Absorbent article

Abstract

To suppress a grainy touch of superabsorbent polymer particles and increase an absorption amount.SOLUTION: An absorbent article comprises an absorbent sheet 50 between a top sheet 22 and an absorber 23. The absorbent sheet 50 includes housing parts 55 and 56 for housing superabsorbent polymer particles 53 between an upper sheet 51 and a lower sheet 52 with liquid permeability, and a joint part 54 surrounding the housing parts 55 and 56. The absorber 23 includes a first area h1 with a first surface height A1 and a second area h1 with a second surface height h2 lower than the first surface height A2, The absorbent sheet 50 includes a first housing part 55 containing 200 g / m2 or less of superabsorbent polymer particles 53, and a second housing part 56 containing more superabsorbent polymer particles 53 than that of the first housing part 55, where the second housing part 56 is located only on the second area A2, and a difference between the first surface height h1 and the second surface height h2 is equal to or more than the thickness of the second housing part 56 when not absorbing yet.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] This invention relates to absorbent articles, including disposable diapers and sanitary napkins. [Background technology]

[0002] This type of absorbent article comprises a crotch area, front and rear portions extending from the front and rear sides of the crotch area, an absorbent body extending from the crotch and rear portions, and a liquid-permeable top sheet provided on the surface of the absorbent body. Its basic function is to absorb and retain excretory fluids such as urine that have permeated the top sheet into the absorbent body.

[0003] In absorbent articles, it is known that back leakage (leakage from the rear of the absorbent article) can be reduced by increasing the absorption capacity of the rear portion. Furthermore, as one method for increasing such absorption capacity, it is known that an absorbent sheet having a liquid-permeable upper sheet and lower sheet, a containment portion in which superabsorbent polymer particles are contained between the upper sheet and the lower sheet, and a joint portion arranged to surround this containment portion is placed between the top sheet and the absorbent material (see, for example, Patent Document 2).

[0004] However, if the amount of superabsorbent polymer particles in the absorbent sheet is increased in order to increase the amount of absorption, the gritty feeling of the superabsorbent polymer particles (hereinafter referred to as "grittiness") may be more easily transmitted when the skin is pressed against the surface of the top sheet, which may lead to a deterioration in the wearing comfort. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2019-88465 [Patent Document 2] Japanese Patent Publication No. 2005-253851 [Overview of the project] [Problems that the invention aims to solve]

[0006] Therefore, the main objective of the present invention is to increase the amount of absorption by the absorbent sheet while suppressing the gritty feeling caused by highly absorbent polymer particles. [Means for solving the problem]

[0007] The absorbent articles that solve the above problems are as follows: <First aspect> A crotch area, and a front portion and a rear portion extending from the front and rear sides of the crotch area, The absorbent material extending over the crotch area and the rear portion, The absorbent body comprises a liquid-permeable top sheet provided on its surface, The absorbent material is a mixed aggregate of superabsorbent polymer particles and short fibers. An absorbent sheet is provided between the top sheet and the uppermost surface of the absorbent material. The absorbent sheet comprises a liquid-permeable upper sheet and a lower sheet, a containment portion between the upper sheet and the lower sheet in which highly absorbent polymer particles are contained, and a joint portion arranged to surround the containment portion. Disposable diapers, The absorbent has a first region having a first surface height and a second region having a second surface height lower than the first surface height. The absorbent sheet is either an empty containment area that does not contain the superabsorbent polymer particles, or contains the superabsorbent polymer particles at a concentration of 200 g / m². 2 It has a first containment section containing the following, and a second containment section containing more of the superabsorbent polymer particles than the first containment section, The second housing is located only on the second region, The difference between the first surface height and the second surface height is greater than or equal to the thickness of the second accommodating portion when it is not absorbed. An absorbent article characterized by the following features.

[0008] (Effects and Benefits) In this absorbent article, when the skin is pressed against the surface of the top sheet, the first region, which is most likely to come into contact with the skin, has no or very few superabsorbent polymer particles in the first containment area, so a gritty feeling is less likely to be transmitted to the skin. Furthermore, in the second region, which has a second containment area with a large amount of superabsorbent polymer particles, the surface height of the absorbent material is lower than that of the first region, and the difference between the surface heights of the first and second regions is greater than or equal to the thickness of the second containment area when unabsorbed. As a result, when the skin is pressed against the surface of the top sheet, the first region supports the skin, and the skin is less likely to be pressed against the absorbent sheet of the second region, thus reducing the gritty feeling transmitted to the skin even on the second region. Moreover, since the amount of superabsorbent polymer particles in the second containment area on the second region can be increased, it is possible to increase the absorption amount while suppressing the gritty feeling caused by the absorbent polymer particles.

[0009] <Second aspect> The absorbent material has a two-layer structure consisting of an upper absorbent and a lower absorbent. The lower absorbent has a rear side region that extends to the side beyond the side edges of the upper absorbent, located behind the crotch area. The first region is the region where the upper absorber and the lower absorber overlap, and the second region is the rear side region. An absorbent article according to the first embodiment.

[0010] (Effects and Benefits) It is known that absorbents are made into a two-layer structure to ensure sufficient absorption, and that the central side is made higher than the sides to ensure a good fit to the buttocks. However, in these cases, there are limitations to ensuring sufficient absorption without compromising the fit. Therefore, it is preferable to utilize the low surface height of the rear side region, as in this embodiment, to position the second accommodating section of the absorbent sheet.

[0011] <Third aspect> The top sheet is provided with lift-up gathers on both sides in the width direction of the surface, The aforementioned rising gathers cover the entire upper part of the second region when unfolded. A second embodiment of an absorbent article.

[0012] (Function and Effect) In absorbent articles that require a certain amount of absorption, rising gathers (generally referred to as three-dimensional gathers) are often provided on both sides in the width direction. Therefore, it is also preferable to utilize these rising gathers to configure the article to cover the entire upper part of the second region in the unfolded state as in this embodiment. As a result, when the skin is pressed against the surface of the topsheet, even if the skin is weakly pressed against the absorbent sheet in the second region, the rising gathers serve as a buffer material, making it difficult for the feeling of stiffness to be transmitted to the skin even on the second region.

[0013] <Fourth Aspect> Taking the boundary between the first region and the second region as the folding position, the side having the second region is folded back above the first region. At the folding position, the first accommodating portion and the second accommodating portion are not located, and the joining portion is located. An absorbent article according to any one of the first to third aspects.

[0014] (Function and Effect) For example, in a product with a two-layer structure as described above, at the boundary between the central region where the upper absorbent body and the lower absorbent body overlap and the rear side region with only the lower absorbent body, after folding the side portion lateral to the boundary onto the central region, it is often sold in a folded state with three folds or two folds in the front-rear direction. However, if an accommodating portion containing superabsorbent polymer particles is located at the folding position, as a result, a large amount of superabsorbent polymer particles are constrained at the folding position, and there is a possibility that the feeling of stiffness is likely to be transmitted during use. In contrast, when, as in this embodiment, a joining portion instead of an accommodating portion is arranged at the folding position, such a problem can be prevented.

