Absorbent article

Abstract

To provide an absorber which suppresses seepage of an adhesive agent and suppresses collapse of SAP.SOLUTION: An absorbent article (1) comprises: an absorbent layer (21) including a high absorbent polymer (SAP); and a core wrap sheet (25) arranged on one side in the thickness direction of the absorbent layer (21). On the other surface of the core wrap sheet (25) in the thickness direction, there is provided a belt-shaped adhesive agent. The average width of the belt-shaped adhesive agent is smaller than the average particle diameter of the high absorbent polymer (SAP). On the other surface of the core wrap sheet (25), when a region provided on outside of the outermost end (21e) of the absorbent layer (21) in the width direction is defined as an outside region (OR), and a region provided on inside of the outermost end (21e) is defined as an inside region (IR), the number of intersections between adhesive agents per unit area on the outside region (OR) is smaller than the number of intersections between the adhesive agents per unit area in the inside region (IR).SELECTED DRAWING: Figure 9

Description

Technical Field

[0001] The present invention relates to absorbent articles.

Background Art

[0002] Conventionally, absorbent articles provided with a so-called SAP sheet, which is formed in a sheet shape by enclosing a large number of superabsorbent polymer (SAP) particles with a base sheet (core wrap sheet), have been known. For example, Patent Document 1 discloses a technique related to an absorbent core (SAP sheet) that extends in the transverse direction and the longitudinal direction, encloses an absorbent material such as SAP in a core wrap, and is formed substantially flat.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In such a SAP sheet, conventionally, a large number of included SAP particles have generally been fixed by an adhesive applied to the inner surface of the core wrap sheet to form a flat shape. However, among a large number of SAP particles, it is difficult for the adhesive to reach the particles that do not face the surface of the core wrap sheet, and the shape of the SAP sheet is likely to collapse due to the displacement of the SAP particles. On the other hand, if the amount of the adhesive applied to the core wrap sheet is increased to suppress the displacement of the SAP particles, there is a risk that the adhesive will ooze out to the outside of the core wrap sheet.

[0005] The present invention has been made in view of the above problems, and an object thereof is to provide an absorber in which the SAP is difficult to collapse while suppressing the oozing of the adhesive.

Means for Solving the Problems

[0006] The main invention for achieving the above object is an absorbent article having, in a deployed state, a longitudinal direction, a width direction, and a thickness direction that are orthogonal to each other, an absorbent layer containing a superabsorbent polymer, and a core wrap sheet disposed on one side of the absorbent layer in the thickness direction, wherein a strip-shaped adhesive is provided on the other side surface of the core wrap sheet in the thickness direction, the average width of the strip-shaped adhesive is smaller than the average particle diameter of the superabsorbent polymer, and among the other side surface of the core wrap sheet, a region located outside the outermost end of the absorbent layer in the width direction is defined as an outer region, and a region located inside the outermost end of the absorbent layer in the width direction is defined as an inner region. When this is done, the number of intersections of the strip-shaped adhesives per unit area in the outer region is less than the number of intersections of the strip-shaped adhesives per unit area in the inner region. The absorbent article is characterized by this. Other features of the present invention will be clarified by the description in this specification and the attached drawings.

Effect of the Invention

[0007] According to the present invention, it is possible to provide an absorber in which the bleeding of the adhesive is suppressed and the SAP is difficult to collapse.

Brief Description of the Drawings

[0008]

Figure 1

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Figure 13

MODE FOR CARRYING OUT THE INVENTION

[0009] At least the following matters become clear from the description of this specification and the accompanying drawings. (Aspect 1) In the unfolded state, an absorbent article having an absorption layer having a longitudinal direction, a width direction, and a thickness direction that are perpendicular to each other and containing a superabsorbent polymer, and a core wrap sheet disposed on one side in the thickness direction of the absorption layer, wherein a strip-shaped adhesive is provided on the other side surface of the core wrap sheet in the thickness direction, the average width of the strip-shaped adhesive is smaller than the average particle size of the superabsorbent polymer, and among the other side surfaces of the core wrap sheet, a region located outside the outermost end of the absorption layer in the width direction is defined as an outer region, and a region located inside the outermost end of the absorption layer in the width direction is defined as an inner region, the number of intersections of the strip-shaped adhesives per unit area in the outer region is smaller than the number of intersections of the strip-shaped adhesives per unit area in the inner region. An absorbent article characterized by this.

[0010] According to the absorbent article of Aspect 1, since the strip-shaped adhesive is provided with a width narrower than the SAP particle diameter, the adhesive easily enters the gaps between the SAP particles, the SAP particles are fixed to each other, and collapse of the shape is suppressed. Further, in the core wrap sheet, in the outer region in the width direction where the SAP particles are not arranged, the bleeding of the adhesive is suppressed by reducing the coating density of the adhesive so that the number of intersections between the adhesives is smaller than that in the inner region in the width direction where the SAP particles are arranged.

[0011] (Aspect 2) The absorbent article according to Aspect 1, wherein a minimum value of the distance between intersections of the strip-shaped adhesives is smaller than an average particle diameter of the superabsorbent polymer when swollen.

[0012] According to the absorbent article of Aspect 2, even when the SAP particles swell by absorbing excreted liquid during use, it becomes difficult for the SAP particles to protrude from the mesh of the strip-shaped adhesive. Thereby, it becomes difficult for the absorption layer (one-side absorption layer) to collapse.

[0013] (Aspect 3) The absorbent article according to Aspect 1 or 2, wherein a minimum value of the distance between intersections of the strip-shaped adhesives is smaller than an average particle diameter of the superabsorbent polymer when not swollen.

[0014] According to the absorbent article of Aspect 3, even before use, it becomes difficult for the SAP particles to protrude from the mesh formed by the intersection of a large number of strip-shaped adhesives. For example, displacement of the position of the SAP during the distribution process of the absorbent article and collapse of the absorption layer (absorbent core) before use are suppressed.

[0015] (Aspect 4) The absorbent article according to any one of Aspects 1 to 3, wherein a thickness of the absorption layer is larger than 1.5 times an average particle diameter of the superabsorbent polymer.

[0016] According to the absorbent article of Aspect 4, in the absorption layer (absorbent core), since at least SAP particles are laminated more than 1.5 layers, water absorption and water retention can be improved as compared with the case of a single-layer absorbent core in which SAP particles are arranged in a planar manner.

[0017] (Aspect 5) The absorbent article according to any one of Aspects 1 to 4, wherein at least a part of the strip-shaped adhesive is present at the central position in the thickness direction of the absorption layer.

[0018] According to the absorbent article of Aspect 5, since the adhesive penetrates to the inside of the absorption layer, displacement between SAP particles is less likely to occur, and the absorption layer (absorbent core) can be made difficult to collapse.

[0019] (Aspect 6) The absorbent article according to any one of Aspects 1 to 5, wherein the residual stress of the adhesive for fixing the superabsorbent polymer to the core wrap sheet is 2 KPa or more and 20 KPa or less.

[0020] According to the absorbent article of Aspect 6, the adhesive for fixing the SAP particles has a resistance (residual stress) such that the SAP particles are not detached from the core wrap sheet (base material sheet) even when an external force or the like is applied. As a result, the probability that the fixing rate of the SAP particles becomes 40% or more increases, and the absorption layer (absorbent core) can be made difficult to collapse.

[0021] (Aspect 7) The absorbent article according to any one of Aspects 1 to 6, which has an intermediate sheet on the other side in the thickness direction of the absorption layer, and a strip-shaped adhesive is provided on one side surface in the thickness direction of the intermediate sheet, and the average width of the strip-shaped adhesive provided on the other side surface of the core wrap sheet is smaller than the average width of the strip-shaped adhesive provided on one side surface of the intermediate sheet.

[0022] According to the absorbent article of Aspect 7, since the adhesive is not excessively applied to the skin side (the other side) of the core wrap sheet, it is possible to suppress the seepage of the adhesive to the non-skin side of the core wrap sheet. On the other hand, if the adhesive is provided in a relatively large amount on the non-skin side (one side) of the intermediate sheet, it means that the amount of the adhesive discharged toward the SAP particles is also large. Therefore, the SAP particles can be more firmly fixed to each other, and the collapse of the absorption layer (absorbent core) can be suppressed.

[0023] (Aspect 8) An absorbent article according to any one of Aspects 1 to 6, wherein an intermediate sheet is provided on the other side in the thickness direction of the absorption layer, a strip-shaped adhesive is provided on one side surface of the intermediate sheet in the thickness direction, and an average width of the strip-shaped adhesive provided on the other side surface of the core wrap sheet is larger than an average width of the strip-shaped adhesive provided on the one side surface of the intermediate sheet.

[0024] According to the absorbent article of Aspect 8, since the amount of the adhesive provided on the intermediate sheet is reduced, it becomes difficult to inhibit the movement of the excreted liquid in the thickness direction in the intermediate sheet. As a result, it is possible to smoothly transfer the excreted liquid and the like to the absorption layer provided on the non-skin side (one side) in the thickness direction of the intermediate sheet.

[0025] (Aspect 9) An absorbent article according to any one of Aspects 1 to 8, wherein the absorption layer is a region having a predetermined width in the width direction and has a low basis weight region where the basis weight is lower than that of the surroundings.

[0026] According to the absorbent article of Aspect 9, in the low basis weight region, it is more difficult to absorb the excreted liquid than in other regions, and the excreted liquid is likely to spread along the low basis weight region. Therefore, even when a force that compresses the absorption layer in the thickness direction acts on the wearer when the absorbent article is worn, such as when the wearer takes a sitting posture, it is possible to easily draw the excreted liquid into the inside of the absorption layer.

[0027] (Aspect 10) The average basis weight of the low basis weight region is greater than 0% and 50% or less of the average basis weight of the region other than the low basis weight region in the absorbent layer, and the absorbent article according to any one of Aspects 1 to 9.

[0028] According to the absorbent article of aspect 10, by setting the average basis weight in the low basis weight region to 50% or less of the average basis weight of other regions, the difference in average basis weight becomes larger compared to the case where it is greater than 50%, and it is possible to easily move liquids such as excreted liquid along the low basis weight region. Further, if the average basis weight in the low basis weight region is greater than 0%, it is possible to suppress at least the entire low basis weight region from being configured as a slit, and it becomes easier to ensure the strength of the low basis weight region.

[0029] (Aspect 11) The minimum value of the distance between the intersections of the strip-shaped adhesives is smaller than the width of the low basis weight region, and the absorbent article according to any one of Aspects 1 to 10.

[0030] According to the absorbent article of aspect 11, since at least one intersection of the adhesives is provided between both end portions of the low basis weight region, it becomes easier to fix the SAP particles in the low basis weight region having low rigidity. Further, there is a high possibility that adhesives exist at both end portions of the low basis weight region. Therefore, it is possible to suppress the low basis weight region in the absorbent layer (absorbent core) from collapsing or being crushed.

