Absorbent article

Abstract

An absorbent article (1) has an upper core (31) and a lower core (32), wherein the upper core (31) has a groove (35) which is recessed in a thickness direction and has a length in a prescribed direction, the upper core (31) has a groove area provided with the groove (35) and a non-groove area not provided with the groove (35), an area where the upper core (31) and the lower core (32) overlap when viewed in the thickness direction is provided with at least a part of the groove area, and the average density of the skin-side portion of the high-absorbency polymer (34) in the groove area is lower than the average density of the skin-side portion of the high-absorbency polymer (34) in the non-groove area.

Description

Technical Field

[0001] This invention relates to absorbent articles. Background Technology

[0002] Patent Document 1 discloses an absorbent article comprising a double-layered absorbent body consisting of an upper absorbent layer and a lower absorbent layer. A slit is provided at the center of the upper absorbent layer in the width direction, extending at least through the upper absorbent layer in the thickness direction. Furthermore, the upper absorbent layer has a higher weight ratio of highly absorbent polymer to pulp fibers compared to the lower absorbent layer. Thus, while wastewater is also supplied to the upper absorbent layer, it is preferentially supplied to the lower absorbent layer through the slit. Liquid components absorbed by the lower absorbent layer are drawn up by the upper absorbent layer after the lower absorbent layer becomes saturated and are retained by the highly absorbent polymer in the upper absorbent layer. Therefore, it exhibits excellent resistance to backflow (re-wetting).

[0003] Prior art literature

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2017-63923 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] However, if a relatively large slit is provided in the upper absorber (upper core) as in Patent Document 1, the lower absorber (lower core) facing the slit will absorb the excrement in localized, point-like areas. There is a limit to the extent to which the excrement diffuses from these point-like absorption areas; the lower absorber cannot absorb the excrement over a large area. The upper absorber also only absorbs the excrement within the area where the lower absorber diffuses the excrement, thus failing to utilize it effectively.

[0008] In addition, in the part where a large slit is set in the upper absorbent, the excrement absorbed by the lower absorbent is not drawn up by the upper absorbent but flows back, which can easily come into contact with the skin, and the prevention of moisture return is not sufficient.

[0009] Therefore, the present invention was made in view of the problems mentioned above, and its object is to improve the diffusion of the drained liquid at the upper core and the lower core in an absorbent article in which the upper core and the lower core are stacked and to suppress back-wetting.

[0010] Solution for solving the problem

[0011] The main invention for achieving the above-mentioned objective is an absorbent article having a length direction, a width direction, and a thickness direction, and having an absorbent core. The absorbent core comprises an upper core having a highly absorbent polymer and a lower core disposed on the non-skin side in the thickness direction relative to the upper core. The upper core has a groove recessed in a portion of the upper core in the thickness direction, the groove having a length in a predetermined direction. When viewed in the thickness direction, the upper core has a grooved region with the groove and a non-groove region without the groove. When viewed in the thickness direction, at least a portion of the grooved region is provided in the overlapping area of ​​the upper core and the lower core. When the upper core is divided into two parts in the thickness direction, the portion located on the skin side is designated as the skin side portion, and the portion located on the non-skin side is designated as the non-skin side portion. In this case, the average density of the highly absorbent polymer on the skin side portion of the grooved region is lower than the average density of the highly absorbent polymer on the skin side portion of the non-groove region.

[0012] Other features of the invention will become apparent from the description in this specification and the accompanying drawings.

[0013] The effects of the invention

[0014] According to the present invention, in an absorbent article in which an upper core and a lower core are stacked, the diffusivity of the drained liquid at the upper core and the lower core can be improved and back-wetting can be suppressed. Attached Figure Description

[0015] Figure 1 This is a schematic three-dimensional diagram of a shorts-type diaper 1 (hereinafter also referred to as "diaper").

[0016] Figure 2 This is a rough top view of the diaper 1 in its unfolded and elongated state, viewed from the side of the skin.

[0017] Figure 3 yes Figure 2 A rough cross-sectional view at line a-a.

[0018] Figure 4 This is a top view of the upper core 31 viewed from the skin side in the thickness direction.

[0019] Figure 5 This is a top view of the lower core 32 viewed from the skin side in the thickness direction.

[0020] Figure 6 This is a top view of the stacked upper core 31 and lower core 32 from the skin side in the thickness direction.

[0021] Figure 7 This is a schematic cross-sectional view of a portion of the upper core 31 and the lower core 32.

[0022] Figure 8A yes Figure 6 A cross-sectional view at line I-I. Figure 8B yes Figure 6 A schematic cross-sectional view at line II-II.

[0023] Figure 9A This is a schematic 3D view of the core-encapsulated wafer 39. Figure 9B This is an explanatory diagram of a modified configuration of the core-cladding sheet 39.

[0024] Figure 10A , Figure 10B These are explanatory diagrams of variations of slots 35 and 36.

[0025] Figure 11A , Figure 11B These are explanatory diagrams of variations of slots 35 and 36.

[0026] Figure 12 This is a cross-sectional schematic diagram of the absorbent core 30 in the second embodiment.

[0027] Figure 13 This is a cross-sectional schematic diagram of the absorbent core 30 in the third embodiment.

[0028] Figure 14A as well as Figure 14B This is a cross-sectional schematic diagram of the absorbent core 30 in the fourth embodiment.

[0029] Figure 15 This is a schematic top view of the diaper 1 of the fifth embodiment, viewed from the side of the skin in its unfolded and stretched state.

[0030] Figure 16 yes Figure 15 A schematic cross-sectional view at point A-A.

[0031] Figure 17 This is a top view of the stacked upper core 31 and lower core 32 from the skin side in the thickness direction.

[0032] Figure 18A This is a top view of the upper core 31 viewed from the skin side in the thickness direction. Figure 18B This is a top view of the lower core 32 viewed from the skin side in the thickness direction.

[0033] Figure 19 This is a top view of the absorbent core 30 of the modified example of the fifth embodiment, viewed from the skin side in the thickness direction. Detailed Implementation

[0034] Based on the description in this specification and the accompanying drawings, at least the following will become clear.

[0035] An absorbent article having a length direction, a width direction, and a thickness direction, and having an absorbent core, characterized in that the absorbent core comprises an upper core having a highly absorbent polymer and a lower core disposed on the non-skin side in the thickness direction relative to the upper core. The upper core has a groove recessed in the thickness direction in a portion thereof, the groove having a length in a predetermined direction. When viewed in the thickness direction, the upper core has a grooved region having the groove and a non-groove region without the groove. When viewed in the thickness direction, at least a portion of the grooved region is provided in the overlapping area of ​​the upper core and the lower core. When the upper core is divided into two parts in the thickness direction, the portion located on the skin side is designated as the skin side portion, and the portion located on the non-skin side is designated as the non-skin side portion. In this case, the average density of the highly absorbent polymer in the skin side portion of the grooved region is lower than the average density of the highly absorbent polymer in the skin side portion of the non-groove region.

[0036] According to this absorbent material, excrement excreted to the skin side of the upper core easily flows to the groove area where the average density of the superabsorbent polymer is low (and is easily absorbed), and diffuses along the groove area in a specified direction. Since the lower core receives and absorbs the excrement diffused through the upper core, excrement is absorbed over a wide area throughout the lower core. Therefore, the diffusivity of excrement at both the upper and lower cores is high, increasing the absorption capacity of the absorbent core. Furthermore, since excrement absorbed through the skin side of the non-groove area of ​​the upper core is retained by the superabsorbent polymer, the reabsorption of excrement towards the skin side of the upper core is suppressed.

[0037] In this absorbent article, the absorbent core is characterized by having a central portion in the width direction and a pair of side portions in the width direction, which are divided into three parts by dividing its maximum width in the width direction. It also has a front side portion located on the front side of the center line dividing the absorbent article into two parts in the length direction when it is in an unfolded and stretched state, and a rear side portion located on the rear side of the center line in the length direction. The rear side portion has a rear first region that serves as the central region when its maximum length is divided into three parts in the length direction. The front side portion has a front first region that serves as the central region when its maximum length is divided into three parts in the length direction. The value obtained by dividing the area of ​​the groove region of the upper core located in the central portion in the width direction of the rear first region by the area of ​​the central portion in the width direction of the rear first region is less than the value obtained by dividing the area of ​​the groove region of the upper core located in the central portion in the width direction of the front first region by the area of ​​the central portion in the width direction of the front first region.

[0038] According to this absorbent material, in the central part of the rear first region, which is easily subjected to the wearer's body pressure, the area ratio of the groove region is small, thus reducing the amount of excrement that returns moisture from the groove region. On the other hand, in the front first region, which is the part that abuts or is close to the discharge port, the area ratio of the groove region is large, which allows a large amount of excrement to spread rapidly and be guided into the interior of the absorbent core, thus suppressing leakage of excrement.

[0039] In this absorbent article, the upper core located at the center of the width direction of the rear first region has a region provided with only one groove having a length in the length direction that is the specified direction.

[0040] According to this absorbent material, in the central part of the rear first region, which is easily subjected to the wearer's body pressure, there is a region where multiple groove regions are not arranged in the width direction, thus suppressing backflow of moisture. In addition, the drain liquid flowing from the drain port to the rear first region can be diffused in the groove region in the length direction and guided into the interior of the absorbent core, thus suppressing the leakage of drain liquid.

[0041] In this absorbent article, the average unit area weight of the absorbent core at the central portion of the rear first region in the width direction is higher than the average unit area weight of the absorbent cores at a pair of the rear first region in the width direction, and the upper cores located at the pair of the rear first region in the width direction include grooves having a length in the length direction as the predetermined direction.

[0042] According to this absorbent material, in the central part of the rear first region, which is easily subjected to the wearer's body pressure, the water retention capacity of the excrement is improved, thus suppressing backflow. In addition, the excrement flowing from the discharge port to the rear first region can be diffused in the groove area on the side in the width direction and guided into the interior of the absorbent core, thus suppressing leakage of the excrement (side leakage).

[0043] In this absorbent article, the rear portion has a rear second region at a position on the front side of the length direction relative to the rear first region, and the front portion has a front second region at a position on the rear side of the length direction relative to the front first region. Between the groove region of the upper core located in the rear second region and the groove region of the upper core located in the front second region in the length direction, the upper core has a region where the non-groove region extends from one end to the other end in the width direction.

[0044] According to this absorbent material, a large amount of drain liquid can be rapidly diffused and guided towards the interior of the absorbent core through the groove area of ​​the second front region, which serves as the contact part with the drain outlet or a portion close to it. The absorbed drain liquid can be retained in the non-groove area, suppressing backflow. Furthermore, since the drain liquid that was not completely absorbed by the second front region and flows to the rear region can be diffused through the groove area of ​​the second rear region and absorbed towards the interior of the absorbent core, leakage of drain liquid can be suppressed.

[0045] In this absorbent article, the rear portion is characterized by having a rear second region located at a position further forward in the length direction than the rear first region, and the value obtained by dividing the area of ​​the groove region of the upper core located at the center of the width direction of the rear second region by the area of ​​the center of the width direction of the rear second region is greater than the value obtained by dividing the area of ​​the groove region of the upper core located at the center of the width direction of the rear first region by the area of ​​the center of the width direction of the rear first region.

[0046] According to this absorbent material, in the central part of the rear first region, which is easily subjected to the wearer's body pressure, the small area ratio of the groove area helps to suppress backflow of moisture. On the other hand, in the rear second region, which is close to the part that comes into contact with the drain outlet, the large area ratio of the groove area allows the drain liquid to spread rapidly and be guided into the interior of the absorbent core, thus suppressing the leakage of the drain liquid.

[0047] In this absorbent article, the front portion is characterized by having a front second region located on the rear side of the front first region in the length direction, and the upper core located in the width direction center of the front second region includes a greater number of grooves having a length in the length direction as the specified direction compared to the upper core located in the width direction center of the front second region.

[0048] Based on this type of absorbent material, compared to the second front area which contacts the wearer's groin, the first front area is less likely to exert body pressure on the wearer. Therefore, even with a large number of channels, it is difficult for moisture to seep back in. Furthermore, in cases where the wearer is male, since the first front area is the contact point with or close to the discharge opening, the numerous channels allow the discharge fluid to spread along its length and be guided towards the interior of the absorbent core, thus suppressing leakage.

[0049] The absorbent article is characterized in that it has a pair of leak-proof wall portions that can stand upright toward the skin on both sides of the absorbent core in the width direction, and when the absorbent article is viewed in the thickness direction in an unfolded and stretched state, the upper core has a groove area that overlaps with the leak-proof wall portions in at least a portion.

[0050] Based on this absorbent material, the drain liquid blocked by the leak-proof wall can diffuse in the tank area and be absorbed into the interior of the absorbent core. Furthermore, since the leak-proof wall functions as a buffer, it is difficult to apply body pressure to the area where the leak-proof wall is located, thus suppressing backflow of moisture into the tank area.

[0051] In this absorbent article, the lower core is characterized by having a highly absorbent polymer, and the average density of the highly absorbent polymer in the upper core is higher than the average density of the highly absorbent polymer in the lower core.