[0015] <Fifth Aspect> The second accommodating portion has at least one first accommodating portion adjacent to it. Part or all of the boundary joining portion located at the boundary between the first accommodating portion and the second accommodating portion is configured to peel off due to the expansion pressure when the superabsorbent polymer particles in the accommodating portion adjacent to the boundary joining portion absorb excreted liquid and expand. An absorbent article in any one of the first to fourth embodiments.

[0016] (Effects and Benefits) When the superabsorbent polymer particles in the containment section absorb and expand, filling the containment section, the upper and lower sheets at the joint can be strongly bonded to prevent the joint around the containment section from separating due to the internal pressure. However, when the superabsorbent polymer particles fill the containment section, there is a risk that the amount and rate of absorption will decrease due to so-called gel blocking (a reduction in the gaps between the superabsorbent polymer particles, preventing the wastewater from reaching the superabsorbent polymer particles inside) and inhibition of expansion. This problem is particularly likely to occur in the second containment section, which contains a larger amount of superabsorbent polymer particles. Therefore, as in this embodiment, it is preferable that part or all of the boundary joint between the first containment section and the second containment section is detachable due to the expansion pressure of the adjacent containment section. As a result, when the superabsorbent polymer particles that have absorbed wastewater and expanded fill at least one of the first and second containment sections, the boundary joint separates, the adjacent first and second containment sections merge, and a combined containment section with an expanded volume is formed. Here, the volume of the combined containment section is greater than the sum of the volumes of the first and second containment sections, and since there are no or only a small amount of superabsorbent polymer particles in the first containment section, gel blocking and absorption inhibition are less likely to occur. In addition, the superabsorbent polymer particles that have absorbed the excretory fluid become gel-like, so they no longer cause a gritty feeling.

[0017] <Sixth aspect> When the maximum volume of the first containment section is defined as the first volume, the volume of the superabsorbent polymer particles contained in the first containment section at absorption saturation is defined as the first volume, the maximum volume of the second containment section is defined as the second volume, and the volume of the superabsorbent polymer particles contained in the second containment section at absorption saturation is defined as the second volume, The first volume is smaller than the second volume. The first volume is larger than the first volume, and the expansion pressure when the superabsorbent polymer particles in the first containment absorb the excrement and expand causes a part or all of the boundary joint located at the boundary between the first containment and the second containment to peel off, The second volume is larger than the second volume, and the expansion pressure when the superabsorbent polymer particles in the second containment absorb the excretory fluid and expand causes part or all of the boundary joint to peel off. A fifth embodiment of an absorbent article.

[0018] (Effects and Benefits) In this embodiment, the boundary joint is preferable because it separates due to the absorption and expansion of either the first or second housing portion. [Effects of the Invention]

[0019] As described above, the present invention offers advantages such as being able to increase the amount of absorption by the absorbent sheet while suppressing the gritty feeling caused by highly absorbent polymer particles. [Brief explanation of the drawing]

[0020] [Figure 1] This is a plan view showing the inner surface of a pad-type disposable diaper in its unfolded state. [Figure 2] This is a plan view showing only the essential parts. [Figure 3] This is a cross-sectional view of the YY direction in Figure 1. [Figure 4] This is a cross-sectional view of XX in Figure 1. [Figure 5] This is a ZZ cross-sectional view of Figure 1. [Figure 6] This is a plan view showing the absorbent sheet. [Figure 7] (a) A cross-sectional view of VV in Figure 6, and (b) a cross-sectional view of WW. [Figure 8] This is a plan view showing the various arrangements of the storage compartments. [Figure 9] This is a plan view showing the absorbent sheet. [Figure 10]This is a cross-sectional view corresponding to the ZZ section in Figure 1. [Figure 11] This is a cross-sectional view corresponding to the ZZ section in Figure 1. [Figure 12] This is a plan view showing only the essential parts. [Modes for carrying out the invention]

[0021] The following provides a detailed explanation of a pad-type disposable diaper 200 as an example of an absorbent article, referring to the attached drawings. The term "crotch area C2" refers to the part that corresponds to the crotch of the body during use. Depending on the product, this may be the area from the center or vicinity of the front-to-back LD of the article to a predetermined front part, as shown in the illustrated form, or a predetermined range in the center of the front-to-back LD of the article. If the article has a narrow constricted portion 23n in the middle of the front-to-back LD of the article or the absorbent body 23 in the middle of the front-to-back LD, it refers to the minimum width portion of either one or both of the constricted portions 23n, or a predetermined front-to-back LD range with the minimum width portion as the center of the front-to-back LD. Furthermore, "front portion F2 (ventral portion)" refers to the part in front of the crotch area C2, and "rear portion B2 (dorsal portion)" refers to the part behind the crotch area C2.

[0022] Each adjacent component in the thickness direction is fixed or joined as necessary, in the same way as known diapers, even in addition to the fixing or joining parts described below. The dotted pattern in the cross-sectional view indicates adhesives such as hot melt adhesives used as fixing or joining means. Hot melt adhesives can be applied by known methods such as slot coating, continuous linear or dotted bead coating, spiral, Z-shaped, or wavy spray coating, or pattern coating (transfer of hot melt adhesive using a relief printing method). Alternatively, or in conjunction with these methods, in the fixing parts of elastic members, hot melt adhesive can be applied to the outer surface of the elastic member to fix the elastic member to the adjacent member. Examples of hot melt adhesives include EVA-based, adhesive rubber-based (elastomer-based), polyolefin-based, and polyester / polyamide-based adhesives, but they can be used without particular limitation. As fixing or joining means for joining each component, material welding methods such as heat sealing or ultrasonic sealing can also be used. In parts where liquid permeability in the thickness direction is required, adjacent components in the thickness direction are fixed or joined in an intermittent pattern. For example, when performing such intermittent fixing or joining using hot melt adhesive, intermittent pattern coating such as spiral, Z-shaped, or wavy can be suitably used. When coating an area wider than the coating width of a single nozzle, intermittent pattern coating such as spiral, Z-shaped, or wavy can be performed with or without spacing in the width direction. As a joining means for joining each component, material welding methods such as heat sealing or ultrasonic sealing can also be used.

