JP6674968B2 - Absorbent articles - Google Patents

Description

  The present invention relates to an absorbent article having an absorbent body having a central region and a side region arranged outside the central region in the width direction, wherein the density of the lateral region is higher than the density of the central region.

  Patent Literature 1 discloses an absorber in which a squeezed portion is formed on a side portion in a width direction of the absorber. Since the compressed portion is formed by compressing the absorber in the thickness direction, the density of the region where the compressed portion is formed is higher than the density of the region where the compressed portion is not formed. The center in the width direction of the absorber is disposed to face the excretion opening of the wearer when worn, and a larger amount of bodily fluid is discharged as compared to the side portions in the width direction of the absorber. At this time, since the density of the squeezed portion located on the side in the width direction of the absorber is higher than the density of the center in the width direction of the absorber, the body fluid discharged to the center in the width direction of the absorber is the width of the absorber. Guided to the side of the direction.

JP-T-2003-144492

  In the absorbent article of Patent Literature 1, if the body fluid is repeatedly discharged or a large amount of the body fluid is discharged, the swelling of the absorber may cause the pressing portion to disappear, and the fluid body may have a reduced ability to draw in the body fluid. For this reason, it is difficult for body fluid to reach the side in the width direction of the absorber, and the absorption performance of the absorber may not be effectively used.

  The present invention has been made in view of the above-described problem, and has as its object to diffuse body fluid discharged to the center in the width direction of an absorber and to effectively utilize the absorption performance of the absorber.

  The absorbent article (disposable diaper 10) according to the present disclosure includes a front-rear direction (front-rear direction L), a width direction orthogonal to the front-rear direction (width direction W), an absorbent core (absorbent core 40a), and the absorbent core. And a top sheet (top sheet 50) disposed on the skin-facing surface side of the absorbent body, the absorbent body comprising: a core wrap (core wrap 40b) that covers A central region (central region 44) which is disposed at the center in the width direction of the absorber and has a central absorption layer (central absorption layer 401); A side region (side region 45) having an absorption layer and side absorption layers (first side absorption layer 402, second side absorption layer 403) arranged on the skin-facing surface side of the central absorption layer; Wherein the topsheet is provided in the central area. Are disposed over the skin facing surface side and the skin facing surface side of the side region, the density of the core wrap is higher than the density of the top sheet, and the density of the side region is the center. The point is that the density is higher than the density of the region.

It is a top view of a disposable diaper in one embodiment. It is sectional drawing of the disposable diaper along the AA line shown in FIG. It is a top view of the absorber of a deployment state. FIG. 4 is a cross-sectional view of the absorber taken along line BB of FIG. 3. It is sectional drawing which showed typically the cross section along the width direction of a top sheet and an absorber. It is sectional drawing which showed typically the disposable diaper wearing state. It is sectional drawing of the disposable diaper in a modification. Table showing the evaluation results of the penetration rate, the amount of re-wetting, the diffusivity of the core wrap on the side facing the skin, and the diffusibility of the core wrap on the side facing the non-skin side of the absorbent articles according to Example 1, Comparative Examples 1 and 2. It is.

At least the following matters will be made clear by the description in the present specification and the accompanying drawings.
Forward and backward,
A width direction orthogonal to the front-rear direction,
An absorbent body having an absorbent core and a core wrap covering the absorbent core,
A top sheet disposed on the skin-facing surface side of the absorber,
The absorber is disposed at the center in the width direction of the absorber, and has a central region having a central absorbent layer, and is disposed on both outer sides in the width direction of the central region, and the central absorbent layer and the central A side region having a side absorption layer disposed on the skin-facing surface side of the absorption layer,
The top sheet is disposed across the skin facing surface side of the central region and the skin facing surface side of the side region,
The density of the core wrap is higher than the density of the top sheet,
An absorbent article, wherein the density of the side region is higher than the density of the central region.

  When the body fluid is discharged from the wearer, it is discharged to the skin-facing surface side of the top sheet covering the central region. In the central region, only the central absorbing layer is arranged, and in the side region, the central absorbing layer and the side absorbing layer are arranged. For this reason, the thickness of the absorber in the central region is relatively thin, and the central region is recessed toward the non-skin-facing surface as compared with the side region. Since the central region is recessed toward the non-skin-facing surface side, a space extending in the front-rear direction can be formed between the wearer and the absorber. The body fluid can be diffused in the front-rear direction by the space, and it becomes easy to effectively utilize the absorption performance over the entire region in the front-rear direction of the absorber.

  Further, since the density of the core wrap is higher than the density of the top sheet, the bodily fluid is easily guided from the top sheet side to the absorber side (non-skin facing surface side). Therefore, the body fluid can be drawn into the absorber side while diffusing in the front-rear direction, and it becomes easy to effectively utilize the absorption performance over the entire area in the thickness direction of the absorber. Since the density of the side region is higher than that of the central region, the body fluid drawn into the central region is guided to the side region. The body fluid can be diffused in the width direction, and it becomes easy to effectively utilize the absorption performance over the entire width direction of the absorber.

Such an absorbent article,
The absorbent core has pulp and a super absorbent polymer,
It is desirable that the basis weight of the superabsorbent polymer in the side region is higher than the basis weight of the superabsorbent polymer in the central region.

  The side regions tend to swell when absorbing body fluids due to the relatively high basis weight of the superabsorbent polymer. As the side region swells, the volume of the space between the wearer and the absorber becomes larger, the body fluid continues to be diffused in the front-rear direction, and it becomes easy to effectively utilize the absorption performance over the entire region in the front-rear direction of the absorber. .