[0052] According to such absorbent materials, even if the excrement absorbed by the lower core turns back to the upper core, the excrement can be retained by the highly absorbent polymer of the upper core, thus inhibiting the backflow of moisture onto the skin side of the absorbent material.

[0053] In this absorbent article, the average density of the highly absorbent polymer on the non-skin side of the non-groove region is lower than the average density of the highly absorbent polymer on the skin side of the non-groove region.

[0054] According to this absorbent material, the excrement transferred to the non-skin side by liquid flow in the groove area of ​​the upper core is easily absorbed by the non-skin side of the non-groove area, where the density of the highly absorbent polymer is low. This improves the diffusion of the excrement on the non-skin side of the upper core. Furthermore, the excrement transferred to the non-skin side of the non-groove area is absorbed by the skin side of the non-groove area and retained by the highly absorbent polymer, thus suppressing the re-wetting of the excrement towards the skin side of the upper core.

[0055] In this absorbent article, the groove is characterized by being a groove recessed from the skin side of the upper core toward the non-skin side in the thickness direction.

[0056] This absorbent material allows excrement that has been drained into the upper core to immediately fall into the space within the upper core's groove and diffuse. This prevents excrement from overflowing onto the skin's side surface of the upper core.

[0057] In this absorbent article, the average density of the highly absorbent polymer on the non-skin side of the groove region is lower than the average density of the highly absorbent polymer on the skin side of the non-groove region.

[0058] This absorbent material improves the permeability of drainage fluid in the upper core's groove area. Furthermore, in cases of repeated drainage, the highly absorbent polymer, which absorbs the drainage fluid, helps to prevent a decrease in permeability from the skin-side of the groove area to the non-skin-side.

[0059] In this absorbent article, the upper core is characterized by having, in addition to the superabsorbent polymer, liquid-absorbing fibers, and the average density of the liquid-absorbing fibers on the non-skin side of the non-groove region is higher than the average density of the liquid-absorbing fibers on the non-skin side of the groove region.

[0060] According to this absorbent material, the excretory fluid transferred to the non-skin side of the upper core through the flow of liquid into the groove area is easily absorbed by the non-skin side of the non-groove area due to capillary action. This increases the diffusivity of the excretory fluid in the upper core.

[0061] In this absorbent article, the lower core is characterized by having a highly absorbent polymer. When the lower core is divided into two parts in the thickness direction, the part located on the skin side is designated as the skin side portion, and the part located on the non-skin side is designated as the non-skin side portion. In this case, in at least a portion of the lower core, the average density of the highly absorbent polymer in the skin side portion of a certain region of the lower core is higher than the average density of the highly absorbent polymer in the non-skin side portion of a region of the upper core opposite to that region.

[0062] Based on such an absorbent material, the rate of liquid transfer from the upper core to the lower core can be suppressed. Therefore, the diffusivity of the excreted liquid at the upper core is improved, and the excreted liquid is absorbed over a wide area in the lower core, which receives it.

[0063] In this absorbent article, the groove is characterized in that the groove includes a main groove having a length in the length direction which is the specified direction and a secondary groove extending from the main groove in the width direction, the plurality of the main grooves being arranged at intervals in the width direction, and the plurality of the secondary grooves being at intervals in the length direction and extending from the main groove in the width direction.

[0064] Based on this absorbent material, the upper core allows excrement to diffuse along its length and also along its width. Furthermore, the upper core's flexibility is enhanced, allowing it to easily deform to conform to the wearer's body.

[0065] In this absorbent article, the lower core has a highly absorbent polymer and a second groove recessed in the thickness direction, a portion of which has a length in the length direction. When viewed in the thickness direction, the lower core has a second groove region with the second groove and a second non-groove region without the second groove. When viewed in the thickness direction, at least a portion of the second groove region is provided in the area where the upper core and the lower core overlap. When the lower core is divided into two parts in the thickness direction, the part located on the skin side is designated as the skin side portion, and the part located on the non-skin side is designated as the non-skin side portion. In this case, the average density of the highly absorbent polymer on the skin side portion of the second groove region is lower than the average density of the highly absorbent polymer on the skin side portion of the second non-groove region.

[0066] This absorbent material guides excretory fluid, which tends to stagnate at the boundary between the upper and lower core layers, into the groove area on the skin side of the lower core layer. As a result, excretory fluid easily transfers from the upper core layer to the lower core layer, increasing the absorption capacity of the lower core layer.

[0067] In this absorbent article, the average density of the highly absorbent polymer on the non-skin side of the second non-groove region is lower than the average density of the highly absorbent polymer on the skin side of the second non-groove region.

[0068] According to this absorbent material, the excrement transferred to the non-skin side by liquid flow in the groove area of ​​the lower core is easily absorbed by the non-skin side of the non-groove area, where the density of the superabsorbent polymer is low. This improves the diffusion of the excrement in the non-skin side of the lower core. Furthermore, the excrement transferred to the non-skin side of the non-groove area is absorbed by the skin side of the non-groove area and retained by the superabsorbent polymer, thus suppressing the re-wetting of the excrement.

[0069] In this absorbent article, the second groove is characterized by being a groove recessed from the non-skin side of the lower core toward the skin side in the thickness direction.

[0070] According to this absorbent material, the fluid permeability of the groove region of the lower core to the non-skin side (the space of the second groove) is improved. Therefore, while reliably guiding the excretory fluid to the non-skin side of the lower core, the excretory fluid diffuses along the second groove, increasing the absorption capacity of the lower core.

[0071] In this absorbent article, the characteristic is that, when viewed in the thickness direction, the groove region of the upper core has a portion that overlaps with the second groove region of the lower core.

[0072] This absorbent material can guide a large amount of excretory fluid absorbed by the upper core's groove area into the lower core's groove area. This prevents excretory fluid from overflowing onto the skin's sides of the upper core.

[0073] In this absorbent article, the lower core has a slit extending through it in the thickness direction at the center of the area abutting the crotch of the wearer in the width direction. The slit has a length in the length direction. When viewed in the thickness direction, the slit of the lower core overlaps with the upper core. Furthermore, at least a portion of the area of ​​the slit of the lower core does not overlap with the groove area of ​​the upper core.

[0074] According to such an absorbent article, by making the part of the absorbent core with slits overlap with the non-groove area of ​​the upper core, it is possible to prevent the rigidity of the absorbent core from being reduced too much and to suppress the distortion of the absorbent core.

[0075] In this absorbent article, the characteristic is that an elastic member that stretches and contracts in the length direction is disposed in the area abutted by the crotch of the wearer, and when viewed in the thickness direction, all areas of the slit of the lower core do not overlap with the groove area of ​​the upper core, and when viewed in the thickness direction, the slit has a portion that overlaps with the elastic member.

[0076] According to this absorbent material, since the slit and the groove area of ​​the upper core do not overlap in the thickness direction, excretory fluid is difficult to transfer from the upper core to the slit, thus preventing excretory fluid from stagnating at the slit. Furthermore, the deformation of the absorbent core protruding towards the skin side due to the slit of the lower core is facilitated by the elastic member. Therefore, the fit of the absorbent core to the wearer's crotch is improved, and the bending of the slit portion of the lower core makes it difficult for excretory fluid to stagnate.

[0077] In this absorbent article, the groove region has a length in the length direction that is the specified direction, the upper core has a region in which the non-groove region extends from one end to the other in the width direction at a position that is more rearward than the slit in the length direction, and in the length direction, the rear end of the lower core is located rearward than the rear end of the upper core.

[0078] Based on this type of absorbent material, the absorbent core can be easily bent along the width of the non-groove area in the length direction, and also easily bent along the rear end of the upper core in the length direction. Therefore, the rear end of the absorbent core can easily follow the wearer's hips, improving the fit of the absorbent core.

[0079] Hereinafter, as an example of an absorbent article involved in this embodiment, an adult shorts-type diaper will be described. However, absorbent articles are not limited to the above-described configuration. Other absorbent articles include, for example, belt-type diapers, baby diapers, incontinence pads, and sanitary napkins.

[0080] ===Basic Components of Shorts-Type Diapers 1===

[0081] Figure 1 This is a schematic three-dimensional diagram of a shorts-type diaper 1 (hereinafter also referred to as "diaper"). Figure 2 This is a rough top view of the diaper 1 in its unfolded and elongated state, viewed from the side of the skin. Figure 3 yes Figure 2 A rough cross-sectional view at line a-a.

[0082] The term "unfolded state" for diaper 1 refers to the state in which the joints 2 of the front waistband 21 and the rear waistband 22, described later, are released and unfolded. The term "stretched state" for diaper 1 refers to the state in which diaper 1 is stretched without wrinkles. Specifically, it means that, without the dimensions of the materials constituting diaper 1 being affected by the elastic members of diaper 1, diaper 1 is stretched until it reaches a length consistent with or close to the dimensions of its individual materials.

[0083] The diaper 1 in its shorts configuration has dimensions in the vertical, width, and thickness directions, and includes an absorbent body 10 and an outer component 20. In the vertical direction, the side containing the waist opening BH of the diaper 1 is designated as the upper side, and the opposite side is designated as the lower side. The length direction of the diaper 1 in its unfolded state corresponds to the vertical direction of the diaper 1 in its shorts configuration and also corresponds to the length direction of the absorbent body 10. In the length direction, the side that contacts the wearer's abdomen is designated as the front side, and the side that contacts the wearer's buttocks is designated as the back side. Furthermore, in the thickness direction, the side that contacts the wearer's skin is designated as the skin side, and the opposite side is designated as the non-skin side.

[0084] The outer component 20 is positioned on the non-skin side relative to the absorbent body 10, and has a front waistband 21, a rear waistband 22, and a crotch portion 23. When the diaper 1 is unfolded, it is folded in half approximately at the center along its length, and the two ends of the front waistband 21 and the rear waistband 22 are joined together in the width direction by welding or the like to form a pair of joints 2, thereby making the diaper 1 into a shorts type.

[0085] On the front waist section 21 and the rear waist section 22, multiple waist elastic members 211 and 221 (e.g., rubber threads) are arranged at intervals along the width direction in the vertical direction (length direction). Additionally, on the front waist section 21 and the rear waist section 22, multiple leg elastic members 212 and 222 (e.g., rubber threads) are arranged along the leg opening LH. The waist elastic members 211 and 221 and the leg elastic members 212 and 222 are fixed in an elongated state between two layers of sheet (e.g., non-woven fabric).

[0086] The crotch portion 23 is made of a piece (e.g., non-woven fabric) that connects the front waist portion 21 and the rear waist portion 22. However, the outer fitting 20 may not have the crotch portion 23.

[0087] The absorbent body 10 includes: an absorbent core 30 that absorbs and retains excretory fluid; a liquid-permeable surface sheet 11 (e.g., nonwoven fabric or a resin film with openings) disposed on the skin side relative to the absorbent core 30; a liquid-permeable intermediate sheet 12 disposed between the surface sheet 11 and the absorbent core 30; a liquid-impermeable back sheet 13 (e.g., a resin film) disposed on the non-skin side relative to the absorbent core 30; a pair of side sheets 14 (e.g., hydrophobic nonwoven fabric) disposed on the side portion in the width direction of the absorbent body 10; a leak-proof elastic member 15; a leg elastic member 16; a crotch elastic member 17; and a cover sheet 18 that covers the crotch elastic member 17 from the non-skin side.

[0088] Although details are not illustrated, the side panel 14 folds back from the non-skin-facing side of the back panel 13 towards the skin-facing side of the surface panel 11. The leak-proof elastic member 15 and the leg-circle elastic member 16 are fixed to the side panel 14 in an extended state along the length. The leak-proof elastic member 15 is disposed on the skin-facing side of the surface panel 11 at the end of the side panel 14 folded inwards in the width direction. The leg-circle elastic member 16 is disposed on the side of the absorbent body 10 in the width direction. The crotch elastic member 17 is disposed at the center of the absorbent body 10 in both the length and width directions, and is fixed between the back panel 13 and the cover panel 18 in an extended state along the length direction.

[0089] The above describes the basic structure of the shorts-type diaper 1, but the structure of the shorts-type diaper 1 is not limited to the above structure.

[0090] ===About Absorbent Body 10 (Absorbent Core 30)===

[0091] <<First Implementation>>

[0092] Figure 4 This is a top view of the upper core 31 viewed from the skin side in the thickness direction. Figure 5This is a top view of the lower core 32 viewed from the skin side in the thickness direction. Figure 6 This is a top view of the stacked upper core 31 and lower core 32 from the skin side in the thickness direction. Figure 7 This is a schematic cross-sectional view of a portion of the upper core 31 and the lower core 32. Figure 8A yes Figure 6 A cross-sectional view at line I-I. Figure 8B yes Figure 6 A schematic cross-sectional view at line II-II. Figure 9A This is a schematic 3D view of the core-encapsulated wafer 39. Figure 9B This is an explanatory diagram of a modified configuration of the core-cladding sheet 39. Figure 10A , Figure 10B , Figure 11A , Figure 11B These are explanatory diagrams of variations of slots 35 and 36.