[0023] Furthermore, in the following description, known nonwoven fabrics can be used as appropriate depending on the part and purpose. The constituent fibers of the nonwoven fabric can be selected without particular limitation, including, for example, polyolefin-based fibers such as polyethylene or polypropylene, polyester-based fibers, polyamide-based fibers, etc. (including single-component fibers as well as composite fibers such as core-sheath fibers), regenerated fibers such as rayon and cupro, and natural fibers such as cotton, and these can also be used in mixtures. To increase the flexibility of the nonwoven fabric, it is preferable to use crimped fibers as constituent fibers. In addition, the constituent fibers of the nonwoven fabric may be hydrophilic fibers (including fibers that have become hydrophilic due to a hydrophilizing agent), hydrophobic fibers, or water-repellent fibers (including fibers that have become water-repellent due to a water-repellent agent). Furthermore, nonwoven fabrics are generally classified according to the length of the fibers, the sheet formation method, the fiber bonding method, and the lamination structure into short fiber nonwoven fabrics, long fiber nonwoven fabrics, spunbond nonwoven fabrics, meltblown nonwoven fabrics, spunlace nonwoven fabrics, thermal bond (air-through) nonwoven fabrics, needle punch nonwoven fabrics, point bond nonwoven fabrics, and laminated nonwoven fabrics (including SMS nonwoven fabrics and SMMS nonwoven fabrics, etc., which have a meltblown layer sandwiched between spunbond layers), and any of these nonwoven fabrics can be used.

[0024] Figures 1 to 4 show a pad-type disposable diaper 200 as an example of an absorbent article. This pad-type disposable diaper 200 has a crotch area C2 and front and rear portions F2 and B2 extending on both sides of it. The dimensions of each part can be determined as appropriate. For example, the total length of the article (length in the front-to-back direction) L can be about 350 to 700 mm, and the total width W1 can be about 130 to 400 mm (however, wider than the width of the absorbent surface of the diaper). In this case, the front-to-back length of the crotch area C2 can be about 10 to 150 mm, the front-to-back length of the front portion F2 can be about 50 to 350 mm, and the front-to-back length of the rear portion B2 can be about 50 to 350 mm. The width W3 of the crotch area C2 can be 150 mm or more, especially 200 to 260 mm, for example, in the case of an adult.

[0025] This pad-type disposable diaper 200 has a basic structure that includes an absorbent material 23 between a liquid-impermeable sheet 21 and a liquid-permeable top sheet 22.

[0026] On the back side of the absorbent 23, a liquid-impermeable sheet 21 is provided so as to slightly protrude from the periphery of the absorbent 23. As the liquid-impermeable sheet 21, in addition to polyethylene film, a sheet that provides moisture permeability without compromising water impermeability can also be used to prevent stuffiness. This water-impermeable and moisture-permeable sheet can be a microporous sheet obtained by melt-kneading an inorganic filler into an olefin resin such as polyethylene or polypropylene to form a sheet, and then stretching it in a uniaxial or biaxial direction.

[0027] Furthermore, the outer surface of the liquid-impermeable sheet 21 is covered with an outer sheet 27 made of nonwoven fabric, and this outer sheet 27 extends outward from the periphery of the liquid-impermeable sheet 21 with a predetermined overhang width. Various nonwoven fabrics can be used as the outer sheet 27. The outer sheet 27 can also be omitted.

[0028] The front side of the absorbent material 23 is covered with a liquid-permeable top sheet 22. In the illustrated configuration, a portion of the absorbent material 23 protrudes from the side edge of the top sheet 22, but the width of the top sheet 22 can be widened so that the side edge of the absorbent material 23 does not protrude. Various nonwoven fabrics can be used as the top sheet 22. One preferred nonwoven fabric for the top sheet 22 is an air-through nonwoven fabric made by hot-air bonding thermoplastic synthetic fibers.

[0029] An intermediate sheet (not shown) can be interposed so as to be in contact with the back surface of the top sheet 22. This intermediate sheet is provided to prevent the urine absorbed by the absorbent material 23 from flowing back, and it is desirable to use a material with low water retention and high liquid permeability, such as various nonwoven fabrics or mesh films. When the front end of the top sheet 22 is set to 0% and the rear end of the top sheet 22 is set to 100%, the front end of the intermediate sheet is preferably located in the range of 0 to 11%, and the rear end of the intermediate sheet is preferably located in the range of 92 to 100%. Furthermore, the width of the intermediate sheet is preferably about 50 to 100% of the total width W3 of the absorbent material 23. The intermediate sheet can also be omitted.

[0030] At both ends of the front-to-back LD of the pad-type disposable diaper 200, the liquid-impermeable sheet 21, the outer sheet 27, and the top sheet 22 extend beyond the front-to-back ends of the absorbent body 23 and are bonded together, forming an end flap section EF where the absorbent body 23 is absent. On both sides of the pad-type disposable diaper 200, the liquid-impermeable sheet 21 and the outer sheet 27 extend outward from the side edges of the absorbent body 23. On the inner surface of the portion from this extended portion to the side of the top sheet 22, the outer fixing portion 24x of the gather sheet 24s in the width direction WD, which forms the rise-up gather 24, is bonded over the entire front-to-back LD, forming a side flap section SF where the absorbent body 23 is absent. These bonded portions are shown as a dot pattern in Figure 1 and can be formed by hot-melt adhesive, heat sealing, or ultrasonic sealing. If the outer sheet 27 is not provided, a liquid-impermeable sheet 21 can be extended to the side flap portion SF in place of the outer sheet 27, forming the outer surface of the side flap portion SF.

[0031] While plastic sheets and meltblown nonwoven fabrics can be used as materials for the Gather Sheet 24s, nonwoven fabrics treated with silicone or similar materials are preferable in terms of skin feel.

[0032] The portion 24c on the widthwise central side of the gathered sheet 24s extends onto the top sheet 22, and an elongated elastic member 24G is fixed to its widthwise central end in an extended state along the front-to-back direction using hot melt adhesive or the like. As this elongated elastic member 24G, commonly used materials such as styrene rubber, polyolefin rubber, urethane rubber, ester rubber, polyurethane, polyethylene, polystyrene, styrene-butadiene, silicone, and polyester can be used, formed in the form of threads, strings, or strips.

[0033] Both gathered sheets 24s have their outer fixing portions 24x in the width direction bonded and fixed to the inner surface of the article (the surface of the top sheet 22 and the inner surface of the outer sheet 27 in the illustrated configuration) over the entire length in the front-to-back direction, while the central portion 24c in the width direction is bonded and fixed to the inner surface of the article (the surface of the top sheet 22 in the illustrated configuration) at both ends in the front-to-back direction, but is not fixed to the inner surface of the article (the surface of the top sheet 22 in the illustrated configuration) between the two ends in the front-to-back direction. This unfixed portion is a leak-proof wall that elastically stands up against the inner surface of the article (the surface of the top sheet 22 in the illustrated configuration), and its starting point 24b is located at the boundary between the outer fixing portion 24x in the width direction and the inner portion 24c of the gathered sheet 24s.

