquid-absorbent fibers in the absorbent core have relatively low rigidity both before and after absorbing excrement, and are less likely to cause discomfort to the wearer. However, in order for the absorbent core to have the desired absorption function, it is necessary to provide a large amount of liquid-absorbent fibers in the absorbent core. This large amount of liquid-absorbent fibers increases the thickness of the absorbent core, making the absorbent article more noticeable from outside the clothing when the article is first worn and after absorbing excrement.

[0242] With respect to the diaper 1000, after placing the weight W1000 on the folded diaper 1000 for 24 hours and then removing the weight W1000, the thinner (smaller) the thickness of the center (center C-C) in the width direction of the folded portion F of the diaper 1000, the thinner the thickness of the diaper 1000 before wearing. The diaper 1000 of the present invention is a thin diaper having a thickness of 6.5 mm or less at the center (center C-C) in the width direction of the folded portion F of the diaper 1000 after removing the weight, and is also provided with cellulose fibers and a superabsorbent polymer (SAP) and low basis weight regions 10211, 10221, 10231 along the longitudinal direction.

[0243] As shown in Fig. 16 and other figures, the absorbent core 1020A has low basis weight regions 10211, 10221, and 10231 along the longitudinal direction. That is, at least one of the skin side layer 1021, the intermediate layer 1022, and the non-skin side layer 1023 has a basis weight (i.e., the total basis weight of the liquid-absorbent fiber 10201 and the SAP: g / m) of the absorbent core 1020A that is lower than the surrounding area. ２15 and other figures, the absorbent body 1020 of this embodiment has low basis weight regions 10211, 10221 in which the skin side layer 1021 and the intermediate layer 1022 are aligned in the longitudinal direction. Similarly, the non-skin side layer 1023 also has a low basis weight region in which the basis weight of the absorbent core 1020A (i.e., the total basis weight of the liquid-absorbent fiber 10201 and the SAP: g / m) is low compared to the surrounding area. ２ ) has a low basis weight region 1231 along its length.

[0244] The diaper 1000 also contains cellulose fibers (so-called pulp fibers) and superabsorbent polymers (SAP). By including the low basis weight regions 10211, 10221, and 10231, when a wearer excretes into the diaper 1000 and the absorbent body 1020 receives the excreted liquid, the excreted liquid is quickly drawn from the low basis weight regions 10211, 10221, and 10231 into the absorbent body 1020 (inside each absorbent core 1020A). Cellulose fibers are soft and have a fast absorption rate, while superabsorbent polymers have a high liquid retention capacity, which facilitates the diffusion of excrement in the longitudinal and thickness directions of the absorbent core 1020A. Therefore, when the diaper 1000 (absorbent body 1020) receives excrement while being worn, the cellulose fibers and superabsorbent polymer provide appropriate absorption function while also making it easier to diffuse the absorbed excrement, thereby reducing the risk of the excrement being absorbed locally in only the area that receives the excrement (the crotch area).

[0245] Furthermore, when the absorbent core 1020A includes multiple absorbent layers, it is preferable that the low basis weight region 10211 of the absorbent layer (skin-side layer 1021) located on the skin side is a slit penetrating through the skin-side layer 1021 in the thickness direction. In this case, excreted liquid falls into the low basis weight region 10211, increasing the rate at which excreted liquid migrates from the skin-side layer 1021 to the intermediate layer 1022. When the low basis weight region 10211 is a slit, some liquid-absorbent fiber 10201 or SAP may be present, as long as it has at least a portion penetrating through in the thickness direction.

[0246] The low basis weight regions 10211, 10221, and 10231 of the skin side layer 1021, the intermediate layer 1022, and the non-skin side layer 1023 are not limited to those described above. The shape, size, number, and location of the low basis weight regions 10211 to 10231 of each layer can be changed as desired. For example, each layer may have only one low basis weight region 10211 to 10231, and these regions may be located on the center line C-C in the width direction of the absorbent cores 1021 to 1023. The low basis weight regions 10211, 10221, and 10231 of each layer 1021, 1022, and 1023 may be configured such that a portion of each layer 1021, 1022, and 1023 is recessed in the thickness direction. Furthermore, the low basis weight regions 10211, 10221, and 10231 only need to have a portion along at least the longitudinal direction, and may have a portion along any direction other than the longitudinal direction. When the absorbent core 1020A has multiple absorbent layers, at least one of the layers may have a low basis weight region.

[0247] Furthermore, since the absorbent core 1020A tends to expand in proportion to the amount of body exudates absorbed, by setting the thickness of the folded portion F of the diaper 1000 in the absorbing state to 20.3 mm or less, the risk of the diaper 1000 becoming excessively thick due to the absorption of body exudates when worn can be reduced compared to when the thickness of the folded portion F of the diaper 1000 in the absorbing state is greater than 20.3 mm. Therefore, even after the diaper 1000 has absorbed body exudates, the risk of the absorber 1020 expanding and sagging downward, or the absorber 1020 causing clothing to bulge, making the diaper 1000 conspicuous from the outside of clothing, can be reduced.

[0248] Furthermore, the lower the value of the torsion test result of the diaper 1000, the lower the torsional rigidity of the diaper 1000, making it easier to soften the diaper 1000. The higher the value of the torsion test result, the higher the torsional rigidity of the diaper 1000, making the diaper 1000 more stiff and more likely to cause discomfort to the wearer. Therefore, when the torsion test value of the diaper 1000 in the absorbed state is 44.1 mN·m or less, the diaper 1000 can be made softer even after absorbing excrement than when the torsion test value is greater than 44.1 mN·m, making the diaper 1000 more easily fit the wearer's body and movements, and making the diaper 1000 less likely to cause stiffness to the wearer, thereby reducing discomfort when worn.

[0249] Therefore, the diaper 1000 has a relatively thin form, with the thickness of the folded portion F being 6.5 mm or less before it is worn and before it absorbs excrement, yet it reduces the risk of the diaper 1000 swelling excessively even after absorbing excrement, which would be noticeable from the outside of the clothing or cause discomfort when worn.

[0250] The "folded in half" refers to a state in which the diaper 1000 in the unfolded state (see Fig. 13) is folded at a fold F at the center CL in the longitudinal direction, and in the case of the diaper 1000 being a pants-type disposable diaper, this refers to the pants-type state shown in Fig. 12. In the case of an absorbent article such as a tape-type disposable diaper or an absorbent pad, the absorbent article may be folded at a fold F at the center in the longitudinal direction of the unfolded absorbent article, and the fold F in the folded state does not necessarily correspond to the lower end of the absorbent article when worn.

[0251] <<<<State of the weight W1000 placed on the diaper 1000>>> Generally, absorbent articles such as the diaper 1000 are stored under a predetermined pressure in the form of a package in which they are distributed and stored as a commodity. The effect of the pressure applied to the diaper 1000 varies depending on the state in which it is stored, and the thickness of the center of the width direction of the folded portion F of the diaper 1000 changes depending on the pressure applied to the diaper. For this reason, after the diaper 1000 is taken out of the package, the weight W1000 (with a base area of ​​150 cm) is placed on the diaper 1000 in a folded state. ２By placing a weight of 5 kg on the diaper 1000 for 24 hours, the pressure applied to the diaper 1000 is equalized.

[0252] As shown in Fig. 19, the diaper 1000 folded in half (in a pants-type state) is placed on a flat surface with either the front waistline portion 1030 or the rear waistline portion 1040 facing downward. Then, the weight W1000 is placed on top of the diaper 1000 so that the widthwise center of the absorbent main body 1010 (the center C-C of the diaper 1000) is aligned with the widthwise center of the weight W1000, and the weight W1000 fits inside the absorbent main body 1010 when viewed in the thickness direction. Fig. 19 is a diagram illustrating the state in which the weight W1000 is placed on the diaper 1000. In this embodiment, the diaper is placed on a flat surface with the front waistline portion 1030 facing downward and the rear waistline portion 1040 facing upward, and the weight W1000 is placed on the rear waistline portion 1040 side. In Figure 19, the weight W1000 may be placed on one diaper 1000, or on a stack of multiple diapers 1000. Because absorbent articles such as the diaper 1000 are lightweight, even when multiple diapers 1000 are stacked, the difference in pressure applied to each diaper 1000 is within the margin of error and is virtually nonexistent. However, when multiple absorbent articles are stacked, the number of stacked absorbent articles must be such that the stacked state of the absorbent articles can be maintained and the absorbent articles will not collapse when stacked. In this embodiment, the weight W1000 was placed on five diapers 1000 stacked in the thickness direction (front-to-back direction) and left to stand for 24 hours, and the thickness of all diapers 1000 was measured using the method described below.

[0253] The W1000 weight has a base area of ​​150 cm ２ In this embodiment, a rectangular weight W1000 is used, the length Lw1 of which is 15 cm in the longitudinal direction (vertical direction) and the length Lw2 of which is 10 cm in the width direction (Lw1 × Lw2 = 150 cm). ２ Since the weight of the weight W1000 is 5 kg, a pressure of 3267 Pa is applied to the diaper 1000 on which the weight W1000 is placed. The weight W1000 can be made of any material, and for example, a metal weight such as stainless steel or iron can be used.

[0254] <<<About the Absorption State>>> The "absorption state" refers to the state in which the diaper 1000 described above is placed on the weight W1000, and then removed from the diaper 1000 in an unfolded and stretched state. 40 ml of artificial urine is dropped over 5 seconds onto the skin-side surface of the diaper 1000 at a position 50 mm forward of the center C-C in the longitudinal direction and at the center C-C in the width direction, and this drop is repeated three times to allow the diaper 1000 to absorb the artificial urine. While the amount of excrement absorbed by the diaper 1000 when worn varies, this absorption state is considered to be equivalent to the average state in which the diaper 1000 absorbs excrement when worn.

[0255] FIG. 20 is a diagram illustrating the process for achieving the absorbent state. Specifically, first, as described above, the weight W1000 is placed on the diaper 1000 and left for 24 hours, after which the weight W1000 is removed from the diaper 1000. Then, as shown in FIG. 20 , the drip position Pt is set to a position 50 mm forward of the longitudinal center of the diaper 1000 in the unfolded and stretched state and at the center C-C in the width direction. This drip position Pt is the position where urination occurs when the diaper 1000 is worn. A cylinder EN is placed on the skin-side surface of the diaper 1000 in the unfolded and stretched state. At this time, the center of the cylinder EN is aligned with the drip position Pt. The cylinder EN is a hollow cylindrical body with an inner diameter Li of 60 mm, an outer diameter Lo of 70 mm, and a height of 50 mm. Although the artificial urine is dripped toward the drip position Pt, there is a risk of slight error or splashing. Therefore, the provision of the cylinder EN facilitates absorption of the artificial urine in the area corresponding to the urination position when the diaper 1000 is worn. The artificial urine was prepared by dissolving 200 g of urea, 80 g of sodium chloride, 8 g of magnesium sulfate, 3 g of calcium chloride, and approximately 1 g of blue No. 1 dye in 10 L of ion-exchanged water. Then, 40 ml of artificial urine was dripped onto the drip position Pt (inside the cylinder EN) over 5 seconds. One minute after the start of the first drip, 40 ml of artificial urine was dripped onto the drip position Pt over 5 seconds. One minute after the start of the second drip, 40 ml of artificial urine was dripped onto the drip position Pt over 5 seconds. This state in which the diaper 1000 has absorbed the artificial urine is referred to as the absorbed state.