[0093] The absorbent core 30 has a two-layer structure, comprising an upper core 31 and a lower core 32 disposed on the non-skin side in the thickness direction compared to the upper core 31. Both the upper core 31 and the lower core 32 contain absorbent fibers 33 (such as pulp fibers or cellulose-based absorbent fibers) and highly absorbent polymers 34 (SAP).

[0094] The planar shapes of the upper core 31 and the lower core 32 are hourglass shapes, narrowing from the central part in the length direction towards the inward side in the width direction. For example... Figure 6 As shown, the lower core 32 is larger than the upper core 31, and the upper core 31 is arranged in a way that converges into the outer periphery of the lower core 32.

[0095] The upper core 31 has a groove 35 recessed in the thickness direction in a portion of the upper core 31. When viewed in the thickness direction, it has a groove area A1 with the groove 35 and a non-groove area A2 without the groove. The groove 35 has a length in the longitudinal direction (prescribed direction) of the diaper 1. In the upper core 31, a plurality of grooves 35 extending in the length direction are arranged at intervals in the width direction and also at intervals in the length direction. In addition, the groove 35 in the first embodiment is an upper groove that is recessed from the skin side of the upper core 31 toward the non-skin side in the thickness direction.

[0096] The lower core 32 also has a groove 36 (second groove) that is recessed in the thickness direction. When viewed in the thickness direction, it has a groove area A3 (second groove area) with the groove 36 and a non-groove area A4 (second non-groove area) without the groove 36. However, unlike the groove 35 of the upper core 31, the groove 36 of the lower core 32 is a recessed groove that extends from the non-skin side of the lower core 32 toward the skin side in the thickness direction. The groove 36 has a length in the length direction of the diaper 1. In the lower core 32, a plurality of grooves 36 extending in the length direction are arranged at intervals in the width direction and also at intervals in the length direction.

[0097] Furthermore, the lower core 32 has a central slit 37 (slit) extending through the lower core 32 in the thickness direction and a pair of side slits 38. The central slit 37 is a generally rectangular slit that is long in the length direction and is located at the center of the crotch area of ​​the diaper 1 in the width direction. The pair of side slits 38 are generally rectangular slits that are long in the length direction and are located on both outer sides of the central slit 37 in the width direction, overlapping at least a portion of the central slit 37 in the length direction. Compared to the side slits 38, the central slit 37 is longer in both the width and length directions. In addition, when viewed in the thickness direction, the central slit 37 completely overlaps with the upper core 31, while most of the side slits 38 do not overlap with the upper core 31.

[0098] Furthermore, the so-called crotch area of ​​diaper 1 refers to the area envisioned as abutting against the wearer's crotch. Specifically, the crotch area is defined as the area on the lower side (inner side in the length direction) of the diaper 1, which is closer to the joint 2 in the vertical direction. Alternatively, the crotch area can also be defined as the area of ​​diaper 1 when it is unfolded and stretched in the length direction. Figure 2 When divided into three parts, the central area is designated as the lower crotch area.

[0099] Here, when the upper core 31 and the lower core 32 are divided into two parts in the thickness direction, the parts located on the skin side are designated as skin-side portions 311 and 321, and the parts located on the non-skin side are designated as non-skin-side portions 312 and 322. Specifically, the skin-side portions 311 and 321 and the non-skin-side portions 312 and 322 are divided by an imaginary line extending horizontally from the center C of the thickest part in the non-groove regions A2 and A4 in the thickness direction.

[0100] Furthermore, in the upper core 31, the average density of the highly absorbent polymer 34 at the skin side 311 of the groove region A1 is lower than the average density of the highly absorbent polymer 34 at the skin side 311 of the non-groove region A2. Therefore, compared to the non-groove region A2, the excretory fluid draining to the skin side of the upper core 31 flows more easily to the groove region A1, which is a low-SAP region. Consequently, the excretory fluid diffuses along the length of the groove region A1, which extends in the longitudinal direction.

[0101] In particular, the groove 35 of the upper core 31 is an upper groove. Therefore, the skin side 311 of the groove region A1 is the space of the groove 35, and the average density of the highly absorbent polymer 34 at the skin side 311 of the groove region A1 is further reduced (becoming zero or close to zero). Since the upper core 31 directly receives the excretory fluid, by making the groove 35 an upper groove, the excretory fluid excreted to the skin side of the upper core 31 can immediately fall into the space of the groove 35, causing it to diffuse along its length. Therefore, even when a large amount of excretory fluid is excreted, the overflow of excretory fluid from the skin side of the upper core 31 can be suppressed.

[0102] Furthermore, if the groove 35 of the upper core 31 is a slit extending through the thickness direction, the excreted liquid will transfer downwards before diffusing along the groove region A1, and will be absorbed in a point-like manner in a portion of the lower core 32. The diffusion range of the excreted liquid from the point-like absorption portion is limited, preventing large-scale absorption of the excreted liquid in the lower core 32. Similarly, since the excreted liquid also transfers to the lower core 32 before diffusing in the upper core 31, it cannot be absorbed in a large-scale manner in the upper core 31.

[0103] In contrast, the groove 35 of the upper core 31 in this embodiment is a groove 35 (recess) that is recessed in the thickness direction of a portion of the upper core 31. Therefore, it can prevent the drained liquid from immediately transferring from the groove region A1 to the lower core 32, and can allow the drained liquid to spread over a wide area of ​​the upper core 31 along the groove region A1.

[0104] In addition, such as Figure 6 As shown, when viewed in the thickness direction, a groove region A1, a portion of the upper core 31, is provided in the area where the upper core 31 and the lower core 32 overlap. Therefore, the lower core 32 can receive and absorb the drained liquid that diffuses along the groove region A1 of the upper core 31. Consequently, the drained liquid also exhibits high diffusivity in the lower core 32, allowing for absorption over a wide area of ​​the lower core 32. Furthermore, after the lower core 32 becomes saturated, the drained liquid can diffuse and be absorbed over a wide area of ​​the upper core 31.

[0105] Furthermore, the lower core 32 in this embodiment has a central slit 37. In this case, a groove region A1 can be provided at the portion of the upper core 31 that overlaps with the portion of the lower core 32 where the central slit 37 is not located in the thickness direction. With this configuration, the lower core 32 can receive and absorb the excreted liquid that diffuses along the groove region A1.

[0106] Furthermore, since the groove 35 of the upper core 31 in this embodiment is different from a slit, the lower core 32 does not protrude towards the skin in the groove region A1. Therefore, it is possible to prevent the excrement absorbed by the portion of the lower core 32 facing the groove region A1 of the upper core 31 from re-wetting and contacting the skin. Additionally, the skin-side portion 311 of the non-groove region A2 of the upper core 31 is a high-absorbency polymer (SAP) region. Therefore, the excrement absorbed by the skin-side portion 311 of the non-groove region A2 is reliably retained by the highly absorbent polymer 34. This suppresses the re-wetting of excrement on the skin-side surface of the upper core 31.

[0107] As described above, in the absorbent core 30 of this embodiment, the diffusion of the drained liquid at the upper core 31 and the lower core 32 is high, resulting in increased absorption capacity. Therefore, even in cases of repeated draining, overflow or leakage of the drained liquid can be suppressed. In addition, back-wetting of the drained liquid can also be suppressed.

[0108] In addition, Figure 7 In the upper core 31, the bottom of the groove 35 is located at the boundary between the skin side 311 and the non-skin side 312, but it is not limited to this; the bottom of the groove 35 can be either shallower or deeper than the boundary. Furthermore, the high-SAP region of the skin side 311 in the non-groove region A2 of the upper core 31 can extend to a position closer to the non-skin side than the bottom of the groove 35 (or the top of the groove 35 if the groove 35 is a lower groove). Additionally, a portion of the non-skin side 312 of the groove region A1 (i.e., a portion of the bottom or top of the groove 35) can also be a high-SAP region. When a portion of the bottom (or top) of the groove 35 is a high-SAP region, the excretory fluid is difficult to guide to the bottom (or top) of the groove 35. Therefore, the excretory fluid easily diffuses on the bottom of the groove 35 (or below the top), increasing the diffusion of the excretory fluid in the upper core 31. The same applies to the lower core 32.

[0109] Furthermore, preferably, in the upper core 31, the average density of the highly absorbent polymer 34 in the non-skin side 312 of the non-groove region A2 is lower than the average density of the highly absorbent polymer 34 in the skin side 311 of the non-groove region A2. With this configuration, the excretory fluid transferred from the skin side 311 of the groove region A1 to the lower (non-skin side 312) is easily transferred to the non-skin side 312 of the non-groove region A2, which is a low SAP region. Therefore, the diffusivity of the excretory fluid at the upper core 31 is improved. For example, the excretory fluid flowing in the non-groove region A2, which is arranged with the groove region A1 in the width direction, also diffuses in the width direction. Moreover, since the excretory fluid that has further diffused through the upper core 31 is received by the lower core 32, the excretory fluid is absorbed over a larger area throughout the lower core 32. However, it is not limited to the above configuration. For example, the average density of the highly absorbent polymer 34 at the non-skin side 312 of the non-groove region A2 is equal to or greater than the average density of the highly absorbent polymer 34 at the skin side 311 of the non-groove region A2.

[0110] Furthermore, the excretory fluid transferred to the non-skin side 312 of the non-groove region A2 is transferred to the lower core 32 and is also absorbed by the skin side 311 of the non-groove region A2. Since the skin side 311 of the non-groove region A2 is a high-SAP area, the absorbed excretory fluid is reliably retained by the highly absorbent polymer 34. This prevents the excretory fluid from becoming damp on the skin side of the upper core 31.

[0111] Furthermore, when the groove 35 of the upper core 31 is an upper groove, a highly absorbent polymer 34 and absorbent fibers are disposed on the non-skin side 312 of the groove region A1. In this case, it is preferable that the average density of the highly absorbent polymer 34 on the non-skin side 312 of the groove region A1 is lower than the average density of the highly absorbent polymer 34 on the skin side 311 of the non-groove region A2.

[0112] With this configuration, the excretory fluid flowing to the skin-side 311 of the upper core 31 in the groove region A1 (space portion) can easily transfer to the non-skin-side 312 (below), which is a low-SAP region. In other words, the fluid permeability in the groove region A1 is improved. Therefore, even in cases of repeated excretion, the fluid permeability of the groove region A1 can be prevented from being impaired by the highly absorbent polymer 34 that has absorbed the excretory fluid.

[0113] Furthermore, when the groove 35 of the upper core 31 is an upper groove, it is preferable that the average density of absorbent fibers in the non-skin side 312 of the non-groove region A2 is higher than the average density of absorbent fibers in the non-skin side 312 of the groove region A1. With this configuration, the excrement transferred to the non-skin side 312 of the groove region A1 is easily transferred to the non-skin side 312 of the non-groove region A2 due to capillary action. Therefore, the diffusivity of the excrement in the upper core 31 is improved. Moreover, the lower core 32, which receives the excrement diffused in the upper core 31, can absorb the excrement over a wider area.

[0114] Furthermore, in this embodiment, the upper core 31 and the lower core 32 each have thin fiber layers 313 and 323 on their skin-side surfaces. The fiber layers 313 and 323 are composed of absorbent fibers 33 and do not contain highly absorbent polymers 34. Through the fiber layers 313 and 323, excretory fluid can easily diffuse in the planar direction on the skin-side surfaces of the upper core 31 and the lower core 32. This improves the diffusivity of excretory fluid at the upper core 31 and the lower core 32. However, one or both of the upper core 31 and the lower core 32 may not have fiber layers 313 and 323. Additionally, the fiber layers 313 and 323 are thin. Therefore, the difference in average density of the highly absorbent polymer 34 between the skin-side portions 311, 321 (including the portions containing the fiber layers 313, 323) and the non-skin-side portions 312, 322 (excluding the portions containing the fiber layers 313, 323) of the upper core 31 or lower core 32 has no effect.

[0115] Alternatively, although not illustrated, a thin fiber layer (excluding the layer of absorbent fiber 33 containing the highly absorbent polymer 34) can be provided on the non-skin side of the upper core 31 and the lower core 32. In this case, the excretory fluid can easily diffuse in the planar direction on the non-skin side of the upper core 31 or the non-skin side of the lower core 32, further improving the diffusion of the excretory fluid at the upper core 31 and the lower core 32.

[0116] Furthermore, the comparison of the average density of the highly absorbent polymer 34 and the average density of the absorbent fibers 33 at different portions of the absorbent core 30 can be performed using known methods. For example, after immersing the absorbent core 30 of the test object in liquid nitrogen and freezing it, a cross-section of the absorbent core 30, including the portion to be compared (e.g., the groove region A1 and the non-groove region A2), is obtained by cutting it in the thickness direction with a razor. After the absorbent core 30 returns to room temperature, a cross-sectional image at 50x magnification is obtained using an electron microscope (e.g., Keyence VE7800). Based on this cross-sectional image, the average density of the highly absorbent polymer 34 at the portion to be compared can be visually compared. Additionally, the average density of the absorbent fibers 33 at the portion to be compared can also be visually compared based on this cross-sectional image. Alternatively, the number of highly absorbent polymers 34 or absorbent fibers 33 per unit area can be counted in the cross-sectional image for comparison.

