JP2023132574A - Absorbent article - Google Patents

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

The present invention relates to absorbent articles including disposable diapers and sanitary napkins.

This type of absorbent article has a crotch area, a front part and a rear part extending to the front and rear sides of the crotch area, an absorbent body spanning the crotch area and the rear side, and a front side of the absorbent body. The basic idea is that the absorbent body absorbs and retains excreted fluids such as urine that have passed through the top sheet.

In absorbent articles, it is known that back leakage (leakage from the rear of the absorbent article) can be reduced by increasing the amount of absorption in the rear portion. In addition, as one method for increasing the amount of absorption, an upper sheet and a lower sheet having liquid permeability, and a storage section in which superabsorbent polymer particles are stored between the upper sheet and the lower sheet, It is also known to arrange an absorbent sheet having a joint part arranged so as to surround the accommodating part between the top sheet and the absorbent body (for example, see Patent Document 2).

However, when the content of superabsorbent polymer particles in the absorbent sheet is increased in order to increase the amount of absorption, when the skin is pressed against the surface of the top sheet, the superabsorbent polymer particles give a crunchy feel (hereinafter referred to as "janky feeling"). ) may be easily transmitted, leading to a worsening of the feeling of wearing.

JP2019-88465A Japanese Patent Application Publication No. 2005-253851

Therefore, the main object of the present invention is to increase the amount of absorption by an absorbent sheet while suppressing the sticky feeling caused by superabsorbent polymer particles.

Absorbent articles that have solved the above problems are as follows.
<First aspect>
a groin region; a front portion and a rear portion extending to the front and rear sides of the groin region, respectively;
an absorbent body covering the crotch region and the rear region;
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 includes an upper sheet and a lower sheet having liquid permeability, a housing section in which superabsorbent polymer particles are housed between the upper sheet and the lower sheet, and the absorbent sheet is arranged to surround the housing section. having a joint made of
It is a disposable diaper,
The absorbent body 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 an empty storage part that does not contain the superabsorbent polymer particles, or a first storage part that contains 200 g/m ² or less of the superabsorbent polymer particles, and a larger amount than the first storage part. a second containing part containing the superabsorbent polymer particles;
The second accommodating portion 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 unabsorbed thickness of the second storage portion.
An absorbent article characterized by:

(effect)
In this absorbent article, when the skin is pressed against the surface of the top sheet, there are no superabsorbent polymer particles on the first area that easily comes into contact with the skin, or there is only a very small number of the first storage areas, so the skin feels stiff. It's hard to convey. In addition, in the second region having the second storage portion with a large amount of superabsorbent polymer particles, the surface height of the absorbent body is lower than the first region, and the difference between the first surface height and the second surface height is is greater than the unabsorbed thickness of the second storage section, so when the skin is pressed against the surface of the top sheet, the first region supports the skin, making it difficult for the skin to be pressed against the absorbent sheet in the second region. As a result, even on the second area, the feeling of stiffness is less likely to be transmitted to the skin. Further, since the number of superabsorbent polymer particles in the second accommodation portion on the second region can be increased, it is possible to increase the amount of absorption while suppressing the sticky feeling caused by the absorbent polymer particles.

<Second aspect>
The absorbent body has a two-layer structure of an upper absorbent body and a lower absorbent body,
The lower absorbent core has rear side regions that extend laterally from both side edges of the upper absorbent core on the rear side of the crotch region,
The first region is a region where the upper absorbent core and the lower absorbent core overlap, and the second region is the rear side region.
Absorbent article of the first aspect.

(effect)
It is known that the absorbent material has a two-layer structure to ensure the amount of absorption, and that the center side is formed higher than both sides to ensure a good fit to the buttocks. There is a limit to how much absorption can be achieved without loss. Therefore, it is preferable to arrange the second accommodating portion of the absorbent sheet by utilizing the low surface height of the rear side region as in this embodiment.

<Third aspect>
Rising gathers are provided on both sides of the top sheet in the width direction,
The rising gathers cover the entire upper part of the second region in an expanded state.
Absorbent article of the second aspect.

(effect)
In absorbent articles that require a certain amount of absorption, raised gathers (generally referred to as three-dimensional gathers) are often provided on both sides in the width direction. Therefore, it is also preferable to use the rising gathers to cover the entire upper part of the second region in the unfolded state as in this embodiment. As a result, when you press your skin against the surface of the top sheet, even if your skin is weakly pressed against the absorbent sheet in the second area, the gathered gathers act as a cushioning material, making it difficult for the feeling of stiffness to be transmitted to your skin even on the second area. .

<Fourth aspect>
The side having the second area is folded back above the first area, with the boundary between the first area and the second area as the folding position,
The first accommodating part and the second accommodating part are not located at the folding position, and the joining part is located.
The absorbent article according to any one of the first to third aspects.

(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 core and lower absorbent core overlap and the rear side region of only the lower absorbent core, the part to the side of the boundary is placed above the central region. After being folded back, it is often sold in a folded state in which it is folded in three or two in the front-back direction. However, if the storage portion containing the superabsorbent polymer particles is located at the folding position, many of the superabsorbent polymer particles are restrained at the folding position, which may result in a loose feeling during use. On the other hand, if the joint part is arranged at the folding position instead of the accommodating part as in this embodiment, such a problem can be prevented.

<Fifth aspect>
The second accommodating part has at least one first accommodating part next to it,
Part or all of the boundary joint located at the boundary between the first storage part and the second storage part is such that the superabsorbent polymer particles in the storage part adjacent to the boundary joint absorb excrement fluid. It is designed to peel off due to the expansion pressure when it expands.
The absorbent article according to any one of the first to fourth aspects.