[0256] <<<<Measuring the Thickness of the Folded Portion F of the Diaper 1000>>> The thickness of the widthwise center (center C-C) of the folded portion F of the diaper 1000 after the weight W1000 has been placed thereon for 24 hours, and the thickness of the widthwise center (center C-C) of the folded portion F of the diaper 1000 in an absorbent state can be measured in the same manner, and both can be measured by well-known methods. For example, the measurement can be performed using an Ozaki Seisakusho Dial Thickness Gauge, Large Type J-B with spring, or an equivalent. Specifically, using an Ozaki Seisakusho Dial Thickness Gauge, Large Type J-B with spring, the measurement point (the widthwise center of the folded portion F) is clamped between a pair of measuring terminals st, and a pressure of 9.0-12.0 gf / cm is measured using the pair of measuring terminals st. ２ In this embodiment, a pressure of 10.5 gf / cm is applied. ２ The measurement is performed by applying pressure to the folded portion F. Figure 21 is a diagram illustrating the measurement of the folded portion F. As shown in Figure 21, the pair of measurement terminals st are circular plates each having a diameter of 50 mm, and are arranged parallel to each other in the vertical direction (thickness direction of the diaper 1000). The pair of measurement terminals st sandwich the folded portion F of the diaper 1000 in the thickness direction (front-to-back direction), and the maximum value at the portion where both measurement terminals st abut against the diaper 1000 is measured as the "thickness." At this time, the measurement is performed with the center C-C of the folded portion F of the diaper 1000 in the width direction and the lower end of the diaper 1000 in the longitudinal direction (vertical direction) aligned with the center of the measurement terminals st.

[0257] <<<Regarding the Torsion Test>>> Figures 22A and 22B are explanatory diagrams of the "torsion test." Figure 22A shows a measurement method in which the diaper 1000 is twisted around a virtual axis Va1 along the width direction of the diaper 1000. Figure 22B shows a measurement method in which the diaper 1000 is twisted around a virtual axis Va2 along the up-down direction of the diaper 1000. Note that in the drawings, the absorbent cores 1021-1024 are shown as having a rectangular shape to avoid complexity. The torque value of the diaper 1000 in the torsion test can be measured using an Imada torque tester (model number: EX-0762) or an equivalent device. The test environment is a room temperature of 20±2°C and a humidity of 60±5%.

[0258] (1) First, prepare the diaper 1000 to be measured (the diaper 1000 in an absorbent state) and identify the position to be clamped by the chuck 1060 of the torque tester. As shown in the left diagrams of Figures 22A and 22B, the maximum width of the absorber 1020 is divided into two equal parts in the width direction, and a line C1 extending along the vertical direction is drawn on the diaper 1000. Also, the length from the top end of the absorber 1020 to the bottom end of the diaper 1000 (the folded position) is divided into two equal parts, and a line C2 extending along the width direction is drawn on the diaper 1000. The intersection of the two lines C1 and C2 is designated as the reference point o.

[0259] (2) In the torque tester, a pair of chucks 1060 are arranged at a distance in the vertical direction, and the direction perpendicular to the vertical direction of the torque tester is defined as the horizontal direction. The width W60 of the chucks 1060 in the horizontal direction is approximately 25 mm. When the diaper 1000 is set between the pair of chucks 1060, the tension applied to the diaper 1000 is set to 1 N. The lower chuck is fixed, and only the upper chuck moves up and down to adjust the tension. The load cell is set to 50 N of tension / compression, and the torque is set to 1 N.

[0260] (3) When twisting the diaper 1000 around a virtual axis Va1 along the width direction as shown in Figure 22A, the gripping positions of the zippers 1060 are position p1, which is 30 mm to the right of the reference point o in the width direction, and position p2, which is 30 mm to the left. In other words, the zipper spacing is 60 mm. Specifically, the lower end of the upper zipper 1060 is aligned with position p2 of the diaper 1000, and the upper end of the lower zipper is aligned with position p1 of the diaper 1000, so that the waist side of the diaper 1000 is located on the right side in the horizontal direction. Furthermore, the center position of the zipper 1060 in the horizontal direction is aligned with the reference point o of the diaper 1000. This allows the vertical center portions of both widthwise ends of the diaper 1000 (more specifically, the vertical center portions of the absorbent cores 1021 to 1024) to be grasped, and the diaper 1000 can be twisted around an imaginary axis Va1 along the widthwise direction of the diaper 1000.

[0261] (4) With the diaper 1000 set as described above, rotate the upper zipper 1060 clockwise (positive rotation) to twist the diaper 1000 (twist the diaper 1000 so that the waist portion of the diaper 1000 in the right diagram of FIG. 22A is positioned toward the front of the page). Then, return the diaper 1000 to its initial state, and rotate the upper zipper 1060 counterclockwise (negative rotation) to twist the diaper 1000 and return it to its initial state. When twisting around the imaginary axis Va1 along the width direction, the rotation speed is 50 rpm, the rotation angle is 65°, and the measurement angle is 60°. The average torque value (mN·m) at a measurement angle of 60° during clockwise rotation and a measurement angle of 60° during counterclockwise rotation is calculated.

[0262] (5) When twisting the diaper 1000 around the imaginary axis Va2 along the vertical direction as shown in Figure 22B, the gripping positions of the zippers 1060 are set to positions p3 and p4, which are 50 mm above and below the reference point o in the vertical direction, respectively. In other words, the zipper spacing is set to 100 mm. Specifically, the lower end of the upper zipper 1060 is aligned with position p3 of the diaper 1000, and the upper end of the lower zipper 1060 is aligned with position p4 of the diaper 1000. Furthermore, the center of the zipper 1060 in the horizontal direction is aligned with the reference point o of the diaper 1000. This allows the diaper 1000 to be twisted around the imaginary axis Va2 along the vertical direction of the diaper 1000 by gripping the widthwise centers of both vertical end portions of the diaper 1000.

[0263] (6) With the diaper 1000 set as described above, rotate the upper zipper 1060 clockwise (positive rotation) to twist the diaper 1000 (twist the diaper 1000 so that the right-hand portion of the diaper 1000 in the width direction in the right diagram of Figure 22B is at the front side of the page). Then, return the diaper 1000 to its initial state, and rotate the upper zipper 1060 counterclockwise (negative rotation) to twist the diaper 1000 and return it to its initial state. When twisting around the imaginary axis Va2 along the vertical direction, the rotation speed is 50 rpm, the rotation angle is 75°, and the measurement angle is 60°. The average torque value (mN·m) at a measurement angle of 60° during clockwise rotation and a measurement angle of 60° during counterclockwise rotation is calculated.

[0264] (7) The torque value when twisting around the virtual axis Va1 ( FIG. 22A ) and the torque value when twisting around the virtual axis Va2 ( FIG. 22B ) are measured multiple times (e.g., n = 3 times) for each. Regardless of the measurement direction, multiple measurements are not performed on the same diaper 1000; a different diaper 1000 is prepared for each torque measurement. Then, the average value of all the multiple (e.g., three) torque values ​​around the virtual axis Va1 and the multiple (e.g., three) torque values ​​around the virtual axis Va2 is calculated (rounded to one decimal place). This average value is the torque value of the diaper 1000 (pants-type absorbent article) before absorption.

[0265] FIG. 23 shows the measurement results for diaper 1000 and products A, B, and C. Products A, B, and C are pants-type disposable diapers for infants that are commercially available. FIG. 23A shows the measurement results for each diaper, and FIG. 23B shows the relationship between post-absorption thickness and post-absorption torque value for the results of FIG. 23A. In FIG. 23A, "presence or absence of low basis weight section" indicates whether or not the diaper has a low basis weight section along the longitudinal direction. "Absorbent core" indicates whether the absorbent core contains cellulose fibers or superabsorbent polymer (SAP). "24-hour thickness" refers to the thickness of each diaper at the center of the width direction of the folded portion when a weight is placed on each diaper in a folded state for 24 hours and then removed. "Absorbed state thickness" refers to the thickness of each diaper at the center of the width direction of the folded portion in the absorbed state. "Absorbed state torque value" refers to the result of a torsion test for each diaper in the absorbed state.

[0266] The results of Figures 23A and 23B are specifically as follows. Diaper 1000 has low basis weight regions 10211 and 10221 along the longitudinal direction and is an absorbent core comprising cellulose fibers and a superabsorbent polymer (SAP). After 24 hours, the thickness was 5.6 mm, the absorbed thickness was 20.3 mm, and the absorbed torque value was 44.1 mN·m. Diaper Product A has a low basis weight portion along the longitudinal direction and is an absorbent core comprising cellulose fibers and a superabsorbent polymer (SAP). After 24 hours, the thickness was 6.5 mm, the absorbed thickness was 27.9 mm, and the absorbed torque value was 51.8 mN·m. Diaper Product B does not have a low basis weight portion along the longitudinal direction and is an absorbent core comprising cellulose fibers and a superabsorbent polymer (SAP). After 24 hours, the thickness was 5.6 mm, the absorbed thickness was 28.5 mm, and the absorbed torque value was 36.6 mN·m. The diaper product C has a low basis weight portion along the longitudinal direction, does not contain cellulose fibers, and has an absorbent core containing only superabsorbent polymer (SAP). After 24 hours, the thickness was 5.6 mm, the absorbed thickness was 31.2 mm, and the absorbed torque value was 46.5 mN m.

[0267] Product A has an absorbent core containing cellulose fibers and SAP fibers and a low basis weight portion along the longitudinal direction, which allows it to have adequate absorption capabilities while also diffusing bodily waste. Because Product A's thickness after removing the weight W1000 is 6.5 mm, it is not thick enough to be noticeable from the outside of clothing immediately after wearing (before absorbing bodily waste). However, because Product A's absorbed state thickness is 27.9 mm and its absorbed state torque value is 51.8 mN·m, Product A is more noticeable from the outside of clothing than diaper 1000 after absorbing bodily waste, and Product A's stiffness is likely to cause discomfort to the wearer.

[0268] Product B has an absorbent core containing cellulose fibers and SAP fibers and a low basis weight portion along the longitudinal direction, providing adequate absorption and dispersibility of bodily waste. Product B has a thickness of 5.6 mm when the weight W1000 is removed, meaning that it is not thick enough to be noticeable from the outside of clothing immediately after wearing (before absorbing bodily waste). However, in the absorbed state, Product B has a thickness of 28.5 mm, making it more noticeable from the outside of clothing than diaper 1000.

[0269] Product C has liquid retention properties because its absorbent core does not contain cellulose fibers but is made of superabsorbent polymer (SAP). Because Product B's thickness after weight W1000 is removed is 5.6 mm, Product B is not thick enough to be noticeable from the outside of clothing immediately after wearing (before absorbing bodily waste). However, in the absorbent state, Product B's absorbed state thickness is 27.9 mm and its absorbed state torque value is 51.8 mN·m. Therefore, after absorbing bodily waste, Product A is more noticeable from the outside of clothing than Diaper 1000, and Product A's stiffness is likely to cause discomfort to the wearer.

[0270] The graph in Figure 23B shows the results for the diaper 1000 in an absorbent state and Products A to C, with the position further to the bottom left indicating a thinner thickness after absorption and a smaller torque value after absorption. As shown in Figure 23B, the diaper 1000 is positioned further to the bottom left than Products A to C. Therefore, it is clear that the diaper 1000 reduces the risk of excessive swelling of the diaper 1000 and reduces discomfort caused by the diaper 1000 becoming stiff, even after absorbing excrement during wear, compared to Products A to C.

[0271] In addition, it is preferable that the absorbent core 1020A has a constricted portion 1020c constricted on the inner side in the width direction in the crotch region M, which is located between the crotch of the wearer when the diaper 1000 is worn. The constricted portion 1020c refers to a portion of the absorbent core 1020A that is located on the outer side in the width direction of the absorbent core 1020A, where the width of the absorbent core 1020A is partially shortened. As shown in Fig. 16 , in this embodiment, the skin-side layer 1021 and the intermediate layer 1022 have constricted portions 10212, 10222, and the non-skin-side layer 1023 has a portion in the longitudinal center of the diaper 1000 where the width-direction length L101 is longer than the width-direction lengths of the skin-side layer 1021 and the intermediate layer 1022. The constricted portion 1020c of the absorbent core 1020A is the region in the longitudinal center of the absorbent core 1020A from one end of L101 to one end of L102 in the width direction (from the other end of L101 to the other end of L102 in the width direction), and is the region shaded diagonally downward to the left in Fig. 16. The absorbent core 1020A includes a skin-side layer 1021, an intermediate layer 1022, and a non-skin-side layer 1023, and the constricted portion 1020c is a region in the thickness direction where the skin-side layer 1021, the intermediate layer 1022, and the non-skin-side layer 1023 are not present. The constricted portion 1020c needs to be provided at least in the crotch region M, and may also be provided at the front end or the rear end in the longitudinal direction. For example, the absorbent body 1020 may have a T-shaped absorbent core 1020A in which a substantially rectangular absorbent core 1020A extending along the longitudinal direction is provided in the central portion in the longitudinal direction, a substantially rectangular absorbent core 1020A extending along the width direction is provided at the front end in the longitudinal direction, and no absorbent core 1020A extending along the width direction is provided at the rear end in the longitudinal direction, and the absorbent core 1020A in the longitudinal center along the longitudinal direction and the absorbent core 1020A at the front end in the width direction are continuous. In such a case, the portion adjacent to the outer side in the width direction of the absorbent core 1020A extending along the longitudinal direction becomes the constricted portion 1020c.In addition, the crotch portion M refers to the portion below the portion overlapping with the side joint portion 2000 in the vertical direction (toward the center CL in the longitudinal direction) when the diaper is in the pants-type state, and in the case of absorbent articles other than pants-type disposable diapers, it refers to the central region when the skin-side layer 1021 and the intermediate layer 1022 are divided into thirds at their maximum longitudinal length.