Such an absorbent article,
It is preferable that the core wrap is disposed on the skin-facing surface of the central absorbent layer and the non-skin-facing surface of the lateral absorbent layer in the side region.

  In the side region, a plurality of core wraps are arranged so as to overlap each other, and it is easy to guide the bodily fluid from the central absorbent layer side to the side absorbent layer side. It becomes easy to effectively utilize the absorption performance over the entire area in the thickness direction of the absorber.

Such an absorbent article,
It is desirable that the length of the side region in the width direction is equal to or greater than the thickness of the side region after absorbing body fluid.

  Since the length in the width direction of the side region is equal to or greater than the thickness after absorbing the body fluid in the side region, the side absorption layer and the central absorption layer overlap even when the absorber is deformed when worn. State is easy to maintain.

Such an absorbent article,
The top sheet has a convex portion and a concave portion that is recessed on the non-skin-facing surface side than the convex portion,
It is preferable that the convex portion and the concave portion extend in the front-rear direction and are arranged in a region overlapping the central region.

  The central region is recessed more toward the non-skin-facing surface than the side region. Therefore, the convex portion and the concave portion overlapping the central region are not easily crushed by the body pressure, and the shape thereof is easily maintained. The convex and concave portions of the top sheet allow the body fluid to diffuse in the front-back direction, and facilitate effective use of the absorption performance over the entire region in the front-back direction of the absorber.

=== About the absorbent article according to the present embodiment ===
Next, an embodiment of a disposable diaper as an absorbent article according to the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic and ratios of dimensions are different from actual ones. Therefore, specific dimensions and the like should be determined in consideration of the following description. In addition, parts having different dimensional relationships and ratios between drawings may be included.

(1) Overall Schematic Configuration of Disposable Diaper FIG. 1 is a plan view of a disposable diaper 10 as an absorbent article according to the present embodiment in an unfolded state. FIG. 2 is a sectional view of the disposable diaper 10 taken along the line AA shown in FIG. FIG. 3 is a plan view of the absorber in a deployed state. FIG. 4 is a cross-sectional view of the absorber taken along line BB shown in FIG. The plan view shown in FIG. 1 is a view in which the leg elastic portion 75 and the elastic member 77 of the three-dimensional gather are extended to a state in which wrinkles of the top sheet 50 and the side sheets 70 and the like constituting the disposable diaper are not formed. The absorbent article of the present embodiment is not limited to a disposable diaper, but may be an absorbent pad.

  The disposable diaper 10 has a front waistline region 20, a crotch region 25, and a rear waistline region 30. The front waistline region 20 is a portion that is in contact with the wearer's front waistline (belly portion). The rear waistline region 30 is a portion in contact with the wearer's rear waistline (back portion). The crotch region 25 is located between the front waist region 20 and the rear waist region 30 and is a region where the leg opening 35 is provided. The leg opening 35 is provided on the outer edge of the disposable diaper, and is a portion disposed along the wearer's leg while the disposable diaper is worn by the wearer. The outer edge is an outer end in the width direction, and the inner edge is an inner end in the width direction.

  In the present embodiment, a direction from the front waistline region 20 to the rear waistline region 30 is referred to as a front-rear direction L, a direction orthogonal to the front-rear direction L is referred to as a width direction W, and a wearer's skin facing surface side T1. The direction opposite to the skin facing surface side T1 and including the non-skin facing surface side T2 of the wearer is referred to as a thickness direction T.

The disposable diaper 10 has at least an absorber 40, a top sheet 50 arranged on the skin-facing surface side T1 of the absorber 40, and a non-skin surface sheet located on the non-skin facing surface side T2 of the absorber 40. . The absorber 40 is arranged at least in the crotch region 25. The absorber 40 has an absorption core 40a and a core wrap 40b. The absorbent core 40a can be made of the same material as a conventional disposable diaper, contains an absorbent material such as pulverized pulp or a high-absorbent polymer (SAP), and can be appropriately made of known members and materials. The core wrap 40b is a sheet that covers the absorbent core 40a that is an absorbent material. The core wrap 40b is made of various nonwoven fabrics or tissues having liquid permeability. The core wrap 40b of the present embodiment has a basis weight of 16 g / m ² and is made of a tissue having a density of 0.002 g / m ³ . The absorber 40 will be described later in detail. The top sheet 50 is formed of a liquid-permeable sheet such as a nonwoven fabric or a woven fabric. The top sheet 50 is a sheet that comes into contact with the wearer's skin. Top sheet 50 of the present embodiment has a basis weight of 27 g / m ² and is formed of an air-through nonwoven fabric having a density of 0.0003 g / m ³ . In addition, an auxiliary sheet that enhances the ability to draw in bodily fluids may be provided between the top sheet 50 and the absorber 40.

  The density of the core wrap 40b is higher than the density of the top sheet 50. Since the density of the core wrap 40b is higher than the density of the top sheet 50, the body fluid is easily guided from the top sheet 50 side to the absorber 40 side (non-skin facing surface side). Therefore, the bodily fluid can be drawn into the absorber 40 side while diffusing in the front-back direction, and it becomes easy to effectively utilize the absorption performance over the entire area of the absorber 40 in the thickness direction. Further, the bodily fluid is hardly transferred from the core wrap to the top sheet side once it is drawn to the absorber side, the liquid return is reduced, and good rewetting property can be obtained.

  The density of the core wrap 40b and the density of the top sheet 50 correspond to the density of the fibers of the core wrap 40b and the density of the fibers of the top sheet 50. The basis weight and density of the sheet (core wrap, top sheet, and the like) and the absorber in the present embodiment can be measured, for example, by the following measurement methods. A sample of the same area is cut out from the object whose basis weight is to be measured. Next, the weight of the sample is measured, and the thickness of the cross section of the sample is measured with a microscope. The basis weight is calculated by dividing each weight by the area, and the density can be calculated by dividing each weight by the volume (thickness × area).