(effect)
Strongly bond the upper sheet and lower sheet at the joint so that when the superabsorbent polymer particles in the storage section absorb and expand and fill the storage section, the joint around the storage section will not separate due to the internal pressure. You can also do it. However, when the container is filled with superabsorbent polymer particles, so-called gel blocking (the gap between the superabsorbent polymer particles decreases and the excreted liquid does not reach the superabsorbent polymer particles inside) and expansion inhibition occur. Absorption amount and absorption rate may decrease. Particularly, such problems are likely to occur in the second storage section that contains a larger amount of superabsorbent polymer particles. Therefore, as in this aspect, it is preferable that part or all of the boundary joint between the first housing part and the second housing part can be peeled off by the expansion pressure of the adjacent housing part. As a result, when at least one of the first accommodating part and the second accommodating part is filled with superabsorbent polymer particles that have expanded by absorbing excretory liquid, the boundary joint part is separated, and the adjacent first accommodating part and the second accommodating part are separated. The two accommodating parts are combined to form a combined accommodating part with an expanded capacity. Here, the volume of the combined accommodating part is larger than the sum of the volumes of the first accommodating part and the second accommodating part, and since there are no or only a small amount of superabsorbent polymer particles in the first accommodating part, the gel blocking and absorption inhibition are less likely to occur. Furthermore, since the superabsorbent polymer particles that have absorbed the excretory fluid become gel-like, they no longer cause a sticky feeling.

<Sixth aspect>
The maximum volume of the first accommodating part is defined as a first volume, the volume of the superabsorbent polymer particles accommodated in the first accommodating part at absorption saturation is defined as the first volume, and the maximum volume of the second accommodating part is defined as a first volume. When a second volume is defined as the volume at absorption saturation of the superabsorbent polymer particles accommodated in the second storage part,
the first volume is smaller than the second volume;
The first volume is larger than the first volume, and due to the expansion pressure when the superabsorbent polymer particles in the first storage part absorb excrement fluid and expand, the first storage part and the first storage part are expanded. Part or all of the boundary joint located at the boundary with the second housing part is peeled off, and
The second volume is larger than the second volume, and part or all of the boundary junction is caused by the expansion pressure when the superabsorbent polymer particles in the second storage part absorb excrement fluid and expand. is starting to peel off,
Absorbent article according to the fifth aspect.

(effect)
In the case of this aspect, the boundary joint part is preferably peeled off by absorption expansion of either the first accommodating part or the second accommodating part.

As described above, according to the present invention, advantages such as being able to increase the amount of absorption by the absorbent sheet while suppressing the sticky feeling caused by the superabsorbent polymer particles are brought about.

FIG. 2 is a plan view showing the inner surface of the pad type disposable diaper in an unfolded state. FIG. 3 is a plan view showing only the main parts. 2 is a sectional view taken along YY line in FIG. 1. FIG. 2 is a sectional view taken along line XX in FIG. 1. FIG. 2 is a sectional view taken along the Z-Z line in FIG. 1. FIG. FIG. 2 is a plan view showing an absorbent sheet. (a) A cross-sectional view along the line VV in FIG. 6, and (b) a cross-sectional view along the line WW in FIG. FIG. 3 is a plan view showing various arrangements of storage parts. FIG. 2 is a plan view showing an absorbent sheet. 2 is a cross-sectional view corresponding to the Z-Z cross section in FIG. 1. FIG. 2 is a cross-sectional view corresponding to the Z-Z cross section in FIG. 1. FIG. FIG. 3 is a plan view showing only the main parts.

Hereinafter, an example of a pad type disposable diaper 200 will be described in detail as an example of an absorbent article with reference to the accompanying drawings. In addition, among the terms, "groin area C2" means a part that corresponds to the groin of the body during use, and depending on the product, the area from the center of the article in the front-rear direction LD to a predetermined part on the front side, as shown in the figure, may vary depending on the product. It may be a range, or it may be a predetermined range in the center of the article in the front-rear direction LD. When the article has a narrow constriction part 23n in the middle of the front-rear direction LD or the middle of the absorber 23 in the front-rear direction LD, it means the smallest width part of one or both of the constriction parts 23n, or the minimum width This refers to a predetermined LD range in the front-rear direction with the region at the center of the LD in the front-rear direction. Further, "front part F2 (ventral part)" means a part on the front side of crotch part C2, and "rear part B2 (dorsal part)" means a part on the back side of crotch part C2.

The constituent members adjacent in the thickness direction are fixed or joined as necessary in the same manner as in known diapers, except for the fixed or joined portions described below. The dotted portion in the cross-sectional view indicates an adhesive such as a hot melt adhesive as the fixing or joining means. Hot melt adhesives can be applied by known methods such as slot coating, continuous line or dotted bead coating, spiral, Z-shaped, wavy, etc. spray coating, or pattern coating (transfer of hot melt adhesive using a letterpress method). It can be applied by any method. Alternatively or additionally, at the fixed portion of the elastic member, a hot melt adhesive can be applied to the outer circumferential surface of the elastic member to secure the elastic member to the adjacent member. Examples of hot melt adhesives include EVA adhesives, adhesive rubber adhesives (elastomer adhesives), polyolefin adhesives, and polyester/polyamide adhesives, which can be used without particular limitation. As the fixing or joining means for joining each component, means for welding materials such as heat sealing or ultrasonic sealing can also be used. In areas where liquid permeability in the thickness direction is required, constituent members adjacent in the thickness direction are fixed or bonded in an intermittent pattern. For example, when such intermittent fixing or bonding is performed using hot melt adhesive, intermittent pattern coating such as spiral, Z-shaped, or wavy patterns can be suitably used, and the coating can be applied over an area larger than the coating width with one nozzle. When coating, intermittent pattern coating such as a spiral, Z-shaped, wavy pattern, etc. can be performed with or without intervals in the width direction. As a joining means for joining each component, means by material welding such as heat sealing or ultrasonic sealing can also be used.

Furthermore, as the nonwoven fabric in the following description, any known nonwoven fabric can be used as appropriate depending on the site and purpose. The constituent fibers of the nonwoven fabric include, for example, polyolefins such as polyethylene or polypropylene, synthetic fibers such as polyester and polyamide (including monocomponent fibers as well as composite fibers such as core-sheath fibers), as well as recycled rayon and cupro. Fibers, natural fibers such as cotton, etc. can be selected without particular limitation, and a mixture of these can also be used. In order to increase the flexibility of the nonwoven fabric, it is preferable that the constituent fibers be crimped fibers. In addition, even if the constituent fibers of the nonwoven fabric are hydrophilic fibers (including fibers made hydrophilic by a hydrophilizing agent), hydrophobic fibers or water-repellent fibers (including fibers made water-repellent by a water-repellent agent) ). In addition, nonwoven fabrics generally vary depending on the fiber length, sheet forming method, fiber binding method, and laminated structure. It is classified into nonwoven fabrics, point bonded nonwoven fabrics, laminated nonwoven fabrics (including SMS nonwoven fabrics with a meltblown layer sandwiched between spunbond layers, SMMS nonwoven fabrics, etc.), and any of these nonwoven fabrics can be used.