[0272] The crotch region M of the diaper 1000 is the region that is sandwiched between the wearer's legs when the diaper 1000 is worn. Therefore, by providing the absorbent core 1020A with the constricted region 1020c in the crotch region, the diaper 1000 can be more easily fitted to the shape of the wearer's body when worn, allowing the wearer to move their legs more easily. Furthermore, even when the diaper 1000 absorbs excrement and the absorbent core 1020A expands, the risk of the constricted region 1020c interfering with the wearer's leg movement can be reduced.

[0273] Here, the widthwise length L101 of the non-skin-side layer 1023 refers to the length from one widthwise end 1023ae of the divided region 1023a of the non-skin-side layer 1023 to the other widthwise end 1023ce of the divided region 1023c. The non-skin-side layer 1023 has a portion longer than the widthwise lengths of the skin-side layer 1021 and the intermediate layer 1022, allowing the non-skin-side layer 1023 to absorb excrement that was not fully absorbed by the skin-side layer 1021 and the intermediate layer 1022, thereby preventing leakage. Furthermore, the number of layers decreases in the longer widthwise portions of the non-skin-side layer 1023, resulting in reduced rigidity. Here, providing a region with reduced rigidity within the area where the constrictions 10212 and 1022 are present improves fit around the crotch when worn.

[0274] The superabsorbent polymer contained in the absorbent core 1020A of the diaper 1000 preferably has a liquid absorption rate of 40 seconds or more as measured by the vortex method. The longer the absorption time as measured by the vortex method, the slower the liquid absorption rate. The superabsorbent polymer contained in the absorbent core 1020A refers to the SAP contained in the entire absorbent core 1020, and specifically refers to the superabsorbent polymer provided in all layers, including the skin-side layer 1021, the intermediate layer 1022, and the non-skin-side layer 1023.

[0275] In the absorbent core 1020A, when excrement is absorbed during wear, the excrement is more likely to diffuse within the absorbent core 1020A than if it were absorbed by the superabsorbent polymer in a vortex process faster than if the superabsorbent polymer had a liquid absorption rate of more than 40 seconds. Therefore, the superabsorbent polymer can locally absorb excrement, reducing the risk of the absorbent core 1020A swelling locally. This reduces the risk of the diaper 1000 becoming excessively stiff in parts, making it easier to soften the diaper 1000 after absorption. This reduces the risk of the diaper 1000 being noticeable from the outside of clothing, reduces discomfort to the wearer, and is less likely to inhibit the wearer's leg movement, even after excrement has been absorbed.

[0276] The liquid absorption rate of SAP using the vortex method can be measured by a known method. For example, 50.0 ml (±0.5 ml) of saline solution with a concentration of 0.900% (±0.009%) and a temperature of 25°C (±2°C) is placed in a 100 ml beaker. The beaker is then placed on a magnetic stirrer and a stir bar is inserted into the beaker. The stir bar is then rotated at 600 rpm (±30 rpm) to ensure that the saline solution in the beaker forms a stable vortex. A stopwatch is then started from the moment 2.00 g (±0.02 g) of the SAP to be measured, taken from the diaper 1000, is placed in the beaker, and the time from when the vortex disappears and the liquid level becomes horizontal is measured. The longer this time, the slower the liquid absorption rate.

[0277] Furthermore, it is preferable that the absorbent core 1020A has multiple absorbent layers (a first absorbent layer and a second absorbent layer), and that the low basis weight portions of the absorbent core 1020A have a first low basis weight portion, a second low basis weight portion, and an overlapping portion between the first low basis weight portion and the second low basis weight portion when viewed in the thickness direction of the diaper 1000. This allows the multiple absorbent layers to ensure the absorption function of the diaper 1000, while the first low basis weight portion and the second low basis weight portion, which overlap in the thickness direction, improve the diffusion of excrement in the thickness direction of the absorbent core 1020A. As a result, it is possible to reduce the risk of the absorbent core 1020A becoming locally thick in areas of the diaper 1000 that receive excrement.

[0278] The absorbent core 1020A of the diaper 1000 of this embodiment has a skin-side layer 1021, an intermediate layer 1022, and a non-skin-side layer 1023, and as low basis weight portions, the skin-side layer 1021 has a low basis weight region 10211, the intermediate layer 1022 has a low basis weight region 10221, and the non-skin-side layer 1023 has a low basis weight region 10231. When viewed in the thickness direction of the diaper 1000, as shown in Fig. 16 , there is an overlapping portion between the low basis weight region 10211 (first low basis weight portion) of the skin-side layer 1021 (first absorbent layer) and the low basis weight region 10231 (second low basis weight portion) of the non-skin-side layer 1023 (second absorbent layer). This makes it easier to promote the diffusion of excrement in the thickness direction, dropping it from the low basis weight region 10211 of the skin-side layer 1021 to the low basis weight region 10231 of the non-skin-side layer 1023 (second absorbent layer), and makes it easier to reduce the risk of the absorbent core 1020A in the diaper 1000 becoming locally thick in the area that receives the excrement.

[0279] Furthermore, it is not limited to the skin-side layer 1021 (first absorbent layer) and the non-skin-side layer 1023 (second absorbent layer), but there may be an overlapping portion in the thickness direction between the low basis weight region 10211 (first low basis weight portion) of the skin-side layer 1021 (first absorbent layer) and the low basis weight region 10221 (second low basis weight portion) of the intermediate layer 1022 (second absorbent layer), or there may be an overlapping portion between the low basis weight region 10221 (first low basis weight portion) of the intermediate layer 1022 (first absorbent layer) and the low basis weight region 10231 (second low basis weight portion) of the non-skin-side layer 1023 (second absorbent layer). In this embodiment, when viewed in the thickness direction, there are overlapping portions among the low basis weight region 10211 of the skin-side layer 1021, the low basis weight region 10221 of the intermediate layer 1022, and the low basis weight region 10231 of the non-skin-side layer 1023. Therefore, the absorbent core 1020A can diffuse body waste in the thickness direction by the low basis weight regions 10211, 10221, and 10231 so that the body waste falls directly from the low basis weight region 10211 to the low basis weight region 10231, thereby reducing the risk of the absorbent core 1020A swelling locally in areas that receive the body waste. Furthermore, the low basis weight regions 10211, 10221, and 10231 in this embodiment are each aligned along the longitudinal direction, which more easily promotes diffusion of body waste in the longitudinal direction.

[0280] Of the multiple absorbent layers included in the absorbent core 1020A, it is preferable to have a non-skin-side layer 1023 (SAP layer) that is provided closest to the skin and is made solely of a superabsorbent polymer. It is also preferable to have an intermediate sheet between this non-skin-side layer 1023 and an absorbent layer (intermediate layer 1022) that is provided closer to the skin than the non-skin-side layer 1023. In this embodiment, the non-skin-side layer 1023 that is located closest to the skin of the absorbent core 1020A is made solely of a superabsorbent polymer. A nonwoven fabric 1027 is provided between the non-skin-side layer 1023 and the intermediate layer 1022 that is provided closer to the skin than the non-skin-side layer 1023. The absorbent core 1020A includes, on the non-skin side, a non-skin side layer 1023 formed solely from a highly liquid-retentive superabsorbent polymer, and the intermediate sheet 1027 is provided on the skin side of the non-skin side layer 1023. This makes it easier for excrement to diffuse in the planar direction on the nonwoven fabric 1027 before it migrates from the intermediate layer 1022 to the non-skin side layer 1023, thereby reducing the risk of the absorbent core 1020A becoming locally thick and providing the diaper 1000 with an appropriate excrement absorption function. Note that the intermediate sheet (nonwoven fabric 1027) provided between the non-skin side layer 1023 and the absorbent layer (intermediate layer 1022) provided on the skin side of the non-skin side layer 1023 is not limited to nonwoven fabric, and may also be a sheet material such as tissue.

[0281] It is also preferable that the absorbent core 1020A has multiple absorbent layers (a first absorbent layer and a second absorbent layer), and that the side ends of the first absorbent layer and the second absorbent layer are located at different positions on one side in the width direction. This makes it possible to provide an area on one side in the width direction of the absorbent core 1020A where either the first absorbent layer or the second absorbent layer is absent, which makes it easier to reduce the rigidity and torsional rigidity of the side end on one side in the width direction of the absorbent core 1020A, thereby reducing discomfort around the wearer's legs and the risk of restricting leg movement.

[0282] The absorbent core 1020A of the diaper 1000 of this embodiment has a skin-side layer 1021, an intermediate layer 1022, and a non-skin-side layer 1023. On one side in the width direction, the side edge of the skin-side layer 1021 (first absorbent layer) and the side edge of the non-skin-side layer 1023 (second absorbent layer) are located at different positions. Specifically, as shown in Fig. 16, in the width direction, the maximum length L102 of the skin-side layer 1021 is longer than the maximum length L103 (and similarly, L101) of the non-skin-side layer 1023. This makes it easier to reduce the rigidity and torsional rigidity of the side edge on one side in the width direction of the absorbent core 1020A, thereby alleviating discomfort around the wearer's legs and reducing the risk of restricting leg movement. Furthermore, in the longitudinal central portion of the diaper 1000, the skin-side layer 1021 has a portion narrower than the width (L101) of the non-skin-side layer 1023, thereby reducing the amount of absorbent core 1020A that comes into contact with the wearer's skin in the crotch region, resulting in a comfortable feel against the skin. In areas other than the longitudinal central portion, the maximum length L102 of the skin-side layer 1021 and the intermediate layer 1022 is longer than the maximum length L103 of the non-skin-side layer 1023, thereby enabling effective absorption and diffusion of excrement in areas closer to the skin than the non-skin-side layer 1023. Similarly, in the diaper 1000, the side edges of the intermediate layer 1022 (first absorbent layer) and the non-skin-side layer 1023 (second absorbent layer) are located at different positions on one widthwise side. Specifically, in the width direction, the maximum length L102 of the intermediate layer 1022 is longer than the maximum length L103 (similarly, L101) of the non-skin side layer 1023.

[0283] Preferably, the absorbent core 1020A has multiple absorbent layers (a first absorbent layer and a second absorbent layer), with one longitudinal end of the first absorbent layer and one longitudinal end of the second absorbent layer being located at different positions. This allows for a region on one longitudinal side of the absorbent core 1020A where either the first or second absorbent layer is absent, thereby reducing the rigidity and torsional rigidity of the end on one longitudinal side of the absorbent core 1020A and facilitating flexible movement in response to the shape and movement of the wearer's body when worn. Furthermore, by having a region on one longitudinal side of the absorbent core 1020A where either the first or second absorbent layer is absent, the thickness of the absorbent core 1020A on at least one of the front and back sides of the diaper 1000 can be reduced, thereby reducing the risk of the diaper 1000 being noticeable from the outside of clothing after absorption.