  Further, since the density of the core wrap 40b is higher than the density of the top sheet 50, the inter-fiber distance of the core wrap 40b is smaller than the inter-fiber distance of the top sheet 50. Since the inter-fiber distance of the core wrap 40b is smaller than the inter-fiber distance of the top sheet 50, the bodily fluid is easily guided from the top sheet 50 side to the absorber 40 side (non-skin facing surface side). Generally, when the inter-fiber distance is large, the void formed between the fibers is large, and the body fluid is easily guided to the void. Since the distance between the fibers of the top sheet 50 is relatively large, the bodily fluid quickly passes (permeates) in the thickness direction of the top sheet 50. On the other hand, when the inter-fiber distance is small, the void formed between the fibers is small. In general, when the space formed between the fibers is small, the interval between the adjacent fibers is narrow, so that the bodily fluid spreads (diffuses) not only in the thickness direction but also in the plane direction along the adjacent fibers. Therefore, when the bodily fluid quickly penetrates through the top sheet 50 in the thickness direction and reaches the core wrap, the bodily fluid reaches the absorbent core through the gap in the thickness direction while diffusing in the plane direction. Therefore, the bodily fluid is easily guided from the top sheet 50 side to the absorber 40 side (non-skin facing surface side).

  The “inter-fiber distance” can be used as an alternative numerical value of the fiber density, and can be measured, for example, by the following method. The distance between fibers of the fiber structure can be measured using a mercury porosimeter (manufactured by Shimadzu Corporation) or the like in accordance with the mercury intrusion method (JIS R 1655). The mercury intrusion method is based on the pressure applied to mercury when mercury is injected between constituent fibers of a fiber structure to be measured, and the volume of mercury pushed into the space between the constituent fibers of the fiber structure. By measuring the above, information on the structure of the fibrous structure can be obtained. Specifically, it can be measured by the method described in paragraph 0036 of Japanese Patent Application No. 2014-209451.

  The back sheet 60a has liquid impermeability and is disposed on the non-skin-facing surface side T2 of the absorbent core 40a and the core wrap 40b. An exterior sheet 60 made of a nonwoven fabric is arranged on the non-skin-facing surface side T2 of the back sheet 60a.

  The side sheet 70 covers an outer edge of the top sheet 50 and extends outside the top sheet 50 in the width direction W. The inner edge of the side sheet 70 is folded outward in the width direction W, and an elastic member 77 that expands and contracts in the front-rear direction is disposed between the two layers of the side sheet 70. The side sheet 70 and the elastic member 77 constitute a three-dimensional gather. The three-dimensional gathers have elastic members 77 that expand and contract in the front-rear direction, and are arranged as a pair on both outer sides in the width direction from the center in the width direction of the disposable diaper.

  The side sheet 70 is provided with a fastening tape 90. The fastening tape 90 extends along the width direction W in the rear waist region 30 and is fixed to the target portion 95 of the front waist region 20 to hold the disposable diaper 10 on the wearer's body. The target portion 95 is configured such that a pair of fastening tapes 90 are respectively fixed thereto. On the outer side in the width direction of the absorber 40, a leg expandable portion 75 formed around the leg opening 35 and expandable in the front-rear direction L is provided.

(2) Configuration of absorber Next, the configuration of the absorber 40 will be described in detail. As shown in FIGS. 3 and 4, the absorber 40 is in the form of one sheet in a developed state. The absorber 40 has a pair of first folding lines FL1 extending in the front-rear direction L and a pair of second folding lines FL2 extending in the front-rear direction L. The pair of first fold lines FL1 and the pair of second fold lines FL2 are fold lines for folding the absorber 40, and are formed in a state where the absorber 40 is folded. The absorber 40 is folded at four locations by a pair of first fold lines FL1 and a pair of second fold lines FL2, and is stacked in a plurality of layers. The pair of first folding lines FL1, the pair of second folding lines FL2, and the first folding line FL1 and the second folding line FL2 are separated from each other in the width direction W. As shown in FIG. 3, in the deployed state of the absorber 40 (the state in which the absorber 40 is not folded by the first folding line FL1 and the second folding line FL2), the second folding line FL2 is wider than the first folding line FL1 in the width direction. It is located outside W. As shown in FIG. 2, in the folded state of the absorber 40 (the state folded by the first fold line FL1 and the second fold line FL2), the second fold line FL2 is wider than the first fold line FL1 in the width direction W. Located inside.

  In the folded state, the absorber 40 includes a central absorbent layer 401 located between the pair of first folding lines FL1, and a pair of first side portions located between the first folding line FL1 and the second folding line FL2. It has an absorption layer 402 and a pair of second side absorption layers 403 located outside the second folding line FL2 in the width direction W. The first side absorption layer 402 and the second side absorption layer 403 are arranged on the skin-facing surface side T1 of the central absorption layer 401, and constitute the side absorption layer of the present application. In the unfolded state shown in FIGS. 3 and 4, the central absorption layer 401 includes the center in the width direction W of the absorber 40 and is a region between the pair of first fold lines FL1. The first side absorption layer 402 is located on both sides of the central absorption layer 401 in the unfolded state, and is a region between the first fold line FL1 and the second fold line FL2. The second side absorption layer 403 is located on both sides of the central absorption layer 401 and the pair of first side absorption layers 402 in the unfolded state, and is located in a region outside the second folding line FL2 in the width direction. is there. The central absorption layer 401, the first side absorption layer 402, and the second side absorption layer 403 are continuous in the width direction W. The central absorption layer 401, the first side absorption layer 402, and the second side absorption layer 403 are covered by one continuous core wrap 40b. The core wrap 40b straddles the central absorption layer 401, the first side absorption layer 402, and the second side absorption layer 403.