[0117] Alternatively, for example, after freezing the absorbent core 30 of the test object, it can be cut to obtain a cross-section of the absorbent core 30, including the area to be compared. The average density of the highly absorbent polymer 34 can also be compared based on an image obtained by irradiating this cross-section with X-rays. In areas where the highly absorbent polymer 34 overlaps significantly, the amount of X-rays transmitted decreases. Therefore, areas with high average density of the highly absorbent polymer 34 in the X-ray image are more densely identified, and comparisons can be made based on the density of the areas to be compared. Furthermore, the weight of the highly absorbent polymer 34 and the weight of the absorbent fiber 33 can be obtained using the measurement method described in Japanese Patent Application No. 2018-542962, and converted into density for comparison.

[0118] As described above, by making the absorbent core 30 a two-layer structure, the amount of excrement that the diaper 1 can absorb can be increased. However, if the excrement is difficult to transfer from the upper core 31 to the lower core 32, there is a possibility that the excrement may stagnate in the space at the boundary between the upper core 31 and the lower core 32 in the thickness direction. In this case, the amount of excrement absorbed at the lower core 32 is reduced, and the absorbency of the lower core 32 cannot be effectively utilized.

[0119] Therefore, in the lower core 32, the average density of the highly absorbent polymer 34 at the skin side 321 of the groove region A3 can be lower than the average density of the highly absorbent polymer 34 at the skin side 321 of the non-groove region A4. Furthermore, when viewed in the thickness direction, at least a portion of the groove region A3 of the lower core 32 can be provided in the area where the lower core 32 overlaps with the upper core 31.

[0120] With this configuration, the excretory fluid transferred in the thickness direction to the boundary between the upper core 31 and the lower core 32 is easily absorbed by the groove region A3, which is a low-SAP region, in the skin-side portion 321 of the lower core 32. Therefore, the stagnation of excretory fluid at the boundary between the upper core 31 and the lower core 32 can be suppressed, allowing the excretory fluid to transfer to the lower core 32. As a result, the lower core 32 can reliably absorb the excretory fluid, preventing a reduction in the amount of excretory fluid that the diaper 1 can absorb. On the other hand, the skin-side portion 321 of the non-groove region A4 of the lower core 32 is a high-SAP region. Therefore, the excretory fluid absorbed by the skin-side portion 321 of the non-groove region A4 is reliably retained by the highly absorbent polymer 34, suppressing the reabsorption of excretory fluid.

[0121] Furthermore, the excretory fluid absorbed by the tank area A3 tends to transfer to the lower space (non-skin side 322). Then, the excretory fluid diffuses along the length of the space in the tank area A3. Therefore, the excretory fluid diffused through the upper core 31 further diffuses in the lower core 32, absorbing the excretory fluid over a larger area in the lower core 32.

[0122] Furthermore, the groove 36 of the lower core 32 is a groove 36 (recess) that is recessed in the thickness direction of a portion of the lower core 32. Therefore, unlike the case where the groove 36 is a slit extending through the thickness direction, it can prevent the drainage liquid from stagnating in the groove 36. That is, the drainage liquid can also diffuse in the part where the absorbent fiber 33 and the superabsorbent polymer 34 are arranged.

[0123] Furthermore, when the groove 36 of the lower core 32 is a downward groove, the downward (space portion) fluid permeability in the groove region A3 is high. This allows the excretory fluid to diffuse after being guided to the non-skin side 322 of the lower core 32, effectively utilizing the lower core 32. Additionally, since the groove 36 of the lower core 32 is not a slit but a downward groove, there is no space portion (recess) of the groove 36 on the skin side of the lower core 32. Therefore, the transfer rate of the excretory fluid from the upper core 31 to the lower core 32 can be appropriately suppressed. Thus, the excretory fluid diffuses in the upper core 31 before transferring to the lower core 32.

[0124] Additionally, preferably, similar to the upper core 31, the average density of the highly absorbent polymer 34 in the lower core 32, which is also the non-skin side 322 of the non-groove region A4, is lower than the average density of the highly absorbent polymer 34 in the skin side 321 of the non-groove region A4.

[0125] With this configuration, the excrement that diffuses along the length of the groove 36 in the non-skin side 322 of the lower core 32 easily transfers to the non-skin side 322 of the non-groove region A4, which is a low-SAP region. Therefore, the diffusivity of the excrement in the lower core 32 is further improved. Furthermore, the excrement transferred to the non-skin side 322 of the non-groove region A4 is drawn up by the skin side 321 of the non-groove region A4. Since the skin side 321 of the non-groove region A4 is a high-SAP region, the drawn-up excrement can be reliably retained, and the re-wetting of the excrement can be suppressed.

[0126] Furthermore, the planar shape of the lower core 32 is larger than that of the upper core 31, and the lower core 32 extends outward in the longitudinal direction from the end 31a of the upper core 31. Preferably, at the portion of the lower core 32 that extends outward in the longitudinal direction from the upper core 31, the drained liquid will not stagnate at the boundary with the upper core 31, and a groove region A3 of the lower core 32 is also provided at this portion.

[0127] This configuration allows excretory fluid to diffuse to the area of ​​the lower core 32 that does not overlap with the upper core 31 when viewed in the thickness direction. Furthermore, the longitudinal end of the lower core 32 gains flexibility and is easily deformable through the groove 36. Therefore, the lower core 32 can easily fit the wearer's lower abdomen or buttocks.

[0128] Furthermore, preferably, when viewed in the thickness direction, the groove region A1 of the upper core 31 has a portion that overlaps with the groove region A3 of the lower core 32. In the first embodiment, most of the grooves 35 of the upper core 31 (except for the two grooves 35A that overlap with the central slit 37) overlap with the grooves 36 of the lower core 32.

[0129] In the upper core 31, the amount of excrement flowing downwards (towards the non-skin side) through the groove region A1 is greater than that in the non-groove region A2. Therefore, if the groove region A1 of the upper core 31 is aligned with the groove region A3 of the lower core 32, the lower core 32's groove region A3 can receive the large amount of excrement flowing through the groove region A1 of the upper core 31, guide it into the interior of the lower core 32 (the space of the non-skin side 322), and allow it to diffuse. This further suppresses the stagnation of excrement at the boundary between the upper core 31 and the lower core 32. In addition, in this embodiment, the groove 35 of the upper core 31 and the groove 36 of the overlapping lower core 32 have the same shape and are arranged in the same position, but this is not a limitation; they may simply overlap by at least a portion.

[0130] Furthermore, preferably, in at least a portion of the lower core 32, the average density of the highly absorbent polymer 34 at the skin-side 321 of a certain region of the lower core 32 is higher than the average density of the highly absorbent polymer 34 at the non-skin-side 311 of a region of the upper core 31 opposite to the aforementioned region. With this configuration, the transfer rate of the excretory fluid from the upper core 31 to the lower core 32 can be moderately suppressed. Thus, the excretory fluid diffuses within the upper core 31 before transferring to the lower core 32.

[0131] Specifically, in the absorbent core 30 of the first embodiment, most of the groove region A1 of the upper core 31 overlaps with the groove region A3 of the lower core 32, and most of the non-groove region A2 of the upper core 31 overlaps with the non-groove region A4 of the lower core 32. As described above, the non-groove region A4 of the skin-side portion 321 of the lower core 32 is a high SAP region, and the non-groove region A2 of the non-skin-side portion 312 of the upper core 31 opposite it is a low SAP region, as described above. On the other hand, the groove region A3 of the skin-side portion 321 of the lower core 32 and the groove region A1 of the non-skin-side portion 312 of the upper core 31 opposite it are both low SAP regions. Therefore, the average density of the highly absorbent polymer 34 in the groove region A3 of the skin-side portion 321 of the lower core 32 can be higher than the average density of the highly absorbent polymer 34 in the groove region A1 of the non-skin-side portion 312 of the upper core 31.

[0132] Furthermore, the lower core 32 has a central slit 37 extending in the length direction at the center of its width in the area that abuts against the wearer's crotch. Therefore, the lower core 32 and the overlapping upper core 31 are bent along the central slit 37 (along the length direction). As a result, the central portion of the absorbent core 30 in the width direction deforms in a manner that protrudes towards the skin relative to the sides, easily fitting the wearer's crotch.

[0133] Furthermore, when viewed in the thickness direction, the groove region A1 of the upper core 31 has a portion that overlaps with the central slit 37. Figure 6 (The groove 35A). In the absorbent core 30, the portion with the central slit 37 weakens the absorption capacity of the excrement, while the excrement can diffuse through the groove region A1 of the upper core 31 that overlaps with the central slit 37. Particularly preferred is that the end of the groove region A1 of the upper core 31 extends outward in the longitudinal direction compared to the central slit 37. With this configuration, the excrement can be transferred to the portion that does not overlap with the central slit 37. As a result, the overflow of excrement in the crotch area can be suppressed.

[0134] However, it is not limited to the above configuration. The rigidity of the portion of the absorbent core 30 where the central slit 37 is located is reduced. Therefore, when viewed in the thickness direction, at least a portion of the region of the central slit 37 of the lower core 32 may not overlap with the groove region A1 (groove 35) of the upper core 31. For example, it may also be as follows Figure 10A As shown in the modified example, all areas of the central slit 37 do not overlap with the groove area A1 of the upper core 31. This configuration prevents further reduction in the rigidity of the absorbent core 30 due to the reduced rigidity caused by the central slit 37, thus suppressing misalignment of the absorbent core 30. Consequently, the absorbent core 30 can maintain its absorption performance for an extended period. Furthermore, fluid accumulation is prone to occur at the central slit 37. Therefore, by designating the area of ​​the upper core 31 overlapping with the central slit 37 as a non-groove area A2, the skin side 311 becomes a high-SAP area, suppressing the transfer of fluid to the central slit 37. This suppresses fluid accumulation at the central slit 37.

[0135] Furthermore, preferably, the groove 35 of the upper core 31 does not extend to the outer periphery of the upper core 31, and the groove 36 of the lower core 32 also does not extend to the outer periphery of the lower core 32. This configuration suppresses misalignment of the upper core 31 and the lower core 32. Additionally, it suppresses the diffusion of excrement to the outer periphery of either the upper core 31 or the lower core 32.

[0136] Furthermore, as described above, in diaper 1, a crotch elastic member 17 that stretches in the longitudinal direction is provided in the area that abuts against the wearer's crotch. Preferably, as... Figure 6 As shown, when viewed in the thickness direction, the central slit 37 and the groove region A1 of the upper core 31 each have a portion that overlaps with the lower elastic member 17.

[0137] With this configuration, the deformation of the absorbent core 30 protruding towards the skin due to the central slit 37 is facilitated by the stretching and contraction of the crotch elastic member 17. Furthermore, the absorbent core 30 becomes soft through the groove area A1, making it easily deformable to fit the wearer's crotch. This deformation is also facilitated by the stretching and contraction of the crotch elastic member 17. Thus, the fit of the diaper 1 to the wearer is increased.

[0138] In addition, preferably, such as Figure 10A As shown in the modified example, even when all areas of the central slit 37 of the lower core 32 do not overlap with the groove area A1 of the upper core 31, the central slit 37 still has a portion that overlaps with the crotch elastic member 17 when viewed in the thickness direction. With this configuration, the deformation of the absorbent core 30 protruding towards the skin is promoted by the crotch elastic member 17 because of the central slit 37, and the portion of the central slit 37 of the lower core 31 bends, making it difficult for the excreted fluid to stagnate.

[0139] Furthermore, at the portion overlapping the central slit 37 of the lower core 32 in the length direction, the side end of the upper core 31 in the width direction is located outside the central slit 37 in the width direction, and inside the side end of the lower core 32 in the width direction. Therefore, the side portion of the lower core 32 in the width direction easily bends along the side end of the upper core 31 in the width direction (along the length direction). In other words, the side portion of the lower core 32 in the width direction easily stands upright towards the skin.

[0140] Furthermore, the lower core 32 has a pair of side slits 38 on both sides of the central slit 37 in the width direction. The position of the side slits 38 in the width direction is approximately the same as the position of the side ends of the upper core 31 in the width direction. Therefore, the side portions of the lower core 32 in the width direction also easily rise towards the skin through the pair of side slits 38. As a result, for the absorbent core 30, in the crotch area, the central portion in the width direction deforms protruding towards the skin, and the side portions in the width direction rise towards the skin, easily deforming the cross-section into a W-shape. Therefore, it is easier to fit the wearer's crotch area.

[0141] Furthermore, preferably, at least one of the grooves 35 of the upper core 31 and 36 of the lower core 32 is provided in the overlapping area of ​​the upper core 31 and the lower core 32, located on the outer side of the central slit 37 of the lower core 32 in the width direction. With this configuration, the high-rigidity overlapping area of ​​the two cores 31 and 32 gains flexibility through the grooves 35 and 36, making it easy to deform and fit the wearer's crotch area.

[0142] Furthermore, preferably, a groove region A3 (groove 36A) of the lower core 32 is provided at a position that is located on the outer side of the side slit 38 in the width direction and overlaps with at least a portion of the side slit 38 in the length direction. With this configuration, the softness of the side portion of the lower core 32 in the width direction, which faces the skin, is improved. Therefore, the side portion of the lower core 32 in the width direction easily deforms along the wearer's thigh, increasing fit.