[0284] The absorbent core 1020A of the diaper 1000 of this embodiment has a skin-side layer 1021, an intermediate layer 1022, and a non-skin-side layer 1023. On one side (e.g., the front side) in the longitudinal direction, one end (front end) of the skin-side layer 1021 (first absorbent layer) and one end (front end) of the non-skin-side layer 1023 (second absorbent layer) are located at different positions. Specifically, as shown in Fig. 16, in the longitudinal direction, the length L104 of the skin-side layer 1021 is longer than the length L105 of the non-skin-side layer 1023. This makes it easier to reduce the rigidity and torsional rigidity of the side end portion on one side in the longitudinal direction of the absorbent core 1020A, thereby alleviating discomfort around the wearer's legs and reducing the risk of restricting leg movement. The rigidity and torsional rigidity of one longitudinal end (front end) of the absorbent core 1020A can be easily reduced, allowing the diaper 1000 to move flexibly in accordance with the shape and movement of the wearer's body when worn. In addition, since the absorbent core 1020A has a thin portion at one longitudinal end, the risk of the diaper 1000 at one longitudinal end (front end) of the absorbent core 1020A being noticeable from the outside of clothing after absorption can be easily reduced.

[0285] As described above, the absorbent core 1020A has the skin-side layer (absorbent core) 1021, the intermediate layer (absorbent core) 1022, and the non-skin-side layer (absorbent core) 1023. The intermediate layer 1022 is located closer to the skin side in the thickness direction than the skin-side layer 1021, and the non-skin-side layer 1023 is located closer to the skin side in the thickness direction than the intermediate layer 1022. The skin-side layer 1021 has a first thickness t101 and is a layer in which the volume occupied by SAP is larger than the volume occupied by liquid-absorbent fibers (cellulose fibers) 10201. The intermediate layer 1022 is a layer (pulp layer) in which the volume occupied by liquid-absorbent fibers 10201 is larger than the volume occupied by SAP. The non-skin-side layer 1023 is a layer (SAP layer) having a third thickness t103, and in which the volume occupied by SAP is larger than the volume occupied by the liquid-absorbent fibers 10201. When excrement is received while the garment is being worn, the skin-side layer 1021, which has a high volume occupancy rate of SAP, first absorbs the excrement while facilitating the diffusion of the excrement to the non-skin-side side in the longitudinal and thickness directions by the low basis weight regions 10211, and the excrement that has migrated from the low basis weight regions 10211 to the intermediate layer 1022, which has a high volume occupancy rate of the liquid-absorbent fibers 10201, is quickly and temporarily absorbed by the intermediate layer 1022. Thereafter, the excrement absorbed between the fibers of the liquid-absorbent fibers 10201 of the intermediate layer 1022 gradually migrates to the non-skin-side layer 1023 due to gravity. Furthermore, because the intermediate layer 1022 also has a low basis weight region 10221, excreted liquid is more likely to migrate from the low basis weight region 10221 to the non-skinside layer 1023, or from the low basis weight region 10231 of the non-skinside layer 1023 to the deeper side of the non-skinside layer 1023. This makes it easier to draw excreted liquid deep into the absorbent core, improving absorbency. Furthermore, because the non-skinside layer 1023 has a high volume occupancy rate of SAP, excreted liquid is firmly absorbed and retained by the SAP of the non-skinside layer 1023. This allows the absorbent core 1020A to have a desired absorption function and flexibility while still being thin, which makes it easier to fit the wearer's body and movements and reduces the risk of the diaper 1000 being noticeable from the outside of clothing even after absorbing excreta.

[0286] In the diaper 1000 of this embodiment, the absorbent core 1020A has multiple absorbent layers, arranged in this order from the skin side to the non-skin side: a skin-side layer 1021 in which the volume occupied by SAP is larger than the volume occupied by the liquid-absorbent fiber 10201; an intermediate layer 1022 in which the volume occupied by the liquid-absorbent fiber 10201 is larger than the volume occupied by SAP; and a non-skin-side layer 1023 in which the volume occupied by SAP is larger than the volume occupied by the liquid-absorbent fiber 10201.This makes it easier to promote planar diffusion of the absorbent core 1020A and diffusion in the thickness direction from the skin side to the non-skin side when the diaper 1000 (absorbent body 1020) receives excrement while being worn, thereby absorbing the excrement locally only in the area that receives the excrement and reducing the risk of the absorbent core 1020A swelling locally. This allows the thickness of the absorbent core 1020A to be thin before absorbing bodily waste, while reducing the risk of the absorber 1020 of the diaper 1000 over-expanding even after absorbing bodily waste, so that the thickness of the folded portion F of the diaper 1000 at the widthwise center when the weight W1000 is removed can be 6.5 mm or less, the thickness of the folded portion F of the diaper 1000 in the absorbed state can be 20.3 mm or less, and the torsion test value of the diaper 1000 in the absorbed state can be 44.1 mN·m or less, thereby reducing the risk of the diaper 1000 being noticeable from the outside of clothing or causing discomfort to the wearer.

[0287] The comparison of the volumes occupied by the liquid-absorbent fiber 10201 and the SAP in each of the skin-side layer 1021, the middle layer 1022, the non-skin-side layer 1023, and the skin-side upper layer 1024 can be confirmed by the following method. For example, with the diaper 1000 in a natural, dry state where no external force is acting, the diaper 1000 (absorbent body 1020) is cut widthwise at any position in the longitudinal direction of the absorbent body 1020, specifically at a position where the four layers 1021 to 1024 are stacked and away from the product folding position. Next, the cut surface is magnified (e.g., 30 to 100 times) and photographed using an optical microscope (e.g., Keyence Corporation's VHX-7000 Digital Microscope or equivalent). The liquid-absorbent fiber 10201 and the SAP are identified in the photographed cross-sectional image. Then, in the cross-sectional image, it is confirmed that the following layers are stacked in this order from the skin side in the thickness direction: a skin-side upper layer 1024 in which the area occupied by the liquid-absorbent fibers 10201 is larger than the area occupied by the SAP; a skin-side layer 1021 in which the area occupied by the SAP is larger than the area occupied by the liquid-absorbent fibers 10201; a middle layer 1022 in which the area occupied by the liquid-absorbent fibers 10201 is larger than the area occupied by the SAP; and a non-skin-side layer 1023 in which the area occupied by the SAP is larger than the area occupied by the liquid-absorbent fibers 10201. If the above is confirmed, the four layers 1021 to 1024 of this embodiment are defined. Cross-sectional images are prepared at multiple locations (e.g., 10 locations) along the longitudinal direction of the absorbent 1020 in which such four layers 1021 to 1024 can be confirmed, and if the area occupied by SAP in all of the cross-sectional images is a layer larger than the area occupied by the liquid-absorbent fiber 10201, then that layer is a layer in which "the volume occupied by SAP is larger than the volume occupied by the liquid-absorbent fiber," and if the area occupied by the liquid-absorbent fiber 10201 is larger than the area occupied by SAP in all of the cross-sectional images, then that layer is a layer in which "the volume occupied by the liquid-absorbent fiber is larger than the volume occupied by SAP."

[0288] In addition, a comparison of the volumes occupied by the liquid-absorbent fibers 10201 and the SAP in each layer can also be made by visualizing the liquid-absorbent fibers 10201 and the SAP using X-ray microtomography (X-ray CT), for example, by the method described below: ScienceDirect, Carbohydrate Polymers 254, Mathias A. Hobisch et al., February 15, 2021, "How cellulose nanofibrils and cellulose microparticles impact paper strength - A visualization approach", Section "3.6. X-ray microtomography", https: / / www.sciencedirect.com / science / article / pii / S0144861720315794.

[0289] Furthermore, a skin-side upper layer 1024 is provided on the skin side of the skin-side layer 1021 in the thickness direction. The skin-side upper layer 1024 has a fourth thickness t104 that is thinner than the first thickness t101 of the skin-side layer 1021, and the volume occupied by the liquid-absorbent fibers 10201 is larger than the volume occupied by the SAP. The skin-side upper layer 1024, which has a high volume occupancy rate of the liquid-absorbent fibers 10201, is located closer to the skin than the skin-side layer 1021, thereby further reducing the wearer's perception of the unevenness of the SAP. Furthermore, because the skin-side upper layer 1024 contains a large amount of the liquid-absorbent fibers 10201, it further improves the ability to draw excreted liquid from a sheet (such as a top sheet) located closer to the skin. Furthermore, the liquid-absorbent fibers 10201 contained in the skin-side upper layer 1024 make it difficult for the SAP of the skin-side layer 1021 to roll within the layer, preventing a deterioration in the tactile feel. The skin-side upper layer 1024 is positioned closer to the skin than the skin-side layer 1021, but is thinner than the first thickness t101 of the skin-side layer 1021, so it can draw in excreted liquid without excessively retaining it, thereby reducing rewetting.

[0290] As described above, the skin-side layer 1021 has a first thickness t101, the intermediate layer 1022 has a second thickness t102, and the non-skin-side layer 1023 has a third thickness t103 (see FIG. 15 ), where the first thickness t101 to the third thickness t103 each refer to an average thickness. In this embodiment, the third thickness t103 of the non-skin-side layer 1023 is thicker than the first thickness t101 of the skin-side layer 1021. Specifically, the third thickness t103 of the non-skin-side layer 1023 is preferably 0.38 mm to 0.58 mm for the S-size diaper 1000 and 0.58 mm to 0.69 mm for the XXL-size diaper 1000. The first thickness t101 of the skin side layer 1021 is preferably 0.3 mm to 0.48 mm for the S size diaper 1000 and 0.45 mm to 0.65 mm for the XXL size diaper 1000. The average thickness of the absorber 1020 is preferably 2.0 to 2.5 mm.

[0291] The average thickness t102 of the intermediate layer 1022 is preferably 0.5 mm or greater. More preferably, it is 0.9 mm to 1.1 mm for the S-size diaper 1000 and 1.28 mm to 1.61 mm for the XXL-size diaper 1000. This allows for better absorption of excreted liquid between the fibers of the liquid-absorbent fibers 10201 of the intermediate layer 1022 than when the average thickness of the intermediate layer 1022 is less than 0.5 mm, for example, compared to when the intermediate layer 1022 is a nonwoven fabric (sheet member) formed of pulp fibers or the like. This allows for quick and temporary absorption of excreted liquid in the intermediate layer 1022, and after diffusing the excreted liquid in the intermediate layer 1022, it quickly transfers the excreted liquid to the non-skin-side layer 1023, ensuring absorbency. However, because an excessively thick intermediate layer 1022 can cause stiffness, the average thickness (second thickness t102) of the intermediate layer 1022 should be 2.5 mm or less.

[0292] The thicknesses (t101 to t103) of the layers 1021 to 1023 can be measured using well-known methods. For example, with the diaper 1000 in a natural, dry state without external forces, the diaper 1000 (absorbent body 1020) is cut widthwise at any longitudinal position in the portion of the diaper 1000 where the absorbent body 1020 is located, specifically at a location where the three layers 1021 to 1023 are stacked and away from the product folding position. To prevent damage to the absorbent body 1020 components, the diaper 1000 is cut at a predetermined location and then measured. Next, using an optical microscope (e.g., Keyence Corporation's VHX-7000 digital microscope or equivalent), the cut surface is raised toward the microscope and magnified (e.g., 30 to 100 times) and photographed. At this time, the focus is on the liquid-absorbent fiber 10201 and the magnified photograph is taken. In the captured cross-sectional image, the layer in which the liquid-absorbent fiber 10201 is visible is determined to be the intermediate layer 1022, and the portions of the absorbent core closer to the skin and closer to the skin are determined to be the skin-side layer 1021 and the non-skin-side layer 1023, respectively. Furthermore, measurement positions (e.g., five positions) are determined in the width direction of the cross-sectional image, and the thickness of each of the layers 1021 to 1023 at each measurement position is obtained. Preferably, cross-sectional images are captured at multiple positions in the longitudinal direction of the absorbent body 1020 to obtain the thickness of each of the layers 1021 to 1023. The average value of the obtained thicknesses is calculated for each of the layers 1021 to 1023, and is designated as the average thickness t101 (first thickness t101) of the skin-side layer 1021, the average thickness t102 (second thickness t102) of the intermediate layer 1022, and the average thickness t103 (third thickness t103) of the non-skin-side layer 1023. When measuring the thickness, the measurement is made on the portions other than the low basis weight regions 10211, 10221, and 10231. Furthermore, when multiple absorbent layers are bonded to adjacent sheet portions (core wrap sheets 1025, 1026, intermediate sheet 1027) via an adhesive, it is difficult to identify the portions where the material (cellulose fiber, SAP) constituting each absorbent layer is actually bonded and fixed to the adjacent sheet portion with the adhesive. Therefore, when it can be determined that adhesive exists between the absorbent layer and the adjacent sheet portion, the distance between adjacent sheet portions in the thickness direction is measured as the "thickness of the absorbent layer."