  The absorber 40 is folded in a valley with respect to the wearer along the first fold line FL1, and is mountain-folded with respect to the wearer in accordance with the second fold line FL2. In the folded state in which the absorber 40 is folded, the first side absorbent layer 402 is disposed on the skin facing surface side T1 of the central absorbent layer 401, and the second side absorbent layer 402 is placed on the skin facing surface side T1 of the first side absorbent layer 402. The partial absorption layer 403 is disposed. The second side absorption layer 403 may be at least partially disposed on the skin-facing surface side T1 of the first side absorption layer 402. Since the absorber 40 is folded along the first folding line FL1 and the second folding line FL2, the dimension in the width direction W is compact.

  In the folded state, the pair of second folding lines FL2 are separated in the width direction W. Only the central absorption layer 401 is arranged between the pair of second fold lines FL2. The region between the pair of second fold lines FL2 is arranged at the center of the absorber 40 in the width direction W and constitutes a central region 44 having a central absorbent layer 401. The region between the first fold line FL1 and the second fold line FL2 is disposed on both outer sides in the width direction W of the central region 44, and includes the central absorption layer 401, the first side absorption layer 402, and the second side portion. The side region 45 having the absorption layer 403 is formed. The absorber 40 has at least a central region 44 and a side region 45.

  The thickness of the central region 44 is smaller than the thickness of the side region 45. In the present embodiment, the thickness of central region 44 is 3.8 to 4.4 mm, and the thickness of side region 45 is 5.0 mm to 5.4 mm. The central region 44 is recessed from the side region 45 on the non-skin-facing surface side T2. The central region 44 is recessed on the non-skin facing surface side T2, and a space S1 extending in the front-rear direction L is formed between the wearer and the absorber 40. The body fluid discharged to the crotch region can be diffused in the front-rear direction L by the space S1, and it becomes easy to effectively utilize the absorption performance over the entire region of the absorber 40 in the front-rear direction. Further, when the bodily fluid is guided from the central region 44 side to the side region 45 side, the inner edge of the side region 45 (side portion on the central region 44 side) swells with the absorption of the bodily fluid. The difference in thickness between the side region 45 and the central region 44 is increased, so that the volume of the space S1 can be secured, and the absorption performance can be more effectively utilized over the entire region of the absorber 40 in the front-rear direction.

  The outer edge of the second side absorbing layer 403 is located outside the first folding line FL1 in the width direction W. Only the second side absorption layer 403 is disposed outside the first folding line FL1 in the width direction W. When a force is applied from the outside in the width direction W to the inside in the width direction W, the second side absorption layer 403 located on the outside in the width direction is pressed inward in the width direction W. When the second side absorbent layer 403 is deformed so as to swell toward the wearer, the walls of the second side absorbent layer 403 can be provided relatively high on both sides of the central region 44. Therefore, lateral leakage of bodily fluids can be suppressed, and leakage of excrement can be further suppressed.

  The outer edge 40E of the folded absorber 40 is arranged around the wearer's leg. The outer edge 40E of the absorber 40 is the outer edge of the second side absorbing layer 403. Only the second side absorption layer 403 is disposed on the outer edge 40E of the folded absorber 40, and has a relatively small thickness. Therefore, it is possible to reduce a sense of discomfort around the leg of the wearer.

  The basis weight of the absorbent material of the first side absorbent layer 402 is lower than the basis weight of the absorbent material of the central absorbent layer 401 and lower than the basis weight of the absorbent material of the second lateral absorbent layer 403. Specifically, the central absorbent layer 401 has pulp and SAP, and the first side absorbent layer 402 has substantially no absorbent material. The first side absorbent layer 402 has a designed absorbent material such as SAP having a basis weight of zero, but may have SAP or pulp mixed in from the central absorbent layer or the like in the manufacturing process. The basis weight of the pulp of the central absorption layer 401 and the basis weight of the pulp of the second side absorption layer 403 are higher than the basis weight of the pulp of the first side absorption layer 402. The first side absorbent layer 402 may include pulp having a lower grammage than the central absorbent layer 401 or the like, or may be composed of only the core wrap 40b without including both pulp and SAP. Since the target basis weight is configured to be low, the bodily fluid can be smoothly guided to the central absorption layer 401 via the first side absorption layer 402. In the modification, the basis weight of the absorbent material of the first side absorbent layer 402 may be the same as the basis weight of the absorbent material of the central absorbent layer 401, or the absorbent material of the second lateral absorbent layer 403. May be the same as the basis weight.

  Since the basis weight of the pulp of the first side absorbent layer 402 is lower than that of the central absorbent layer 401 and the second lateral absorbent layer 403, it is possible to prevent the side region 45 from becoming too thick, and It becomes easy to guide the body fluid to the central absorption layer 401 located on the surface side T2. Further, since the pulp weight of the central absorbent layer 401 is higher than the pulp weight of the pulp of the first lateral absorbent layer 402, the bodily fluid is easily transferred from the first lateral absorbent layer 402 to the central absorbent layer 401. It becomes easy to guide the body fluid to the central absorption layer 401 located on the skin facing surface side T2. A difference in rigidity is formed between the first fold line FL1 and the second fold line FL2 due to a difference in basis weight of the pulp. Therefore, it becomes easier to fold the absorber 40 based on the first fold line FL1 and the second fold line FL2.