[0031] (Aspect 12) On the other side in the thickness direction of the absorbent layer, there is an intermediate sheet, and in the low basis weight region, there is a portion where the core wrap sheet and the intermediate sheet are joined in the thickness direction, and the absorbent article according to any one of Aspects 1 to 11.

[0032] According to the absorbent article of Aspect 12, if the core wrap sheet and the intermediate sheet are joined at at least a part of the portion where the low basis weight region is provided, movement of the SAP particles across the low basis weight region is suppressed. That is, each of the absorbent layers (absorbent cores) divided by the low basis weight region is likely to maintain its shape independently. Therefore, it is difficult for the absorbent layer (absorbent core) as a whole to collapse.

[0033] (Aspect 13) An absorbent article according to any one of Aspects 1 to 12, having an absorber including the absorbent layer and the core wrap sheet, and having intermittent regions where the superabsorbent polymer is not provided at front and rear ends in the longitudinal direction of the absorber.

[0034] According to the absorbent article of Aspect 13, since no SAP particles are arranged in the intermittent region, the core wrap sheet is likely to be directly joined to a member (for example, an intermediate sheet or the like) arranged to face in the thickness direction. As a result, the SAP particles constituting the absorbent layer (absorbent core) are less likely to jump out to both ends in the front-rear direction, and the absorbent layer is less likely to collapse.

[0035] (Aspect 14) An absorbent article according to any one of Aspects 1 to 13, wherein an average basis weight of the superabsorbent polymer on the front side of the central position in the longitudinal direction of the absorber is smaller than an average basis weight of the superabsorbent polymer on the rear side of the central position in the longitudinal direction of the absorber.

[0036] According to the absorbent article of Aspect 14, by increasing the average basis weight of the SAP particles in the longitudinal front region located near the wearer's excretion opening during wearing, it becomes easier to quickly absorb excreted liquids such as urine, and urine leakage on the ventral side can be suppressed.

[0037] (Aspect 15) The average basis weight of the superabsorbent polymer on the front side of the absorber in the longitudinal direction is equal to or greater than the average basis weight of the superabsorbent polymer on the rear side of the absorber in the longitudinal direction. The absorbent article according to any one of Aspects 1 to 13.

[0038] According to the absorbent article of Aspect 15, when worn, by increasing the average basis weight of the SAP particles in the longitudinal rear region located on the wearer's back side (hip side), it is possible to suppress the excretion fluid such as urine from flowing around the hip to the back side and leaking outward from the upper end of the back side.

[0039] (Aspect 16) The absorbent article according to any one of Aspects 1 to 15, wherein a second absorbent layer containing the superabsorbent polymer and liquid-absorbent fibers is laminated with the absorbent layer in the thickness direction.

[0040] According to the absorbent article of Aspect 16, since the absorbent core has a laminated structure of two or more layers (absorbent layer and second absorbent layer), the water absorption and water retention capacity are improved as compared with the case where the absorbent core has only one layer.

[0041] (Aspect 17) The absorbent article according to any one of Aspects 1 to 16, wherein the second absorbent layer is disposed on the other side of the absorbent layer.

[0042] According to the absorbent article of Aspect 17, since the second absorbent layer containing liquid-absorbent fibers having a faster water absorption rate than the SAP particles is disposed on the skin side (the other side) in the thickness direction, the excretion fluid is quickly drawn from the skin side to the non-skin side and is easily retained by the absorbent layer disposed on the non-skin side. As a result, the DRY property is improved on the skin side, and it is possible to make it difficult for the wearer to feel discomfort or uneasiness.

[0043] (Aspect 18) The absorbent article according to any one of Aspects 1 to 16, wherein the second absorbent layer is disposed on the one side of the absorbent layer.

[0044] According to the absorbent article of Aspect 18, since the absorbent layer containing SAP particles having a higher water retention property than the liquid-absorbent fibers is disposed on the non-skin side (one side) in the thickness direction, the water retention property on the skin side is enhanced, and it is possible to hardly cause rewet. Therefore, it is possible to hardly cause discomfort or unpleasantness to the wearer.

[0045] (Aspect 19) The absorbent article according to any one of Aspects 1 to 18, wherein the core wrap sheet is composed of a nonwoven fabric.

[0046] According to the absorbent article of Aspect 19, when applying an adhesive or laminating SAP particles while conveying a nonwoven fabric as a base sheet in the MD direction, since the base sheet made of the nonwoven fabric is hardly torn, an absorber (absorbent core) having a stable shape can be formed. Further, by conveying the base sheet while sucking it by a suction mechanism or the like, it is possible to easily fix the SAP particles on the base sheet.

[0047] (Aspect 20) An absorber having a longitudinal direction, a width direction, and a thickness direction that are orthogonal to each other, and having a base sheet and a superabsorbent polymer laminated on the base sheet, the superabsorbent polymer having a high basis weight region where the basis weight is higher than the surroundings, the high basis weight region being arranged such that the point having the maximum thickness in the thickness direction is intermittently located in the longitudinal direction and the width direction, the maximum thickness being within 3 mm, and the interval between adjacent points having the maximum thickness being not more than 5 times the maximum thickness.

[0048] According to Aspect 20, the high flatness regions are arranged such that the points with the maximum thickness in the thickness direction are intermittently located in the longitudinal direction and the width direction, and low flatness regions are formed around each of the high flatness regions. The absorber is easily deformed along the unevenness of the wearer's body with the low flatness regions as folding starting points, improving the fit. Also, since the maximum thickness of the absorber is within 3 mm and the distance between adjacent points with the maximum thickness is 5 times or less the maximum thickness, a large number of high flatness regions and low flatness regions can be arranged while maintaining the thinness of the absorber. Therefore, according to Aspect 20, in an absorber having a superabsorbent polymer, the thinness can be maintained while improving the fit during wearing.

[0049] (Aspect 21) An absorber according to Aspect 20, wherein the maximum thickness is within 2 mm and the distance between adjacent points with the maximum thickness is 4 times or less the maximum thickness.

[0050] According to Aspect 20, in an absorber having a superabsorbent polymer, the thinness can be further maintained while improving the fit during wearing.

[0051] (Aspect 22) An absorber according to Aspect 20, wherein the high flatness region does not contain fibrous materials other than the superabsorbent polymer.

[0052] According to Aspect 22, a thinner absorber can be formed compared to an absorber containing fibrous materials.

[0053] (Aspect 23) An absorber according to Aspect 20, wherein in plan view, the diameter of the circumscribed circle circumscribing each of the plurality of high flatness regions is 2 mm or more and 4 mm or less.

[0054] According to Aspect 23, by reducing the size of each of the plurality of high areal weight regions in plan view, a large number of high areal weight regions and low areal weight regions can be arranged on the base sheet, and the absorber can be easily deformed along the unevenness of the wearer's body, improving the fit.

[0055] (Aspect 24) An absorber according to Aspect 20, characterized by having a low areal weight laminated region in which the superabsorbent polymer is laminated between adjacent points of the maximum thickness, and a non-laminated region in which there is no superabsorbent polymer between other adjacent points of the maximum thickness.

[0056] According to Aspect 24, as a low areal weight region serving as a folding start point, it has a low areal weight laminated region capable of absorbing and holding excreted liquid, and a non-laminated region that is more easily bendable due to the absence of a superabsorbent polymer. Therefore, even in the low areal weight region, it is possible to achieve both ease of deformation along the unevenness of the wearer's body and the absorption and holding power of excreted liquid.

[0057] (Aspect 25) An absorber according to Aspect 24, characterized in that the low areal weight laminated region is intermittently arranged in the longitudinal direction and the width direction, and the non-laminated region is intermittently arranged in the longitudinal direction and the width direction.

[0058] According to Aspect 25, by arranging the low areal weight laminated region and the non-laminated region sparsely in a plane, it is possible to have both ease of deformation along the unevenness of the wearer's body and the absorption and holding power of excreted liquid with a planar spread.

[0059] (Aspect 26) An absorber according to Aspect 25, characterized in that in plan view, among the diameters of the inscribed circles inscribed in each of the plurality of non-laminated regions, the maximum diameter is equal to or less than the maximum thickness.

[0060] According to Aspect 26, by reducing the size in plan view of the non-laminated region without the superabsorbent polymer, leakage of excreted liquid through the non-laminated region can be suppressed.

[0061] (Aspect 27) An absorber according to Aspect 26, wherein the number of the low basis weight laminated regions is different in each region trisected in the longitudinal direction, or the number of the non-laminated regions is different in each region trisected in the longitudinal direction.

[0062] According to Aspect 27, by arranging the low basis weight laminated regions and the non-laminated regions randomly in a plane, the absorber can be easily deformed along the unevenness of the wearer's body, and the fit can be improved.

[0063] (Aspect 28) An absorber according to Aspect 25, wherein the number of points where the non-laminated region is adjacent and located on one side or the other side in the width direction among the points having the maximum thickness is larger than the number of points where the non-laminated region is adjacent and located on one side or the other side in the longitudinal direction.

[0064] According to Aspect 28, it is possible to suppress the loss of flexibility in the width direction when the absorber is in a swollen state.

[0065] (Aspect 29) An absorber according to Aspect 20, having another sheet positioned so as to sandwich the superabsorbent polymer between the substrate sheet, and having a joined region where the substrate sheet and the another sheet are joined between adjacent points having the maximum thickness, and a non-joined region where the substrate sheet and the another sheet are not joined between another adjacent points having the maximum thickness.

[0066] According to Aspect 29, by having a joined region serving as a folding start point and a non-joined region where the superabsorbent polymer can be disposed between the substrate sheet and another sheet, it is possible to achieve both ease of deformation along the unevenness of the wearer's body and absorption and retention power of excreted liquid.

[0067] (Aspect 30) The absorber according to Embodiment 20, wherein a difference between a highest point and a lowest point in the thickness direction on one surface side of the base sheet is different from a difference on the other surface side of the base sheet.

[0068] According to Aspect 30, an absorber having characteristics according to the purpose can be formed.

[0069] (Aspect 31) The absorber according to Aspect 30, having a non-laminated region on one surface side of the base sheet where the superabsorbent polymer does not exist between adjacent points having the maximum thickness, and in a plan view, among diameters of inscribed circles inscribed in each of a plurality of the non-laminated regions, the maximum diameter is equal to or less than the difference on the one surface side.

[0070] According to Aspect 31, by reducing the size in a plan view of the non-laminated region without the superabsorbent polymer, leakage of excreted liquid through the non-laminated region can be suppressed.