[0034] The pad-type disposable diaper 200 in this example has an absorbent body 23 that absorbs and retains the liquid portion of excrement, consisting of an upper absorbent body 23A located on the outermost side and a lower absorbent body 23B located on the back side. The number of layers of the absorbent body 23 is not particularly limited and can be a single layer as shown in Figure 11, or three or more layers as not shown. The absorbent body 23 can preferably be a mixed aggregate made by mixing and accumulating hydrophilic short fibers such as pulp fibers and superabsorbent polymer particles.

[0035] The superabsorbent polymer particles contained in the absorbent body 23 can be those used in this type of absorbent article. For example, when sieving is performed using a 500 μm standard sieve (JIS Z8801-1:2006) (shaking for 5 minutes), and the particles that fall below this sieving are then sieved again using a 180 μm standard sieve (JIS Z8801-1:2006) (shaking for 5 minutes), it is desirable that the proportion of particles remaining on the 500 μm standard sieve is 30% by weight or less, and the proportion of particles remaining on the 180 μm standard sieve is 60% by weight or more. When multiple absorbents are stacked, such as when there is an upper absorbent body 23A and a lower absorbent body 23B, superabsorbent polymer particles with different particle size distributions can be used in each absorbent body.

[0036] Furthermore, while there are no particular limitations on the superabsorbent polymer particles, those with a water absorption rate of 20 to 50 seconds and a water absorption capacity of 50 to 80 g / g are preferably used. Examples of superabsorbent polymer particles include starch-based, containment rose-based, and synthetic polymer-based materials. Examples include starch-acrylic acid (salt) graft copolymers, saponified starch-acrylonitrile copolymers, crosslinked sodium carboxymethyl containment roses, and acrylic acid (salt) polymers.

[0037] The absorbent body 23 can be wrapped in a packaging sheet 26, such as crepe paper, which has liquid permeability and liquid retention properties, as needed to maintain its shape and the presence of highly absorbent polymer particles, thereby forming an integrated absorbent element. When multiple absorbent bodies are stacked, such as when there is an upper absorbent body 23A and a lower absorbent body 23B, each absorbent body can be wrapped individually in a packaging sheet, or multiple absorbent bodies can be wrapped together in a single packaging sheet. In some cases, the packaging sheet 26 may be omitted.

[0038] The dimensions of the absorbent body 23 in the front-to-back direction and width direction can be determined as appropriate, as long as at least one of them extends to the crotch and rear portions. Typically, it is preferable that the absorbent body 23 extends from the front portion F2 to the rear portion B2. When the absorbent body has a two-layer structure, the upper absorbent body 23A can have the same dimensions as the lower absorbent body 23B, but as shown in the illustrated example, it is desirable that the total length and width of the upper absorbent body 23A are shorter than those of the lower absorbent body 23B. Typically, the total length of the upper absorbent body 23A can be about 60-90% of the total length of the lower absorbent body 23B, and the total width of the upper absorbent body 23A can be about 60-90% of the total width of the lower absorbent body 23B.

[0039] The total basis weight (sum of short fibers and superabsorbent polymer particles) of the absorbent material 23 can be determined as appropriate. For example, in the case of a single-layer absorbent material 23, the total basis weight is 500 to 2000 g / m². 2 It can be set to a certain extent, and in the case of a two-layer absorbent 23, the total basis weight of the upper absorbent 23A is 200-700 g / m². 2 It can be set to a certain extent, and the total basis weight of the lower absorbent 23B is 200-700 g / m². 2 It can be considered to be of a certain degree.

[0040] The proportion of superabsorbent polymer particles in the absorbent body 23 can be determined as appropriate. For example, in the case of a single-layer absorbent body 23, it can contain 0.4 to 1.5 times (by weight) the amount of superabsorbent polymer particles compared to the short fibers. In the case of a double-layer absorbent body 23, the upper absorbent body 23A can contain 0.5 to 2.0 times (by weight) the amount of superabsorbent polymer particles compared to the short fibers, and the lower absorbent body 23B can contain 0.2 to 1.0 times (by weight) the amount of superabsorbent polymer particles compared to the short fibers. The thickness of the absorbent body 23 (excluding the region having grooves, which will be described later) is not particularly limited. For example, in the case of a single-layer absorbent body 23, its thickness can be about 5 to 30 mm. In the case of a double-layer absorbent body 23, the thickness of the upper absorbent body 23A can be about 2.5 to 20 mm, and the thickness of the lower absorbent body 23B can be about 2.5 to 20 mm.

[0041] The overall shape of the absorbent body 23 can be determined as appropriate, and it can be rectangular, but it is preferable that it has a narrow constricted portion 23n in the middle of the front-to-back direction LD including the crotch area C2. When the absorbent body has a two-layer structure, it is preferable that at least the larger absorbent body 23 (lower absorbent body 23B in the illustrated example) has a predetermined portion in the middle of the front-to-back direction including the crotch area C2 formed as a narrow constricted portion 23n. The minimum width W5 of this constricted portion 23n is preferably about 50-65% of the width W3 of the non-constricted portions located before and after the constricted portion 23n. Furthermore, when the front end of the article is set to 0% and the rear end of the article to 100%, it is preferable that the front end of the constricted portion 23n is located in the range of 10-25%, the rear end of the constricted portion 23n is located in the range of 40-65%, and the part of the constricted portion 23n that has the minimum width W5 (minimum width part) is preferably located in the range of 25-30%.

[0042] The absorbent body 23 has a first region A1 having a first surface height h1 and a second region A2 having a second surface height h2 that is lower than the first surface height h1. The absorbent body 23 in the illustrated example has a two-layer structure consisting of an upper absorbent body 23A and a lower absorbent body 23B. The lower absorbent body 23B has a rear side region 23S that extends to the sides beyond the side edges of the upper absorbent body 23A, behind the crotch area C2. Therefore, in this case, the region 23M where the upper absorbent body 23A and the lower absorbent body 23B overlap becomes the first region A1, and the rear side region becomes the second region A2.

[0043] Furthermore, as shown in the illustrated example, if a groove 23D extending in the front-to-back direction LD is provided on the uppermost surface of the absorbent 23 across the crotch area C2 and the rear portion B2 (the groove 23D can also be omitted), In the region where the upper absorber 23A and the lower absorber 23B overlap, the portion without the groove 23D becomes the first region A1 having a first surface height h1, and the bottom of the groove 23D becomes the second region A2 having a second surface height h2. Note that, as shown in the examples in Figures 10 and 11, if a slit is provided that penetrates the absorber 23 from its top surface to its bottom surface in the thickness direction, the surface height of the absorber 23 in the slit portion is 0. Therefore, in this case, the slit portion becomes the second region A2 having a second surface height h2 that is lower than the first surface height h1.