  The thickness of the first side absorption layer 402 is smaller than the thickness of the center absorption layer 401 and smaller than the thickness of the second side absorption layer 403. The first fold line FL1 and the second fold line FL2 are boundaries where the thickness and the basis weight of the absorber 40 change, and become boundaries where the rigidity changes. Therefore, it is easy to fold the absorber 40 based on the first fold line FL1 and the second fold line FL2.

  The basis weight of the superabsorbent polymer in the side region 45 is higher than the basis weight of the superabsorbent polymer in the central region 44. The basis weight of the side region 45 is the combined basis weight of the central absorption layer 401, the first side absorption layer 402, and the second side absorption layer 403 stacked in the side region 455. Since the side region 45 has a relatively high basis weight of the superabsorbent polymer, it swells easily when absorbing body fluid. As the side region 45 swells, the volume of the space between the wearer and the absorber becomes larger, the body fluid continues to be diffused in the front-back direction, and the absorption performance is effectively utilized throughout the front-back direction of the absorber 40. It will be easier.

  The basis weight of the pulp in the side region 45 is higher than the basis weight of the pulp in the central region 44. Since the pulp has a relatively high basis weight, the side region 45 tends to be thick in a state before the absorption of body fluid. In addition, since the side region 45 also has a high basis weight of SAP, the side region 45 is likely to be thick even in a state after absorbing body fluid. Therefore, the volume of the space S1 extending in the front-rear direction between the wearer and the absorber can be continuously maintained, the body fluid is diffused in the front-rear direction L, and the absorption performance is effectively utilized over the entire region of the absorber 40 in the front-rear direction L. Easier to do.

The density of the side region 45 is higher than the density of the central region 44. In the present embodiment, the density of the side region 45 is 0.172 to 0.186 g / m ³ , and the density of the central region 44 is 0.106 to 0.122 g / m ³ . Since the density of the side region 45 is higher than the density of the central region 44, the body fluid drawn into the central region 44 is easily guided to the side region 45. The body fluid can be diffused in the width direction W, and it becomes easy to effectively utilize the absorption performance over the entire width direction of the absorber. Note that the absorber 40 of the present embodiment is obtained by compressing in the thickness direction T with the first side absorption layer 402 and the second side absorption layer 403 arranged on the central absorption layer 401. . The density can be measured by cutting a sample from each of the central region 44 and the side region 45 and calculating by the above-described measuring method.

  The length of the side region 45 in the width direction W is equal to or greater than the thickness of the side region 45 after absorbing body fluid. Since the length in the width direction W of the side region 45 is equal to or greater than the thickness of the side region 45 after absorbing the body fluid, even when the absorber 40 is deformed at the time of wearing, the side absorption layer and the central absorption layer It is easy to maintain the state where the layers are overlapped, and it is easy to continue to absorb the body fluid repeatedly discharged. Note that the thickness of the side region 45 after absorbing the bodily fluid is a thickness in a state where the absorber 40 has absorbed the maximum amount of bodily fluid. In the present embodiment, the length of the side region 45 in the width direction W and the thickness of the side region 45 after absorbing body fluid are 8 mm.

  In the side region 45, the core wrap 40b is disposed on the skin-facing surface side T1 of the central absorbent layer 401 and on the non-skin-facing surface side T2 of the first lateral absorbent layer 402. In the side region 45, the core wraps 40b overlap at least two layers. By arranging a plurality of core wraps 40b in the side region 45, the body fluid can be easily guided from the central absorption layer 401 side to the side absorption layer side. It becomes easy to effectively utilize the absorption performance over the entire area in the thickness direction of the absorber 40. The core wrap 40b of the present embodiment is formed by laminating four layers between the central absorption layer 401 and the second side absorption layer 403 in the side region 45. Since a plurality of relatively high-density core wraps 40b are stacked, the ability to draw in bodily fluids from the top sheet 50 side to the absorber 40 side can be further improved.

(3) Configuration of Topsheet Next, the configuration of the topsheet 50 will be described in detail with reference to FIG. FIG. 5 is a cross-sectional view schematically showing a cross section of the top sheet 50 and the absorber 40 along the width direction W. The top sheet 50 has a convex part 52 and a concave part 51. The recess 51 is recessed on the non-skin-facing surface side T2 than the projection 52. The top sheet 50 has a ridge groove structure having a ridge formed by the convex portion 52 and a groove formed by the concave portion 51. The concave portion 51 and the convex portion 52 extend in the front-rear direction L, respectively. The concave portions 51 are arranged at intervals in the width direction W, and the convex portions 52 are arranged at intervals in the width direction W. The concave portions 51 and the convex portions 52 are arranged alternately in the width direction W. In the present embodiment, “extends along the front-back direction” may be any configuration having at least a certain range in the front-rear direction, and includes a configuration extending in the front-rear direction while being inclined with respect to the front-rear direction.

  Since the top sheet 50 has the concave portion 51 and the convex portion 52, and the central region 44 of the absorber 40 is recessed on the non-skin-facing surface side T2, a space S1 extending in the front-rear direction between the wearer and the absorber is provided. The body fluid can be diffused in the front-rear direction L by the unevenness of the top sheet. In addition, the convex portion 52 and the concave portion 51 overlapping the central region 44 are not easily crushed by body pressure, and the shapes thereof are easily maintained. The protrusions 52 and the recesses 51 of the top sheet 50 allow the bodily fluid to diffuse in the front-rear direction L, and facilitate effective use of the absorption performance over the entire region of the absorber 40 in the front-rear direction.