[0071] (Aspect 32) The absorber according to Aspect 30, wherein a weight of the superabsorbent polymer laminated below the highest point on one surface side of the base sheet is 50% or more of a weight of the superabsorbent polymer laminated on the entire base sheet.

[0072] According to Aspect 32, by laminating a desired weight of the superabsorbent polymer in a concave region of the base sheet, a high basis weight region can be formed at an appropriate position.

[0073] (Aspect 33) The absorber according to aspect 30, when a region below the intermediate position between the highest point and the lowest point is defined as a concave region, in a plan view, the sum of the lengths of the plurality of concave regions on a virtual line passing through the centers of the plurality of concave regions along the longitudinal direction is 50% or more of the length of the entire base material sheet.

[0074] According to aspect 33, by laminating a superabsorbent polymer on a desired region of the base material sheet, a high basis weight region and a low basis weight region can be formed at appropriate positions.

[0075] (Aspect 34) The absorber according to aspect 30, when a region below the intermediate position between the highest point and the lowest point is defined as a concave region, in a plan view, the sum of the lengths of the plurality of concave regions on a virtual line passing through the centers of the plurality of concave regions along the width direction is 50% or more of the length of the entire base material sheet.

[0076] According to aspect 34, by laminating a superabsorbent polymer on a desired region of the base material sheet, a high basis weight region and a low basis weight region can be formed at appropriate positions.

[0077] ===Embodiment=== As an absorbent article according to the present invention, a pant-type disposable diaper 1 for infants (hereinafter also referred to as "diaper 1") will be described as an example. However, the absorbent articles according to the present invention include tape-type disposable diapers, short-type napkins, absorbent pads, sanitary napkins, and other absorbent articles. Further, the wearer of the absorbent article is not limited to infants, and may be a living organism such as an adult or an animal.

[0078] <Configuration of Diaper 1> FIG. 1 is a schematic perspective view of the diaper 1. FIG. 2 is a plan view of the diaper 1 in a deployed and extended state as seen from the skin side. FIG. 3 is a schematic cross-sectional view taken along the center line CL of FIG. 2. The “extended state” of the diaper 1 refers to a state in which the entire diaper 1 is extended without wrinkles. Specifically, it refers to a state in which the dimensions of each member constituting the diaper 1 (for example, the absorbent body 10, the waist circumferential portions 30, 40, etc. described later) are extended until they match or are close to the dimensions of the member alone. The “deployed state” of the diaper 1 refers to a state in which the pair of side joints 2 provided on both sides of the diaper 1 are separated and the diaper 1 is opened and flattened.

[0079] The diaper 1 has a vertical direction, a width direction, and a front-back direction that are orthogonal to each other, and has a waist opening BH and a pair of leg openings LH. The upper side in the vertical direction corresponds to the waist opening BH side, and the lower side corresponds to the crotch side. The front side in the front-back direction corresponds to the front side of the wearer, and the rear side corresponds to the back side of the wearer. The width direction is a direction along the expansion and contraction direction of the thread rubbers 33, 43 of the front waist circumferential portion 30 and the rear waist circumferential portion 40. The vertical direction is a direction along the orthogonal direction orthogonal to the expansion and contraction direction.

[0080] The diaper 1 is a so-called three-piece type pant diaper having a liquid-absorbent absorbent body 10 and a pair of waist circumferential portions 30, 40. Of the pair of waist circumferential portions, the one that covers the abdominal side of the wearer is also referred to as the front waist circumferential portion 30, and the one that covers the back side of the wearer is also referred to as the rear waist circumferential portion 40.

[0081] In the unfolded state of FIG. 2, the diaper 1 has a longitudinal direction, a width direction, and a thickness direction that are perpendicular to each other. The longitudinal direction is along the longitudinal direction of the absorbent body 10 and along the up-and-down direction of the pant-type diaper 1. The thickness direction is the direction in which the materials constituting the diaper 1 are laminated, as shown in FIG. 3. The side in contact with the wearer's skin in the thickness direction is defined as the skin side, and the opposite side is defined as the non-skin side. Further, in the unfolded state, the front torso portion 30 and the rear torso portion 40 are arranged in parallel with a longitudinal interval therebetween, and the absorbent body 10 is stretched between them. Each longitudinal end of the absorbent body 10 is joined and fixed to the skin side of the nearest torso portions 30 and 40, respectively, and the external shape forms a substantially H shape in plan view. Then, from this state, it is folded in half along the center line CL in the longitudinal direction of the absorbent body 10. In this folded state, the front torso portion 30 and the rear torso portion 40 facing each other are joined and connected at the side portions on both sides in the width direction, forming a pair of side joining portions 2. The side joining portions 2 are formed by known joining means such as welding and adhesion.

[0082] The absorbent body 10 has an absorber 20 (details will be described later), a liquid-permeable topsheet 12 disposed closer to the skin side than the absorber 20, and a backsheet 13 disposed closer to the non-skin side than the absorber 20. The backsheet 13 has a two-layer structure of a liquid-impermeable sheet 13a and a hydrophobic exterior sheet 13b disposed on the non-skin side thereof. However, the absorbent body 10 may be provided with other sheet members. For example, a second sheet (not shown) may be provided between the topsheet 12 and the absorber 20 in the thickness direction.

[0083] On both sides in the width direction of the absorbent body 10, a pair of leak - proof wall portions 15 are provided along the longitudinal direction of the absorbent body 10. In FIG. 3, in the width direction, a part of the outer packaging sheet 13b extends outside both ends of the absorbent body 20 and is bent at a plurality of locations on the skin - side, thereby forming a pair of leak - proof wall portions 15. At the tip of the leak - proof wall portion 15, a leak - proof wall elastic member 16 such as a thread rubber is attached in a state of extending along the longitudinal direction of the absorbent body 10, and the leak - proof wall portion 15 is configured to be able to stand up on the skin - side. Also, on both sides in the width direction of the absorbent body 10, leg - around elastic members 17 such as thread rubber are attached in a state of extending along the longitudinal direction of the absorbent body 10.

[0084] The front - side body - around portion 30 and the rear - side body - around portion 40 each have a skin - side sheet 31, 41, a non - skin - side sheet 32, 42, and a plurality of body - around elastic members 33, 43 such as thread rubber. The plurality of body - around elastic members 33, 43 are arranged side by side in the vertical direction between the skin - side sheet 31, 41 and the non - skin - side sheet 32, 42 and are attached in a state of extending in the width direction. Due to the elasticity of the body - around elastic members 33, 43, the front - side body - around portion 30 and the rear - side body - around portion 40 fit around the wearer's body. Also, cover sheets 34, 44 may be provided so as to cover the upper end portion of the absorbent body 10 from the skin - side. The cover sheets 34, 44 can suppress the opening of the absorbent body 10.

[0085] Also, as shown in FIG. 2, the planar shapes of the front - side body - around portion 30 and the rear - side body - around portion 40 in the deployed and extended state are different. The front - side body - around portion 30 has a length in the vertical direction that is approximately the same as that of the side joint portion 2 and is a rectangular shape that is long in the width direction. The rear - side body - around portion 40 has a rectangular portion that overlaps with the front - side body - around portion 30 and a substantially trapezoidal portion 40E that extends downward from it. The extended portion 40E can cover the wearer's buttocks.

[0086] Although the basic configuration of the diaper 1 has been described above, the above configuration is only an example and is not limited thereto. For example, the front torso portion 30 and the rear torso portion 40 may be formed of a single continuous member, or an outer member of the crotch portion connecting the front torso portion 30 and the rear torso portion 40 may be provided. Further, the elastic members such as the torso elastic members 33 and 43 may be sheet-like elastic members instead of thread rubber.

[0087] <Regarding the absorber 20> FIG. 4 is a schematic cross-sectional view of the absorber 20. FIG. 5 is a plan view of the absorbent cores 21 to 23 superimposed. In FIG. 4, one side in the thickness direction is defined as the non-skin side, and the other side in the thickness direction is defined as the skin side.

[0088] As shown in FIG. 4, the absorber 20 has absorbent cores 21 to 23 and an intermediate sheet 26 between a core wrap sheet 25 provided on one side (non-skin side) and a core wrap sheet 24 provided on the other side (skin side) in the thickness direction. The absorbent cores 21 to 23 are members that absorb and hold excreted liquids such as urine and contain liquid-absorbent fibers 201 and superabsorbent polymers. The liquid-absorbent fibers 201 and the superabsorbent polymers (Super Absorbent Polymer: hereinafter also referred to as SAP) are not particularly limited as long as they can be used as the absorbent core of the absorbent article. For example, examples of the liquid-absorbent fibers 201 include wood pulp fibers, non-wood pulp fibers such as bagasse, kenaf, bamboo, hemp, and cotton, regenerated cellulose fibers such as rayon fibers, and semi-synthetic fibers such as acetate fibers. Examples of SAP include starch-based, cellulose-based, and synthetic polymer-based high molecular absorbents. Further, the core wrap sheets 24 and 25 and the intermediate sheet 26 are liquid-permeable sheets, and examples thereof include tissue and non-woven fabric.

[0089] The absorbent cores 21 to 23 have, in order from one side (non-skin side) to the other side (skin side) in the thickness direction, a one-side absorbent layer 21, an intermediate absorbent layer 22, and an other-side absorbent layer 23. The one-side absorbent layer 21 and the other-side absorbent layer 23 are layers in which the volume occupied by the SAP is larger than the volume occupied by the liquid-absorbent fibers 201. The intermediate absorbent layer 22 is a layer in which the volume occupied by the liquid-absorbent fibers 201 is larger than the volume occupied by the SAP. In FIG. 4, while the other-side absorbent layer 23 and the intermediate absorbent layer 22 are integrally formed so as to be adjacent to each other in the thickness direction, the one-side absorbent layer 21 is provided separately from the intermediate absorbent layer 22 and the other-side absorbent layer 23 by an intermediate sheet 26. Further, in FIG. 4, among the integrally formed other-side absorbent layer 23 and intermediate absorbent layer 22, the other-side absorbent layer 23 is mainly composed of SAP, and the intermediate absorbent layer 22 is mainly composed of liquid-absorbent fibers 201. That is, the other-side absorbent layer 23 and the intermediate absorbent layer 22 are configured as different types of layers. On the other hand, the intermediate absorbent layer 22 and the other-side absorbent layer 23 may be configured in a state where the SAP and the liquid-absorbent fibers 201 are uniformly mixed. That is, the intermediate absorbent layer 22 and the other-side absorbent layer 23 may be formed as the same type of layer.