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 a front part F2 and a rear part B2 extending on both sides of the crotch part C2. The dimensions of each part can be determined as appropriate; for example, the total length (length in the front-rear direction) L of the article may be approximately 350 to 700 mm, and the total width W1 may be approximately 130 to 400 mm (but wider than the width of the absorbent surface of the diaper). In this case, the length of the groin area C2 in the front-back direction is about 10 to 150 mm, the length of the front part F2 is about 50 to 350 mm, and the length of the back part B2 is about 50 to 350 mm. be able to. Further, the width W3 of the crotch portion C2 can be, for example, 150 mm or more, particularly about 200 to 260 mm, for adults.

The present pad type disposable diaper 200 has a basic structure including an absorbent body 23 between a liquid-impermeable sheet 21 and a liquid-permeable top sheet 22.

On the back side of the absorbent body 23, a liquid-impermeable sheet 21 is provided so as to slightly protrude from the periphery of the absorbent body 23. As the liquid-impermeable sheet 21, in addition to a polyethylene film, it is also possible to use a sheet that has moisture permeability without impairing water-blocking properties from the viewpoint of preventing stuffiness. This water-blocking and moisture-permeable sheet is 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 the sheet in uniaxial or biaxial directions. Can be used.

Further, the outer surface of the liquid-impermeable sheet 21 is covered with an exterior sheet 27 made of a nonwoven fabric, and this exterior sheet 27 protrudes outward from the periphery of the liquid-impermeable sheet 21 with a predetermined protrusion width. Various nonwoven fabrics can be used as the exterior sheet 27. The exterior sheet 27 can also be omitted.

The front side of the absorbent body 23 is covered with a top sheet 22 having liquid permeability. In the illustrated embodiment, the absorbent body 23 partially protrudes from the side edges of the top sheet 22, but the width of the top sheet 22 can be increased so that the side edges of the absorbent body 23 do not protrude. Various nonwoven fabrics can be used as the top sheet 22. One of the preferred nonwoven fabrics for the top sheet 22 is an air-through nonwoven fabric made by bonding thermoplastic synthetic fibers with hot air.

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

At both ends of the pad-type disposable diaper 200 in the front-rear direction LD, the liquid-impermeable sheet 21, the outer sheet 27, and the top sheet 22 are extended from the front and rear ends of the absorbent body 23 to both front and rear sides and bonded together. An end flap portion EF in which no. 23 does not exist is formed. On both sides of the pad-type disposable diaper 200, the liquid-impermeable sheet 21 and the exterior sheet 27 extend outward from the side edges of the absorbent body 23, and the portion from this extension to the side of the top sheet 22 A fixed part 24x on the outside in the width direction WD of the gather sheet 24s forming the rising gathers 24 is pasted to the inner surface thereof over the entire length in the front-rear direction LD, and constitutes a side flap part SF where the absorbent body 23 does not exist. . These bonded parts are shown in a dotted pattern in FIG. 1 and can be formed using hot melt adhesive, heat sealing, or ultrasonic sealing. When the exterior sheet 27 is not provided, the liquid-impermeable sheet 21 can be extended to the side flap part SF in place of the exterior sheet 27 to form the outer surface side of the side flap part SF.

Although a plastic sheet or a melt-blown nonwoven fabric can be used as the material for the gather sheet 24s, a nonwoven fabric treated with water-repellent material such as silicone is preferably used in terms of feel to the skin.

A portion 24c on the center side in the width direction of the gather sheet 24s extends above the top sheet 22, and at the end on the center side in the width direction, a slender elastic member 24G is stretched in the front-rear direction. It is fixed with melt adhesive or the like. The elongated elastic member 24G may be formed into a thread, string, or band shape such as styrene rubber, polyolefin rubber, urethane rubber, ester rubber, polyurethane, polyethylene, polystyrene, styrene-butadiene, silicone, polyester, etc. , commonly used materials can be used.

Both gather sheets 24s have fixed portions 24x on the outside in the width direction bonded and fixed to the inner surface of the article (in the illustrated embodiment, the surface of the top sheet 22 and the inner surface of the exterior sheet 27) over the entire front and back direction, and a portion 24c on the center side in the width direction. However, it is bonded and fixed to the inner surface of the article (the surface of the top sheet 22 in the illustrated form) at both ends in the front and back direction, and is not fixed to the inner surface of the article (the surface of the top sheet 22 in the illustrated form) between both ends in the front and rear direction. . This non-fixed portion serves as a leak-preventing wall that elastically stands up against the inner surface of the article (in the illustrated embodiment, the surface of the top sheet 22), and its starting point 24b is connected to the fixed portion 24x on the outside in the width direction of the gather sheet 24s. It is located at the border with the inner portion 24c.

The pad-type disposable diaper 200 of this example has an upper absorbent body 23A located on the outermost side and a lower absorbent body 23B provided on the back side, as the absorbent body 23 that absorbs and retains the liquid content of excrement. ing. The number of layers of the absorber 23 is not particularly limited, and may be a single layer as shown in FIG. 11, or three or more layers (not shown). As the absorbent body 23, a mixed aggregate formed by mixing and accumulating hydrophilic short fibers such as pulp fibers and superabsorbent polymer particles can be suitably used.