[0293] Using the above-mentioned method, five samples were prepared by cutting the longitudinal end of the absorbent body 1020 and then cutting the absorbent body 1020 so that the longitudinal length was 10 mm from that point.The average thicknesses measured were as follows: for the S size, the first thickness t101 was 0.41 mm, the second thickness t102 was 0.99 mm, and the third thickness t103 was 0.47 mm; and for the XXL size, the first thickness t101 was 0.56 mm, the second thickness t102 was 1.47 mm, and the third thickness t103 was 0.63 mm.

[0294] In the absorbent core 1020A of the diaper of this embodiment, the average basis weight of the non-skinside layer 1023 is higher than the average basis weight of the skinside layer 1021. The preferred average basis weight of the non-skinside layer 1023 is 50 g / m ２ ~350g / m ２ Specifically, when the diaper 1000 is a size S, the average basis weight of the non-skinside layer 1023 is 173 g / m ２ The average basis weight of the skin side layer 1021 is preferably about 82 g / m ２ When the diaper 1000 is an XXL size, the average basis weight of the non-skin side layer 1023 is about 300 g / m ２ The average basis weight of the skin side layer 1021 is preferably 171 g / m ２ The skin-side layer 1021 having a low average basis weight is less likely to swell after retaining water, and therefore the skin-side layer 1021 is less likely to suffer from absorption inhibition due to swelling of the SAP. As a result, the feel of the skin side (gritty feeling of the SAP) is less likely to deteriorate.

[0295] Furthermore, it is preferable that the average total area occupied by SAP per unit area in a cross section taken along the thickness direction of the skin-side layer 1021 is greater than the average total area occupied by SAP per unit area in a cross section taken along the thickness direction of the non-skin-side layer 1023. This makes it easier for the non-skin-side layer 1023 containing SAP to retain excrement than the skin-side layer 1021 containing SAP in the absorbent core 1020A, thereby reducing the risk of excrement absorbed through the skin-side surface of the absorbent core 1020A being retained by the skin-side layer 1021 and causing localized swelling in the skin-side layer 1021. Reducing localized swelling in the absorbent core 1020A and lowering the torsional rigidity of the diaper 1000 makes it easier for the diaper 1000 to fit the wearer's body and reduces discomfort during wear. It also reduces the risk of the diaper 1000 being noticeable from the outside of clothing after absorption. On the other hand, the non-skin side layer 1023, which has a larger average total area occupied by SAP per unit area, has a higher liquid retention capacity than the skin side layer 1021, and therefore reduces the risk of excrement once absorbed by the non-skin side layer 1023 rewetting toward the skin side layer 1021, even in the case of repeated excrement.

[0296] The "average value of the total area occupied by SAP per unit area in a cross section taken along the thickness direction of the skin-side layer 1021 (non-skin-side layer 1023)" can be determined as follows, for example, using the volume comparison method described above. The absorbent body 1020 is cut at 10 locations along the width direction at any position in the longitudinal direction of the absorbent body 1020, specifically, at a location where the skin-side layer 1021 and the non-skin-side layer 1023 are laminated and away from the product folding position. The cut surfaces are photographed under magnification using the optical microscope, and the "total area occupied by SAP per unit area" of the skin-side layer 1021 and the "total area occupied by SAP per unit area" of the non-skin-side layer 1023 are determined for each of the cut surfaces, and their average value is defined as the "average value of the total area occupied by SAP per unit area."

[0297] Furthermore, it is preferable that the total water retention capacity of the superabsorbent polymer present in the skin-side layer 1021 is less than the total water retention capacity of the superabsorbent polymer present in the non-skin-side layer 1023. This makes it easier for the non-skin-side layer 1023 in the absorbent core 1020A to retain excrement (liquid) than the skin-side layer 1021, thereby reducing the risk of the absorbent core 1020A swelling locally at the portion where excrement is received on the skin-side of the absorbent core 1020A during wear, and reducing the risk of the local swelling of the diaper 1000 after absorption being noticeable from the outside of clothing. In other words, the skin-side layer 1021, which has a low total water retention capacity, reduces the risk of the superabsorbent polymer swelling and inhibiting excrement absorption, and the skin-side layer 1021 is more likely to promote rapid absorption and diffusion of excrement. Furthermore, the non-skin-side layer 1023, which has a larger total water retention capacity, retains the excrement dispersed closer to the skin than the non-skin-side layer 1023, thereby reducing localized swelling of the absorbent core 1020A. Furthermore, the torsional rigidity of the diaper 1000 is reduced, allowing the diaper 1000 to fit the wearer's body more easily, thereby reducing discomfort when worn.

[0298] Furthermore, the skin-side layer 1021 has a low total water retention capacity compared to the non-skin-side layer 1023, but has a high volume occupancy rate of SAP, and therefore has adequate water retention. Therefore, when excreted liquid from the intermediate layer 1022 or the non-skin-side layer 1023 attempts to return to the skin side, the SAP in the skin-side layer 1021 absorbs and retains the excreted liquid, thereby preventing the excreted liquid from rewetting.

[0299] The total water retention capacity of the SAP present in the skin-side layer 1021 and the total water retention capacity of the SAP present in the non-skin-side layer 1023 can be measured by the following measurement method. First, 0.9% saline (an amount sufficient to fully immerse the sample) is prepared in a water tank. Next, test pieces are prepared. To prepare the test pieces, one absorbent body 1020 is cut into 50 mm pieces in the longitudinal direction. Note that when the absorbent body 1020 is cut into 50 mm pieces, the longitudinal length of the last test piece does not have to be less than 50 mm. First, to measure the total water retention capacity of the SAP present in the skin-side layer 1021, each test piece is separated as follows. (Layer Separation Method 1) 1) Peel off the core wrap sheet 1026 from the non-skin-facing side 2) Peel off the non-skin-side layer 1023 3) Peel off the nonwoven fabric 1027 4) Peel off the liquid-absorbent fiber 10201 layer (corresponding to the middle layer 1022) from the remaining sheet 5) The sum of 1) to 4) above is designated as X1 6) The rest of X1 is designated as X2 (X2 essentially includes the skin-side layer 1021, the skin-side upper layer 1024, and the core wrap sheet 1025) For the next test piece, an absorbent body 1020 separate from the one absorbent body described above is prepared and similarly cut into 50 mm pieces in the longitudinal direction. To measure the total water retention capacity of the SAP present in the non-skin-side layer 1023, each cut test piece is separated as follows. (Layer separation method 2) 1) Peel off the core wrap sheet 1025 from the skin-facing side. 2) Of the remaining sheets, do not peel off the layer of liquid absorbent fiber 10201 (corresponding to the middle layer 1022) (this will peel off the skin-side upper layer 1024, the skin-side layer 1021, and the middle layer 1022). 3) Peel off the nonwoven fabric 1027. 4) The above 1) to 3) are designated X4. 5) The rest of the above X4 is designated X3 (X3 essentially includes the non-skin-side layer 1023 and the core wrap sheet 1026).

[0300] Next, samples X1 to X4 are each placed in a mesh plastic bag, sealed, and the weight (A) before water absorption is measured. After measurement, each sample X1 to X4 is immersed in physiological saline for 30 minutes. After 30 minutes, each sample is removed from the water tank, and with the core wrap sheet side of each sample facing downwards, an acrylic plate (320 x 545 mm, thickness 3 to 5 mm, weight 400 to 600 g) and a 5 kg weight are placed on top, and left for 20 minutes. After 20 minutes, the weight and acrylic plate are removed, and the weight (B) of each sample is measured. Weight (B) - weight (A) is the amount of water absorption.

[0301] After weight measurement, each sample is dehydrated using a centrifuge at 75 G for 90 seconds. After dehydration, the weight (C) of each removed sample is measured. Weight (C) - weight (A) is the water retention capacity. Note that dehydration using a centrifuge can remove water adhering to the liquid absorbent fiber 10201, core wrap sheet, and nonwoven fabric, and only the amount of water chemically retained by the SAP is determined. Therefore, the water retention capacity calculated by "weight (C) - weight (A)" above is the water retention capacity of the SAP present in each sample. Therefore, the water retention capacity of sample X2 is the water retention capacity of the SAP present in the skin-side layer 1021, and the water retention capacity of sample X3 is the water retention capacity of the SAP present in the non-skin-side layer 1023. In this embodiment, in order to compare the "total water retention capacity" of the SAP present in the skin-side layer 1021 with the "total water retention capacity" of the SAP present in the non-skin-side layer 1023, measurements were carried out on each test piece cut into 50 mm pieces as described above, and the sum of the water retention capacity of X2 of each test piece is the "total water retention capacity of the SAP present in the skin-side layer 1021," and the sum of the water retention capacity of X3 of each test piece is the "total water retention capacity of the SAP present in the non-skin-side layer 1023."

[0302] As an example, the water retention capacity of the above-mentioned X2 (one sample) was 25.4 g, and the water retention capacity of the above-mentioned X3 (one sample) was 41.1 g. In other words, when comparing the water retention capacities of test pieces with a longitudinal length of 50 mm, the water retention capacity of the SAP present in the non-skin side layer 1023 is clearly greater. Therefore, it can be seen that in the diaper 1000 of this embodiment, the total water retention capacity of the SAP present in the non-skin side layer 1023 is greater than the total water retention capacity of the SAP present in the skin side layer 1021.

[0303] Furthermore, it is desirable that the SAP contained in the skin-side layer 1021 have a slower liquid absorption rate, as measured by the vortex method, than the SAP contained in the non-skin-side layer 1023. This facilitates diffusion of excrement in the planar direction or toward the non-skin-side surface rather than absorption by the skin-side layer 1021, facilitating diffusion of excrement throughout the absorbent core 1020A. This reduces the likelihood of excrement being retained in only localized areas of the skin-side layer 1021 and reduces the risk of localized swelling of the absorbent core 1020A. This reduces the risk of the diaper 1000 being noticeable from the outside of clothing after absorption, while also reducing the torsional rigidity of the diaper 1000, allowing it to better fit the wearer's body and movements, thereby reducing discomfort to the wearer. Furthermore, absorbing more excrement in the non-skin-side layer 1023 can prevent rewetting of the skin-side layer 1021. The liquid absorption rate of the SAP by the vortex method can be measured by a known method, for example, the same method as described above.

[0304] One way to slow down the liquid absorption rate measured by the vortex method of the SAP contained in the skin-side layer 1021 compared to the SAP contained in the non-skin-side layer 1023 is to use different types of SAP, such as SAPs with different compositions, shapes, sizes, and arrangements, for the SAP used in the skin-side layer 1021 and the SAP used in the non-skin-side layer 1023.

[0305] Regarding the absorbent core 1020A, the density of the absorbent core 1020A is 0.2 g / cm ３ The higher the density of the absorbent core 1020A, the thinner the absorbent core 1020A can be made and the greater the amount of liquid-absorbent fiber (cellulose fiber) and superabsorbent polymer for absorbing excrement. This makes it easier to achieve a thinner absorbent core 1020A and improve the excrement diffusion. Therefore, it is preferable that the density of the absorbent core 1020A is 0.2 g / cm or more. ３ By setting the density of the absorbent core 1020A to 0.2 g / cm or more, ３Since the absorbent core 1020A is made smaller, it is easier to disperse excrement than if it were smaller, which reduces the risk of the absorbent core 1020A swelling locally. This reduces the risk of the diaper 1000 being noticeable from the outside of clothing after absorption. In addition, it is easier to reduce the torsional rigidity of the diaper 1000, which makes it easier to fit the wearer's body and movements when worn, and reduces discomfort when worn.