[0044] The groove 23D can be formed by making the basis weight of the region of the absorber 23 having the groove 23D lower than the rest of the absorber, or by forming it on the upper surface of the absorber 23 by compression processing such as embossing. For example, as shown in Figures 3 to 5, a slit is provided that penetrates from the upper surface to the lower surface of the upper absorber 23A in the thickness direction, and the lower absorber 23B does not have a slit, so that the basis weight of the region having the groove 23D is lower than the rest of the upper absorber 23A and the lower absorber 23B as a whole. In this case, the bottom surface of the groove 23D is formed by the upper surface of the lower absorber 23B. Alternatively, as shown in Figure 10, by providing a slit that penetrates from the upper surface of the upper absorber 23A to the lower surface of the lower absorber 23B in the thickness direction, the basis weight of the region having the groove 23D is lower than the rest of the upper absorber 23A and the lower absorber 23B as a whole. In this case, the bottom surface of the groove 23D is formed by the liquid-impermeable sheet 21. Similarly, in the case of a single-layer absorbent 23, as shown in Figure 11, the basis weight of the region having grooves 23D in the absorbent 23 can be made lower than the other parts by providing a slit that penetrates from the top surface to the bottom surface in the thickness direction. In this case as well, the bottom surface of grooves 23D is formed by a liquid-impermeable sheet 21. The above examples show examples in which slits are provided in the absorbent 23, but instead of slits, grooves 23D can also be formed by making the accumulation amount of short fibers and superabsorbent polymer particles lower than the surrounding area. In this case, the bottom surface of grooves 23D is formed by the surface of the absorbent 23 having grooves 23D.

[0045] The width W2 of the groove 23D can be determined as appropriate, but is usually preferably 15 to 40 mm, and particularly preferably 20 to 30 mm. The total length of the groove 23D can be determined as appropriate, but is usually preferably 0.2 to 0.75 times the total length Y1 of the absorber 23, and particularly preferably 0.35 to 0.6 times. The depth D2 of the groove 23D can be determined as appropriate, but in the unabsorbed, unfolded state, is preferably 0.4 to 1 times the thickness 23t of the absorber 23 (the sum of the thicknesses of all absorbers 23 if there are multiple layers of absorbers 23), and particularly preferably 0.5 to 0.7 times.

[0046] As shown in Figures 5 to 7, an absorbent sheet 50 is provided between the top sheet 22 and the uppermost surface of the absorbent material 23. The absorbent sheet 50 has a liquid-permeable upper sheet 51 and lower sheet 52, a containment section 55, 56 between the upper sheet 51 and lower sheet 52 in which superabsorbent polymer particles 53 are contained, and a joint section 54 arranged to surround the containment section 55, 56. The portions of the upper sheet 51 and lower sheet 52 located in the containment section 55, 56 are not joined. The containment section 55, 56 contains superabsorbent polymer particles 53 at a density of 200 g / m². 2 The following (more preferably 30-150 g / m²) 2 The device has a first containment section 55 containing ) and a second containment section 56 containing more (preferably 2 to 8 times the basis weight) superabsorbent polymer particles 53 than the first containment section 55. Part or all of the first containment section 55 may be an empty containment section that does not contain superabsorbent polymer particles 53.

[0047] Furthermore, the second accommodating portion 56 is located only on the second region A2, and it is preferable that the difference between the first surface height h1 and the second surface height h2 is greater than or equal to the thickness of the second accommodating portion 56 when unabsorbed (more preferably 1.1 to 2.2 times). In this case, when the skin is pressed against the surface of the top sheet 22, there are no highly absorbent polymer particles 53 or only a very small number of them in the first accommodating portion 55 on the first region A1 that is most likely to come into contact with the skin, so the gritty feeling is less likely to be transmitted to the skin. Furthermore, in the second region A2, which has a second storage section 56 with a large amount of superabsorbent polymer particles 53, the surface height of the absorbent material 23 is lower than that of the first region A1, and the difference between the first surface height h1 and the second surface height h2 is greater than or equal to the thickness of the second storage section 56 when unabsorbed. As a result, when the skin is pressed against the surface of the top sheet 22, the first region A1 supports the skin, and the skin is less likely to be pressed against the absorbent sheet 50 in the second region A2. Consequently, the gritty feeling is less likely to be transmitted to the skin even on the second region A2. Moreover, since the amount of superabsorbent polymer particles 53 in the second storage section 56 on the second region A2 can be increased, the amount of absorption can be increased while suppressing the gritty feeling caused by the absorbent polymer particles. In particular, as shown in the illustrated example, when the central side is formed higher than the side sides to consider the fit to the buttocks, there is a limit to how much absorption can be secured without compromising the fit. Therefore, it is preferable to utilize the low surface height of the rear side region 23S to position the second storage section 56 of the absorbent sheet 50 as described above.

[0048] Furthermore, in products requiring a certain level of absorption, it is common to provide lift-up gathers 24 (generally called three-dimensional gathers) on both sides of the width direction WD, as shown in the illustrated example. Therefore, it is also preferable to use these lift-up gathers 24 to cover the entire upper part of the second region A2 when it is unfolded. As a result, when the skin is pressed against the surface of the top sheet 22, even if the skin is lightly pressed against the absorbent sheet 50 of the second region A2, the lift-up gathers 24 act as a buffer, making it less likely for the gritty feeling to be transmitted to the skin on the second region A2.

[0049] As shown in the illustrated example, by distributing and holding the superabsorbent polymer particles 53 in multiple containment sections 55 and 56, uneven distribution of the superabsorbent polymer particles 53 in the absorbent sheet 50 can be prevented. The number of first containment sections 55 and second containment sections 56 may be one each, but depending on the arrangement of the first region A1 and the second region A2, multiple first containment sections 55 can be arranged in the first region A1 with at least the length of the joint 54 in between, or multiple second containment sections 56 can be arranged in the second region A2 with at least the length of the joint 54 in between, together with or instead of the first containment sections 55.

[0050] The planar arrangement of the containment sections 55, 56 (and similarly the group of superabsorbent polymer particles 53) can be determined as appropriate, but a regularly repeating planar arrangement is preferred. For example, as shown in Figure 6, it is preferable to adopt an arrangement in which multiple rows of containment sections 55, 56 are arranged with a predetermined spacing in the width direction WD, with spacing in the front-to-back direction LD (including staggered arrangements as shown in the illustrated example, as well as matrix arrangements, etc.). The containment sections 55, 56 can be arranged without gaps with the joint section 54 as the boundary. In this case, examples of arrangements of the containment sections 55, 56 include a rhombic lattice as shown in Figure 8(a), a hexagonal lattice as shown in Figure 8(b) (these are also called staggered arrangements), a square lattice as shown in Figure 8(c), a rectangular lattice as shown in Figure 8(d), and a parallelepiped lattice as shown in Figure 8(e) (as shown in the illustration, two groups of numerous parallel diagonal rows intersect each other) (including those inclined at an angle of less than 90 degrees with respect to the expansion and contraction direction). When the housing sections 55 and 56 are arranged with a relatively large gap between them, as shown in Figure 6, all parts other than the housing sections 55 and 56 can be made into joint sections 54. However, as shown in Figure 9, joint sections 54 may be provided in an annular shape along the outer circumference of each housing section 55 and 56, and non-jointed sections that substantially do not contain superabsorbent polymer particles 53 may be provided between adjacent annular joint sections 54.