As the superabsorbent polymer particles contained in the absorbent body 23, those used in this type of absorbent article can be used as they are. When the particles falling under the sieving sieve are sieved using a 180 μm standard sieve (JIS Z8801-1:2006) (shaking for 5 minutes), the particles falling under the 500 μm standard sieve are It is desirable that the proportion of particles remaining on the top is 30% by weight or less, and the proportion of particles remaining on a standard sieve of 180 μm is 60% by weight or more. When a plurality of absorbent bodies are stacked, as in the case of having an upper absorbent body 23A and a lower absorbent body 23B, superabsorbent polymer particles having a different particle size distribution can be used for each absorbent body.

Further, the superabsorbent polymer particles are not particularly limited, but those having a water absorption rate of 20 to 50 seconds and a water absorption amount of 50 to 80 g/g can be suitably used. Highly absorbent polymer particles include starch-based, loin-based and synthetic polymer-based particles, including starch-acrylic acid (salt) graft copolymers, saponified starch-acrylonitrile copolymers, and sodium carboxymethyl. A crosslinked product of loin loin or an acrylic acid (salt) polymer can be used.

If necessary, the absorbent body 23 may be wrapped in a packaging sheet 26 having liquid permeability and liquid retention properties such as crepe paper to form an integral absorbent element in order to maintain the shape and superabsorbent polymer particles. can. When a plurality of absorbent bodies are laminated, as in the case of having an upper absorbent body 23A and a lower absorbent body 23B, in addition to wrapping each absorbent body individually with a packaging sheet, the plurality of absorbent bodies are wrapped integrally with a packaging sheet. be able to. In some cases, the packaging sheet 26 may be omitted.

As long as at least one of the absorbent body 23 covers the crotch region and the rear side portion, the dimensions in the front and back direction and the dimensions in the width direction can be determined as appropriate. In normal cases, it is preferable that the absorber 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 may have the same dimensions as the lower absorbent body 23B, but as shown in the illustration, the overall length and width of the upper absorbent body 23A are longer than those of the lower absorbent body 23B. It is also desirable that it be short. Normally, the total length of the upper absorbent core 23A can be approximately 60 to 90% of the total length of the lower absorbent core 23B, and the total width of the upper absorbent core 23A can be approximately 60 to 90% of the total width of the lower absorbent core 23B. be able to.

The total basis weight (total of short fibers and superabsorbent polymer particles) of the absorbent body 23 can be determined as appropriate. As an example, in the case of a single-layer absorbent body 23, the total basis weight can be approximately 500 to 2000 g/m ² , and in the case of a two-layer absorbent body 23, the total basis weight of the upper absorbent body 23A is 200 to 700 g/m 2 . m ² or so, and the total basis weight of the lower absorbent core 23B can be approximately 200 to 700 g/m ² .

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

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

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 lower than the first surface height h1. The absorbent core 23 in the illustrated example has a two-layer structure of an upper absorbent core 23A and a lower absorbent core 23B, and the lower absorbent core 23B is located on the rear side of the crotch area C2 and on both sides of both side edges of the upper absorbent core 23A. It has a rear side region 23S extending outward. Therefore, in this case, the region 23M where the upper absorbent core 23A and the lower absorbent core 23B overlap becomes the first region A1, and the rear side region becomes the second region A2.

Further, as shown in the illustrated example, when a groove 23D is provided on the uppermost surface of the absorbent body 23 and extends in the front-rear direction LD across the crotch portion C2 and the rear side portion B2 (the groove 23D can be omitted),
Of the area where the upper absorbent body 23A and the lower absorbent body 23B overlap, a portion that does not have the groove 23D becomes a first area A1 having a first surface height h1, and the bottom of the groove 23D has a second surface height h2. The second area A2 has the following characteristics. Note that, as in the example shown in FIGS. 10 and 11, when a slit is provided that penetrates the absorber 23 in the thickness direction from the upper surface to the lower surface, the surface height of the absorber 23 at this slit portion is 0. Therefore, the slit portion in this case becomes a second region A2 having a second surface height h2 lower than the first surface height h1.

The grooves 23D can be formed by lowering the basis weight of the region of the absorbent body 23 having the grooves 23D than the other parts, or by compression processing such as embossing on the upper surface of the absorbent body 23. can. For example, as shown in FIGS. 3 to 5, a slit passing through the upper absorbent body 23A from the upper surface to the lower surface in the thickness direction is provided, and no slit is provided in the lower absorbent core 23B, and the upper absorbent core 23A and the lower absorbent core are As a whole of 23B, the area having the grooves 23D can have a lower basis weight than the other parts. In this case, the bottom surface of the groove 23D is formed by the top surface of the lower absorbent body 23B. Furthermore, as shown in FIG. 10, by providing a slit that penetrates in the thickness direction from the upper surface of the upper absorbent core 23A to the lower surface of the lower absorbent core 23B, the grooves 23D are formed throughout the upper absorbent core 23A and the lower absorbent core 23B. It is also possible to set the area having a lower basis weight than other parts. 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 body 23, as shown in FIG. 11, by providing a slit that penetrates the absorbent body 23 in the thickness direction from the upper surface to the lower surface, the basis weight of the region of the absorbent body 23 having the grooves 23D can be reduced. , it can also be lower than other parts. In this case as well, the bottom surface of the groove 23D is formed by the liquid-impermeable sheet 21. The above example is an example in which slits are provided in the absorbent body 23, but instead of the slits, the grooves 23D may be formed by making the amount of accumulation of short fibers and superabsorbent polymer particles lower than the surrounding area. You can also do it. In this case, the bottom surface of the groove 23D is formed by the surface of the absorber 23 having the groove 23D.

Although the width W2 of the groove 23D can be determined as appropriate, it is usually preferably 15 to 40 mm, particularly preferably 20 to 30 mm. Although the total length of the groove 23D can be determined as appropriate, it is usually preferably 0.2 to 0.75 times the total length Y1 of the absorber 23, particularly preferably 0.35 to 0.6 times. The depth D2 of the groove 23D can be determined as appropriate, but the depth D2 of the absorber 23 in the unabsorbed and expanded state is 0 of the thickness 23t of the absorber 23 (the sum of the thicknesses of all the absorbers 23 when the absorber 23 has multiple layers). It is preferably .4 to 1 times, and particularly preferably 0.5 to 0.7 times.