[0306] As described above, the diaper 1000 includes a core wrap sheet 1025 that covers the skin-facing side of the absorbent core 1020A (skin-side layer 1021, skin-side upper layer 1024), and a top sheet (surface sheet) 1012 that is located closer to the skin than the core wrap sheet 1025. The density of the absorbent core 1020A and the top sheet 1012 is preferably higher than that of the top sheet 1012. Having a higher density for the absorbent core 1020A than that of the top sheet 1012 results in higher planar diffusion in the top sheet 1012 than when the density of the surface sheet is higher than that of the absorbent core. This allows the planarly diffused excrement to move perpendicularly to the non-skin side in the thickness direction, thereby reducing localized swelling in the absorbent core 1020A. This helps reduce the risk of the diaper 1000 being noticeable from the outside of clothing after absorption. Furthermore, the torsional rigidity of the diaper 1000 can be easily reduced, making it easier to fit the wearer's body and movements, and reducing discomfort when worn.

[0307] In addition, the top sheet 1012 arranged on the skin side of the core wrap sheet 1025 may be arranged on the skin side of the core wrap sheet 1025, and may be arranged in a form in which the absorbent body 1020 (core wrap sheet 1025) and the top sheet 1012 are in contact with each other, or one or more sheet members or other components may be arranged between the absorbent body 1020 (core wrap sheet 1025) and the top sheet 1012.

[0308] It preferably has a core wrap sheet 1025 covering the skin-facing side of the absorbent core 1020A (skin-side layer 1021, skin-side upper layer 1024), a top sheet (surface sheet) 1012 provided on the skin side of the core wrap sheet 1025, a core wrap sheet 1026 covering the non-skin-facing side of the absorbent core 1020A (non-skin-side layer 1023), and a back sheet 1013 provided on the non-skin side of the core wrap sheet 1026, and it preferably has a portion where the top sheet 1012 and the back sheet 1013 are bonded. In this embodiment, the back sheet 1013 is formed of a back sheet 1013a which is a liquid-impermeable sheet and a back sheet 1013b which is an exterior sheet. The non-skin-facing side of the top sheet 1012 and the skin-facing side of the back sheet 1013 are bonded to each other. The portion where the back sheet 1013 and the top sheet 1012 are bonded may be a portion where the back sheet 1013 and the top sheet 1012 are directly bonded together, or a portion where the back sheet 1013 and the top sheet 1012 are indirectly bonded together via another member.

[0309] By having this portion where the back sheet 1013 and the top sheet 1012 are bonded, it is possible to reduce the number of components overlapped in the thickness direction of the absorbent main body 1010 compared to when the top sheet 1012 is folded up to the non-skin side (non-skin side) of the core wrap sheet 1026 or when the back sheet 1013 is folded up to the skin side (skin side) of the core wrap sheet 1025. The fewer the number of components overlapped in the thickness direction of the absorbent main body 1010, the thinner the absorbent main body 1010 can be. This reduces the risk of the diaper 1000 being noticeable from the outside of clothing. Furthermore, the thinner the absorbent main body 1010 and the diaper 1000 are, the lower the rigidity of the diaper 1000, which makes it easier for the diaper 1000 to fit the wearer's body and movements when worn, and reduces discomfort when worn.

[0310] The layer (skin-side layer 1021 or non-skin-side layer 1023) comprising a superabsorbent polymer in the absorbent core 1020A of the absorbent body 1020 may be modified as follows. FIG. 24 is a schematic cross-sectional view of the absorbent body 1020 showing a modified example of the skin-side layer 1021. As shown in FIG. 24 , the modified skin-side layer 1021 has high-basis weight regions 10213 in which the basis weight of SAP is higher than that of the surrounding areas. In the high-basis weight regions 10213, points S of maximum thickness in the thickness direction are located intermittently in the longitudinal and width directions. As a result, the high-basis weight regions 10213 are arranged intermittently in the longitudinal and width directions. Furthermore, low-basis weight regions 10214 in which the basis weight of SAP is lower than that of the high-basis weight regions 10213 are formed between adjacent points S of maximum thickness (i.e., around the high-basis weight regions 10213). However, if the points S of maximum thickness are located intermittently in the longitudinal direction and the width direction, a portion of the space between adjacent points S of maximum thickness may be formed by the high basis weight region 10213. In other words, a portion of the space between adjacent points S of maximum thickness (D1020) may be connected by the high basis weight region 10213.

[0311] The low basis weight region 10214 has a low basis weight laminated region 10214E where SAP is laminated, and a non-laminated region 10214N where no SAP is present. Here, "no SAP present" not only means that no SAP particles are present, but also includes a situation where only a small number of SAP particles are laminated, and substantially no SAP particles are present.

[0312] In the modified absorbent body 1020, the low basis weight regions 10214 (low basis weight laminated regions 10214E and non-laminated regions 10214N) serve as folding points, allowing the absorbent body 1020 to easily deform along the contours of the wearer's body, improving fit. Furthermore, the low basis weight regions 10214 serving as folding points include the low basis weight laminated regions 10214E, which can absorb and retain excrement, and the non-laminated regions 10214N, which are more easily bent due to the absence of SAP. This allows the absorbent body 10200 to easily deform along the contours of the wearer's body and still have the ability to absorb and retain excrement, even in the low basis weight regions 10214, which have a lower basis weight of SAP than the high basis weight regions 10213.

[0313] The absorbent core 1020A is not limited to the above-described configuration. For example, a diaper 1000 may be configured to include the absorbent core 1020A shown in Fig. 25 , such that, after a weight W1000 is placed on the diaper 1000 in a folded state for 24 hours and then the weight W1000 is removed, the thickness of the diaper 1000 at the center of the width direction of the folded portion F is 6.5 mm or less, the thickness of the diaper 1000 at the center of the width direction of the folded portion F in an absorbed state is 20.3 mm or less, and the torque value in a torsion test is 44.1 mN·m or less. Fig. 25 is a cross-sectional schematic diagram of a modified absorbent body 1020. The absorbent core 1020A of the absorbent body 1020 shown in Fig. 25 includes liquid-absorbent fibers (cellulose fibers) 10201 and SAP (superabsorbent polymer), has a basis weight lower than that of the surrounding area, and has a low basis weight region 10211 along the longitudinal direction. The modified absorbent core 1020A also has a core wrap sheet 1025 that covers at least a portion of the skin-facing side of the absorbent core 1020A, and a core wrap sheet 1026 that covers at least a portion of the non-skin-facing side of the absorbent core 1020A.

[0314] As shown in FIG. 25, the liquid-absorbent fiber 10201 and SAP are bonded to the non-skin side of the core wrap sheet 1025, which is located closer to the skin than the absorbent core 1020A. The basis weight of the liquid-absorbent fiber 10201 bonded to the core wrap sheet 1025 is 5 g / m. ２ 90g / m or more ２ and the basis weight of the SAP adhered to the core wrap sheet 1025 is 5 g / m or less. ２ 90g / m or more ２ 25 , the absorbent core 1020A has a skin-side portion H1 where the liquid-absorbent fiber 10201 and SAP are adhered to the non-skin-side surface of the core wrap sheet 1025. Note that the "basis weight of the liquid-absorbent fiber 10201 adhered to the core wrap sheet 1025" and the "basis weight of the SAP adhered to the core wrap sheet 1025" each refer to the basis weight of the portion excluding the low-basis weight region 10211.

[0315] The diaper 1000 having such an absorbent core 1020A still has the function of absorbing body waste as a disposable diaper, but the thickness of the absorbent core 1020A can be reduced, thereby reducing the thickness of the diaper 1000 and reducing the risk of it being noticeable from the outside of clothing. Furthermore, because the diaper 1000 can be made soft, it can easily fit the wearer's body and movements, reducing the discomfort felt by the wearer.

[0316] 25, it is preferable that the liquid-absorbent fiber 10201 and SAP are bonded to the non-skin side of the core wrap sheet 1025 located closer to the skin than the absorbent core 1020A, and that the liquid-absorbent fiber 10201 and SAP are bonded to the skin side of the core wrap sheet 1026 located closer to the skin than the absorbent core 1020A. The liquid-absorbent fiber 10201 not bonded to either the core wrap sheet 1025 or the core wrap sheet 1026 accounts for 5% or less by weight of the liquid-absorbent fiber 10201 contained in the absorbent core 1020A, and that the density of the liquid-absorbent fiber 10201 bonded to the non-skin side of the core wrap sheet 1025 is uniform, and that the density of the SAP bonded to the non-skin side of the core wrap sheet 1025 is uniform. 25, the absorbent core 1020A has a skin-side portion H1 where the liquid-absorbent fiber 10201 and SAP are bonded to the non-skin-side surface of the core wrap sheet 1025, a skin-side portion H3 where the liquid-absorbent fiber 10201 and SAP are bonded to the skin-side surface of the core wrap sheet 1026, and a middle portion H2 that is not bonded to either the core wrap sheet 1025 or the core wrap sheet 1026. In other words, it is preferable that the densities of the liquid-absorbent fiber 10201 and SAP in the skin-side portion H1 are uniform, and that the liquid-absorbent fiber 10201 in the middle portion H2 account for 5% or less by weight of the liquid-absorbent fiber 10201 in the entire absorbent core 1020A.

[0317] Even in the diaper 1000 having such an absorbent core 1020A, the uniform density of the liquid-absorbent fibers 10201 and SAP bonded to the core wrap sheets 1025 and 1026 allows the thickness of the absorber 1020 to be thinner than when the liquid-absorbent fibers 10201 and SAP are not uniform, thereby reducing the thickness of the diaper 1000 and reducing the risk of it being noticeable from the outside of clothing. Furthermore, the diaper 1000 is made soft and allows excrement to be easily moved into the absorbent core 1020A, making it easier for the diaper 1000 to fit the wearer's body and movements, reducing discomfort to the wearer and improving the absorbency of the disposable diaper.

[0318] When the absorbent core 1020A has multiple absorbent layers, it is preferable that one or more absorbent layers (skin-side layer 1021, intermediate layer 1022) located away from the skin-side absorbent layer (skin-side upper layer 1024) in the thickness direction do not contain nonwoven fabric. In this embodiment, the skin-side layer 1021 and the intermediate layer 1022 are layers provided with SAP and cellulose fibers (pulp fibers) and do not contain a sheet member such as a nonwoven fabric. This reduces the risk of the diaper 1000 becoming excessively thick due to the absorption of bodily exudates compared to when the absorbent layer located away from the skin-side upper layer 1024 contains a nonwoven fabric, and reduces the risk of the diaper 1000 being noticeable from the outside of clothing after absorption. Furthermore, the diaper 1000 can be made soft even after absorbing bodily exudates, making it easier to fit the wearer's body and reducing discomfort when worn.

[0319] Furthermore, as shown in Figure 15, when the absorbent core 1020A has multiple absorbent layers, it is preferable that the absorbent layer (skin-side upper layer 1024) closest to the skin in the thickness direction does not contain absorbent resin powder. In this embodiment, the skin-side upper layer 1024 is formed solely from liquid-absorbent fibers 10201 made of cellulose fibers (pulp fibers). The absence of absorbent resin powder, such as SAP, in the skin-side upper layer 1024 reduces the risk of localized thickness increases due to the absorption of bodily waste and reduces the risk of the diaper 1000 being noticeable from the outside of clothing after absorption. Furthermore, the diaper 1000 can be softened even after absorbing bodily waste, making it easier to fit the wearer's body and reducing discomfort when worn.