[0051] If the first housing section 55 is placed only on the first region A1, an arrangement of housing sections 55 and 56 can be selected such that the boundary junction 54, located at the boundary between the first housing section 55 and the second housing section 56, is positioned at the boundary between the first region A1 and the second region A2. For example, if the boundary between the first region A1 and the second region A2 extends linearly along the front-rear direction LD, as shown in the illustrated example, an arrangement can be adopted in which multiple rows of housing sections 55 and 56 are arranged with spacing in the front-rear direction LD and spacing in the width direction WD, with the boundary junction 54 extending linearly along the front-rear direction LD, as shown in Figures 6 and 8(c) and 8(d). On the other hand, if a part of the first housing section 55 adjacent to the boundary junction 54 is placed on the second region A2, an arrangement of housing sections 55 and 56 can be adopted such that the boundary junction 54 is zigzag, as shown in Figures 8(a), 8(b), and 8(e).

[0052] In products with a two-layer structure, such as the example shown in Figure 5, as shown in Figure 12, the product is often sold in a folded state where the portion 202 to the side of the boundary 201 between the central region where the upper absorbent 23A and the lower absorbent 23B overlap and the rear side region 23S consisting only of the lower absorbent 23B is folded over onto the central region, and then folded in thirds or in half in the front-to-back direction LD. However, if the housing sections 55 and 56 containing superabsorbent polymer particles 53 are located at the folding position, the superabsorbent polymer particles 53 are largely constrained at the folding position, which may result in a gritty feeling being easily transmitted during use. This problem is particularly pronounced when the product is folded over at a position that passes through the second housing section 56, which contains a large amount of superabsorbent polymer particles 53. Therefore, when folding the side having the second region A2 over the first region A1, using the boundary 201 between the first region A1 and the second region A2 as the folding position, it is preferable to position the joining portion 54 at the folding position instead of the first housing portion 55 and the second housing portion 56, as this can prevent such problems.

[0053] To facilitate the arrangement of the superabsorbent polymer particles 53 during manufacturing and to ensure volume after absorption and expansion, at least one of the upper sheet 51 and lower sheet 52 in the containment sections 55 and 56 may be a recess that is recessed to the outside of the containment sections 55 and 56 when unfolded. However, as shown in Figures 5 to 7, there may be no recess, and the superabsorbent polymer particles 53 may simply be sandwiched between the upper sheet 51 and the lower sheet 52. The recess can be formed by shaping the target sheet, such as by embossing. The depth of the recess is not particularly limited, but it is preferably 1.0 to 7.0 mm, and especially preferably 1.0 to 5.0 mm.

[0054] The upper sheet 51 and lower sheet 52 are not particularly limited as long as they are made of liquid-permeable material, similar to the top sheet 22. Since the upper sheet 51 and lower sheet 52 affect the absorption rate, dry nonwoven fabrics made from hydrophilic fibers, especially natural fibers such as cotton and pulp, are particularly suitable for the upper sheet 51 and lower sheet 52. Among these, airlaid pulp nonwoven fabrics with 70% or more pulp by weight (the remainder when it is less than 100% by weight can be appropriate synthetic fibers) are particularly suitable. The method of forming the web of the nonwoven fabric is not particularly limited, but in order to prevent the detachment of the superabsorbent polymer particles 53, methods that increase the fiber density, such as the spunbond method and the meltblown method, are preferred. In addition, the fineness, basis weight and thickness of the nonwoven fabric should be approximately 2.0 to 7.0 dtex and 18 to 50 g / m², respectively. 2 A thickness of approximately 0.10 to 0.60 mm is preferable.

[0055] The planar shape of the storage sections 55 and 56 can be determined as appropriate, and can be a hexagon, rhombus, square, rectangle, circle, ellipse, etc. The area between adjacent storage sections 55 and 56 may be a joint 54 throughout, but since the joint 54 has low or no liquid permeability, the joint 54 may be provided only at positions along the edges of the storage sections 55 and 56 in the area between adjacent storage sections 55 and 56, and the remaining parts may be areas where the upper sheet 51 and lower sheet 52 are not joined. In addition to arranging storage sections 55 and 56 of the same planar shape and dimensions, multiple types of storage sections 55 and 56 with at least one different shape and dimension can also be combined and arranged, although this is not shown.

[0056] The dimensions of each storage section 55, 56 can be determined as appropriate; for example, the width dimension WD 55x can be approximately 14 to 38 mm. The front-to-back dimension LD 55y can be approximately 15 to 200 mm. The area of ​​each storage section 55, 56 is 210 to 7600 mm². 2 The spacing between adjacent storage compartments in the front-to-back direction (55d, or minimum spacing if it varies) can be approximately 5 to 30 mm. As shown in the example in Figure 6, when there are multiple rows of storage compartments in the width direction, the spacing between adjacent rows of storage compartments in the width direction (55e, or minimum spacing if it varies) can be approximately 5 to 30 mm.

[0057] The joint portion 54 is arranged to surround each housing portion 55, 56 and, insofar as it forms a boundary between adjacent housing portions 55, 56, it can be formed in a continuous linear shape or in a dotted linear shape (discontinuously in the direction surrounding each housing portion 55, 56). It is preferable that there are no superabsorbent polymer particles 53 in the region between adjacent housing portions 55, 56, or if there are, there are fewer than in the housing portions 55, 56.

[0058] The dimensions of the joint 54 can be determined as appropriate, but if the area is large, it may result in a hard texture, so in the case of intermittent joints 54, it is preferable that each joint 54 is small, and in the case of continuous joints 54, it is preferable that each joint 54 is narrow.

[0059] The joint 54 can be a welded joint formed by welding the upper sheet 51 and the lower sheet 52 together, for example, by ultrasonic welding or heat sealing, or it can be an adhesive joint formed by joining them via a hot melt adhesive. The joint 54 may not peel off due to the expansion pressure of the superabsorbent polymer particles 53 in the adjacent containment portion, but except for the edge joint 54E closest to the periphery of the absorbent sheet, it may peel off due to the expansion pressure of the superabsorbent polymer particles 53 in the adjacent containment portion.