As shown in FIGS. 5 to 7 and the like, between the top sheet 22 and the uppermost surface of the absorbent core 23, there are an upper sheet 51 and a lower sheet 52 having liquid permeability, and between the upper sheet 51 and the lower sheet 52. An absorbent sheet 50 is provided which has accommodating portions 55 and 56 in which superabsorbent polymer particles 53 are accommodated, and a joint portion 54 arranged so as to surround the accommodating portions 55 and 56. The portions of the upper sheet 51 and the lower sheet 52 located in the accommodating portions 55 and 56 are not joined. In addition, the accommodating sections 55 and 56 include a first accommodating section 55 containing superabsorbent polymer particles 53 of 200 g/m ² or less (more preferably 30 to 150 g/m ² ) and a larger amount (more than the first accommodating section 55) It has a second storage section 56 containing superabsorbent polymer particles 53 (preferably 2 to 8 times the basis weight). A part or all of the first storage section 55 may be an empty storage section that does not contain the superabsorbent polymer particles 53.

The second accommodating part 56 is located only on the second area A2, and the difference between the first surface height h1 and the second surface height h2 is when the second accommodating part 56 is not absorbed. (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 or very few superabsorbent polymer particles 53 on the first region A1, which is likely to come into contact with the skin, or there is only a very small number of the first accommodation portions 55, so that a feeling of tightness occurs. It is difficult to convey to the skin. In addition, in the second region A2 having the second storage portion 56 with a large amount of superabsorbent polymer particles 53, the surface height of the absorber 23 is lower than the first region A1, and the first surface height h1 and The difference between the surface height h2 of As a result, the skin is less likely to be pressed against the absorbent sheet 50 in the area A2, and as a result, the feeling of tightness is less likely to be transmitted to the skin even on the second area A2. Further, since it is possible to increase the number of superabsorbent polymer particles 53 in the second accommodating portion 56 on the second region A2, it is possible to increase the amount of absorption while suppressing the feeling of stiffness caused by the absorbent polymer particles. In particular, as in the illustrated example, when the center side is formed higher than both sides in consideration of fit to the buttocks, there is a limit to securing the amount of absorption without impairing the fit, so the rear side area It is preferable to arrange the second accommodating portion 56 of the absorbent sheet 50 by utilizing the low surface height of the absorbent sheet 23S.

Furthermore, in products that require a certain amount of absorption, raised gathers 24 (generally referred to as three-dimensional gathers) are often provided on both sides in the width direction WD, as shown in the illustrated example. Therefore, it is also preferable to use the rising gathers 24 to cover the entire upper part of the second area A2 in the unfolded state. As a result, when the skin is pressed against the surface of the top sheet 22, even if the skin is weakly pressed against the absorbent sheet 50 in the second area A2, the riser gathers 24 act as a cushioning material, and there is no feeling of tightness even on the second area A2. It becomes difficult to be transmitted to the skin.

As shown in the illustrated example, by distributing and holding the superabsorbent polymer particles 53 in a large number of accommodating portions 55 and 56, it is possible to prevent the superabsorbent polymer particles 53 from being unevenly distributed in the absorbent sheet 50. The number of the first accommodating portions 55 and the second accommodating portions 56 may be one each, but depending on the arrangement of the first area A1 and the second area A2, the number of the first accommodating portions 55 and the second accommodating portions 56 may be one. A plurality of first accommodating parts 55 are arranged at intervals of , or a plurality of second accommodating parts 56 are arranged together with or in place of this in the second region A2 at intervals of at least the length of the joint parts 54 . be able to.

Although the planar arrangement of the accommodating portions 55 and 56 (that is, the group of superabsorbent polymer particles 53) can be determined as appropriate, a regularly repeated planar arrangement is preferable. For example, as shown in FIG. 6, a plurality of rows of housing portions 55 and 56 are arranged at intervals in the front-rear direction LD, and a plurality of rows are arranged at predetermined intervals in the width direction WD (a staggered arrangement as shown in the illustrated example). In addition to arrays, it is preferable to employ arrays (including matrix arrays, etc.). The accommodating parts 55 and 56 can be arranged without any gap with the joint part 54 as a boundary. In this case, the accommodating portions 55 and 56 may be arranged in an orthorhombic lattice pattern as shown in FIG. 8(a), a hexagonal lattice pattern as shown in FIG. 8(c), a rectangular lattice as shown in FIG. 8(d), and a parallel lattice as shown in FIG. Examples include a form in which two groups of rows are provided so as to intersect with each other (including a form where these are inclined at an angle of less than 90 degrees with respect to the direction of expansion and contraction). When arranging the accommodating parts 55 and 56 at a certain distance, the entire part other than the accommodating parts 55 and 56 can be used as the joint part 54 as shown in FIG. 6, but as shown in FIG. The joint portion 54 may be annularly provided along the outer periphery of the housing portions 55 and 56, and a non-joint portion substantially free of superabsorbent polymer particles 53 may be provided between adjacent annular joint portions 54.

When the first accommodating part 55 is arranged only on the first area A1, the boundary joint part 54 located at the boundary between the first accommodating part 55 and the second accommodating part 56 is placed between the first area A1 and the second area. It is possible to select an arrangement of the accommodating portions 55 and 56 such that they can be located on the border with A2. For example, when the boundary between the first area A1 and the second area A2 extends linearly along the front-rear direction LD as shown in the illustrated example, as shown in FIGS. 6 and 8(c)(d), A plurality of rows in which the storage portions 55 and 56 are arranged at intervals in the front-rear direction LD are provided at predetermined intervals in the width direction WD, and the boundary joint portions 54 extend linearly along the front-rear direction LD. Can be adopted. On the other hand, if a part of the first accommodating part 55 adjacent to the boundary joint part 54 is located on the second area A2, as shown in FIGS. It is possible to adopt an arrangement of the accommodating portions 55 and 56 such that the accommodating portions 55 and 56 have a zigzag shape.