[0090] The one-side absorbent layer 21 is formed in a substantially rectangular shape in plan view as shown in FIG. 5, and has a low basis weight region 211 where the basis weight of the absorbent core (that is, the total basis weight of the liquid-absorbent fibers 201 and the SAP: g / m 2 ) is lower than that of the periphery. In FIG. 5, two low basis weight regions 211, 211 are provided along the longitudinal direction on both sides of the center position CW in the width direction. Due to these low basis weight regions 211, 211, the one-side absorbent layer 21 is divided into three divided regions 21a to 21c. By providing the low basis weight region 211 in the one-side absorbent layer 21, excreted liquids such as urine easily move in the thickness direction and the longitudinal direction of the one-side absorbent layer 21, and it becomes easier to hold the liquid such as excreted liquid in the SAP over a wide range of the one-side absorbent layer 21.

[0091] Incidentally, the low basis weight region 211 may be a slit that penetrates the one-side absorption layer 21 in the thickness direction. In this case, it is possible to efficiently diffuse liquid such as exudate over a wide range of the low basis weight region 211. However, liquid-absorbent fibers 201 and SAP may be present in the low basis weight region 211 of the one-side absorption layer 21. Also, the low basis weight region 211 may be a part of the one-side absorption layer 21 that is recessed in the thickness direction.

[0092] The intermediate absorption layer 22 and the other-side absorption layer 23 are integrally formed and have the same planar shape. In the present embodiment, as shown in FIG. 5, in the central portion in the longitudinal direction, it is formed in a substantially hourglass shape having constricted portions 222 and 232 constricted inward in the width direction. Also, in FIG. 5, a part of the one-side absorption layer 21 extends outward in the width direction from the constricted portions 222 and 232 of the intermediate absorption layer 22 and the other-side absorption layer 23. With such a configuration, while reducing the discomfort when the wearer opens and closes the legs by the constricted portions 222 and 232, it is possible to dispose SAP outside the constricted portions 222 and 232 of the intermediate absorption layer 22 and the other-side absorption layer 23 having a narrow width. Thereby, while improving the fit in the crotch portion of the wearer, lateral leakage of excreted liquid can be suppressed.

[0093] Similar to the one-side absorption layer 21, at least one of the intermediate absorption layer 22 and the other-side absorption layer 23 has a basis weight of the absorbent core (total basis weight of the liquid-absorbent fibers 201 and SAP: g / m 2) preferably has a low basis weight region. As shown in FIG. 4, in the absorber 20 of the present embodiment, both the intermediate absorption layer 22 and the other-side absorption layer 23 have low basis weight regions 221 and 231. When the wearer excretes into the diaper 1 and the other-side absorption layer 23 provided on the skin side receives the excreted liquid, the excreted liquid is quickly drawn into the interior (intermediate absorption layer 22) of the absorber 20 from the low basis weight region 231. In the intermediate absorption layer 22, since the volume occupancy rate of the liquid-absorbent fibers 201, which have a higher liquid absorption rate than SAP, is high, the excreted liquid that has migrated from the low basis weight region 231 to the intermediate absorption layer 22 is quickly temporarily absorbed by the intermediate absorption layer 22. Also, in the other-side absorption layer 23, the volume occupancy rate of SAP, which has a low liquid absorption rate, is high. Therefore, even in the region of the other-side absorption layer 23 other than the low basis weight region 231, the excreted liquid is likely to migrate to the intermediate absorption layer 22 before being absorbed by the SAP in the other-side absorption layer 23.

[0094] Thereafter, the excreted liquid absorbed between the fibers of the liquid-absorbent fibers 201 in the intermediate absorption layer 22 gradually migrates to the one-side absorption layer 21 by gravity. In the one-side absorption layer 21, the volume occupancy rate of SAP is high. Therefore, the excreted liquid is firmly absorbed and held by the SAP in the one-side absorption layer 21. Thus, in the absorber 20 of the present embodiment, the excreted liquid can be quickly drawn in and held from the skin side to the non-skin side of the absorbent cores 21 to 23.

[0095] In each layer of the absorbent cores 21 to 23, the comparison of the volumes occupied by the liquid-absorbent fibers 201 and the SAP can be confirmed by a well-known method. For example, in the diaper 1 in a natural state without an external force acting thereon and in a dry state, at an arbitrary position in the longitudinal direction of the absorbent body 20, specifically, at a location where the three layers 21 to 23 are laminated and at a location away from the product folding position, the diaper 1 (absorbent body 20) is cut along the width direction. Next, using an optical microscope (e.g., Keyence digital microscope VHX-7000 or equivalent), the cut surface is magnified (e.g., 30 to 100 times) and photographed. In the photographed cross-sectional image, the liquid-absorbent fibers 201 and the SAP are identified. Then, in the cross-sectional image, it is confirmed that the one-side absorbent layer 21 in which the area occupied by the SAP is larger than the area occupied by the liquid-absorbent fibers 201, the intermediate absorbent layer 22 in which the area occupied by the liquid-absorbent fibers 201 is larger than the area occupied by the SAP, and the other-side absorbent layer 23 in which the area occupied by the SAP is larger than the area occupied by the liquid-absorbent fibers 201 are laminated in order from one side (non-skin side) in the thickness direction. When the above is confirmed, the absorbent cores 21 to 23 of the present embodiment are used. Preferably, it is desirable to confirm that the three layers 21 to 23 are overlapped in cross-sectional images at a plurality of locations in the longitudinal direction of the absorbent body 20. Also, based on the photographed cross-sectional image, it can be confirmed that the one-side absorbent layer 21 has a low basis weight region 211 and that the low basis weight region 211 is a slit.

[0096] <Regarding the formation of the absorbent body 20> Next, an outline of the method for forming the absorbent body 20 will be described. Here, a method for forming mainly the one-side absorbent layer 21 among the absorbent body 20 will be described. FIG. 6 is a diagram schematically showing a part of an absorbent body forming apparatus 100 for forming the absorbent body 20. The absorbent body forming apparatus 100 includes a transport mechanism 110 for transporting a base sheet in the transport direction, a particle supply mechanism 120 for supplying superabsorbent polymer (SAP) particles toward the base sheet, and a first adhesive discharge mechanism 140 to a third adhesive discharge mechanism 160 for discharging an adhesive together with an air flow toward the base sheet.

[0097] In the following description, the conveyance direction in which the base sheet is conveyed is also referred to as the "MD direction", and the direction orthogonal to the MD direction (the depth direction of the paper surface in FIG. 6) is also referred to as the "CD direction". In the present embodiment, the MD direction is the direction along the longitudinal direction of the absorber 20, and the CD direction is the direction along the width direction of the absorber 20.

[0098] The absorbent body forming apparatus 100 conveys a core wrap sheet continuous body 25a formed by continuously arranging core wrap sheets 25 in the longitudinal direction as a base sheet in the MD direction, and laminates superabsorbent polymer (SAP) particles on the core wrap sheet continuous body 25a (base sheet) to manufacture an absorbent core 21 (one-side absorbent layer 21).

[0099] The conveying mechanism 110 includes a conveying conveyor, a plurality of conveying rollers, and the like. The conveying roller may be a driving roller that is driven to rotate by a driving source such as a motor, or a driven roller that rotates passively without a driving source. Further, the conveying conveyor is preferably a suction belt conveyor that uses the upper surface of an endless belt that circulates driven as a conveying surface and conveys the base sheet while adsorbing it with a plurality of intake holes (not shown) provided on the conveying surface. In the present embodiment, as shown in FIG. 6, the conveying surface of the conveying mechanism 110 is inclined by a predetermined angle θ with respect to the horizontal plane so that the downstream side in the MD direction is lowered. By doing so, when the SAP particles supplied from the particle supply mechanism 120 described later bounce back on the surface of the base sheet, the bounced-back SAP particles tend to move downstream due to gravity, and the arrangement of the SAP particles at unintended positions can be reduced.

[0100] The first adhesive discharge mechanism 140 discharges an adhesive such as hot melt adhesive (HMA) onto a predetermined region of the core wrap sheet continuum 25a (base material sheet) conveyed in the MD direction. FIGS. 7A and 7B are diagrams for explaining the configuration of the first adhesive discharge mechanism 140. The first adhesive discharge mechanism 140 is provided vertically above the conveyance surface on which the base material sheet is being conveyed, and has a plurality of adhesive discharge portions 141, 141.... Each adhesive discharge portion 141 is provided with a plurality of discharge nozzles 142, 142... that discharge the adhesive toward the base material sheet, arranged at a predetermined interval along the CD direction as shown in FIG. 7B. In the CD direction of the adhesive discharge portion 141, the region where the discharge nozzles 142, 142... are provided is defined as the adhesive discharge region 141f. That is, the adhesive discharge region 141f represents the range in the CD direction within which the adhesive discharge portion 141 can discharge the adhesive. The adhesive discharged from the discharge nozzle 142 is extended in a fibrous shape (i.e., a thin strip shape) by the air jetted from the same discharge nozzle 142, and lands on the base material sheet in a spiral shape or an Ω shape. On the other hand, discharge nozzles 142 are not provided at both ends of the adhesive discharge portion 141 in the CD direction, and no adhesive is discharged from these both ends. Hereinafter, the region where the discharge nozzles 142 are not provided at both ends in the CD direction is defined as the adhesive non-discharge region 141n.

[0101] Each of the adhesive discharge portions 141 forms an adhesive discharge row by being arranged side by side in the CD direction. In FIG. 7A, the first adhesive discharge mechanism 140 is constituted by a first adhesive discharge row 140A in which four adhesive discharge portions 141 are arranged side by side and a second adhesive discharge row 140B in which five adhesive discharge portions 141 are arranged side by side. However, the number of adhesive discharge portions 141 constituting the adhesive discharge rows 140A and 140B is not limited to this, and is appropriately adjusted according to the width of the adhesive discharge range in the CD direction.

[0102] The adhesive discharge part 141 that constitutes the first adhesive discharge row 140A and the adhesive discharge part 141 that constitutes the second adhesive discharge row 140B are arranged with their positions shifted from each other in the CD direction as shown in Fig. 7A. Specifically, they are arranged so that the non-adhesive discharge regions 141n of each other do not overlap in the CD direction. Then, by discharging the adhesive from each adhesive discharge region 141f of the first adhesive discharge row 140A and the second adhesive discharge row 140B onto the base material sheet conveyed in the MD direction, it is possible to prevent a region where no adhesive is applied from being formed on the base material sheet in the CD direction.

[0103] In the present embodiment, in the central part in the CD direction, a region where the adhesive discharge regions 141f of the first adhesive discharge row 140A and the second adhesive discharge row 140B overlap is defined as the central region CR. Also, in both side parts in the CD direction, a region where the adhesive discharge regions 141f of the first adhesive discharge row 140A and the second adhesive discharge row 140B do not overlap is defined as the end region SR. As shown in Fig. 7A, in the central region CR, the adhesive is discharged from the adhesive discharge regions 141f of the first adhesive discharge row 140A and the second adhesive discharge row 140B, whereas in the end region SR, the adhesive is discharged only from the adhesive discharge regions 141f provided at both ends of the second adhesive discharge row 140B. Therefore, in the end region SR, the amount of adhesive discharged per unit area is less than that in the central region CR.