  The concave portion 51 is a portion where the basis weight of the fiber is lower than the average basis weight of the fiber of the top sheet 50, and the convex portion 52 is a portion where the basis weight of the fiber is higher than the average basis weight of the fiber of the top sheet 50. . The thickness T51 of the concave portion 51 is smaller than the thickness T52 of the convex portion 52. The density of the concave portions 51 is higher than the density of the convex portions 52. According to such a configuration, a density difference occurs between the convex portion 52 and the concave portion 51. Due to this density difference, the bodily fluid moves from the convex portion of the convex portion 52 to the concave portion 51 quickly. Therefore, the body fluid is easily drawn in by the concave portion 51 of the top sheet, and the absorbability can be improved.

  The top sheet 50 is disposed so as to straddle the skin facing surface side T1 of the central region 44 and the skin facing surface side T1 of the side region 45. The top sheet 50 extending in the width direction from the skin-facing surface side T1 of the central region 44 does not extend between the central absorbing layer 401 and the first side absorbing layer 402, and extends on the skin-facing surface side T1 of the side region 45. Extend. In the side region 45, the topsheet 50 is not disposed between the central absorption layer 401 and the first side absorption layer 402 and between the first side absorption layer 402 and the second side absorption layer 403. According to such a configuration, when a force inward in the width direction W is applied to the side region 45, the side absorption layer is less likely to move inward in the width direction W, and the deformation of the absorber 40 is effectively prevented. Can be suppressed. In addition, the folded structure of the absorber 40 can be maintained, and the three absorbent layers of the central absorbent layer 401, the first side absorbent layer 402, and the second lateral absorbent layer 403 efficiently absorb excrement and excrete it. Leakage of objects can be suppressed. In addition, since the top sheet 50 is disposed over the central region 44 and the side region 45 and is not caught between the central absorption layer 401 and the side absorption layer, the density of the top sheet 50 in the plane direction of the top sheet 50 is small. A difference is hardly generated, and local retention of urine on the surface or inside of the top sheet 50 can be suppressed. In addition, at the boundary between the central region 44 and the side region 45, a space S2 surrounded by the skin facing surface of the central region 44, the skin facing surface of the side region 45, and the top sheet 50 is formed. It can temporarily hold bodily fluids and diffuse bodily fluids in the front-back direction.

(4) Bonding mode between absorbers and bonding mode between absorber and non-skin sheet Next, the bonding mode between absorbers and the bonding mode between absorber and non-skin sheet will be described. The disposable diaper 10 is provided with a first joint R1, a second non-joint NR2, a third joint R3, and a third non-joint NR3 in the folded state in which the absorber 40 is folded. (See FIG. 6). Each joint is a region where an adhesive such as a hot-melt adhesive is arranged, and each non-joint is a region where an adhesive such as a hot-melt adhesive is not arranged or is more adhered than a joint. This is the area where the adhesive is arranged so that the force is weakened. By having the first joint portion R1, the second non-joint portion NR2, the third joint portion R3, and the third non-joint portion NR3, unintended deformation of the disposable diaper 10 when worn is suppressed, and leakage of excrement is prevented. Can be suppressed. FIG. 6 is a cross-sectional view schematically showing a disposable diaper worn state. When the disposable diaper 10 is worn on a wearer, the disposable diaper 10 is sandwiched between both feet of the wearer. A force is applied to the disposable diaper 10 from the outside in the width direction W to the inside in the width direction W. At this time, since the outer edge of the second side absorption layer 403 is located outside the first folding line in the width direction, the force from the outside in the width direction to the inside in the width direction is not applied. Hang on the outer edge of the. The second side absorbing layer 403 absorbs a force from the outside in the width direction to the inside in the width direction by being deformed. Therefore, it is possible to prevent the central absorption layer 401 from being deformed by the force.

  The first joint portion R1 is a portion where the skin-facing surface of the central absorbent layer 401 and the non-skin-facing surface of the first side absorbent layer 402 are joined. The first joining portion R1 may be provided on the entire surface where the skin-facing surface of the central absorbent layer 401 and the non-skin-facing surface of the first side absorbent layer 402 face each other, or may be provided on a part of the facing surface. It may be provided. By providing the first joining portion R1, when a force is applied to the disposable diaper 10 from the outside in the width direction to the inside in the width direction, the central absorbent layer 401 and the first side absorbent layer 402 are provided. Is prevented from shifting, and the folding structure along the first folding line FL1 is easily maintained. Therefore, it is possible to prevent the unintended deformation of the central absorbent layer 401 and the entire absorbent body from entering the width, and the absorbent body 40 can be arranged at a constant width with respect to the crotch of the wearer. The excrement can be absorbed by the absorber 40 having a certain width, and leakage of the excrement can be suppressed.

  The second non-bonded portion NR2 is a portion where the skin-facing surface of the first side absorbent layer 402 and the non-skin-facing surface of the second side absorbent layer 403 are not bonded in the worn state. The second non-joining portion NR2 is provided at least on the entire surface of the crotch region 25 where the skin facing surface of the first side absorbing layer 402 and the non-skin facing surface of the second side absorbing layer 403 face each other. The second non-joined portion NR2 straddles the center of the disposable diaper 10 in the front-rear direction, and extends in the crotch region 25 in the front-rear direction. The second non-bonded portion NR2 of the present embodiment is a region where the adhesive is not disposed, and is in a non-bonded state even in the folded state. In the second non-joined portion NR2, the skin-facing surface of the first side absorbent layer 402 and the non-skin-facing surface of the second side absorbent layer 403 are joined in the folded state, and are worn to the outside in the width direction. The structure may be such that when a force inward in the width direction is applied from the first portion, the non-joining state is established before the first joining portion. Since the skin-facing surface of the first side absorbent layer 402 and the non-skin-facing surface of the second side absorbent layer 403 are not joined in the crotch region 25 when worn, a force from the outside in the width direction to the inside in the width direction. , The left and right second side absorbent layers 403 are deformed so as to rise to the wearer side with the first side absorbent layer 402 joined to the central absorbent layer 401 as a base point, and the second side absorbent layer is formed. A space S3 is formed on the non-skin-facing surface side T2 of the layer 403. The excrement is held by the space S3 between the first side absorption layer 402 and the second side absorption layer 403, and leakage of the excretion can be suppressed.