In a product with a two-layer structure such as the example shown in FIG. 5, as shown in FIG. 12, the boundary between the central region where the upper absorbent core 23A and the lower absorbent core 23B overlap and the rear side region 23S of only the lower absorbent core 23B At 201, the portion 202 on the side of the boundary 201 is folded back onto the central region, and then folded into three or two in the front-rear direction LD, and is often sold in a folded state. However, if the accommodating parts 55 and 56 containing the superabsorbent polymer particles 53 are located at the folding position, many of the superabsorbent polymer particles 53 are restrained at the folding position, and as a result, there is a risk that a stiff feeling may be easily transmitted during use. There is. This problem becomes particularly noticeable when the sheet is folded back at a position passing through the second storage section 56 containing a large amount of superabsorbent polymer particles 53. Therefore, when folding back the side having the second area A2 above the first area A1 using the boundary 201 between the first area A1 and the second area A2 as the folding position, the folding position includes the first storage part 55 and the second area A2. It is preferable to position the joint portion 54 without positioning the second accommodating portion 56 because such a problem can be prevented.

In order to facilitate the arrangement of the superabsorbent polymer particles 53 during manufacturing and to secure the volume after absorption and expansion, at least one of the upper sheet 51 and the lower sheet 52 in the storage sections 55 and 56 is stored in an expanded state. Although the portions 55 and 56 may have concave portions concave to the outside, as shown in FIGS. It's okay if it's just sandwiched in. The recessed portion can be formed by subjecting the target sheet to a shaping process such as embossing. Although the depth of the recess is not particularly limited, it is preferably about 1.0 to 7.0 mm, particularly about 1.0 to 5.0 mm.

The upper sheet 51 and the lower sheet 52 are not particularly limited as long as they are made of a liquid-permeable material like the top sheet 22. Since the upper sheet 51 and the lower sheet 52 have an influence on the absorption rate, they should be dry-laid nonwoven fabrics made from hydrophilic fibers, especially natural fibers such as cotton and pulp, especially 70% by weight or more of pulp (less than 100% by weight). The air-laid pulp nonwoven fabric (in which case, the remaining amount can be made of an appropriate synthetic fiber) is one of the ones particularly suitable for the upper sheet 51 and the lower sheet 52. The method of forming the nonwoven fabric web is not particularly limited, but in order to prevent the superabsorbent polymer particles 53 from detaching, methods that increase the fiber density, such as spunbonding and melt-blowing, are preferred. Further, the fineness, basis weight, and thickness of the nonwoven fabric are preferably about 2.0 to 7.0 dtex, about 18 to 50 g/m ² , and about 0.10 to 0.60 mm, respectively.

The planar shape of the accommodating portions 55 and 56 can be determined as appropriate, and may be a hexagon, a rhombus, a square, a rectangle, a circle, an ellipse, or the like. The entire area between the adjacent accommodating parts 55 and 56 may be a joint part 54, but since the joint part 54 has low or no liquid permeability, the area between the adjacent accommodating parts 55 and 56 is The joint portion 54 may be provided only at a position along the edges of the storage portions 55 and 56, and the other portion may be a portion where the upper sheet 51 and the lower sheet 52 are not joined. In addition to arranging the accommodating parts 55 and 56 with the same planar shape and the same size, it is also possible to arrange a combination of accommodating parts 55 and 56 of a plurality of types having different shapes and/or dimensions (not shown).

The dimensions of each of the accommodating portions 55 and 56 can be determined as appropriate; for example, the dimension 55x in the width direction WD can be about 14 to 38 mm. Further, the dimension 55y in the front-rear direction LD can be about 15 to 200 mm. The area of each accommodating portion 55, 56 can be approximately 210 to 7600 mm ² . The spacing 55d (minimum spacing if variable) between the accommodating portions adjacent in the front-rear direction can be approximately 5 to 30 mm. As in the example shown in FIG. 6, when there is a plurality of rows of storage sections in the width direction, the interval 55e between the rows of storage sections adjacent in the width direction (minimum interval if variable) is approximately 5 to 30 mm. be able to.

The joint portion 54 is arranged so as to surround each of the accommodating portions 55 and 56, and may be formed in a continuous line shape as long as it forms a boundary between adjacent accommodating portions 55 and 56. It can also be formed intermittently in the surrounding direction. It is preferable that the superabsorbent polymer particles 53 are not present in the area between the adjacent accommodating parts 55 and 56, or even if they are present, the number of superabsorbent polymer particles 53 is smaller than in the accommodating parts 55 and 56.

The dimensions of the joints 54 can be determined as appropriate, but if the area is large, the texture may become hard, so in the case of intermittent joints 54, it is preferable that the individual joints 54 are small; In the case of a typical joint 54, it is preferable that the width of each joint 54 is narrow.

The joint portion 54 may be, for example, a welded portion where the upper sheet 51 and the lower sheet 52 are welded together by ultrasonic welding or heat sealing, or may be an adhesive portion where the upper sheet 51 and the lower sheet 52 are joined via a hot melt adhesive. . The bonded portion 54 may not be peeled off due to the expansion pressure of the superabsorbent polymer particles 53 in the accommodation section adjacent to the bonded portion, but the bonded portions other than the edge bonded portion 54E closest to the periphery of the absorbent sheet are The material may be peeled off due to the expansion pressure of the superabsorbent polymer particles 53 in the accommodation section adjacent to the container.