[0104] Returning to FIG. 6, after the adhesive is applied to a predetermined region of the base sheet (the core wrap sheet continuum 25a) by the first adhesive discharge mechanism 140, SAP particles are supplied to the base sheet from the particle supply mechanism 120 disposed on the downstream side in the MD direction of the first adhesive discharge mechanism 140. The particle supply mechanism 120 discharges the SAP particles together with gravity supply or pressurized air and supplies the SAP particles toward the base sheet. The SAP particles that have reached the base sheet accumulate on the adhesive applied by the first adhesive discharge mechanism 140 to form the one-side absorption layer 21 (absorbent core 21). When the base sheet is conveyed by the suction belt conveyor, the supplied SAP particles are also more likely to stay on the base sheet due to the intake of the conveyor, and it is difficult to cause misalignment or the like. In the present embodiment, the particle supply mechanism 120 supplies SAP particles to the central region CR in the CD direction (see FIG. 7A). That is, the one-side absorption layer 21 is formed in a region overlapping the central region CR in the CD direction. The reason for this will be described later.

[0105] Next, an adhesive is discharged onto the base sheet from the second adhesive discharge mechanism 150 disposed on the downstream side in the MD direction of the particle supply mechanism 120 with respect to the SAP particles (one-side absorption layer 21) deposited in a predetermined region of the base sheet. FIG. 8 is a diagram for explaining the configuration of the second adhesive discharge mechanism 150. The second adhesive discharge mechanism 150 has substantially the same configuration and function as the first adhesive discharge mechanism 140. That is, the second adhesive discharge mechanism 150 has adhesive discharge portions 151, 151... each including a plurality of adhesive discharge nozzles (see FIG. 7B, not shown in FIG. 8). Each adhesive discharge portion 151 has an adhesive discharge region 151f, which is a region where the adhesive discharge nozzles are provided in the CD direction, and an adhesive non-discharge region 151n, which is a region where the adhesive discharge nozzles are not provided. Then, each adhesive discharge portion 151 is arranged side by side in the CD direction to form adhesive discharge rows 150A and 150B, and the adhesive is discharged from each adhesive discharge region 151f toward the base sheet.

[0106] Also, in the central portion in the CD direction, a region where the adhesive discharge regions 151f of the first adhesive discharge row 150A and the second adhesive discharge row 150B overlap is defined as the central region CR, and in both end portions in the CD direction, regions where the adhesive discharge regions 151f of the first adhesive discharge row 150A and the second adhesive discharge row 150B do not overlap are defined as the end regions SR. At this time, the amount of adhesive discharged per unit area in the central region CR is larger than the amount of adhesive discharged per unit area in the end region SR. That is, more adhesive is discharged onto the SAP particles (one-side absorption layer 21) provided overlapping with the central region CR than onto the end region SR.

[0107] Next, an adhesive is discharged from the third adhesive discharge mechanism 160 toward the base material sheet (and the one-side absorption layer 21) (see FIG. 6). The third adhesive discharge mechanism 160 is provided on the downstream side in the MD direction of the second adhesive discharge mechanism 150 and has substantially the same functions and configuration as the second adhesive discharge mechanism 150. That is, the third adhesive discharge mechanism 160 discharges more adhesive onto the SAP particles (one-side absorption layer 21) provided overlapping with the central region CR in the CD direction than onto the end region SR.

[0108] Next, on the downstream side in the MD direction of the third adhesive discharge mechanism 160, a continuous intermediate sheet 26a formed by continuously arranging the intermediate sheet 26 in the longitudinal direction is supplied from above the SAP particles (one-side absorption layer 21). The supplied continuous intermediate sheet 26a is joined to the base material sheet (core wrap sheet continuous body 25a) and the SAP particles (one-side absorption layer 21) via an adhesive, and thereby, an absorbent core 21 in which the SAP particles (one-side absorption layer 21) are sandwiched in the thickness direction between the core wrap sheet 25 and the intermediate sheet 26 is formed.

[0109] Although not shown in FIG. 6, for the absorbent core 21 (base material sheet) conveyed in the MD direction, a continuous body of an adhesive, liquid-absorbent fibers 201, SAP, an adhesive, and the core wrap sheet 24 is further supplied, whereby an absorber 20 having a laminated structure as shown in FIG. 4 is formed.

[0110] As described above, the absorbent core 21 (one-sided absorbent layer 21) of the present embodiment is formed by sandwiching SAP particles in the thickness direction by a base sheet (core wrap sheet 25 and intermediate sheet 26). Conventionally, when forming such an absorbent core, it has been common to apply an adhesive to the inner surface of the base sheet that sandwiches the SAP particles and fix the SAP particles with the adhesive. However, in this method, the SAP particles arranged at positions facing the base sheet coated with the adhesive are in direct contact with the adhesive and are firmly fixed, while the SAP particles arranged at a distance from the base sheet in the thickness direction are difficult to fix because they do not come into contact with the adhesive. That is, among the SAP particles (SAP layer) stacked in the thickness direction, the SAP particles arranged adjacent to the base sheet (adhesive) are likely to be adhered to by the adhesive on both sides in the thickness direction, but the adhesive is difficult to reach the SAP particles arranged in the central part in the thickness direction. As a result, the relative positions of the SAP particles are likely to shift in the central part in the thickness direction, and there is a risk that the absorbent core may lose its shape.

[0111] Also, in order to suppress the displacement of the SAP particles, if the amount of the adhesive applied to the inner surface of the base sheet is increased, the adhesive may ooze out to the outside of the base sheet (the skin side or the non-skin side surface of the absorber 20), causing discomfort to the user or deteriorating the absorption performance.

[0112] In contrast, in the present embodiment, since the average width of the adhesive discharged in a strip (fiber) shape from the first adhesive discharge mechanism 140 to the third adhesive discharge mechanism 160 is smaller than the average particle size of the SAP particles, the adhesive easily penetrates between the SAP particles. Specifically, the average width of the strip-shaped adhesive is 0.016 to 0.018 mm, while the average particle size of the SAP particles is 0.3 to 0.4 mm (see FIG. 10). Further, in the present embodiment, the second adhesive discharge mechanism 150 and the third adhesive discharge mechanism 160 directly discharge the adhesive toward the SAP particles deposited on the base sheet (see FIG. 6). Therefore, the thin strip-shaped adhesive easily penetrates between adjacent SAP particles and moves from the other side to one side in the thickness direction, and the adhesive easily spreads to each SAP particle. As a result, the SAP particles are easily fixed to each other, and the collapse of the absorbent core is suppressed.

[0113] The average particle size of SAP can be measured as follows using an electromagnetic sieve shaker (for example, AS-200 type manufactured by Retsch). The electromagnetic sieve shaker has first to seventh sieves with different mesh sizes (for example, mesh sizes: 850, 600, 500, 355, 300, 250, 150 μm) and a tray. First, measure the weights of the first to seventh sieves and the tray and set the measured value as A. Next, stack the tray, sieves with mesh sizes of 150, 250, 300, 355, 500, 600, and 850 μm from the bottom and set them in the shaker. Next, put 50 g of SAP on the topmost sieve with a mesh size of 850 μm, cover it, and hold it down with a presser. Next, start shaking with the shaker settings of 1.35 mm amplitude (amplitude adjustment dial is 45 for the AS-200 type), continuous operation, and operation time of 30 minutes, and conduct a 30-minute shaking test. After the shaking test, for each of the first to seventh sieves, measure the weight of the SAP remaining on the sieve and the weights of the sieve and the tray and record the measured value as B. From these data, calculate the distribution of SAP for each particle size = (B - A) / (total weight of SAP remaining on each sieve and tray) × 100 (%).

[0114] FIG. 12 shows an example of the measurement results of the particle size distribution of SAP. FIG. 12 shows the particle size distribution of two types of SAP (both commercially available SAP) that can be used as the absorbent core, measured as samples A and B based on the above-described shaking test. For example, for sample A, as a result of the shaking test, if the distribution of SAP remaining on the fourth sieve (mesh size 355 μm) is 48.3%, it means that the distribution of SAP with a particle size of 355 to 500 μm in sample A is 48.3%. From such data, the average particle size of SAP can be determined. Also, the SAP particle size may be calculated from an enlarged microscope image like FIG. 10 without relying on such a shaking test.

[0115] Further, in the present embodiment, in the base material sheet (core wrap sheet 25), the adhesive discharged per unit area in the region where SAP particles are supplied is less than the adhesive discharged per unit area in the region where SAP particles are not supplied. For example, as described with reference to FIG. 7, the first adhesive discharge mechanism 140 discharges the adhesive from two adhesive discharge columns, the first adhesive discharge column 140A and the second adhesive discharge column 140B, in the central region CR in the CD direction, while in the end region SR in the CD direction, the adhesive is discharged only from the second adhesive discharge column 140B. Then, SAP particles are supplied to the central region CR by the particle supply mechanism 120.

[0116] FIG. 9 is a plan view for explaining a region where SAP particles and an adhesive are provided in the core wrap sheet 25. In FIG. 9, the state of the core wrap sheet 25 in the deployed and extended state as viewed from the skin side (the other side) in the thickness direction is shown. In the core wrap sheet 25 (skin side surface) of FIG. 9, in the divided regions 21a to 21b shown by hatching, one-side absorption layers 21 (absorbent cores 21) are formed by providing SAP particles. And, in the core wrap sheet 25, a region located inside the outermost ends 21es, 21es of the one-side absorption layer 21 in the width direction is defined as the inner region IR. Also, in the core wrap sheet 25, a region located outside the outermost ends 21es, 21es of the one-side absorption layer 21 in the width direction is defined as the outer region OR. As described above, in the present embodiment, since the inner region IR is formed by supplying SAP particles to the central region CR, at least in the CD direction, the inner region IR coincides with the central region CR described in FIG. 7A. Similarly, since the outer region OR is formed by not supplying SAP particles to the end region SR, at least in the CD direction, the outer region OR coincides with the end region SR described in FIG. 7A. However, it is not necessary for the positions of the inner region IR (outer region OR) and the central region CR (end region SR) to completely coincide, and the positions of the two may be slightly deviated in the CD direction. For example, in the CD direction, the position of the outer end 21es of the one-side absorption layer 21 may be shifted outside or inside the boundary between the central region CR and the end region SR.