[0143] However, it is not limited to the above configuration. The lower core 31 may also be configured without one or both of the central slit 37 and the side slits 38.

[0144] Furthermore, the groove 36 of the lower core 32 is preferably configured separately from the outer periphery of the central slit 37 or the side slit 38. This configuration helps to suppress misalignment of the lower core 32.

[0145] Furthermore, preferably, the width (length in the width direction) of the central slit 37 and the side slits 38 is greater than the width (length in the width direction of the main grooves 351 and 361, and length in the length direction of the grooves 352 and 362) of the upper core 31 and the lower core 32. With this configuration, the absorbent core 30 can easily deform into a W-shape through the central slit 37 and the side slits 38. On the other hand, by not making the widths of the grooves 35 and 36 too large, distortion of the absorbent core 30 can be prevented. The width of the central slit 37 and the side slits 38 is preferably, for example, about 7mm to 50mm, so that the absorption performance is not excessively reduced. The width of the grooves 35 and 36 is preferably, for example, about 1mm to 8mm. Additionally, the length in the length direction of the central slit 37 and the side slits 38 can be the length that abuts against the wearer's crotch, for example, about 50 to 300mm, preferably about 100 to 250mm.

[0146] Furthermore, the slot 35 of the upper core 31 and the slot 36 of the lower core 32 each have main slots 351 and 361 with length in the longitudinal direction and secondary slots 352 and 362 extending from the main slots 351 and 361 in the width direction. Specifically, a plurality of secondary slots 352 and 362 extend from the main slots 351 and 361 in the width direction at intervals in the longitudinal direction. Such main slots 351 and 361 are arranged in a plurality of spaced-apart configurations in both the width and length directions.

[0147] By channeling fluids from grooves 352 and 362, the excretory fluid discharged to the skin-side portion of the upper core 31 and the excretory fluid guided to the non-skin-side portion 322 (space portion) of the lower core 32 can diffuse not only in the length direction but also in the width direction. This further enhances the diffusivity of the excretory fluid at the upper core 31 and the lower core 32.

[0148] Furthermore, by making the absorbent core 30 a two-layer structure, the absorption capacity of the excreted liquid is increased. On the other hand, the rigidity of the absorbent core 30 is increased, making it less prone to deformation. However, in this embodiment, the upper core 31 and the lower core 32 have grooves 35 and 36. In particular, the upper core 31 and the lower core 32 overlap, and the grooves 35 and 36 are provided in the areas where rigidity is increased. Therefore, the absorbent core 30 can obtain softness and easily deform along the wearer's body.

[0149] Furthermore, grooves 35 and 36 not only have main grooves 351 and 361 along the length direction, but also secondary grooves 352 and 362 along the width direction. Therefore, the upper core 31 and the lower core 32 are easily bent not only along the length direction, but also easily bent along the width direction starting from the secondary grooves 352 and 362. Consequently, the absorbent core 30 easily bends along the length direction from the wearer's lower abdomen to the buttocks.

[0150] Furthermore, in the first embodiment, a large portion of the groove 35 of the upper core 31 overlaps with the groove 36 of the lower core 32. In addition, not only does the main groove 351 of the upper core 31 overlap with the main groove 361 of the lower core 32, but the secondary grooves 352 of the upper core 31 and 362 of the lower core 32 also overlap. Therefore, the overlapping area of ​​the upper core 31 and the lower core 32 is more prone to bending along the grooves 35 and 36 in the length or width direction, and is more likely to deform along the wearer's body.

[0151] Furthermore, the adjacent slots 352 and 362 are aligned along their length in the width direction. Consequently, the upper core 31 and the lower core 32 can easily be bent along the width direction starting from slots 352 and 362, and can easily deform along the wearer's body.

[0152] In addition, such as Figure 6 As shown, the upper core 31 and the lower core 32, located further back in the longitudinal direction than the central slit 37, have non-groove regions A2 and A4 that extend continuously from one end in the width direction to the other, regions A21, A41, and A42. Thus, at the rear ends of the upper core 31 and the lower core 32, by providing regions A21, A41, and A42 that are continuous in the width direction without grooves 35 and 36, the upper core 31 and the lower core 32 can easily bend in the longitudinal direction along these regions (starting from the ends of the grooves 35 and 36 in the longitudinal direction). In other words, the grooves 35 and 36 extending in the longitudinal direction do not easily obstruct the bending of the upper core 31 and the lower core 32 in the longitudinal direction. Therefore, the rear ends of the upper core 31 and the lower core 32 can easily follow the rounded hips of the wearer.

[0153] Furthermore, such as Figure 6 As shown, the rear end 32a of the lower core 32 is located at the rear compared to the rear end 31a of the upper core 31, and the rear end 31a of the upper core 31 is located in the non-groove region A42 of the lower core 32, which is continuous in the width direction. Therefore, the rear end of the lower core 32 can easily bend in the length direction along the rear end 32a of the upper core 31. As a result, the rear end of the lower core 32 can easily follow the rounded hips of the wearer.

[0154] Furthermore, as described above, by making the rear end of the absorbent core 30 easily bendable in the longitudinal direction, the W-shaped deformation in the crotch area of ​​the absorbent core 30 (the deformation obtained by the central slit 37 and the side slits 38) can be prevented from being transmitted to the rear of the absorbent core 30. As a result, the rear end of the absorbent core 30 can easily follow the wearer's buttocks.

[0155] Furthermore, when viewed in the thickness direction, the area where the upper core 31 and the lower core 32 do not overlap (the area of ​​the lower core 32 only) has low rigidity and high flexibility. Therefore, although not shown in the figure, in the area where only the lower core 32 exists, the width of the groove 36 of the lower core 32 (specifically, the length in the width direction of the main groove 361 and the length direction from the length of the groove 362) can be reduced compared to the area where the upper core 31 and the lower core 32 overlap. With this configuration, misalignment of the lower core 32 can be suppressed.

[0156] Furthermore, when viewed in the thickness direction, the boundary portion (outer periphery of the upper core 31) of the region that does not overlap with the regions of the upper core 31 and the lower core 32 is prone to becoming the starting point of bending of the absorbent core 30, and on the other hand, it is also prone to becoming the starting point of distortion of the absorbent core 30. Therefore, it is preferable not to provide groove regions A1 and A3 in the aforementioned boundary portions, and it is particularly preferable not to provide groove region A3 of the lower core 32. With this configuration, distortion of the absorbent core 30 can be suppressed.

[0157] It can also be like Figure 8A as well as Figure 8B As shown, a core sheet 39, serving as a liquid-permeable sheet (such as thin paper or non-woven fabric), is provided at the boundary between the upper core 31 and the lower core 32. As the core sheet 39, such as... Figure 9A As shown, an example of a nonwoven fabric with raised portions 391 and recesses 392 extending in the length direction can be illustrated. The raised portions of the core sheet 39 allow the excrement to diffuse in the length direction, improving the diffusion of the excrement at the upper core 31 or lower core 32. Furthermore, the raised portions of the core sheet 39 are not limited to extending in the length direction; they can also extend in the width direction or other directions. Additionally, the raised portions of the core sheet 39 increase the space for storing the excrement. Therefore, even when a large amount of excrement is excreted, the excrement can be temporarily stored in the storage space of the core sheet 39, thus preventing the excrement from overflowing onto the skin side of the upper core 31. Alternatively, although not shown, raised portions 391 and recesses 392 extending in the length direction can be intermittently arranged in the core sheet 39. In this case, the excrement can also diffuse in the width direction at the intervals between the raised portions.

[0158] Furthermore, by placing the aforementioned core-filled sheet 39 at the boundary between the upper core 31 and the lower core 32 (by making the concave and convex surfaces of the core-filled sheet 39 face the non-skin side of the upper core 31), the excretory fluid can be further diffused on the non-skin side of the upper core 31. However, the core-filled sheet 39 is not limited to a sheet with concave and convex surfaces.

[0159] Furthermore, the core cladding 39 is not limited to being disposed only at the boundary between the upper core 31 and the lower core 32. For example, it may also be as follows: Figure 9BAs shown, the core sheet 39 is arranged in such a way that it is rolled in from the non-skin side of the lower core 32 toward the skin side. With this configuration, the core sheet 39 can suppress misalignment of the lower core 32. Alternatively, it can be placed in areas other than the boundary between the upper core 31 and the lower core 32 (e.g., except for...). Figure 9B A core sheet 39 is disposed on the lower core 32 (excluding the p1 to p2 portions). With this configuration, the adhesive binding the core sheet 39 and the absorbent core 30 can be eliminated at the boundary between the upper core 31 and the lower core 32, improving the fluid permeability from the upper core 31 to the lower core 32. Additionally, it can be combined with... Figure 9B The core sheet 39 is arranged in reverse, rolling in from the skin-side to the non-skin-side of the lower core 32. In this case, even if the lower core 32 is completely rolled in, although the core sheet 39 is stacked, since the stacked area is located on the non-skin-side of the lower core 32, the liquid transfer from the upper core 31 to the lower core 32 is smoother compared to when it is placed between the upper core 31 and the lower core 32, thus inhibiting the accumulation of excretory fluid. Furthermore, the core sheet 39 can be placed either in part or around the upper core 31, or it can be omitted from the absorbent core 30.

[0160] Furthermore, the shape, number, and arrangement of the slots 35 in the upper core 31 and the slots 36 in the lower core 32 are not limited to... Figures 4-6 The illustrated structure. For example, in Figure 10B In the absorbent core 30, the grooves 35B and 36B on the side of the upper core 31 in the width direction are inclined inward toward the center of the length direction. Therefore, the front end of the absorbent core 30, which stands upright from the narrowest part of the lower core 32, can easily be deformed into an inverted triangular cup shape to cover the lower abdomen of the wearer, thus improving the fit of the diaper 1.

[0161] Additionally, for example, such as Figure 11A As shown, in the central portion of the absorbent core 30 along its length, secondary grooves 352 and 362 extend from the main grooves 351 and 361, while at the ends of the absorbent core 30 along its length, secondary grooves 352 and 362 are not provided. Furthermore, the ends of the lower core 32 along its length are designated as non-groove regions A4. This allows the area ratios of the groove regions A1 and A3 at the ends of the upper core 31 or the lower core 32 along its length to be smaller than the area ratios of the groove regions A1 and A3 in the central portion. This configuration helps to suppress misalignment of the absorbent core 30.

[0162] Alternatively, for example, it can also be like Figure 11BAs shown, the grooves 35 and 36 are extended to both ends of the upper core 31 and the lower core 32 along their length. This configuration allows the excreted liquid to diffuse further along its length. Alternatively, the absorbent core 30 may have continuous non-groove regions A22 and A43 in the width direction, positioned behind the central slit 37, running along the wearer's buttocks. Figure 11B Although not shown in the figure, the grooves 35 and 36 can be made to extend continuously from the front end to the rear end of the upper core 31 and the lower core 32 along their length direction.

[0163] Furthermore, the groove 35 of the upper core 31 and the groove 36 of the lower core 32 are not limited to having a predetermined length in the length direction; for example, they may also be grooves extending in other directions such as the width direction. Additionally, the groove 35 of the upper core 31 and the groove 36 of the lower core 32 may extend in different directions. Furthermore, when viewed in the thickness direction, the groove 35 of the upper core 31 and the groove 36 of the lower core 32 may not overlap at all. Additionally, the groove 35 of the upper core 31 and the groove 36 of the lower core 32 may not have grooves 352 and 362. Furthermore, groove regions A1 and A3 may not be provided in the areas where the upper core 31 and the lower core 32 do not overlap when viewed in the thickness direction.

[0164] <<Second Implementation Method>>

[0165] Figure 12 This is a cross-sectional schematic diagram of the absorbent core 30 in the second embodiment. The upper core 31 of the second embodiment is the same as the upper core 31 of the first embodiment. Furthermore, the lower core 32 of the second embodiment, like the lower core 32 of the first embodiment, has a groove 36 (lower groove) recessed from the non-skin side towards the skin side. However, in the second embodiment, the highly absorbent polymer 34 is evenly distributed throughout the lower core 32 (except for the fiber layers 313 and 323). That is, the average density difference of the highly absorbent polymer 34 in each part of the lower core 32 is equal, and smaller than the average density difference of the highly absorbent polymer 34 in each part of the upper core 31 (e.g., the groove region A1 and non-groove region A2 of the skin side 311).

[0166] In this case, the lower core 32 can also receive the excrement diffused in the upper core 31, and the excrement can be absorbed over a large area of ​​the lower core 32. Furthermore, when a fiber layer 323 is provided on the skin side of the lower core 32, the excrement can be further diffused in the planar direction on the skin side of the lower core 32. Moreover, since the highly absorbent polymer 34 is equally distributed in the groove region A3 and non-groove region A4 of the skin side 321, the diffused excrement can be directly transferred to the non-skin side 322. The excrement transferred to the non-skin side 322 diffuses in the longitudinal direction within the space of the groove 36 of the lower core 32, and the excrement can be absorbed over a large area of ​​the lower core 32. Additionally, in the case of the lower core 32 of the second embodiment, since there is no high SAP region on the skin side 321, even with repeated excretion, the high absorbent polymer 34 absorbing the excrement can prevent damage to fluid permeability.