[0060] Whether or not the joint 54 can be peeled off can be determined by the relationship between the expansion pressure and the bonding strength of the joint 54. Furthermore, the degree of expansion pressure can be adjusted by the relationship between the maximum volume of the containment sections 55 and 56 and the volume of the superabsorbent polymer particles 53 contained therein at absorption saturation (determined by the content of superabsorbent polymer particles 53), and the bonding strength of the joint 54 can be adjusted by the size of the area of ​​the joint 54, the strength of the welding, the type of adhesive, etc. For example, if the joint 54 is to not be peeled off due to the expansion pressure of the superabsorbent polymer particles 53 in the containment sections 55 and 56 adjacent to the joint 54, then the volume of the superabsorbent polymer particles 53 contained in the containment sections 55 and 56 at absorption saturation should be smaller than the maximum volume of the containment sections 55 and 56 adjacent to the joint 54. Conversely, if the separation is to occur due to the expansion pressure of the superabsorbent polymer particles 53 in the housing sections 55 and 56 adjacent to the joint 54, then the volume of the superabsorbent polymer particles 53 at absorption saturation contained in the housing sections 55 and 56 should be greater than the maximum volume of the housing sections 55 and 56 adjacent to the joint 54. In the former case, the housing sections 55 and 56 that satisfy this size relationship must be both of the pair of housing sections 55 and 56 adjacent to each other with respect to the joint 54, but in the latter case, it may be just one or both of the pair of housing sections 55 and 56 adjacent to each other with respect to the joint 54. For example, if neither the upper sheet 51 nor the lower sheet 52 has recesses that are recessed on the outside of the housing sections 55 and 56 when unfolded, and the superabsorbent polymer particles 53 are simply sandwiched between the upper sheet 51 and the lower sheet 52, then in order to prevent the joint 54 from peeling, the basis weight of the superabsorbent polymer particles 53 in each housing section 55 and 56 should be, for example, 100 to 300 g / m².2 It can be set to, and in order to peel the joint part 54, the basis weight of the superabsorbent polymer particles 53 in the first accommodating part 55 is, for example, 30 to 150 g / m 2 It can be set to, and the basis weight of the superabsorbent polymer particles 53 in the second accommodating part 56 is, for example, 130 to 300 g / m 2 It can be set to this.

[0061] When the superabsorbent polymer particles 53 in the accommodating parts 55 and 56 absorb and expand and fill the accommodating parts 55 and 56, if the upper sheet 51 and the lower sheet 52 at the joint part 54 are strongly joined so that the joint part 54 is not peeled off by the internal pressure, when the superabsorbent polymer particles 53 fill the accommodating parts 55 and 56, there is a risk that the absorption amount and absorption rate will decrease due to so-called gel blocking (the gaps between the superabsorbent polymer particles 53 decrease and the excreted liquid cannot spread to the internal superabsorbent polymer particles 53) and expansion inhibition. Particularly, such a problem is likely to occur in the second accommodating part 56 containing a larger amount of superabsorbent polymer particles 53. Therefore, it is preferable that a part or all of the boundary joint part 54 between the first accommodating part 55 and the second accommodating part 56 can be peeled off by the expansion pressure of the adjacent accommodating parts 55 and 56. As a result, when the superabsorbent polymer particles 53 that have absorbed and expanded by absorbing the excreted liquid fill at least one of the first accommodating part 55 and the second accommodating part 56, the boundary joint part 54 is peeled off, and the adjacent first accommodating part 55 and second accommodating part 56 are combined to form a combined accommodating part 55 and 56 with an enlarged volume. Here, the volume of the combined accommodating parts 55 and 56 is larger than the sum of the volumes of the first accommodating part 55 and the second accommodating part 56, and since there are no or only a small amount of superabsorbent polymer particles 53 in the first accommodating part 55, gel blocking and absorption inhibition are less likely to occur. In addition, since the superabsorbent polymer particles 53 that have absorbed the excreted liquid become gel-like, they no longer bring a granular feeling.

[0062] In this case, since the first housing section 55 contains a small amount of superabsorbent polymer particles 53, if the first volume is about the same as the second volume, it is difficult to separate the boundary joint 54 by the expansion pressure in the first housing section 55 alone. Therefore, it is preferable that the boundary joint 54 be separated by the absorption and expansion of either the first housing section 55 or the second housing section 56. Specifically, it is preferable that the maximum volume of the first containment section 55 is defined as the first volume, the volume of the superabsorbent polymer particles 53 contained in the first containment section 55 when absorption saturates is defined as the first volume, the maximum volume of the second containment section 56 is defined as the second volume, and the volume of the superabsorbent polymer particles 53 contained in the second containment section 56 when absorption saturates is defined as the second volume, in which case the first volume is smaller than the second volume, and the first volume is larger than the first volume, so that when the superabsorbent polymer particles 53 in the first containment section 55 absorb excrement and expand, the expansion pressure causes a part or all of the boundary joint 54 located at the boundary between the first containment section 55 and the second containment section 56 to peel off, and also that the second volume is larger than the second volume, so that when the superabsorbent polymer particles 53 in the second containment section 56 absorb excrement and expand, the expansion pressure causes a part or all of the boundary joint 54 to peel off.

[0063] As long as the second storage section 56 is located only on the second region A2, the first storage section 55 may be located only on the first region A1, or it may be located on both the first region A1 and the second region A2. For example, in the example with the groove 23D shown in Figure 5, the bottom of the groove 23D is the second region A2, and the first storage section 55 can be provided on it. Conversely, as shown in Figure 11, the second storage section 56 can also be provided on the bottom of the groove 23D. Although not shown, by combining these, the second storage section 56 can also be provided on the bottom of the groove 23D in the example shown in Figure 5. Also, although not shown, both the second storage section 56 and the first storage section 55 can be arranged on a single second region A2.

[0064] As shown in Figure 5, the absorbent sheet 50 may be arranged so that one sheet covers multiple second regions A2, or, as shown in Figure 10, if there are multiple second regions A2, multiple absorbent sheets 50 can be arranged.

[0065] <Explanation of terms used in the specification> When the following terms are used in this specification, they have the following meanings unless otherwise specified in the specification.

[0066] "Front-back direction" refers to the direction indicated by the symbol LD in the diagram (vertical direction), and "width direction" refers to the direction indicated by WD in the diagram (left-right direction). The front-back direction and the width direction are orthogonal to each other.

[0067] • "MD direction (machine direction or line flow direction)" and "CD direction (lateral direction perpendicular to the MD direction)" refer to the "MD direction" and "CD direction" of the processing equipment, with one being the front-to-back direction and the other being the width direction. Furthermore, the MD direction in the product is the direction of fiber orientation of the nonwoven fabric. Fiber orientation is the direction along which the fibers of the nonwoven fabric run, and can be determined, for example, by a measurement method conforming to the fiber orientation test method by zero-distance tensile strength of the TAPPI standard method T481, or by a simple measurement method that determines the fiber orientation direction from the ratio of tensile strength in the front-to-back direction and the width direction. In the illustrated form, the front-to-back direction is the MD direction and the width direction is the CD direction, similar to most disposable diaper products.

[0068] "Front side" refers to the side that is closer to the wearer's skin when worn, while "back side" refers to the side that is further away from the wearer's skin when worn.

[0069] "Surface" refers to the side of a material that is closer to the wearer's skin when worn, while "back" refers to the side that is further away from the wearer's skin when worn.