[0117] FIG. 10 is a photograph taken by magnifying a part of the skin side surface of the core wrap sheet 25 in the inner region IR by 40 times. FIG. 11 is a photograph taken by magnifying a part of the skin side surface of the core wrap sheet 25 in the outer region OR by 40 times. It can be seen that in the inner region IR of FIG. 10, a plurality of strip-shaped (fibrous) adhesives and SAP particles are arranged. On the other hand, in the outer region OR of FIG. 11, a plurality of strip-shaped (fibrous) adhesives are arranged, but SAP particles are not arranged. Also, in FIGS. 10 and 11, since a nonwoven fabric is used as the core wrap sheet 25, the embosses formed when manufacturing the nonwoven fabric are also arranged.

[0118] As is apparent from FIG. 10, the width of the strip-shaped (fibrous) adhesive is smaller than the particle diameter of the SAP particles, and it can be seen that the adhesive penetrates between the SAP particles. Therefore, as described above, the SAP particles are easily fixed to each other via the adhesive, the displacement of the SAP particles hardly occurs, and the collapse of the absorbent core is suppressed.

[0119] Also, compared with FIG. 10, it can be seen that in FIG. 11, the amount of the strip-shaped adhesive applied per unit area (that is, the coating density) is lower. That is, the number of intersections of the strip-shaped (fibrous) adhesives per unit area in the outer region OR (see FIG. 11) is smaller than the number of intersections of the strip-shaped (fibrous) adhesives per unit area in the inner region IR (see FIG. 10). Thus, in the outer region OR where the SAP particles are not arranged, by making the coating density of the adhesive applied to the core wrap sheet 25 lower than that in the inner region IR where the SAP particles are arranged, it is possible to suppress the adhesive from bleeding out to the outside (non-skin side surface) of the core wrap sheet 25. On the other hand, in the inner region IR, by increasing the coating density of the adhesive that fixes the SAP particles to each other, it is possible to make it difficult for the SAP particles to be displaced.

[0120] The number of intersections of the strip-shaped (fibrous) adhesives per unit area can be counted by taking pictures such as those in FIGS. 10 and 11 and performing, for example, image analysis. Further, when measuring the coating amount (coating density) of the adhesive in the outer region OR and the inner region IR, for example, after coloring the adhesive using bamboo charcoal or the like, taking a picture, converting the taken image into data, and then performing binarization processing to extract the adhesive. Then, the coating density of the adhesive can be obtained by calculating the area of the portion where the adhesive is applied in the region to be measured.

[0121] In addition, FIG. 10 shows an image of the skin side surface of the core wrap sheet 25 in the inner region IR of the diaper 1 before use. That is, FIG. 10 shows the state before the SAP particles absorb and swell with a liquid such as excreted fluid. In this state, the minimum value of the distance between the intersections of the strip-shaped adhesives is smaller than the particle size (average particle size) of the SAP particles. For example, the distance di between the intersections of a certain strip-shaped adhesive shown in FIG. 10 is clearly smaller than the diameter Dsap of a certain SAP. Therefore, it is difficult for the SAP particles to protrude from the mesh formed by the intersection of a large number of strip-shaped adhesives. As a result, the collapse of the one-side absorption layer 21 is easily suppressed. For example, when the diaper 1 is manufactured in a manufacturing factory and distributed in the market, it is possible to suppress the occurrence of displacement of the SAP during the distribution process and the collapse of the one-side absorption layer 21 (absorbent core) before the diaper 1 is used.

[0122] Also, when the diaper 1 is in use, since the SAP particles absorb and swell with a liquid such as excreted fluid, the particle size (average particle size) of the SAP particles becomes even larger than the diameter Dsap shown in FIG. 10. That is, the minimum value of the distance between the intersections of the strip-shaped adhesives is smaller than the particle size (average particle size) of the swollen SAP particles. Therefore, even in a state where the SAP swells by absorbing excreted fluid during the use of the diaper 1, it is difficult for the SAP particles to protrude from the mesh of the strip-shaped adhesives. As a result, the one-side absorption layer 21 (absorbent core) is less likely to collapse even during the use of the diaper 1.

[0123] Also, the thickness of the one - side absorption layer 21 (absorbent core) is preferably greater than 1.5 times the average particle diameter of the SAP particles. As described with reference to FIG. 6, in this embodiment, the SAP particles are supplied so as to be scattered on the base sheet (core wrap sheet 25) coated with the adhesive to form the one - side absorption layer 21. At this time, a part of the SAP particles are laminated so as to overlap in the thickness direction, and a one - side absorption layer 21 (absorbent core) having a thickness of at least greater than 1.5 times the average particle diameter of the SAP particles is formed. For example, when the average particle diameter of the SAP particles is 0.3 - 0.4 mm, a one - side absorption layer 21 having a thickness of about 0.475 - 0.63 mm is formed. In the one - side absorption layer 21 (absorbent core), since at least more than 1.5 layers of SAP particles are laminated, the water absorption and water retention can be improved as compared with the case of a single - layer absorbent core in which the SAP particles are arranged in a planar manner.

[0124] And in this embodiment, in such a one - side absorption layer 21 (absorbent core) with 1.5 layers or more, an adhesive exists at the central position in the thickness direction. In this embodiment, the width of the strip - shaped (fibrous) adhesive is significantly smaller than the average particle diameter of the SAP particles (see FIG. 10), and a part of the adhesive is directly discharged toward the SAP particles by the second adhesive discharge mechanism 150 or the third adhesive discharge mechanism 160 (see FIG. 6). Therefore, the adhesive discharged onto the SAP particles moves from the upper side (skin side) to the lower side (non - skin side) of the gap between the SAP particles in the thickness direction based on gravity and the pressure during discharge, and easily reaches the central position in the thickness direction of the one - side absorption layer 21 (absorbent core). That is, since the adhesive easily penetrates to the inside of the one - side absorption layer 21, displacement between the SAP particles is less likely to occur, and the one - side absorption layer 21 can be made difficult to collapse. When the base sheet (core wrap sheet 25) is sucked to one side in the thickness direction by the suction mechanism, the adhesive discharged onto the SAP particles is also sucked to one side (non - skin side) in the thickness direction, and more easily reaches the central position in the thickness direction of the one - side absorption layer 21 (absorbent core).

[0125] In addition, the residual stress of the adhesive applied to fix the SAP particles on the skin side surface of the core wrap sheet 25 is preferably 2 KPa or more and 20 KPa or less. The adhesive for fixing the SAP particles is required to have a resistance force (residual stress) that does not cause the SAP particles to fall off from the core wrap sheet 25 (base material sheet) even when an external force or the like associated with the swelling of the SAP particles is applied. When the residual stress of the adhesive is 2 KPa or more and 20 KPa or less, the probability that the fixing rate of the SAP becomes 40% or more increases, and the one-sided absorption layer 21 can be made difficult to collapse.

[0126] Here, the fixing rate of the SAP indicates the ratio of the SAP that does not fall off even when the absorbent sheet to be measured is put into physiological saline (0.9 mass% saline) being stirred at a predetermined rotation speed, and can be an index of the fixability of the swollen SAP to the base material sheet of the absorbent sheet. The larger the numerical value of the SAP fixing rate, the higher the fixability of the SAP to the base material sheet of the absorbent sheet, indicating that it is difficult for the SAP to fall off not only before use but also after liquid absorption. The SAP fixing rate is measured according to the following procedures 1 to 5.

[0127] (Procedure 1) As a measurement sample, prepare an absorbent sheet having a square shape with a side length of 5 cm in plan view. After gripping the end of the measurement sample and once suspending the measurement sample vertically, measure the weight of the measurement sample (initial sample weight). (Procedure 2) Immerse the entire measurement sample in physiological saline, and take out the measurement sample from the physiological saline 30 minutes after the start of immersion. (Procedure 3) Put a cylindrical stirrer with a diameter of 35 mm and an axial length of 12 mm and 300 ml of physiological saline into a beaker with a capacity of 300 ml, and use a magnetic stirrer to rotate the stirrer at a rotation speed of 60 ±5 rpm to stir the physiological saline. Put the measurement sample that has undergone Procedure 2 into the stirred physiological saline, and take out the measurement sample from the physiological saline 30 seconds after the input. (Step 4) After leaving the wet measurement sample that has undergone the above Step 3 still in the thermostatic chamber set at a temperature of 105°C inside the chamber for 12 hours, measure the weight of the dried measurement sample (the weight of the sample after the stirring process). (Step 5) Subtract the total weight of the members other than the water-absorbing polymer from each of the initial sample weight and the sample weight after the stirring process, and calculate the initial water-absorbing polymer weight (W0) and the water-absorbing polymer weight after the stirring process (W1) respectively. Then, calculate the fixing ratio of the water-absorbing polymer of the measurement sample (absorbent sheet) according to the following formula. Fixing ratio of water-absorbing polymer (%) = (W1 / W0) × 100

[0128] In the above Step 1, the reason for gripping the edge of the measurement sample (an absorbent sheet in a square shape with a side length of 5 cm in plan view) and once suspending it vertically is to remove non-fixed substances such as the water-absorbing polymer arranged non-fixedly on the base sheet (for example, the water-absorbing polymer simply sprinkled from above the base sheet without being fixed with an adhesive or the like). In this suspension operation of the measurement sample, it is only necessary to grip the edge of the measurement sample and suspend it vertically for about 3 to 5 seconds, and do not tap or swing the suspended measurement sample significantly. Also, when suspending the measurement sample, first, grip the edge of the measurement sample using tweezers or the like and suspend it for 3 to 5 seconds, and then grip the edge on the opposite side to the edge gripped during such suspension and suspend it for 3 to 5 seconds. Also, in the above Step 1, when it is not possible to prepare a 5-cm square absorbent sheet as the measurement sample (for example, when the size of the absorbent sheet is small and the size of the measurement sample is less than 5 cm square), collect a plurality of small-sized measurement samples with a size less than 5 cm square from the sheet to be evaluated, and make the total area of one side of these plurality of measurement samples equal to 25 cm2. Then, for each of the plurality of measurement samples, measure the fixing ratio of the water-absorbing polymer according to the above Steps 1 to 5, and take the average value of the plurality of obtained fixing ratios of the water-absorbing polymer as the fixing ratio of the water-absorbing polymer of the absorbent sheet.

[0129] Examples of the measuring instruments used in the procedure 3 include the following. · Magnetic stirrer: HI-304N (manufactured by HANNA, reversing stirrer) · Stirring bar: Star head NALGENE (6600-0035) [35φ×12mm] · Beaker: 300 ml [78φ×103mm]

[0130] The residual stress of the adhesive is measured by the following method. <Method for Measuring Residual Stress of Adhesive> Using a rotational rheometer (manufactured by Anton paar, model "Physica MCR301"), an adhesive to be measured is interposed between a circular receiving plate that supports the measurement sample from below in a plan view and a circular pressing plate that is disposed opposite above the receiving plate. The adhesive in this state forms a circular shape in plan view, has a thickness of 1.5 mm, a diameter of 12 mm, and a temperature of 30°C. Then, from such a state, the pressing plate is rotated to apply 30% strain to the adhesive. After 20 minutes have elapsed since the strain was applied to the adhesive, the shear stress of the adhesive is measured, and the measured value is taken as the residual stress of the adhesive.