[0167] Furthermore, although not illustrated, in a lower core 32 where highly absorbent polymer 34 is uniformly arranged, the groove 36 of the lower core 32 can also be an upper groove (a groove that is recessed from the skin side to the non-skin side). In this case, the excretory fluid received from the upper core 31 can diffuse in the space of the groove 36 of the lower core 32.

[0168] <<Third Implementation Method>>

[0169] Figure 13 This is a cross-sectional schematic diagram of the absorbent core 30 in the third embodiment. The upper core 31 of the third embodiment is the same as the upper core 31 of the first embodiment. In addition, the lower core 32 of the third embodiment does not have a groove 36, and highly absorbent polymer 34 is evenly distributed throughout the entire lower core 32 (except for the fiber layers 313 and 323). Although the lower core 32 is provided with a central slit 37, etc., it is more prone to misalignment than the upper core 31. However, since the lower core 32 of the third embodiment does not have a groove 36, misalignment of the lower core 32 is less likely to occur.

[0170] In this case, the lower core 32 can also receive the excrement diffused in the upper core 31, and the excrement can be absorbed over a large area of ​​the lower core 32. Furthermore, when a fiber layer 323 is provided on the skin side of the lower core 32, the excrement can be further diffused in the planar direction on the skin side of the lower core 32. Moreover, since the highly absorbent polymer 34 is evenly distributed on the skin side 321, the diffused excrement can be directly transferred to the non-skin side 322. Additionally, in the case of the lower core 32 of the third embodiment, since there is no high SAP region on the skin side 321, even with repeated excretion, the high absorbent polymer 34 absorbing the excrement can prevent damage to fluid permeability.

[0171] <<Implementation Method 4>>

[0172] Figure 14A as well as Figure 14B This is a cross-sectional schematic diagram of the absorbent core 30 in the fourth embodiment. The groove 35 of the upper core 31 in the fourth embodiment is the lower groove, unlike the upper core 31 in the first embodiment. In this case, also in the skin-side portion 311 of the upper core 31, the average density of the superabsorbent polymer 34 in the groove region A1 is lower than the average density of the superabsorbent polymer 34 in the non-groove region A2. With this configuration, the excretion fluid discharged to the upper core 31 is easily absorbed by the groove region A1, which is a low-SAP region. Furthermore, the excretion fluid transferred to the non-skin-side portion 312 (the space portion of the groove 35) of the groove region A1 diffuses along its length. Since the lower core 32 receives the excretion fluid diffused in the upper core 31, the excretion fluid can be absorbed over a large area of ​​the lower core 32.

[0173] When the slot 35 of the upper core 31 is a lower slot, the slot 36 of the lower core 32 can also be a lower slot. Figure 14A ), or it can be the upper slot ( Figure 14B Alternatively, it can be the lower core 32 described in the second or third embodiment.

[0174] In addition, such as Figure 14B As shown, by aligning the positions of the groove 35 (lower groove) of the upper core 31 and the groove 36 (upper groove) of the lower core 32, the space for temporarily storing the excretory fluid flowing through the skin side 311 of the upper core 31 is increased, allowing the stored excretory fluid to diffuse along the grooves 35 and 36. Therefore, even when a large amount of excretory fluid is excreted, overflow of excretory fluid onto the skin side of the upper core 31 can be prevented.

[0175] Furthermore, when the groove 35 of the upper core 31 is a lower groove, the upper core 31 tends to deform in a way that the central portion in the width direction protrudes towards the skin relative to the sides. As a result, the lower core 32 is facilitated by the deformation of the central slit 37, and the absorbent core 30 easily conforms to the wearer's crotch area. Conversely, when the groove 36 of the lower core 32 is an upper groove, the lower core 32 tends to deform in a way that the central portion in the width direction protrudes towards the non-skin side relative to the sides. This allows it to easily deform along the rounded shape of the buttocks.

[0176] <<Fifth Implementation Method>>

[0177] Figure 15 This is a schematic top view of the diaper 1 of the fifth embodiment, viewed from the side of the skin in its unfolded and stretched state. Figure 16 yes Figure 15 A schematic cross-sectional view at point A-A. Figure 17 This is a top view of the stacked upper core 31 and lower core 32 from the skin side in the thickness direction. Figure 18AThis is a top view of the upper core 31 viewed from the skin side in the thickness direction. Figure 18B This is a top view of the lower core 32 viewed from the skin side in the thickness direction. Figure 19 This is a top view of the absorbent core 30 of the modified example of the fifth embodiment, viewed from the skin side in the thickness direction.

[0178] like Figure 16 As shown, the upper core 31 of the fifth embodiment has a groove 35 (upper groove) that is recessed from the skin side of the upper core 31 toward the non-skin side in the thickness direction. For example... Figure 18B As shown, the lower core 32 has a central slit 37 and a pair of side slits 38, but does not have the groove that is part of the recess of the lower core 31.

[0179] like Figure 17 As shown, the absorbent core 30 has a "central portion in the width direction" and a pair of "side portions in the width direction" which are divided into three parts (three equal parts) by dividing its maximum width in the width direction. In addition, the absorbent core 30 has a "front side portion 30F" which is located in front of the product center line CL in the length direction and a "rear side portion 30B" which is located in rear of the product center line CL in the length direction.

[0180] The so-called product centerline CL (centerline) refers to the diaper 1 in its unfolded and stretched state. Figure 15 The absorbent core 30 is divided into two parts (bisections) along its length. Furthermore, the center of the absorbent core 30 along its length is not limited to being aligned with the product centerline CL; it can be offset. That is, the absorbent core 30 can also be positioned biased towards the front or back of the diaper 1. In this case, the front portion 30F and the back portion 30B have different lengths along their lengths.

[0181] Furthermore, the rear portion 30B of the absorbent core 30 has a region that divides its maximum length (from the center line CL of the product to the rearmost end of the absorbent core 30) into three equal parts along its length. The central region at this time is called "rear first region 30B1", the region that is forward of rear first region 30B1 is called "rear second region 30B2", and the region that is backward of rear first region 30B1 is called "rear third region 30B3".

[0182] Similarly, the front portion 30F of the absorbent core 30 has a region that is divided into three parts (equal parts) along its length direction, with its maximum length (from the center line CL of the article to the foremost point of the absorbent core 30). The central region at this time is called "front region 1 30F1", the region that is behind front region 1 30F1 is called "front region 2 30F2", and the region that is in front of front region 1 30F1 is called "front region 30F3".

[0183] In other words, in the following description, the rectangular area defined by the maximum width and maximum length of the absorbent core 10 is divided into a front region and a rear region in the length direction, with the product centerline CL as the boundary. Correspondingly, the absorbent core 30 is also divided into regions corresponding to the nine parts obtained by dividing the front region and the rear region into nine parts.

[0184] Furthermore, while the fifth embodiment exemplifies shorts-type diapers 1 as an absorbent article, the absorbent article of the fifth embodiment can also be applied to other absorbent articles such as belt-type diapers or absorbent pads. When applied to belt-type diapers or absorbent pads, the center line of the article is determined when they are unfolded along their length. Figure 17 The absorbent core is divided as shown.

[0185] As described in the first embodiment, the average density of the superabsorbent polymer 34 is lower on the skin-side portion of the groove region A1 of the upper core 31 compared to the skin-side portion of the non-groove region A2. Therefore, excrement from the wearer easily flows to the groove region A1, diffuses along the groove region A1, and is easily absorbed into the interior of the absorbent core 31. This configuration prevents unabsorbed excrement from overflowing from the surface of the diaper 1 and leaking to the outside. Furthermore, by allowing the excrement to diffuse, the upper core 31 can be effectively utilized over a wide area in the planar direction.

[0186] In particular, when the groove 35 of the upper core 31 is an upper groove, the excrement can immediately fall into the space of the groove 35, thus further suppressing the leakage (overflow) of the excrement. However, it may also be a lower groove as in the upper core 31 of the fourth embodiment. In this case, the excrement is easily absorbed from the skin side of the groove area A1, which is a low SAP area, into the interior of the absorbent core 30, thus suppressing the leakage of the excrement.

[0187] Furthermore, it can be used in conjunction with the first embodiment. Figure 7 Similarly, in the absorbent core 30 shown, the grooves 35 of the upper core 31 are not grooves compressed in the thickness direction. In the groove region A1, compared to the non-groove region A2, the unit area weight (g / m²) of the upper core 31 (absorbent fibers 33 and highly absorbent polymer 34) is higher. 2 Low. With this configuration, the drain liquid flows more easily to the tank area A1 and is easily absorbed from the tank area A1 into the interior of the absorbent core 31, which can suppress the leakage of the drain liquid.

[0188] Additionally, the unit area weight (g / m²) of the upper core 31 in the groove region A1 and the non-groove region A2 2The comparison can be confirmed using well-known methods. For example, after immersing the upper core 31 in liquid nitrogen and freezing it, a cross-section of the upper core 31, including the areas to be compared (groove region A1 and non-groove region A2), is obtained by cutting it in the thickness direction with a razor. After the upper core 31 returns to room temperature, the cross-sectional image is observed using an electron microscope, and the amount of material in the groove region A1 and non-groove region A2 can be compared visually or by counting the amount of material.

[0189] Furthermore, the manufacturing method for the upper core 31 (absorbent core 30), which has a lower weight per unit area in the groove region A1 than in the non-groove region A2, can be achieved, for example, by laminating the material of the upper core 31 onto a patterned plate with protrusions on the bottom surface corresponding to those in the groove region A1. Additionally, by controlling the amount of material (absorbent fibers 33 and highly absorbent polymer 34) supplied to the patterned plate, the weight per unit area and average density of the material can be controlled.

[0190] As described above, the excrement is easily absorbed into the interior of the absorbent core 30 through the groove region A1 of the upper core 31. However, the upper core 31 is thin in the groove region A1, and the density of the highly absorbent polymer 34 on the skin side 311 is low, or the overall weight per unit area of ​​the groove region A1 is low. Therefore, the excrement is prone to re-wetting.

[0191] Therefore, in the absorbent core 30 of the fifth embodiment, the value obtained by dividing the area of ​​the groove region A1 of the upper core 31 located at the center of the width direction of the rear first region 30B1 by the area of ​​the center of the width direction of the rear first region 30B1 is less than the value obtained by dividing the area of ​​the groove region A1 of the upper core 31 located at the center of the width direction of the front first region 30F1 by the area of ​​the center of the width direction of the front first region 30F1. Specifically, as Figure 17 As shown, in the center of the rear first region 30B1 in the width direction, there is only one main groove 351 that has a length in the length direction compared to the width direction. In contrast, in the center of the front first region 30F1 in the width direction, there are four main grooves 351.

[0192] The central portion of the rear first region 30B1 in the absorbent core 30, in the width direction, is a part where body pressure is easily applied when the wearer is in a seated or supine sleeping position. Therefore, by reducing the area ratio of the groove 35 in the central portion of the rear first region 30B1 in the width direction, even if strong body pressure is applied to the rear first region 30B1, the amount of back-wetting liquid from the groove region A1 can be reduced.

[0193] In contrast to the rear portion 30B, the front portion 30F of the absorbent core 30 is the part that comes into contact with the wearer's excretory opening and is easily drained of excrement, and it is also the part where body pressure is difficult to apply when the wearer sits down. In particular, compared to the second front region 30F2, which comes into contact with the wearer's crotch, and the third front region 30F3, which easily adheres to the wearer through the waist elastic members 211, 221 of the diaper 1, the first front region 30F1 is difficult to apply body pressure to. Therefore, by increasing the area ratio of the groove 35 in the central part of the first front region 30F1 in the width direction, a large amount of excrement drained by the wearer can be quickly guided from the groove region A1 into the interior of the absorbent core 30. In addition, since body pressure is difficult to apply, it is also difficult for moisture to return. In particular, when the wearer is male, the first front area 30F1 is more likely to come into contact with the wearer's excretory opening, thus more effectively absorbing the excretory fluid into the interior of the absorbent core 30.

[0194] Furthermore, the absorbent core 30 in the fifth embodiment is also, like the absorbent core 30 described in the previous embodiments, composed of an upper core 31 and a lower core 32 stacked together, with at least a portion of a groove region A1 provided in the overlapping portion of the upper core 31 and the lower core 32. That is, the groove region A1 is provided in the region where the upper core 31 and the lower core 32 are stacked, the absorbent core 30 has a high weight per unit area, and the retention force of the drained liquid is high. Therefore, even if a large amount of drained liquid is absorbed from the groove region A1 into the interior of the absorbent core 30, compared to a single-layer absorbent core, back-moisture from the groove region A1 can be suppressed.