Whether or not the bonded portion 54 can be peeled off can be determined based on the relationship between the expansion pressure and the bonding strength of the bonded portion 54 . In addition, the degree of expansion pressure is determined by the size relationship between the maximum volume of the storage portions 55 and 56 and the volume of the superabsorbent polymer particles 53 contained therein at absorption saturation (determined by the content of the superabsorbent polymer particles 53). The bonding strength of the bonding portion 54 can be adjusted by adjusting the area of the bonding portion 54, the strength of welding, the type of adhesive, etc. For example, when the joint 54 is not to be separated due to the expansion pressure of the superabsorbent polymer particles 53 in the storage parts 55, 56 adjacent to the joint 54, The volume of the superabsorbent polymer particles 53 contained in the storage portions 55 and 56 at absorption saturation may be made smaller than the maximum volume. On the other hand, if it is assumed that the superabsorbent polymer particles 53 in the accommodating parts 55 and 56 adjacent to the joint part 54 are peeled off due to the expansion pressure, etc. , the volume of the superabsorbent polymer particles 53 contained in the storage portions 55 and 56 at absorption saturation may be increased. In the former case, the accommodating parts 55 and 56 that satisfy these size relationships need to be both of the pair of accommodating parts 55 and 56 that are adjacent to each other with the joint 54 as the boundary, but in the latter case, the accommodating parts 55 and 56 must be both adjacent to each other with the joint 54 as the boundary. It may be only one of the pair of adjacent accommodating portions 55, 56, or both of them. As an example, both the upper sheet 51 and the lower sheet 52 do not have recesses that are recessed to the outside of the accommodating parts 55 and 56 in the unfolded state, and the superabsorbent polymer particles 53 are simply placed between the upper sheet 51 and the lower sheet 52. In order to prevent the bonded portion 54 from peeling when only the particles are sandwiched, the basis weight of the superabsorbent polymer particles 53 in each accommodation portion 55, 56 can be set to, for example, 100 to 300 g/m ² . In order to peel off the portion 54, the basis weight of the superabsorbent polymer particles 53 in the first accommodating portion 55 can be, for example, 30 to 150 g/m ² , and the basis weight of the superabsorbent polymer particles 53 in the second accommodating portion 56 The basis weight of 53 can be, for example, 130 to 300 g/m ² .

When the superabsorbent polymer particles 53 in the accommodating parts 55, 56 absorb and expand and fill the accommodating parts 55, 56, the joints 54 around the accommodating parts 55, 56 are bonded so that they do not separate due to the internal pressure. When the upper sheet 51 and the lower sheet 52 in the section 54 are strongly joined, when the superabsorbent polymer particles 53 fill the accommodation sections 55 and 56, so-called gel blocking (the gap between the superabsorbent polymer particles 53 is reduced). , the amount of absorption and absorption rate may decrease due to the fact that the excreted liquid does not reach the internal superabsorbent polymer particles 53) and the inhibition of expansion. In particular, such a problem is likely to occur in the second storage section 56 that contains a larger amount of superabsorbent polymer particles 53. For this reason, it is preferable that a part or all of the boundary joint 54 between the first accommodating part 55 and the second accommodating part 56 can be separated by the expansion pressure of the adjacent accommodating parts 55 and 56. As a result, when at least one of the first accommodating part 55 and the second accommodating part 56 is filled with superabsorbent polymer particles 53 that have expanded by absorbing excretory fluid, the boundary joint part 54 is separated, and the adjacent first accommodating part 54 is separated. The accommodating portion 55 and the second accommodating portion 56 are combined to form combined accommodating portions 55 and 56 with an expanded 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 the superabsorbent polymer particles 53 are not present in the first accommodating part 55, or Since only a small amount is present, gel blocking and absorption inhibition are less likely to occur. Moreover, since the superabsorbent polymer particles 53 that have absorbed the excretory fluid become gel-like, they no longer give a sticky feeling.

In this case, since the content of superabsorbent polymer particles 53 in the first accommodating part 55 is small, if the first volume is approximately the same as the second volume, only the expansion pressure in the first accommodating part 55 causes the boundary joint part 54 to It is difficult to peel off. Therefore, it is preferable that the boundary joint part 54 is peeled off by absorption expansion of either the first accommodating part 55 or the second accommodating part 56. Specifically, the maximum volume of the first accommodating part 55 is defined as the first volume, the volume of the superabsorbent polymer particles 53 accommodated in the first accommodating part 55 at absorption saturation is defined as the first volume, and the maximum volume of the first accommodating part 55 is defined as the first volume. 56 is the second volume, and the volume of the superabsorbent polymer particles 53 accommodated in the second storage part 56 at absorption saturation is the second volume, the first volume is smaller than the second volume, The first volume is larger than the first volume, and due to the expansion pressure when the superabsorbent polymer particles 53 in the first storage part 55 absorb excrement fluid and expand, the first storage part 55 and the second storage part Part or all of the boundary joint part 54 located at the boundary with the part 56 is peeled off, and the second volume is larger than the second volume, and the high absorbency in the second storage part 56 is Preferably, part or all of the boundary joint 54 is peeled off by the expansion pressure when the polymer particles 53 absorb excretory fluid and expand.

As long as the second storage part 56 is located only on the second area A2, the first storage part 55 may be located only on the first area A1, but the first storage part 55 may be located only on the first area A1 and the second area A2. It may be located on both sides. For example, in the example shown in FIG. 5 having a groove 23D, the bottom of the groove 23D is the second area A2, but the first accommodating part 55 can be provided above it. Conversely, as shown in FIG. 11, the second accommodating portion 56 can also be provided on the bottom of the groove 23D. Although not shown, the second accommodating portion 56 can also be provided on the bottom of the groove 23D in the example shown in FIG. 5 by combining these. Further, although not shown, both the second accommodating part 56 and the first accommodating part 55 can be arranged on a single second area A2.

The absorbent sheet 50 may be arranged so as to cover a plurality of second areas A2 with one sheet as shown in FIG. 5, or when there are a plurality of second areas A2 as shown in FIG. An absorbent sheet 50 can also be arranged.

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

・"Anteroposterior direction" means the direction indicated by the symbol LD in the figure (vertical direction), and "width direction" means the direction indicated by WD in the figure (horizontal direction), and the longitudinal direction and the width direction are orthogonal.

・“MD direction (machine direction or line flow direction)” and “CD direction (lateral direction perpendicular to the MD direction)” mean the “MD direction” and “CD direction” of the processing equipment, and either one One direction is the front-rear direction, and the other direction is the width direction. Further, 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 a nonwoven fabric follow. This can be determined by a simple measurement method that determines the orientation direction. In the illustrated form, like most disposable diaper products, the front-rear direction is the MD direction, and the width direction is the CD direction.

- "Front side" means the side closer to the wearer's skin when worn, and "back side" means the side farther from the wearer's skin when worn.

- "Front side" means the side of the member that is closer to the wearer's skin when worn, and "back side" means the side farther from the wearer's skin when worn.