[0131] In the measurement of the residual stress described above, when the adhesive to be measured is unused (not applied to the base sheet and not a component of the absorbent sheet), the unused adhesive is directly used as the measurement target. On the other hand, when the adhesive to be measured is a component of the absorbent sheet, the adhesive is collected from the absorbent sheet by the following solvent extraction method, and the collected adhesive is used as the measurement target.

[0132] <Solvent Extraction Method for Adhesive> First, in a container such as a beaker, an absorbent sheet containing an adhesive and a solvent capable of dissolving the adhesive are mixed to obtain an adhesive solution in which the adhesive is dissolved in the solvent. Next, the adhesive solution is collected from the container, and the solvent is removed from the adhesive solution, for example, by drying it under reduced pressure using a rotary evaporator, to obtain an adhesive. The adhesive thus obtained is used as a measurement target in the measurement of the residual stress described above. The solvent used for dissolving the adhesive may be appropriately selected according to the type of the adhesive and the like. When the adhesive to be measured is, for example, a hot melt adhesive, examples of the solvent used for dissolving the adhesive include toluene, methyl ethyl ketone, and heptane.

[0133] Further, after the adhesive is discharged from the second adhesive discharge mechanism 150 or the third adhesive discharge mechanism 160 toward the SAP particles (one-side absorption layer 21), when the intermediate sheet 26 is disposed from above the SAP particles (see FIG. 6), a part of the adhesive coated on the surface of the SAP particles adheres to the intermediate sheet 26. That is, a part of the strip-shaped adhesive discharged by the second adhesive discharge mechanism 150 or the like is provided on the non-skin side surface of the intermediate sheet 26.

[0134] In the present embodiment, the adhesive is applied such that the average width of the strip-shaped adhesive provided on the non-skin side surface (the surface facing the one-side absorption layer 21) of the intermediate sheet 26 is larger than the average width of the strip-shaped adhesive provided on the skin side surface (the surface facing the one-side absorption layer 21) of the core wrap sheet 25. With such a configuration, it is difficult for the adhesive to be excessively applied to the skin side surface of the core wrap sheet 25, so it is easy to suppress the adhesive from oozing out to the non-skin side of the core wrap sheet 25. On the other hand, if the adhesive is provided in a larger amount on the non-skin side surface of the intermediate sheet 26, it means that the amount of the adhesive discharged toward the SAP particles is also larger. Therefore, the SAP particles are fixed more firmly to each other, and the deformation of the one-side absorption layer 21 can be suppressed.

[0135] Conversely, the average width of the strip-shaped adhesive provided on the non-skin side surface of the intermediate sheet 26 (the surface facing the one-side absorption layer 21) may be made smaller than the average width of the strip-shaped adhesive provided on the skin side surface of the core wrap sheet 25 (the surface facing the one-side absorption layer 21). In this case, since the amount of the adhesive provided on the intermediate sheet 26 is reduced, it becomes difficult to inhibit the movement of excreted fluid in the thickness direction in the intermediate sheet 26. That is, it is possible to smoothly transfer excreted fluid and the like to the one-side absorption layer 21 provided on the non-skin side in the thickness direction of the intermediate sheet 26.

[0136] Further, in the one-side absorption layer 21 of the absorber 20, a low basis weight region 211 with a basis weight lower than that of the surrounding area is provided. In the low basis weight region 211, it is more difficult to absorb excreted fluid than in other regions, and the excreted fluid is likely to spread along the low basis weight region 211. For example, by promoting the diffusion of excreted fluid in the thickness direction, the excreted fluid can easily move to the inside of the one-side absorption layer 21. Therefore, even when a force that compresses the absorber 20 in the thickness direction acts, such as when the wearer takes a sitting posture during wearing of the diaper 1, the excreted fluid can be easily drawn into the inside of the absorber 20.

[0137] And the average basis weight in the low basis weight region 211 of the one-side absorption layer 21 is preferably greater than 0% and 50% or less of the average basis weight in other regions (regions other than the low basis weight region 211) of the one-side absorption layer 21. If the average basis weight in the low basis weight region 211 is 50% or less of the average basis weight in other regions, the difference in basis weight between the low basis weight region 211 and other regions becomes larger compared to the case where it is greater than 50%, and it is possible to easily move a liquid such as excreted fluid along the low basis weight region 211. Further, if the average basis weight in the low basis weight region 211 is greater than 0%, it is possible to suppress the entire low basis weight region 211 from being formed as slits, so that the strength of the low basis weight region 211 is easily ensured. That is, by providing SAP particles with a certain size of basis weight, it is possible to improve the liquid diffusibility while suppressing the collapse of the shape of the one-side absorption layer 21.

[0138] In addition, the distance (width) W211 in the width direction of the low basis weight region 211 is greater than the minimum value of the intersection distance di (see FIG. 10) between the strip-shaped adhesives. If the intersection distance di between the strip-shaped adhesives is greater than the distance W211 in the width direction of the low basis weight region 211, there is a possibility that no intersection of the adhesives is arranged between both end portions of the low basis weight region 211. In the low basis weight region 211, the SAP is likely to be displaced, and the shape of the low basis weight region 211 itself may not be maintained. On the other hand, in the present embodiment, the intersection distance di between the strip-shaped adhesives is smaller than the distance W211 in the width direction of the low basis weight region 211, and at least one intersection of the adhesives is provided between both end portions of the low basis weight region 211. Therefore, the SAP particles are easily fixed in the low basis weight region 211 with low rigidity. In addition, the possibility that the adhesives exist at both end portions of the low basis weight region 211 is increased. Therefore, it is possible to prevent the low basis weight region 211 from collapsing or being crushed in the one-side absorption layer 21.

[0139] In addition, in the low basis weight region 211, it is preferable that there is a portion where the core wrap sheet 25 and the intermediate sheet 26 are joined in the thickness direction. For example, in FIG. 4, if the core wrap sheet 25 and the intermediate sheet 26 are joined at least in part of the portion where the low basis weight region 211 is provided, each of the divided regions 21a, 21b, 21c of the one-side absorption layer 21 is firmly divided in the CD direction, and it is possible to suppress the movement of the SAP particles across the low basis weight region 211 between adjacent divided regions. That is, each of the divided regions 21a, 21b, 21c is likely to maintain its shape independently. Therefore, it is difficult for the one-side absorption layer 21 as a whole to collapse.

[0140] Further, the absorber 20 has intermittent regions at both longitudinal ends where no SAP particles are provided. In FIG. 9, in the longitudinal direction of the core wrap sheet 25 (absorber 20), a front intermittent region FA where no SAP particles are arranged is provided in front of the front end 21ef of the one-side absorption layer 21. Similarly, in the longitudinal direction, a rear intermittent region BA where no SAP particles are arranged is provided behind the rear end 21eb of the one-side absorption layer 21. Since no SAP particles are arranged in the front intermittent region FA and the rear intermittent region BA, the core wrap sheet 25 is joined to a member (for example, the intermediate sheet 26 in FIG. 4, etc.) arranged to face the skin side in the thickness direction via an adhesive applied to the skin side surface of the core wrap sheet 25. Thereby, it becomes difficult for the SAP particles constituting the one-side absorption layer 21 to jump out to both ends in the front-rear direction, and it becomes difficult for the one-side absorption layer 21 to lose its shape.

[0141] Also, in the longitudinal direction of the absorber 20, it is preferable that the average basis weight of the SAP provided in the region in front of the central position CL is larger than the average basis weight of the SAP provided behind the central position CL. The region in the front in the longitudinal direction is located closer to the wearer's excretory opening when the diaper 1 is worn compared to the region in the rear. Therefore, by increasing the average basis weight of the SAP in the front region in the longitudinal direction close to the excretory opening, it becomes easier to quickly absorb excretory fluids such as urine, and it becomes easier to suppress urine leakage on the ventral side.

[0142] On the other hand, in the longitudinal direction of the absorber 20, it is also possible that the average basis weight of the SAP provided behind the central position CL is equal to or greater than the average basis weight of the SAP provided in the region in front of the central position CL. In this case, the water absorbency can be enhanced in the wearer's dorsal region when the diaper 1 is worn. For example, when the wearer is sleeping on their back while wearing the diaper 1, there is a possibility that excretory fluids such as urine will flow around the buttocks to the dorsal side and leak outside the absorber 20. In such a case, by making the average basis weight of the SAP in the rear region in the longitudinal direction as large as possible, it becomes easier to suppress urine leakage from the dorsal side.

[0143] In addition, in the absorber 20 of the present embodiment, an intermediate absorption layer 22 containing liquid-absorbent fibers 201 and SAP and the other-side absorption layer 23 (corresponding to the second absorption layer) are provided so as to be laminated on the other side in the thickness direction of the one-side absorption layer 21. That is, the absorber 20 is composed of two or more absorption cores laminated in the thickness direction. By having a structure of two or more layers of absorption cores, the water absorption and water retention capacity are improved as compared with the case where there is only one layer of absorption core. Further, by providing a layer (intermediate absorption layer 22) containing liquid-absorbent fibers 201 having a faster water absorption rate than SAP particles, liquid diffusion is likely to occur between the plurality of layers, and the water absorption and water retention properties of the entire absorber 20 (absorption core) can be improved.

[0144] In the present embodiment, as shown in FIG. 4, the one-side absorption layer 21 mainly containing SAP particles is disposed on the non-skin side (one side) in the thickness direction, and the intermediate absorption layer 22 and the other-side absorption layer 23 (second absorption layer) containing liquid-absorbent fibers 201 having a faster water absorption rate than SAP particles are disposed on the skin side (the other side) in the thickness direction. Therefore, the excreted liquid is quickly drawn from the skin side to the non-skin side and is easily retained in the one-side absorption layer 21. As a result, the DRY property is improved on the skin side, and it is possible to make it difficult for the wearer to feel discomfort or unpleasantness.

[0145] On the other hand, contrary to the case of FIG. 4, a configuration may be adopted in which the one-side absorption layer 21 mainly containing SAP particles is disposed on the skin side (the other side) in the thickness direction, and the intermediate absorption layer 22 and the other-side absorption layer 23 (second absorption layer) containing liquid-absorbent fibers (pulp fibers) 201 having a faster water absorption rate than SAP particles are disposed on the non-skin side (one side) in the thickness direction. In this case, since the water retention property on the skin side is enhanced, it is possible to make it difficult to cause a so-called rewet phenomenon in which the excreted liquid absorbed by the absorption core returns to the skin side of the wearer. Therefore, it is possible to make it difficult for the wearer to feel discomfort or unpleasantness.