[0320] In the diaper 1000 of the above-described embodiment, the absorbent core 1020A includes the skin-side upper layer 1024 closest to the skin, but the skin-side layer 1021 may be the layer of the absorbent core 1020A closest to the skin without including the skin-side upper layer 1024. That is, of the multiple absorbent layers of the absorbent core 1020A, the absorbent layer closest to the skin in the thickness direction may be the skin-side layer 1021. In such a case, when the skin-side layer 1021 includes a superabsorbent polymer (water-absorbent polymer) and is the layer of the absorbent core 1020A closest to the skin in the thickness direction, it is preferable that the liquid permeation rate under load of the superabsorbent polymer (water-absorbent polymer, water-absorbent resin powder) provided in the skin-side layer 1021 exceeds 10 seconds. This reduces the risk of the thickness of the diaper 1000 increasing locally due to the absorption of bodily waste compared to when the liquid permeation rate under load in the skin-side layer 1021 is 10 seconds or less, and reduces the risk of the diaper 1000 after absorption becoming noticeable from the outside of clothing. Furthermore, even after absorbing bodily waste, the diaper 1000 can be made soft, making it easier to fit the wearer's body and reducing discomfort when worn.

[0321] ===Other=== The above embodiments are intended to facilitate understanding of the present invention and are not intended to limit the present invention. The present invention may be modified or improved without departing from the spirit thereof, and it goes without saying that the present invention includes equivalents thereof.

[0322] 16 has a shorter longitudinal length than the skin side layer 1021 and the intermediate layer 1022, but this is not limited thereto, and the longitudinal lengths may be the same. Alternatively, the longitudinal length of the non-skin side layer 1023 may be longer than the skin side layer 1021 and the intermediate layer 1022, and the back side (rear side) end (rear end) of the non-skin side layer 1023 may be located outside (rear side) of the back side (rear side) ends (rear ends) of the skin side layer 1021 and the intermediate layer 1022. Conversely, the longitudinal length of the back side (rear side) of the non-skin side layer 1023 may be even shorter than the length in this embodiment. In this case, material can be reduced, and the rigidity of the absorbent core on the back side is reduced, resulting in increased flexibility. Furthermore, since the back region is also away from the wearer's urinary excretion opening, even if the length of the non-skin side layer 1023 in the longitudinal direction is short, the problem of leakage of excreted fluid is unlikely to occur.

[0323] In the above-described embodiment, as shown in Fig. 15, an adhesive and an intermediate sheet 1027 are provided between the intermediate layer 1022 and the non-skin side layer 1023, but this is not limiting. The intermediate layer 1022 and the non-skin side layer 1023 may be laminated adjacent to each other in the thickness direction without the adhesive or the intermediate sheet 1027 or both. This prevents the adhesive or nonwoven fabric from interfering with the transfer of excreted fluid from the intermediate layer 1022 to the non-skin side layer 1023, and increases the rate of absorption by the non-skin side layer 1023.

[0324] In the above-described embodiment, the skin-side layer 1021 and the non-skin-side layer 1023 are integrally formed. However, the intermediate layer 1022 and the non-skin-side layer 1023 may also be integrally formed. In this case, a sheet such as an adhesive or a nonwoven fabric may or may not be interposed between the intermediate layer 1022 and the skin-side layer 1021. Furthermore, in this case, the skin-side layer 1021 may be an SAP layer composed only of SAP, or may be a layer composed of SAP and liquid-absorbent fibers. However, it is preferable that the average value of the total area occupied by SAP per unit area in a cross section taken along the thickness direction of the skin-side layer 1021 is greater than the average value of the total area occupied by SAP per unit area in a cross section taken along the thickness direction of the non-skin-side layer 1023. This allows the SAP in the skin-side layer 1021 to suppress rewet.

[0325] Furthermore, even when the intermediate layer 1022 and the non-skin side layer 1023 are integrated, it is desirable that the SAP contained in the skin side layer 1021 have a liquid absorption rate, as measured by the vortex method, that is slower than the SAP contained in the non-skin side layer 1023. This makes it easier for the excrement to diffuse in the planar direction or toward the non-skin side rather than being absorbed by the skin side layer 1021, making it easier to diffuse the excrement within the absorbent core 1020A, reducing the likelihood of the excrement being retained only in localized areas of the skin side layer 1021 and reducing the risk of localized swelling of the absorbent core 1020A.

[0326] Furthermore, even when the intermediate layer 1022 and the non-skin-side layer 1023 are integrated, it is preferable that the total water retention capacity of the superabsorbent polymer present in the skin-side layer 1021 is less than the total water retention capacity of the superabsorbent polymer present in the non-skin-side layer 1023. This makes it easier for the non-skin-side layer 1023 in the absorbent core 1020A to retain excrement (liquid) than the skin-side layer 1021, thereby reducing the risk of the absorbent core 1020A swelling locally at the portion that receives excrement from the skin-side surface of the absorbent core 1020A when worn, and making it easier to reduce the risk of the local swelling of the diaper 1000 after absorption being noticeable from the outside of clothing.

[0327] In the above-described embodiment, the absorbent core 1020A is formed of the skin-side upper layer 1024, the skin-side layer 1021, the intermediate layer 1022, and the non-skin-side layer 1023 as shown in Fig. 15 , but the absorbent cores 1021-1023 (absorbent cores 1021-1024) are not limited to this. The absorbent core 1020A may be formed of any material as long as it contains cellulose fibers and SAP. For example, the absorbent core 1020A may be formed of three layers without the skin-side upper layer 1024. Alternatively, the absorbent core 1020A may be formed of a total of two layers: one layer containing a mixture of SAP and cellulose fibers, and one layer made of an SAP sheet. The absorbent core 1020A may be formed of a single layer containing cellulose fibers and a superabsorbent polymer.

[0328] In the above-described embodiment, three layers, namely, the skin-side layer 1021, the intermediate layer 1022, and the non-skin-side layer 1023 (four layers, namely, the skin-side upper layer 1024, the skin-side layer 1021, the intermediate layer 1022, and the non-skin-side layer 1023) are laminated over substantially the entire absorbent cores 1021-1023 (absorbent cores 1021-1024), but this is not limitative and it is sufficient that three layers (1021-1023) or four layers (1021-1024) are laminated in any part. Preferably, the three layers (1021-1023) or four layers (1021-1024) are laminated at and near the position that comes into contact with the wearer's urinary excretion opening when the diaper 1000 is worn. Similarly, the low basis weight regions 10211, 10221 of the skin-side layer 1021 and the intermediate layer 1022 and the low basis weight region 10231 of the non-skin-side layer 1023 may also be provided at or near the position where the wearer's urine excretion opening comes into contact. By doing so, excreted liquid can be quickly drawn to the back of the absorbent cores 1021-1023 at positions that directly receive a large amount of excreted liquid during excretion.

[0329] In the above-described embodiment, the skin side layer 1021 and the intermediate layer 1022 are integrally formed, but this is not limiting, and the skin side layer 1021 and the intermediate layer 1022 do not have to be integrally formed. For example, an adhesive or a nonwoven fabric may be disposed between the skin side layer 1021 and the intermediate layer 1022. The use of an adhesive can better fix the SAP contained in the skin side layer 1021, and the use of a nonwoven fabric can further diffuse excreted liquid in the planar direction on the nonwoven fabric.

[0330] DESCRIPTION OF SYMBOLS 1 Pants-type disposable diaper (absorbent article) 2 Side joint portion 10 Absorbent body 12 Top sheet 13a Back sheet (liquid-impermeable sheet) 13b Back sheet (outer sheet) 15 Leakage barrier portion 16 Leakage barrier elastic member 17 Leg-hole elastic member 20 Absorbent body 201 Liquid-absorbent fiber SAP High-absorbent polymer 21 Skin-side layer (absorbent core) 211 Low basis weight region 22 Intermediate layer (absorbent core) 221 Low basis weight region 23 Non-skin-side layer (absorbent core) 231 Low basis weight region 24 Skin-side upper layer (absorbent core) 25 Core wrap sheet 26 Core wrap sheet 27 Nonwoven fabric 30 Front waist portion 31 Skin-side sheet 32 ​​Non-skin-side sheet 33 Waist-hole elastic member 34 Cover sheet, 40 Rear waistline portion, 41 Skin side sheet, 42 Non-skin side sheet, 43 Waistline elastic member, 44 Cover sheet, 50 Dot-like compressed portion, TR Outer end region, UR Inner region, 1000 Diaper (pants-type disposable diaper, absorbent article), 2000 Side joint portion, 3000 Leakage barrier portion, 1010 Absorbent body, 1012 Top sheet (surface sheet), 1013 Back sheet (rear sheet), 1013a Back sheet (liquid-impermeable sheet, rear sheet), 1013b Back sheet (exterior sheet, rear sheet), 1015 Side sheet, 1016 Leakage barrier wall elastic member, 1017 Leg gather elastic member, 1020 Absorbent body, 1020A Absorbent core, 10201 Liquid absorbent fiber (cellulose fiber), SAP superabsorbent polymer, 1021 skin side layer (absorbent core), 10211 low basis weight region, 1022 intermediate layer (absorbent core), 10221 low basis weight region, 1023 non-skin side layer (absorbent core), 10231 low basis weight region, 1024 skin side upper layer (absorbent core), 1025 core wrap sheet (skin side core wrap sheet portion), 1026 core wrap sheet (non-skin side core wrap sheet portion), 1027 nonwoven fabric (intermediate sheet), 1030 front waistline portion, 1031 skin side sheet, 1032 non-skin side sheet, 1033 waistline elastic member, 1034 cover sheet, 1040 back waistline portion, 1041 skin side sheet, 1042 non-skin side sheet, 1043 Waist elastic member, 1044 cover sheet,1050 Point-shaped compression part, F Folding part

Claims

1. An absorbent article having an absorbent core which, in an unfolded state, has a longitudinal direction, a width direction, and a thickness direction which are perpendicular to one another, and which contains liquid-absorbent fibers and a superabsorbent polymer, wherein the absorbent core has: a skin-side layer having a first thickness, and in which the volume occupied by the superabsorbent polymer is larger than the volume occupied by the liquid-absorbent fibers; a middle layer having a second thickness, and in which the volume occupied by the liquid-absorbent fibers is larger than the volume occupied by the superabsorbent polymer; and a non-skin-side layer having a third thickness, and in which the volume occupied by the superabsorbent polymer is larger than the volume occupied by the liquid-absorbent fibers, wherein the middle layer is located closer to the skin in the thickness direction than the skin-side layer, and the non-skin-side layer is located closer to the skin in the thickness direction than the middle layer, and the total water retention capacity of the superabsorbent polymer present in the skin-side layer is different from the total water retention capacity of the superabsorbent polymer present in the non-skin-side layer.

2. An absorbent article according to claim 1, characterized in that the total water retention capacity of the superabsorbent polymer present in the non-skin-side layer is greater than the total water retention capacity of the superabsorbent polymer present in the skin-side layer.

3. An absorbent article having an absorbent core which, in an unfolded state, has a longitudinal direction, a width direction, and a thickness direction which are orthogonal to one another, and which contains a liquid-absorbent fiber and a superabsorbent polymer, wherein the absorbent core has: a skin-side layer having a first thickness, and in which the volume occupied by the superabsorbent polymer is larger than the volume occupied by the liquid-absorbent fiber; an intermediate layer having a second thickness, and in which the volume occupied by the liquid-absorbent fiber is larger than the volume occupied by the superabsorbent polymer; and a non-skin-side layer having a third thickness, and in which the volume occupied by the superabsorbent polymer is larger than the volume occupied by the liquid-absorbent fiber, wherein the intermediate layer is located closer to the skin side in the thickness direction than the skin-side layer, and the non-skin-side layer is located closer to the skin side in the thickness direction than the intermediate layer, and the average value of the total area occupied by the superabsorbent polymer per unit area in a cross section of the skin-side layer along the thickness direction, an absorbent article characterized in that the average value of the total area occupied by the superabsorbent polymer per unit area in a cross section along the thickness direction of the non-skin side layer is different, and a skin side upper layer is provided on the skin side in the thickness direction of the skin side layer, the skin side upper layer being thinner than the first thickness and the volume occupied by the liquid absorbent fiber being larger than the volume occupied by the superabsorbent polymer.

4. An absorbent article as described in claim 3, characterized in that the average value of the total area occupied by the superabsorbent polymer per unit area in a cross section along the thickness direction of the non-skin side layer is greater than the average value of the total area occupied by the superabsorbent polymer per unit area in a cross section along the thickness direction of the skin side layer.