[0070] "Area ratio" refers to the proportion of the target portion to a unit area. It is calculated by dividing the total area of ​​the target portion (for example, the portion where the containment area is formed in an unabsorbed absorbent sheet) within the target area by the area of ​​the target area and expressing it as a percentage. In configurations where many target portions are provided at intervals, it is desirable to set the target area to a size that includes three or more target portions and then calculate the area ratio.

[0071] • "Elongation rate" refers to the value relative to the natural length, which is set at 100%. For example, an elongation rate of 200% is equivalent to an elongation ratio of 2.

[0072] "Weight" is measured as follows: After pre-drying the sample or test piece, leave it in a test room or apparatus under standard conditions (temperature 23°C, relative humidity 50°C) to reach a constant weight. Pre-drying means bringing the sample or test piece to a constant weight in an environment of 100°C. Note that pre-drying is not necessary for fibers with an official moisture content of 0.0%. Using a sample-taking template (100mm x 100mm) from the test piece that has reached a constant weight, cut out a sample of dimensions 100mm x 100mm. Measure the weight of the sample, multiply it by 100 to calculate the weight per square meter, and this is the weight.

[0073] The "thickness" of the absorber is measured using a thickness measuring instrument from Ozaki Seisakusho Co., Ltd. (Peacock, large dial thickness gauge, model JB (measurement range 0-35 mm) or model K-4 (measurement range 0-50 mm)), with the sample and the thickness measuring instrument held horizontally.

[0074] • For "thickness" other than that specified above, an automatic thickness measuring instrument (KES-G5 handy compression measurement program) was used, with a load of 0.098 N / cm². 2 , and pressure area: 2cm 2 Automatic measurement is performed under these conditions.

[0075] • Water absorption is measured according to JIS K7223-1996 "Test method for water absorption of superabsorbent polymers".

[0076] The water absorption rate shall be the "time to the endpoint" when 2 g of superabsorbent polymer and 50 g of physiological saline solution are used in the JIS K7224-1996 "Test method for water absorption rate of superabsorbent polymers".

[0077] "Artificial urine" is a mixture of urea: 2 wt%, sodium chloride: 0.8 wt%, calcium chloride dihydrate: 0.03 wt%, magnesium sulfate heptahydrate: 0.08 wt%, and deionized water: 97.09 wt%, and should be used at a temperature of 40 degrees Celsius unless otherwise specified.

[0078] "Deployed state" refers to a state in which the body is unfolded flat without any contraction (including contraction due to elastic members, etc.) or slack.

[0079] Unless otherwise specified, the dimensions of each part refer to the dimensions in the unfolded state, not the natural length state.

[0080] Unless otherwise specified, the tests and measurements shall be conducted in a test room or apparatus under standard conditions (temperature 23±1°C, relative humidity 50±2%). [Industrial applicability]

[0081] The present invention can be used not only for pad-type disposable diapers as in the above example, but also for tape-type disposable diapers, pant-type disposable diapers, and other types of disposable diapers, regardless of their form. It can also be used for absorbent articles other than disposable diapers, such as sanitary napkins. [Explanation of Symbols]

[0082] 200...Pad-type disposable diaper, 21...Liquid-impermeable sheet, 22...Top sheet, 23...Absorbent core, 23A...Upper absorbent core, 23B...Lower absorbent core, 23D...Groove, 23S...Rear side area, 24...Stand-up gather, 24s...Gather sheet, 26...Packaging sheet, 27...Outer sheet, 50...Absorbent sheet, 51...Upper sheet, 52...Lower sheet, 53...Superabsorbent polymer particles, 54...Joint, 55, 56...Storage area, 55...First storage area, 56...Second storage area, A1...First area, A2...Second area, B2...Rear side part, C2...Crotch area, F2...Front side part, LD...Front-to-back direction, WD...Width direction, h1...First surface height, h2...Second surface height.

Claims

1. a crotch portion, a front portion and a rear portion extending to the front and rear of the crotch portion, respectively; an absorbent body extending across the crotch portion and the rear portion; A liquid-permeable top sheet provided on the front side of the absorbent body, The absorbent body is a mixed aggregate of superabsorbent polymer particles and short fibers, an absorbent sheet is provided between the top sheet and the uppermost surface of the absorbent body; The absorbent sheet has a liquid-permeable upper sheet and a lower sheet, a storage section between the upper sheet and the lower sheet in which superabsorbent polymer particles are stored, and a joining section arranged so as to surround the storage section. A disposable diaper, the absorbent body has a first region having a first surface height and a second region having a second surface height that is lower than the first surface height; The absorbent sheet is an empty storage portion that does not contain the superabsorbent polymer particles, or the superabsorbent polymer particles are contained in an amount of 200 g / m 2 and a second storage section containing more of the superabsorbent polymer particles than the first storage section, the second accommodating portion is located only on the second region, a difference between the first surface height and the second surface height is equal to or greater than a thickness of the second storage section before absorption; An absorbent article characterized by:

2. The absorbent body has a two-layer structure of an upper absorbent body and a lower absorbent body, the lower absorbent body has rear side regions that extend laterally beyond both side edges of the upper absorbent body, rearward of the crotch region; The first region is a region where the upper absorbent body and the lower absorbent body overlap, and the second region is the rear side region. The absorbent article of claim 1.

3. The top sheet has rising gathers provided on both sides of the surface in the width direction, The rising gathers cover the entire upper part of the second region in a deployed state. The absorbent article according to claim 2.

4. The side having the second region is folded back above the first region with the boundary between the first region and the second region as a folding position, At the folding position, the first storage section and the second storage section are not positioned, and the joint section is positioned. The absorbent article according to any one of claims 1 to 3.

5. The second storage section has at least one first storage section adjacent thereto, a part or all of the boundary joining portion located at the boundary between the first storage portion and the second storage portion is configured to be peeled off by an expansion pressure generated when the superabsorbent polymer particles in the storage portion adjacent to the boundary joining portion absorb excrement and expand; The absorbent article according to any one of claims 1 to 4.

6. When the maximum volume of the first storage section is defined as a first volume, the volume of the superabsorbent polymer particles stored in the first storage section at the time of saturated absorption is defined as a first volume, the maximum volume of the second storage section is defined as a second volume, and the volume of the superabsorbent polymer particles stored in the second storage section at the time of saturated absorption is defined as a second volume, the first volume is smaller than the second volume; The first volume is larger than the second volume, and a part or all of the boundary joining portion located at the boundary between the first storage portion and the second storage portion is peeled off by an expansion pressure when the superabsorbent polymer particles in the first storage portion absorb excrement and expand, and the second volume is larger than the second volume, and a part or all of the boundary bonded portion is peeled off by an expansion pressure generated when the superabsorbent polymer particles in the second storage portion absorb excrement and expand. The absorbent article according to claim 5.

Images