  The third joint portion R3 is a portion where the second side absorbent layer 403 and the non-skin sheet are joined. More specifically, the non-skin-facing surface of the second side absorbent layer 403 and the skin-facing surface of the back sheet 60a as the non-skin surface sheet are joined at the third joint portion R3. The range in the front-rear direction L of the second side absorbing layer 403 is the entire area in the front-rear direction L of the absorber 40. The range in the width direction W of the third joint R3 is a certain range extending from the outer edge of the second side absorption layer 403 to the inside in the width direction W. The third joint R3 is located outside the first fold line FL1 in the width direction W, and is separated from the first fold line FL1. A third non-joined portion NR3 is provided on the inner side in the width direction W than the third joined portion R3. The third non-joined portion NR3 is a portion where the second side absorbent layer 403 and the non-skin sheet are not joined. The third non-joined portion NR3 straddles the center of the disposable diaper 10 in the front-rear direction, and extends in the front-rear direction L in the crotch region 25. The third non-joining portion NR3 is inside the third joining portion R3 in the width direction W and outside the first folding line FL1 in the width direction W. In a region inside the width direction from the first folding line FL1, the central absorption layer 401 and the back sheet 60a are joined.

  The second side absorption layer 403 and the back sheet 60a are joined by the third joint R3 and are not joined by the third non-joint NR3. Therefore, when a force is applied from the outside in the width direction W to the inside in the width direction W, the absorber 40 in contact with the third non-joining portion NR3 with the third joining portion R3 as a base point rises toward the wearer. A space S4 that is deformed and surrounded by the second side absorbent layer 403, the back sheet 60a, and the central absorbent layer 401 can be provided at least in the crotch region 25 (see FIG. 6). Urine can be accommodated by the space S4. Further, urine can be diffused in the front-rear direction L by the space S4, and body fluid can be retained in the entire region of the absorber 40 in the front-rear direction L. Therefore, even when used for a long time, the body fluid can be absorbed by the entire absorbent body 40 and leakage of the body fluid can be suppressed. In addition, moisture can be diffused in the front-rear direction L by the space S4, and stuffiness can be suppressed, and the feeling of wearing can be improved.

  The third joint R3 is arranged in a region overlapping the inner edge of the elastic member 77. In the configuration in which the three-dimensional gather has a plurality of elastic members, the inner edge of the elastic member 77 is the inner edge of the elastic member located on the innermost side in the width direction. The inner edge of the elastic member 77 of the three-dimensional gather shrinks due to the expansion and contraction of the elastic member 77 and stands on the wearer side. The absorber in a region overlapping the inner edge of the elastic member 77 is joined to the back sheet 60a by the third joint R3, and is not easily deformed. Therefore, when the three-dimensional gathers contract, the shape of the absorber 40 is easily maintained, and the three-dimensional gathers easily rise from the absorber 40 toward the wearer. Therefore, a space for accommodating excrement can be provided widely between the three-dimensional gather and the absorber 40, and leakage of excrement can be suppressed. As a result, it is possible to effectively prevent the excrement from leaking while maintaining the folded structure of the absorber 40.

(5) Absorbent Article According to Modification Next, a disposable diaper 10A as an absorbent article according to a modification will be described with reference to FIG. In the description of the modification, the same components as those of the embodiment are denoted by the same reference numerals, and description thereof will be omitted. FIG. 7 is a cross-sectional view of a cross section along a width direction of a disposable diaper 10A according to a modification. In the absorbent body 40 of the disposable diaper 10A according to the modification, the central absorbent layer 401 and the side absorbent layer 404 are not integrated, but are configured separately. The side absorption layer 404 is a single layer. The central region 44 is a region where only the central absorption layer 401 is arranged, and the side region 45 is a region where the central absorption layer 401 and the side absorption layer 404 are arranged.

  With the disposable diaper 10A according to the modified example, a space extending in the front-rear direction can be formed between the wearer and the absorber. The body fluid can be diffused in the front-rear direction by the space, and it becomes easy to effectively utilize the absorption performance over the entire region in the front-rear direction of the absorber. Further, the density of the side region 45 is higher than the density of the central region 44, and the body fluid drawn into the central region 44 is guided to the side region 45. The body fluid can be diffused in the width direction, and it becomes easy to effectively utilize the absorption performance over the entire width direction of the absorber.

(6) Example Next, comparative evaluation of the absorption performance of an absorbent article having a different core wrap will be described. Using the absorbent article according to Example 1 and the absorbent articles according to Comparative Examples 1 and 2, the penetration rate, the rewetting amount, and the diffusivity were evaluated. The absorbent article according to Example 1 and the absorbent articles according to Comparative Examples 1 and 2 are the same except for the configuration of the core wrap. The core wrap of Example 1 is disposed on the skin-facing surface side and the non-skin-facing surface side of the absorbent core, and each is constituted by a tissue having a density of 0.002 g / m ³ . The core wrap of Comparative Example 1 is disposed on the skin-facing surface side and the non-skin-facing surface side of the absorbent core, and is formed of an SMS nonwoven fabric having a density of 0.0009 g / m ³ . The absorbent article of Comparative Example 2 has no core wrap. Note that the density of the top sheet is 0.0003 g / m ³ .