[0195] In addition, Figure 17 The example shown is an absorbent core 30 in which the width and length of the upper core 31 are shorter than those of the lower core 32. However, this is not a limitation. For example, the lower core 32 may be shorter than the upper core 31 in both width and length directions, or the upper core 31 may be longer (or shorter) in width direction than the lower core 32 in width direction, while the upper core 31 may be shorter (or longer) in length direction than the lower core 32 in length direction. Figure 17 In the middle, the lower core 32 extends to both sides of the upper core 31 in the length direction. However, it is not limited to this. For example, the upper core 31 may extend to both sides of the lower core 32 in the length direction, or the lower core 32 may extend to the upper core 31 in the length direction on one side of the length direction, and the upper core 31 may extend to the lower core 32 in the length direction on the other side of the length direction.

[0196] Furthermore, most of the excreted liquid that is not absorbed by the absorbent core 30 at the discharge port abutment flows towards the rear side in the length direction through the central portion in the width direction of the absorbent core 30. Therefore, a groove 35 for the upper core 31 can be provided in the central portion in the width direction of the rear first region 30B1. However, this is a region where body pressure is easily applied and moisture easily returns. Therefore, it is preferable that, Figure 17 As shown, the upper core 31 located at the center of the rear first region 30B1 in the width direction has a region where only one main channel 351 is positioned, which has a length in the length direction but not in the width direction. That is, preferably, there is a region where multiple main channels 351 are not arranged in the width direction. With this configuration, the drain liquid flowing out from the drain port abutment portion can diffuse in the length direction and be absorbed into the interior of the absorbent core 30. Furthermore, the area ratio of the channel region A1 can be kept to a small value, and the amount of back moisture from the channel region A1 can be reduced.

[0197] In addition, with Figure 17 Alternatively, multiple main grooves 351 can be arranged in the width direction in a portion of the front side (near the discharge port contact portion) of the central part in the width direction of the rear first region 30B1. In addition, in the central part in the width direction of the rear first region 30B1, grooves 35 extending in a direction different from the length direction can be provided, or grooves 35 can be not provided at all.

[0198] Furthermore, the comparison of the area ratio of the grooved regions A1 of the upper core 31 and the confirmation of the number of grooved regions A1 can be performed by known methods. For example, when the grooved regions A1 can be visually confirmed by separating the absorbent core 30 (upper core 31) from the diaper 1 or exposing it, it can be done by methods known to the public. Figure 17 As shown, after dividing the absorbent core 30, the area ratio or quantity of the groove region A1 in the target area is compared visually. Alternatively, the groove region A1 (outline) can be determined from image data obtained by photographing the upper core 31 from the thickness direction, and the area of ​​the groove region A1 can be actually calculated and compared using area calculation software.

[0199] Furthermore, as mentioned above, the X-ray transmission decreases in areas where the highly absorbent polymer 34 overlaps significantly. Therefore, when the density (weight per unit area) of the highly absorbent polymer 34 in the groove region A1 is less than that in the non-groove region A2, the groove region A1 can be determined based on an image obtained by irradiating the upper core 31 with X-rays in the thickness direction. That is, a concentration difference exists between the groove region A1 and the non-groove region A2 in the X-ray image. Therefore, the groove region A1 can be determined visually based on the density of the X-ray image, and the area ratio or number of groove regions A1 in the target area can be compared. Alternatively, the groove region A1 (outline) can be determined by binarizing the X-ray image, and the area of ​​the groove region A1 can be actually calculated using area calculation software and compared.

[0200] Furthermore, most of the excreted liquid that is not absorbed by the absorbent core 30 at the discharge port contact portion flows towards the rear side in the length direction through the central portion in the width direction of the absorbent core 30. Therefore, it is preferable to increase the average unit area weight (g / m²) of the absorbent core 30 (upper core 31 and lower core 32) in the central portion in the width direction of the rear first region 30B1 compared to the pair of width-direction sides of the rear first region 30B1. 2 Specifically, such as Figure 17 As shown, in a portion of the width-direction side (rectangular region) of the rear first region 30B1, there is no upper core 31 or lower core 32. In contrast, in the width-direction central portion, there are upper core 31 and lower core 32 throughout the entire area (the entire rectangular region).

[0201] With this configuration, the absorbent core 30 in the central part of the rear first region 30B1 in the width direction can absorb and retain a large amount of excrement flowing out from the discharge port contact part. In addition, although the central part of the rear first region 30B1 in the width direction is a part where the wearer's body pressure is easily applied, it can suppress moisture return.

[0202] Furthermore, any discharged liquid that is not completely absorbed by the absorbent core 30 located in the central part of the rear first region 30B1 in the width direction tends to flow to the side in the width direction. Therefore, by providing the main channel 351 in the side in the width direction, the discharged liquid can be diffused in the length direction and absorbed into the interior of the absorbent core 30. As a result, leakage of the discharged liquid, especially side leakage, can be suppressed.

[0203] Furthermore, the comparison of the average weight per unit area of ​​the absorbent core 30 can be performed using well-known methods. For example, separating the absorbent core 30 from the diaper 1, such as... Figure 17The absorbent core 30 is divided as shown. Then, the absorbent core 30 (the laminate of the upper core 31 and the lower core 32) located at the center and side portions in the width direction of the rear first region 30B1 are cut off, and their respective weights (g) are measured. Additionally, the area a (m²) of the center portion in the width direction of the rear first region 30B1 is measured. 2 Furthermore, by dividing the weight (g) of the absorbent core 30 located at the center and side portions in the width direction of the rear first region 30B1 by the area a (m²),... 2 ), calculate the weight per unit area (g / m²) 2 ).

[0204] in addition, Figure 17 The illustrated upper core 31 has an hourglass shape in planar shape. The upper core 31 is narrowest in the front second region 30F2, and its width widens towards the front and rear sides in the longitudinal direction compared to the front second region 30F2. The narrow portion of the upper core 31 (front second region 30F2) becomes the abutment of the discharge port or a portion close to it. Therefore, a groove region A1 can be provided on the width-direction side of the portion that widens towards the rear side in the longitudinal direction compared to the narrow portion of the upper core 31.

[0205] With this configuration, as described above, the drained liquid flowing from the discharge port abutment portion through the central portion in the width direction of the absorbent core 30 to the rearward side, and any drained liquid not completely absorbed in the central portion in the width direction of the absorbent core 30, flows to the side portion in the width direction of the absorbent core 30. This drained liquid can be diffused through the tank area A1 and absorbed into the interior of the absorbent core 30. Therefore, leakage of the drained liquid, especially side leakage, can be suppressed.

[0206] In addition, preferably, such as Figure 18A As shown, between the groove region A1 of the upper core 31 located in the rear second region 30B2 and the groove region A1 of the upper core 31 located in the front second region 30F2 in the length direction, the upper core 31 has a non-groove region A2 that extends from one end to the other in the width direction.

[0207] With this configuration, in the front second region 30F2, which is the part that abuts or is close to the drain outlet, the drain liquid is absorbed into the interior of the absorbent core 30 through the tank region A1. This drain liquid is reliably absorbed and retained in the non-tank region A2, which is located further back than the front second region 30F2 and is the region where the absorbent core 30 has a higher weight per unit area, thus suppressing backflow. Furthermore, any drain liquid that is not completely absorbed by the absorbent core 30 located in the front second region 30F2 and flows to the rear side diffuses through the tank region A1 of the rear second region 30B2 and is absorbed into the interior of the absorbent core 30, thus suppressing leakage of the drain liquid.

[0208] Furthermore, it is preferable that the value obtained by dividing the area of ​​the groove region A1 of the upper core 31 located at the center of the width direction of the rear second region 30B2 by the area of ​​the center of the width direction of the rear second region 30B2 is greater than the value obtained by dividing the area of ​​the groove region A1 of the upper core 31 located at the center of the width direction of the rear first region 30B1 by the area of ​​the center of the width direction of the rear first region 30B1. Specifically, in the center of the width direction of the rear first region 30B1, only one main groove 351 with a length in the length direction relative to the width direction is provided, while in contrast, three main grooves 351 are provided in the center of the width direction of the rear second region 30B2.

[0209] In the second rear region 30B2 near the discharge port, by increasing the area ratio of the groove region A1, a large amount of excrement discharged by the wearer can be quickly absorbed into the interior of the absorbent core 30, thus suppressing leakage of the excrement. On the other hand, in the first rear region 30B1 where the wearer's body pressure is easily applied, by decreasing the area ratio of the groove region A1, back-wetting can be suppressed.

[0210] However, it is not limited to the above-mentioned structure; it can also be as follows: Figure 19 As shown in the variant example, the same number (one in this case) of main slots are provided in the central part of the rear second region 30B2 in the width direction as in the central part of the rear first region 30B1. For example, in cases where the wearer has a large amount of excretion, such as Figure 17 As shown, a large number of groove areas A1 can be provided in the center of the width direction of the second rear region 30B2. On the other hand, in the case of wearers with low excretion volume, even as Figure 19 The smaller number of groove areas A1 located in the center of the width direction of the second rear region 30B2, as shown, can also suppress leakage of the drain liquid.

[0211] Furthermore, it is preferable that, compared to the upper core 31 located at the center of the width direction in the second front region 30F2, the upper core 31 located at the center of the width direction in the first front region 30F1 has a large number of main grooves 351 that are longer in the length direction than in the width direction. Figure 17 In the upper core 31, two main grooves 351 are provided in the second front region 30F2, and four main grooves 351 are provided in the first front region 30F1. Preferably, the area ratio of the groove region A1 in the first front region 30F1 can be larger than the area ratio of the groove region A1 in the second front region 30F2.

[0212] As mentioned above, compared to the second front region 30F2 where the wearer's groin area abuts, the first front region 30F1 is less susceptible to body pressure from the wearer. Therefore, even with an increased number of main channels 351, the backflow of excrement can be suppressed. Furthermore, in the case of a male wearer, the more forward portion becomes the abutment part of the excrement opening. Therefore, by increasing the number of main channels 351 in the first front region 30F1, the large amount of excrement discharged from the excrement opening can be rapidly diffused through multiple main channels 351 and absorbed into the interior of the absorbent core 30, thus suppressing leakage of excrement.

[0213] Furthermore, a main trough 351 is provided at the center of the width direction of the first rear region 30B1 and the center of the width direction of the second rear region 30B2, on the center line dividing the rectangular area into two parts in the width direction. With this configuration, the discharge liquid flowing from the discharge port abutment part through the center of the width direction of the absorbent core 30 to the rear side can easily flow into the trough region A1 and be easily absorbed into the interior of the absorbent core 30.

[0214] In contrast, in the central part of the width direction of the first front region 30F1 and the central part of the width direction of the second front region 30F2, the main groove 351 is not provided on the center line dividing the rectangular area into two parts in the width direction, but the main groove 351 is provided on both sides. With this configuration, it is difficult for the wearer's excrement outlet to come into contact with the main groove 351, thus ensuring the unit area weight of the absorbent core 30 in the part that receives the largest amount of excrement liquid. As a result, back-moisture can be effectively suppressed.

[0215] In addition, diaper 1 Figure 15 As shown, the absorbent core 30 (absorbent body 10) has a pair of leak-proof wall portions 19 on both sides in the width direction, which can stand upright towards the skin. Specifically, as... Figure 16 As shown, the side panel 14 is folded back from the side portion of the back panel 13 in the width direction of the non-skin side towards the side portion of the surface panel 11 in the width direction of the skin side. At the end of the folded-back side panel 14 on the inner side in the width direction, the leak-proof wall elastic member 15 is fixed in a state of elongation in the length direction.

[0216] In addition, such as Figure 15As shown, the side panel 14 is joined to the skin side of the surface panel 11 via a first joint 191 and a second joint 192 coated with an adhesive or the like. The first joint 191 extends from one end of the absorbent body 10 along its length to the other end. The second joint 192 is located at both ends of the absorbent body 10 along its length, at a position closer to the first joint 191 in the width direction. Therefore, the portion of the side panel 14 that is closer to the skin side in the width direction than the first joint 191 (the support point) and closer to the length direction than the second joint 192 (the support point) can stand upright towards the skin, serving as a leak-proof wall portion 19.

[0217] In the case where the diaper 1 has a leak-proof wall portion 19, it is preferable that the diaper 1 in its unfolded and stretched state is viewed in the thickness direction. Figure 15 When the upper core 31 has a groove area A1 that overlaps with the leak-proof wall portion 19, the upper core 31 can absorb the drain liquid blocked by the leak-proof wall portion 19 from the groove area A1 into the interior of the absorbent core 30, and can prevent the drain liquid from leaking beyond the leak-proof wall portion 19.

[0218] Furthermore, in the area where the leak-proof wall portion 19 is provided, the wearer's skin does not directly contact the surface sheet 11, but rather through the side sheet 14. Therefore, even if excrement seeps back from the groove area A1 that overlaps with the leak-proof wall portion 19 in the thickness direction, the wearer is less likely to feel the moisture, preventing a decrease in the comfort of wearing the diaper 1. Additionally, the leak-proof wall portion 19, which rises towards the skin due to the contraction of the leak-proof wall elastic member 15, easily functions as a cushioning element, making it difficult to apply body pressure to the wearer in the area where the leak-proof wall portion 19 is provided. Therefore, even with the groove area A1 located where it overlaps with the leak-proof wall portion 19 in the thickness direction, moisture seepage can be suppressed.