・"Area ratio" means the ratio of the target area to the unit area, and the total area of the target area in the target area (for example, the part where the storage part is formed in the unabsorbed absorbent sheet) is calculated by the area of the target area. It is expressed as a percentage. In a configuration in which a large number of target parts are provided at intervals, it is desirable to set the target area to a size that includes three or more target parts and calculate the area ratio.

- "Elongation rate" means a value when the natural length is 100%. For example, an extension ratio of 200% is synonymous with an extension ratio of 2 times.

・“Basic weight” is measured as follows. After pre-drying the sample or test piece, it is left in a test room or apparatus under standard conditions (temperature of the test location: 23°C, 1°C, relative humidity: 50°C, 2%) to reach a constant weight. Pre-drying refers to making the sample or test piece constant weight in an environment at a temperature of 100°C. Note that fibers with an official moisture content of 0.0% do not need to be pre-dried. From the test piece that has reached a constant weight, use a sampling template (100 mm x 100 mm) to cut out a sample with dimensions of 100 mm x 100 mm. Measure the weight of the sample, multiply by 100 to calculate the weight per square meter, and use it as the basis weight.

・The "thickness" of the absorber can be measured using a thickness measuring device manufactured by Ozaki Seisakusho Co., Ltd. (Peacock, dial thickness gauge large type, model J-B (measuring range 0 to 35 mm) or model K-4 (measuring range 0 to 50 mm)) Measure with the sample and thickness measuring device horizontal.

- "Thickness" other than the above is automatically measured using an automatic thickness measuring device (KES-G5 Handy Compression Measurement Program) under the conditions of load: 0.098 N/cm ² and pressurized area: 2 cm ² .

- Water absorption is measured according to JIS K7223-1996 "Water absorption test method for super absorbent resin".

・Water absorption rate is the "time to end point" when JIS K7224-1996 "Water absorption rate test method for super absorbent resin" is performed using 2 g of super absorbent polymer and 50 g of physiological saline. .

・"Artificial urine" contains urea: 2wt%, sodium chloride: 0.8wt%, calcium chloride dihydrate: 0.03wt%, magnesium sulfate heptahydrate: 0.08wt%, and ion exchange water: 97%. It is a mixture of .09 wt% and is used at a temperature of 40 degrees unless otherwise specified.

・The term "deployed state" means a state in which the product is flattened without contraction (including any contraction such as contraction caused by an elastic member) or slack.

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

- If there is no description of the environmental conditions for the test or measurement, the test or measurement shall be conducted in a test room or equipment under standard conditions (test location: temperature 23 ± 1°C, relative humidity 50 ± 2%). do.

The present invention can be used in any form, such as pad type disposable diapers such as the above example, tape type disposable diapers, pants type disposable diapers, etc., and can also be used in absorbent articles other than disposable diapers, such as sanitary napkins. It is available.

200...Pad type disposable diaper, 21...Liquid-impermeable sheet, 22...Top sheet, 23...Absorber, 23A...Upper absorber, 23B...Lower absorber, 23D...Groove, 23S...Rear side area, 24...Rise up Gather, 24s...Gather sheet, 26...Packaging sheet, 27...Exterior sheet, 50...Absorbent sheet, 51...Upper sheet, 52...Lower sheet, 53...Super absorbent polymer particles, 54...Joint part, 55, 56...Accommodation part, 55...first storage part, 56...second storage part, A1...first area, A2...second area, B2...rear side part, C2...crotch area, F2...front side part, LD...front-back direction, WD ...width direction, h1...first surface height, h2...second surface height.

Claims (6)

a groin region; a front portion and a rear portion extending to the front and rear sides of the groin region, respectively;
an absorbent body covering the crotch region and the rear region;
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 includes an upper sheet and a lower sheet having liquid permeability, a housing section in which superabsorbent polymer particles are housed between the upper sheet and the lower sheet, and the absorbent sheet is arranged to surround the housing section. having a joint made of
It is a disposable diaper,
The absorbent body 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 an empty storage part that does not contain the superabsorbent polymer particles, or a first storage part that contains 200 g/m ² or less of the superabsorbent polymer particles, and a larger amount than the first storage part. a second containing part containing the superabsorbent polymer particles;
The second accommodating portion 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 unabsorbed thickness of the second storage portion.
An absorbent article characterized by: The absorbent body has a two-layer structure of an upper absorbent body and a lower absorbent body,
The lower absorbent core has rear side regions that extend laterally from both side edges of the upper absorbent core on the rear side of the crotch region,
The first region is a region where the upper absorbent core and the lower absorbent core overlap, and the second region is the rear side region.
The absorbent article according to claim 1. Rising gathers are provided on both sides of the top sheet in the width direction,
The rising gathers cover the entire upper part of the second region in an expanded state.
The absorbent article according to claim 2. The side having the second area is folded back above the first area, with the boundary between the first area and the second area as the folding position,
The first accommodating part and the second accommodating part are not located at the folding position, and the joining part is located.
The absorbent article according to any one of claims 1 to 3. The second accommodating part has at least one first accommodating part next to it,
Part or all of the boundary joint located at the boundary between the first storage part and the second storage part is such that the superabsorbent polymer particles in the storage part adjacent to the boundary joint absorb excrement fluid. It is designed to peel off due to the expansion pressure when it expands.
The absorbent article according to any one of claims 1 to 4. The maximum volume of the first accommodating part is defined as a first volume, the volume of the superabsorbent polymer particles accommodated in the first accommodating part at absorption saturation is defined as the first volume, and the maximum volume of the second accommodating part is defined as a first volume. When a second volume is defined as the volume at absorption saturation of the superabsorbent polymer particles accommodated in the second storage part,
the first volume is smaller than the second volume;
The first volume is larger than the first volume, and due to the expansion pressure when the superabsorbent polymer particles in the first storage part absorb excrement fluid and expand, the first storage part and the first storage part are expanded. Part or all of the boundary joint located at the boundary with the second housing part is peeled off, and
The second volume is larger than the second volume, and part or all of the boundary junction is caused by the expansion pressure when the superabsorbent polymer particles in the second storage part absorb excrement fluid and expand. is starting to peel off,
The absorbent article according to claim 5.

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