  "Permeability" means the ease with which liquid excrement supplied on the surface of the top sheet 50 facing the skin is separated from the surface facing the skin to the non-skin facing surface. Then, the liquid waste is separated from the skin-facing surface side of the top sheet 50 to the non-skin-facing surface side and quantitatively evaluated based on the time required for the liquid waste to disappear from the top sheet 50 (that is, the “separation speed”). be able to.

  The permeation rate was determined by dropping 40 ml, 80 ml, and 120 ml of the simulated urine once onto the top sheet 50 of the absorbent article of the evaluation test sample, and calculating the time (seconds) in which all of the simulated urine migrated into the top sheet 50. The measured time is defined as the permeation speed (second). Next, a time (second) in which the simulated urine passes through the top sheet 50 and moves to the absorber side is measured, and the measured time is defined as a loosening speed (second). The simulated urine is prepared by dissolving 200 g of urea, 80 g of sodium chloride, 8 g of magnesium sulfate, 3 g of calcium chloride, and about 1 g of a pigment (Blue No. 1) in 10 L of ion-exchanged water.

The amount of re-wet was measured with a filter paper (Advantech Toyo Co., Ltd. Qualitative Filter Paper No. 2, 100 mm × (100 mm) 50 g were placed on top of each other, and a weight was placed on top of it so that the pressure was 35 g / cm ² . After 3 minutes, the filter paper was taken out, and the “rewet amount” was calculated according to the following equation. The smaller the rewetting amount, the smaller the liquid return, and the better the rewetting property.
Rewet amount (g) = filter paper mass after test (g)-initial filter paper mass (g)

  The diffusivity of the sheet can be evaluated, for example, by the Klemm water absorbency of the sheet measured according to JIS P8141 "Paper and paperboard-Water absorption test method-Krem method". The Klemm water absorbency is the height at which the lower end of the test piece is immersed vertically in water and the water rises for 10 minutes due to the capillary phenomenon. high.

  FIG. 8 shows the penetration speed, the amount of re-wetting, the diffusivity of the core wrap on the side facing the skin, and the diffusivity of the core wrap on the side facing the non-skin side of the absorbent articles according to Example 1, Comparative Examples 1 and 2. .

  The absorbent article according to Example 1, the absorbent article according to Comparative Example 1, and the absorbent article according to Comparative Example 2 had no significant difference in the permeation rate. However, the absorbent article according to Example 1 was able to obtain better results as compared with the comparative example in the case of 120 ml having a small amount of re-wetting and a particularly large amount of absorption. In addition, in the absorbent article according to Example 1, both the diffusivity of the core wrap on the skin facing surface side and the diffusivity of the core wrap on the non-skin facing surface side obtained high values. The absorbent article according to Example 1 obtained a high numerical value especially in the diffusivity of 80 ml and 120 ml having a large absorption amount, and was able to obtain a good result also in the diffusibility of the bodily fluid.

  As described above, the contents of the present invention have been disclosed through the embodiments of the present invention. However, it should not be understood that the description and drawings forming a part of the present disclosure limit the present invention. From this disclosure, various alternative embodiments, examples, and operation techniques will be apparent to those skilled in the art. Therefore, the technical scope of the present invention is determined only by the matters specifying the invention according to the claims that are appropriate from the above description.

  An absorbent article that can diffuse body fluid discharged to the center in the width direction of the absorber and effectively utilize the absorption performance of the absorber can be provided.

10, 10A: disposable diaper 20: front waist region 25: inseam region 30: rear waist region 40: absorber 40a: absorbent core 40b: core wrap 401: central absorbent layer 402: first side absorbent layer 403: second lateral portion Absorbing layer 44: Central area 45: Side area 50: Top sheet 51: Concave section 52: Convex section 60: Exterior sheet 60a: Back sheet L: Back and forth direction T: Thickness direction W: Width direction FL1: First fold line FL2: Second fold line R1: first joint NR2: second non-joint R3: third joint NR3: third non-joint

Claims (4)

Forward and backward,
A width direction orthogonal to the front-rear direction,
An absorbent body having an absorbent core and a core wrap covering the absorbent core,
A top sheet disposed on the skin-facing surface side of the absorber,
The absorber is disposed at the center in the width direction of the absorber, and has a central region having a central absorbent layer, and is disposed on both outer sides in the width direction of the central region, and the central absorbent layer and the central A side region having a side absorption layer disposed on the skin-facing surface side of the absorption layer,
The top sheet is disposed across the skin facing surface side of the central region and the skin facing surface side of the side region,
The density of the core wrap is higher than the density of the top sheet,
Density of the side areas, rather higher than the density of the central region,
The absorbent article , wherein the core wrap is disposed on the skin-facing surface of the central absorbent layer and the non-skin-facing surface of the side absorbent layer in the side region . The absorbent core has pulp and a super absorbent polymer,
The absorbent article according to claim 1, wherein a basis weight of the superabsorbent polymer in the side region is higher than a basis weight of the superabsorbent polymer in the central region. The absorbent article according to claim 1 , wherein a length of the side region in the width direction is equal to or greater than a thickness of the side region after absorbing body fluid. The top sheet has a convex portion and a concave portion that is recessed on the non-skin-facing surface side than the convex portion,
The absorbent article according to any one of claims 1 to 3 , wherein the convex portion and the concave portion extend in the front-rear direction and are arranged in a region overlapping the central region.

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