[0219] In addition, preferably, such as Figure 16 As shown, when both the lower core 32 and the upper core 31 have highly absorbent polymer 34, the average density of the highly absorbent polymer 34 in the upper core 31 is higher than the average density of the highly absorbent polymer 34 in the lower core 32.

[0220] Compared to the excrement present between absorbent fibers, the excrement held by the superabsorbent polymer 34 is less likely to move freely and become damp again. Therefore, by increasing the average density of the superabsorbent polymer 34 at the upper core 31, the superabsorbent polymer 34 at the upper core 31 can reliably retain the excrement that is dampening from the lower core 32 to the upper core 31. Thus, even when wearer body pressure is applied to the absorbent core 30, dampness can be suppressed from the upper core 31 to the surface sheet 11.

[0221] Furthermore, the lower core 32 in the fifth embodiment is configured to have slits 37 and 38 but not the groove region A3 (groove 36), but it is not limited to this. For example, the lower core 32 may have both slits 37 and 38 and the groove region A3, or it may have the groove region A3 but not the slits 37 and 38.

[0222] When the lower core 32 has a grooved region A3, the area ratio of the grooved region A3 of the lower core 32 located in the central part of the width direction of the rear first region 30B1 can be set to be relatively small, similar to the upper core 31. For example, it can be smaller than the area ratio of the grooved region A3 of the lower core 32 located in the central part of the width direction of the front first region 30F1. With this configuration, the weight per unit area of ​​the absorbent core 30 (upper core 31 and lower core 32) located in the central part of the width direction of the rear first region 30B1 can be increased, and excrement can be reliably absorbed and retained. Therefore, even if the wearer's body pressure is strongly applied to the rear first region 30B1, the re-wetting of excrement can be suppressed. On the other hand, by increasing the area ratio of the groove region A3 of the lower core 32 in the central part of the width direction of the first region 30F1 on the front side, the stagnation of excrement at the boundary between the upper core 31 and the lower core 32 can be suppressed, and the excrement flowing through the upper core 31 can be quickly absorbed and diffused into the interior of the lower core 32. Therefore, leakage of excrement from the skin side of the diaper 1 when the upper core 31 has not completely absorbed the excrement can be prevented.

[0223] Furthermore, when viewing the absorbent core 30 in the thickness direction, the groove regions A1 of the upper core 31 and A3 of the lower core 32 can be either aligned or staggered. When aligned, the drained liquid absorbed from the groove region A1 of the upper core 31 can be rapidly absorbed into the interior of the lower core 32 and diffused through the groove region A3 of the lower core 32. Conversely, when the groove regions A1 and A3 are staggered, localized reduction in the weight per unit area of ​​the absorbent core 30 with each groove region A1 and A3 can be suppressed, and backflow of moisture from the groove regions A1 and A3 can be prevented.

[0224] The embodiments of the present invention have been described above. However, the above embodiments are intended to facilitate understanding of the present invention and are not intended to limit the scope of the invention. Furthermore, changes or modifications can be made to the present invention without departing from its concept, and the present invention naturally includes equivalent configurations.

[0225] For example, the lower core 32 is not limited to an absorbent core obtained by shaping the absorbent fiber 33 containing the highly absorbent polymer 34 into a predetermined shape. The lower core 32 may also be a SAP sheet obtained by attaching the SAP layer to a hydrophilic sheet, or an air-laid sheet obtained by shaping the absorbent fiber into a sheet using an air-laid method.

[0226] Explanation of reference numerals in the attached figures

[0227] 1 (Shorts type) Diaper (Absorbent item), 2 Joint, 10 Absorbent body, 11 Surface sheet, 12 Middle sheet, 13 Back sheet, 14 Side sheet, 15 Leak-proof elastic member, 16 Leg elastic member, 17 Crotch elastic member (elastic member), 18 Cover sheet, 20 Outer garment member, 21 Front waist section, 22 Back waist section, 23 Crotch section, 211, 221 Waist elastic member, 212, 222 Leg elastic member, 30 Absorbent core, 31 Upper core, 32 Lower core, 33 Absorbent fiber, 34 High absorbent polymer, 35 Groove, 36 Groove (second groove), 37 Central slit (slit), 38 Side slit, 39 Core cover, A1 Groove area, A2 Non-groove area, A3 Groove area (second groove area), A4 Non-groove area (second non-groove area).

Claims

1. An absorbent article having a length direction, a width direction, and a thickness direction, and having an absorbent core, characterized in that, The aforementioned absorbent core includes an upper core having a highly absorbent polymer and a lower core disposed on the non-skin side in the thickness direction compared to the upper core. The aforementioned upper core has a groove in which a portion of the upper core is recessed in the aforementioned thickness direction. The aforementioned groove has a length in a specified direction. When viewed in the aforementioned thickness direction, the upper core layer has a grooved area with the aforementioned grooves and a non-groove area without the aforementioned grooves. When viewed in the aforementioned thickness direction, at least a portion of the aforementioned groove region is provided in the area where the upper core and the lower core overlap. When the upper core is divided into two parts along the aforementioned thickness direction, the part located on the skin side is designated as the skin-side portion, and the part located on the non-skin side is designated as the non-skin-side portion. In this case... The average density of the highly absorbent polymer on the skin side of the aforementioned groove region is lower than the average density of the highly absorbent polymer on the skin side of the aforementioned non-groove region. The above-mentioned absorbent core It has a central portion in the width direction and a pair of side portions in the width direction, which are divided into three parts by dividing its maximum width in the aforementioned width direction. Furthermore, the absorbent article, when divided into two parts along its length direction, has a front portion whose center line is located at the front of the length direction and a rear portion whose center line is located at the rear of the length direction, compared to the expanded and stretched state. The aforementioned rear portion has a first rear region that serves as the central region when its maximum length is divided into three parts along the aforementioned length direction. The aforementioned front portion has a first front region that serves as the central region when its maximum length is divided into three parts along the aforementioned length direction. The value obtained by dividing the area of ​​the groove region of the upper core located at the center of the width direction of the rear first region by the area of ​​the center of the width direction of the rear first region is less than the value obtained by dividing the area of ​​the groove region of the upper core located at the center of the width direction of the front first region by the area of ​​the center of the width direction of the front first region. The average weight per unit area of ​​the absorbent core at the central portion of the rear first region in the width direction is higher than the average weight per unit area of ​​the absorbent cores at the pair of side portions of the rear first region in the width direction. The upper core, located on a pair of width-direction sides of the aforementioned rear first region, includes a groove having a length in the aforementioned length direction, which is the aforementioned defined direction.

2. The absorbent article as claimed in claim 1, characterized in that, The upper core located in the central part of the width direction of the aforementioned rear first region has a region in which only one groove with a length in the length direction that is the aforementioned specified direction is provided.

3. The absorbent article as claimed in claim 1, characterized in that, The aforementioned rear portion has a second rear portion located on the front side of the aforementioned rear portion in the longitudinal direction, which is closer to the first rear portion than the first rear portion. The aforementioned front portion has a second front region located rearward in the longitudinal direction than the aforementioned first front region. Between the groove region of the upper core located in the rear second region in the aforementioned length direction and the groove region of the upper core located in the front second region, the upper core has a region where the non-groove region extends from one end to the other in the aforementioned width direction.

4. The absorbent article as claimed in claim 1, characterized in that, The aforementioned rear portion has a second rear portion located on the front side of the aforementioned rear portion in the longitudinal direction, which is closer to the first rear portion than the first rear portion. The value obtained by dividing the area of ​​the groove region of the upper core located at the center of the width direction of the rear second region by the area of ​​the center of the width direction of the rear second region is greater than the value obtained by dividing the area of ​​the groove region of the upper core located at the center of the width direction of the rear first region by the area of ​​the center of the width direction of the rear first region.

5. The absorbent article as claimed in claim 1, characterized in that, The aforementioned front portion has a second front region located rearward in the longitudinal direction than the aforementioned first front region. Compared with the upper core located at the center of the width direction of the aforementioned front second region, the upper core located at the center of the width direction of the aforementioned front first region includes a greater number of grooves having a length in the aforementioned length direction, which is the aforementioned defined direction.

6. The absorbent article as claimed in claim 1, characterized in that, The aforementioned absorbent article has a pair of leak-proof walls on both sides of the absorbent core in the width direction, which can stand upright towards the skin. When the absorbent article is viewed in its unfolded and stretched state in the aforementioned thickness direction, the upper core has at least a portion of the groove area that overlaps with the aforementioned leak-proof wall portion.

7. The absorbent article as claimed in claim 1, characterized in that, The aforementioned lower core layer contains a highly absorbent polymer. The average density of the highly absorbent polymer in the upper core is higher than the average density of the highly absorbent polymer in the lower core.

8. The absorbent article as claimed in claim 1, characterized in that, The average density of the highly absorbent polymer on the non-skin side of the non-groove region is lower than the average density of the highly absorbent polymer on the skin side of the non-groove region.

9. The absorbent article as claimed in claim 1, characterized in that, The groove described above is a groove that is recessed from the skin side of the upper core towards the non-skin side in the thickness direction.

10. The absorbent article as claimed in claim 9, characterized in that, The average density of the highly absorbent polymer on the non-skin side of the aforementioned groove region is lower than the average density of the highly absorbent polymer on the skin side of the aforementioned non-groove region.

11. The absorbent article as claimed in claim 10, characterized in that, In addition to the aforementioned highly absorbent polymer, the upper core also contains absorbent fibers. The average density of the absorbent fibers on the non-skin side of the non-groove region is higher than the average density of the absorbent fibers on the non-skin side of the groove region.

12. The absorbent article as claimed in claim 1 or 2, characterized in that, The aforementioned lower core layer contains a highly absorbent polymer. When the lower core is divided into two parts along the aforementioned thickness direction, the part located on the skin side is designated as the skin-side portion, and the part located on the non-skin side is designated as the non-skin-side portion. In this case... In at least a portion of the lower core, the average density of the highly absorbent polymer on the skin side of a certain region of the lower core is higher than the average density of the highly absorbent polymer on the non-skin side of a region of the upper core opposite to that region.

13. The absorbent article as claimed in claim 1, characterized in that, The aforementioned groove includes a main groove having a length in the aforementioned length direction, which is the aforementioned defined direction, and a secondary groove extending from the main groove in the aforementioned width direction. Multiple main slots are arranged at intervals in the aforementioned width direction. The plurality of the aforementioned slots are spaced apart in the aforementioned length direction and extend from the aforementioned main slot in the aforementioned width direction.

14. The absorbent article as claimed in claim 1, characterized in that, The aforementioned lower core has a highly absorbent polymer and a second groove in which a portion of the lower core is recessed in the thickness direction. The second groove described above has a length in the aforementioned length direction. When viewed in the aforementioned thickness direction, the lower core layer has a second groove region where the second groove is provided and a second non-groove region where the second groove is not provided. When viewed in the aforementioned thickness direction, at least a portion of the aforementioned second groove region is provided in the area where the upper core and the lower core overlap. When the lower core is divided into two parts along the aforementioned thickness direction, the part located on the skin side is designated as the skin-side portion, and the part located on the non-skin side is designated as the non-skin-side portion. In this case... The average density of the highly absorbent polymer on the skin side of the second groove region is lower than the average density of the highly absorbent polymer on the skin side of the second non-groove region.

15. The absorbent article as claimed in claim 14, characterized in that, The average density of the highly absorbent polymer on the non-skin side of the second non-groove region is lower than the average density of the highly absorbent polymer on the skin side of the second non-groove region.

16. The absorbent article as claimed in claim 14 or 15, characterized in that, The second groove mentioned above is a groove that is recessed from the non-skin side of the lower core towards the skin side in the thickness direction.

17. The absorbent article as claimed in claim 14, characterized in that, When viewed in the aforementioned thickness direction, the aforementioned groove region of the upper core has a portion that overlaps with the aforementioned second groove region of the lower core.

18. The absorbent article as claimed in claim 1, characterized in that, The lower core has a slit extending through it in the thickness direction at the center of the area where it abuts the wearer's crotch. The aforementioned slit has a length in the aforementioned longitudinal direction. When viewed in the aforementioned thickness direction, the aforementioned slit of the lower core overlaps with the aforementioned upper core, and at least a portion of the region of the aforementioned slit of the lower core does not overlap with the aforementioned groove region of the aforementioned upper core.

19. The absorbent article as claimed in claim 18, characterized in that, An elastic member that stretches and contracts along the aforementioned length direction is provided in the area where the wearer's crotch area abuts. When viewed in the aforementioned thickness direction, none of the regions of the aforementioned slits in the lower core layer overlap with the aforementioned groove regions of the upper core layer. When viewed in the aforementioned thickness direction, the aforementioned slit has a portion that overlaps with the aforementioned elastic member.

20. The absorbent article as claimed in claim 18 or 19, characterized in that, The aforementioned groove region has a length in the length direction that is defined above. The upper core layer, located behind the slit in the longitudinal direction, has a region where the non-groove area extends continuously from one end to the other in the width direction. In the aforementioned length direction, the rear end of the lower core is located on the rear side compared to the rear end of the upper core.

Images