5. An absorbent article as described in claim 1, characterized in that an upper skin-side layer, thinner than the first thickness and having a volume occupied by the liquid-absorbent fiber greater than the volume occupied by the superabsorbent polymer, is provided on the skin-side side of the skin-side layer in the thickness direction.

6. An absorbent article as set forth in claim 3 or 5, wherein the skin-side layer has a low basis weight region in which the absorbent core has a lower basis weight than the surrounding area, and the skin-side upper layer is arranged so as to overlap the low basis weight region of the skin-side layer in a plan view.

7. An absorbent article according to claim 1 or 2, characterized in that the third thickness is greater than the first thickness.

8. An absorbent article according to claim 1 or 2, characterized in that the average basis weight of the non-skin side layer is higher than the average basis weight of the skin side layer.

9. An absorbent article according to claim 1 or 3, wherein the skin-side layer has a different type of superabsorbent polymer from that of the non-skin-side layer, and the superabsorbent polymer contained in the skin-side layer has a slower liquid absorption rate as measured by the vortex method than the superabsorbent polymer contained in the non-skin-side layer.

10. An absorbent article according to claim 1 or 3, characterized in that the skin-side layer and the intermediate layer are laminated adjacently in the thickness direction without any adhesive or nonwoven fabric therebetween.

11. An absorbent article according to claim 1 or 3, characterized in that the intermediate layer and the non-skin-side layer are laminated adjacently in the thickness direction without any adhesive or nonwoven fabric therebetween.

12. An absorbent article according to claim 1 or 3, characterized in that at least one of the skin-side layer, the intermediate layer and the non-skin-side layer has a low-basis weight region in which the absorbent core has a lower basis weight than the surrounding area.

13. An absorbent article as claimed in claim 1 or 3, wherein one of the skin-side layer, the intermediate layer and the non-skin-side layer has a low basis weight region in which the absorbent core has a basis weight lower than that of the surrounding area, and at least one of the skin-side layer, the intermediate layer and the non-skin-side layer other than the layer having the low basis weight region has another low basis weight region in which the absorbent core has a basis weight lower than that of the surrounding area, and in a planar view of the absorbent core, the low basis weight region has a portion that overlaps with the other low basis weight region.

14. An absorbent article as claimed in claim 1 or 3, characterized in that, in the central part of the longitudinal direction of the absorbent article, the non-skin side layer has a portion whose widthwise length is longer than the widthwise lengths of the skin side layer and the intermediate layer.

15. An absorbent article according to claim 14, wherein the maximum lengths of the skin side layer and the intermediate layer in the width direction are longer than the maximum length of the non-skin side layer.

16. An absorbent article according to claim 1 or 3, characterized in that, in the longitudinal direction, the lengths of the skin-side layer and the intermediate layer are longer than the length of the non-skin-side layer.

17. An absorbent article as set forth in claim 1 or 3, characterized in that at least one of the skin-side layer and the non-skin-side layer has a plurality of point-like compressed portions formed so as to compress the absorbent core in a point-like manner in the thickness direction.

18. An absorbent article as described in claim 1 or 3, characterized in that a core wrap sheet is arranged closer to the skin in the thickness direction than the skin side layer, a strip of adhesive is provided on the non-skin side surface of the core wrap sheet in the thickness direction, the average width of the strip of adhesive is smaller than the average particle size of the superabsorbent polymer, and the minimum value of the distance between intersections of the strip of adhesive is smaller than the average particle size of the superabsorbent polymer when maximally swollen.

19. An absorbent article according to claim 1 or 2, comprising an absorbent body, the absorbent body having an absorbent core comprising a skin-side layer, an intermediate layer and a non-skin-side layer laminated at least in the thickness direction, the intermediate layer not including a nonwoven fabric.

20. The absorbent article according to claim 19, wherein the layer of the absorbent core closest to the skin does not contain water-absorbent resin powder.

21. The absorbent article according to claim 19, wherein the superabsorbent polymer contained in the layer of the absorbent core closest to the skin has a liquid permeation rate under load of more than 10 seconds.

22. An absorbent article having an absorbent core in an unfolded state, which has a longitudinal direction, a width direction, and a thickness direction that are perpendicular to one another, wherein the absorbent core comprises cellulose fibers and a superabsorbent polymer, the absorbent core has a basis weight lower than that of the surrounding area and has a low basis weight portion along the longitudinal direction, and when the absorbent article is folded in half at a fold in the center in the longitudinal direction, the base area is 150 cm ２ a weight of 5 kg is placed on the absorbent article for 24 hours, and then the weight is removed from the absorbent article, the thickness of the folded portion at the center in the width direction is 6.5 mm or less; 40 ml of artificial urine is dropped three times over 5 seconds onto the skin side of the absorbent article in the unfolded and stretched state after the weight is removed, at a position 50 mm forward of the center in the longitudinal direction and at the center in the width direction, and in an absorbed state after the artificial urine has been absorbed, the thickness of the folded portion at the center in the width direction of the absorbent article is 20.3 mm or less; and An absorbent article characterized in that, in a torsion test in which the center portions in the longitudinal direction of both widthwise ends of the absorbent article in the folded state are grasped and twisted around an imaginary axis along the width direction, and the center portions in the width direction of both widthwise ends of the absorbent article in the folded state are grasped and twisted around an imaginary axis along the longitudinal direction, the torque value of the absorbent article is 44.1 mN・m or less.

23. An absorbent article as set forth in claim 22, characterized in that the absorbent core has a constricted portion constricted on the inside in the width direction in the crotch portion that is located between the crotch of the wearer when worn.

24. An absorbent article according to claim 22 or 23, characterized in that the liquid absorption rate of the superabsorbent polymer measured by the vortex method is 40 seconds or more.

25. An absorbent article according to claim 22 or 23, characterized in that the core wrap sheet provided on at least one of the skin side or non-skin side of the absorbent core is a hydrophilic nonwoven fabric.

26. An absorbent article as set forth in claim 22 or 23, comprising a skin-side core wrap sheet portion covering at least a portion of the skin-facing side of the absorbent core, the cellulose fibers and the superabsorbent polymer being bonded to the non-skin-facing side of the skin-side core wrap sheet portion, and the basis weight of the cellulose fibers bonded to the skin-side core wrap sheet portion being 5 g / m ２ Above, 90g / m ２ The basis weight of the superabsorbent polymer adhered to the skin-side core wrap sheet portion is 5 g / m or less. ２ Above, 160g / m ２ An absorbent article characterized by the following:

27. An absorbent article as described in claim 22 or 23, comprising: a skin-side core wrap sheet portion covering at least a portion of the skin-side side of the absorbent core; and a non-skin-side core wrap sheet portion covering at least a portion of the non-skin-side side of the absorbent core; the cellulose fibers and the superabsorbent polymer are adhered to the non-skin-side side of the skin-side core wrap sheet portion; the cellulose fibers and the superabsorbent polymer are adhered to the skin-side side of the non-skin-side core wrap sheet portion; the cellulose fibers not adhered to either the skin-side core wrap sheet portion or the non-skin-side core wrap sheet portion account for 5% or less by weight of the cellulose fibers; the density of the cellulose fibers adhered to the non-skin-side side of the skin-side core wrap sheet portion is uniform; and the density of the superabsorbent polymer adhered to the non-skin-side side of the skin-side core wrap sheet portion is uniform.

28. An absorbent article as described in claim 22 or 23, wherein the absorbent core has a plurality of absorbent layers, the plurality of absorbent layers having a first absorbent layer and a second absorbent layer, the low basis weight portion having a first low basis weight portion provided in the first absorbent layer and a second low basis weight portion provided in the second absorbent layer, and the absorbent article having a portion where the first low basis weight portion and the second low basis weight portion overlap when viewed in the thickness direction.

29. An absorbent article as described in claim 22 or 23, wherein the absorbent core has a plurality of absorbent layers, each of the plurality of absorbent layers having an SAP layer formed solely from the superabsorbent polymer, the SAP layer being located furthest away from the skin among the plurality of absorbent layers, and an intermediate sheet being provided between the absorbent layer located closer to the skin than the SAP layer.

30. An absorbent article as described in claim 22 or 23, characterized in that the absorbent core has a plurality of absorbent layers, the plurality of absorbent layers having a first absorbent layer and a second absorbent layer, and on one side in the width direction, the side end of the first absorbent layer and the side end of the second absorbent layer are located at different positions.

31. An absorbent article as described in claim 22 or 23, characterized in that the absorbent core has a plurality of absorbent layers, the plurality of absorbent layers having a first absorbent layer and a second absorbent layer, and one end of the first absorbent layer in the longitudinal direction and one end of the second absorbent layer in the longitudinal direction are located at different positions.

32. An absorbent article as claimed in claim 22 or 23, wherein the absorbent core comprises: a skin-side layer having a first thickness and in which the volume occupied by the superabsorbent polymer is greater than the volume occupied by the cellulose fibers; an intermediate layer having a second thickness and in which the volume occupied by the cellulose fibers is greater than the volume occupied by the superabsorbent polymer; and a non-skin-side layer having a third thickness and in which the volume occupied by the superabsorbent polymer is greater than the volume occupied by the cellulose fibers, wherein the intermediate layer is located on the non-skin side in the thickness direction relative to the skin-side layer, and the non-skin-side layer is located on the non-skin side in the thickness direction relative to the intermediate layer.

33. An absorbent article as described in claim 32, characterized in that the superabsorbent polymer contained in the skin-side layer has a liquid absorption rate measured by the vortex method that is slower than the superabsorbent polymer contained in the non-skin-side layer.

34. An absorbent article as set forth in claim 32, characterized in that the average value of the total area occupied by the superabsorbent polymer per unit area in a cross section along the thickness direction of the skin-side layer is greater than the average value of the total area occupied by the superabsorbent polymer per unit area in a cross section along the thickness direction of the non-skin-side layer.

35. An absorbent article according to claim 32, characterized in that the total water-holding capacity of the superabsorbent polymer present in the skin-side layer is less than the total water-holding capacity of the superabsorbent polymer present in the non-skin-side layer.

36. An absorbent article as described in claim 22 or 23, comprising: a skin-side core wrap sheet portion covering at least a portion of the skin-facing side of the absorbent core; a non-skin-side core wrap sheet portion covering at least a portion of the non-skin-facing side of the absorbent core; a top sheet provided on the skin side of the skin-side core wrap sheet portion; and a back sheet provided on the non-skin side of the non-skin-side core wrap sheet portion, characterized in that the top sheet and the back sheet have a portion where they are adhered to each other.

37. An absorbent article according to claim 22 or 23, wherein the density of the absorbent core is 0.2 g / cm ３ An absorbent article characterized by the above.

38. An absorbent article as claimed in claim 22 or 23, comprising a skin-side core wrap sheet portion covering at least a portion of the skin-facing side of the absorbent core, and a surface sheet provided on the skin side of the skin-side core wrap sheet portion, wherein the density of the absorbent core is higher than the density of the surface sheet.

39. An absorbent article as described in claim 32, characterized in that the absorbent core has a plurality of absorbent layers including the skin-side layer, the intermediate layer, and the non-skin-side layer, and that one or more of the plurality of absorbent layers, which are located on the non-skin side of the absorbent layer located closest to the skin in the thickness direction, do not contain nonwoven fabric.

40. An absorbent article as described in claim 32, characterized in that the absorbent core has a plurality of absorbent layers including the skin-side layer, the intermediate layer, and the non-skin-side layer, and that of the plurality of absorbent layers, the absorbent layer located closest to the skin in the thickness direction does not contain absorbent resin powder.

41. An absorbent article as described in claim 32, wherein the absorbent core has a plurality of absorbent layers including the skin-side layer, the intermediate layer, and the non-skin-side layer, and among the plurality of absorbent layers, the absorbent layer located closest to the skin in the thickness direction comprises the superabsorbent polymer, and the liquid permeation rate under load of the superabsorbent polymer in the absorbent layer located closest to the skin exceeds 10 seconds.

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