[0146] In addition, in the absorber 20 of the diaper 1, the core wrap sheet that coats the absorbent core (SAP particles) is formed of a non-woven fabric. Generally, since a non-woven fabric has higher strength and is less likely to tear compared to tissues and the like, it is suitable as a base sheet when forming the absorber 20. For example, as described with reference to FIG. 6, when applying an adhesive or laminating SAP particles while transporting the non-woven fabric as a base sheet in the MD direction, since the base sheet is less likely to tear, an absorber 20 with a stable shape can be formed. Further, since it is possible to transport the base sheet while sucking it by a suction mechanism or the like, it is easy to fix the SAP particles on the base sheet. In this case, the sucked adhesive is likely to move through the gaps between the SAP particles and reach the inside (the central position in the thickness direction) of the absorbent core, so it is easy to suppress the displacement of the positions of the SAP particles.

[0147] ===Others=== The above-described embodiments are for facilitating the understanding of the present invention and are not for limiting and interpreting the present invention. It goes without saying that the present invention can be changed and improved without departing from its gist, and equivalents thereof are included in the present invention.

[0148] In the above-described embodiment, the absorber 20 composed of a plurality of layers as shown in FIG. 4 has been described, but the absorber 20 is not limited to the configuration shown in FIG. 4. For example, a configuration in which the intermediate sheet 26 is not provided may be used, or a configuration having only the one-side absorption layer 21 as the absorbent core may be used. Further, the absorber 20 may be such that one side in the thickness direction of FIG. 4 is the skin side and the other side is the non-skin side.

[0149] The absorbent core (one - side absorbent layer 21 and the other - side absorbent layer 23) of the absorber 20 may be deformed as follows. FIG. 13 is a schematic cross - sectional view of the absorber 20 showing a modified example of the one - side absorbent layer 21. The one - side absorbent layer 21 of the modified example has a high - basis - weight region 213 where the basis weight of the SAP is higher than that of the surrounding area. And, among the high - basis - weight region 213, the point S which is the maximum thickness in the thickness direction is intermittently located in the longitudinal direction and the width direction. Thereby, the high - basis - weight region 213 is intermittently arranged in the longitudinal direction and the width direction. Further, a low - basis - weight region 214 where the basis weight of the SAP is lower than that of the high - basis - weight region 213 is formed between adjacent points S of the maximum thickness (that is, around the high - basis - weight region 213). However, as long as the point S of the maximum thickness is intermittently located in the longitudinal direction and the width direction, a part of the area between adjacent points S of the maximum thickness may be formed by the high - basis - weight region 213. That is, a part of the area between adjacent points S of the maximum thickness may be connected by the high - basis - weight region 213.

[0150] The low - basis - weight region 214 has a low - basis - weight laminated region 214E where the SAP is laminated and a non - laminated region 214N where there is no SAP. Here, "no SAP" means, in addition to the meaning that there are no SAP particles, that there are very few laminated SAP particles and substantially no SAP particles are present.

[0151] In the absorber 20 of the modified example, the low - basis - weight region 214 (the low - basis - weight laminated region 214E and the non - laminated region 214N) serves as a folding starting point, making it easier to deform along the unevenness of the wearer's body and improving the fit. Further, as the low - basis - weight region 214 serving as the folding starting point, it has a low - basis - weight laminated region 214E that can absorb and hold excreted liquid and a non - laminated region 214N that is more easily bent due to the absence of SAP. Thereby, even in the low - basis - weight region 214 where the basis weight of the SAP is lower than that of the high - basis - weight region 213, it is possible to achieve both ease of deformation along the unevenness of the wearer's body and the absorption and holding power of excreted liquid.

Explanation of Signs

[0152] 1 Diaper (absorbent article, pants - type disposable diaper), 2 Side joint part, 10 Absorbent body, 12 Top sheet, 13a Back sheet (liquid-impermeable sheet), 13b Back sheet (outer sheet), 15 Leakage-preventing wall part, 16 Leakage-preventing wall elastic member, 17 Elastic member around legs, 20 Absorbent, 21 One-side absorbent layer (absorbent core), 211 Low basis weight region, 21a Divided region, 21b Divided region, 21c Divided region, 22 Intermediate absorbent layer (absorbent core), 221 Low basis weight region, 222 Gathered part, 23 The other-side absorbent layer (absorbent core), 231 Low basis weight region, 232 Gathered part, 24 Core wrap sheet, 25 Core wrap sheet, 26 Intermediate sheet, 30 Front-side body circumference part, 31 Skin-side sheet, 32 Non-skin-side sheet, 33 Body circumference elastic member, 34 Cover sheet, 40 Rear-side body circumference part, 41 Skin-side sheet, 42 Non-skin-side sheet, 43 Body circumference elastic member, 44 Cover sheet, 100 Absorbent forming device, 110 Conveying mechanism, 120 Particle supply mechanism, 140 First adhesive discharge mechanism, 140A Adhesive discharge row, 140B Adhesive discharge row, 141 Adhesive discharge part, 141f Adhesive discharge region, 141n Adhesive non-discharge region, 142 Discharge nozzle, 150 Second adhesive discharge mechanism, 150A Adhesive discharge row, 150B Adhesive discharge row, 151 Adhesive discharge part, 151f Adhesive discharge region, 151n Adhesive non-discharge region, 160 Third adhesive discharge mechanism, 201 Liquid-absorbent fiber, SAP Superabsorbent polymer, the inner region of the IR, the outer region of the OR

Claims

1. In the unfolded state, having a longitudinal direction, a width direction, and a thickness direction that are perpendicular to each other, An absorbent article having an absorbent layer containing a superabsorbent polymer and a core wrap sheet disposed on one side in the thickness direction of the absorbent layer, A strip-shaped adhesive is provided on the other side surface of the core wrap sheet in the thickness direction, The average width of the strip-shaped adhesive is smaller than the average particle diameter of the superabsorbent polymer, Among the other side surfaces of the core wrap sheet, a region located outside the outermost end of the absorbent layer in the width direction is defined as the outer region, When a region located inside the outermost end of the absorbent layer in the width direction among the other side surfaces of the core wrap sheet is defined as the inner region, The number of intersections of the strip-shaped adhesives per unit area in the outer region is Less than the number of intersections of the strip-shaped adhesives per unit area in the inner region. The absorbent article is characterized by this.

2. The absorbent article according to Claim 1, The minimum value of the distance between intersections of the strip-shaped adhesives is smaller than the average particle diameter of the superabsorbent polymer when swollen. The absorbent article is characterized by this.

3. The absorbent article according to Claim 2, The minimum value of the distance between intersections of the strip-shaped adhesives is smaller than the average particle diameter of the superabsorbent polymer when not swollen. The absorbent article is characterized by this.

4. The absorbent article according to any one of Claims 1 to 3, The thickness of the absorbent layer is greater than 1.5 times the average particle diameter of the superabsorbent polymer. The absorbent article is characterized by this.

5. The absorbent article according to Claim 4, At least a part of the strip-shaped adhesive exists at the central position in the thickness direction of the absorbent layer. The absorbent article is characterized by this.

6. The absorbent article according to any one of Claims 1 to 3, The residual stress of the adhesive for fixing the superabsorbent polymer to the core wrap sheet is 2 kPa or more and 20 kPa or less. The absorbent article is characterized by this.

7. The absorbent article according to any one of Claims 1 to 3, On the other side in the thickness direction of the absorbent layer, it has an intermediate sheet, A strip-shaped adhesive is provided on one side surface of the intermediate sheet in the thickness direction, The average width of the strip-shaped adhesive provided on the other side surface of the core wrap sheet is An absorbent article, characterized in that it is smaller than the average width of the strip-shaped adhesive provided on one side of the intermediate sheet. **Claim 8** An absorbent article according to any one of claims 1 to 3, wherein an intermediate sheet is provided on the other side in the thickness direction of the absorbent layer, wherein a strip-shaped adhesive is provided on one side surface of the intermediate sheet in the thickness direction, wherein the average width of the strip-shaped adhesive provided on the other side surface of the core wrap sheet, is larger than the average width of the strip-shaped adhesive provided on one side surface of the intermediate sheet, and the absorbent article is characterized by this. **Claim 9** An absorbent article according to any one of claims 1 to 3, wherein the absorbent layer is a region having a predetermined width in the width direction, and has a low basis weight region where the basis weight is lower than that of the surroundings, and the absorbent article is characterized by this. **Claim 10** An absorbent article according to claim 9, wherein the average basis weight of the low basis weight region is larger than 0% and 50% or less of the average basis weight of the region other than the low basis weight region in the absorbent layer, and the absorbent article is characterized by this. **Claim 11** An absorbent article according to claim 10, wherein the minimum value of the distance between the intersections of the strip-shaped adhesives is smaller than the width of the low basis weight region, and the absorbent article is characterized by this. **Claim 12** An absorbent article according to claim 11, wherein an intermediate sheet is provided on the other side in the thickness direction of the absorbent layer, and in the low basis weight region, it has a portion where the core wrap sheet and the intermediate sheet are joined in the thickness direction, and the absorbent article is characterized by this. **Claim 13** An absorbent article according to any one of claims 1 to 3, having an absorber including the absorbent layer and the core wrap sheet, wherein intermittent regions where the superabsorbent polymer is not provided are provided at the front and rear ends of the absorber in the longitudinal direction, and the absorbent article is characterized by this. **Claim 14** An absorbent article according to claim 13, wherein the average basis weight of the superabsorbent polymer on the front side of the central position of the absorber in the longitudinal direction, is smaller than the average basis weight of the superabsorbent polymer on the rear side of the central position of the absorber in the longitudinal direction, and the absorbent article is characterized by this. **Claim 15** An absorbent article according to claim 13, wherein the average basis weight of the superabsorbent polymer on the front side of the central position of the absorber in the longitudinal direction, An absorbent article, characterized in that it is above the average basis weight of the superabsorbent polymer on the rear side of the central position in the longitudinal direction of the absorber.

16. An absorbent article according to any one of Claims 1 to 3, wherein a second absorbent layer containing the superabsorbent polymer and liquid-absorbent fibers is laminated with the absorbent layer in the thickness direction.

17. An absorbent article according to Claim 16, wherein the second absorbent layer is disposed on the other side of the absorbent layer.

18. An absorbent article according to Claim 16, wherein the second absorbent layer is disposed on the one side of the absorbent layer.

19. An absorbent article according to any one of Claims 1 to 3, wherein the core wrap sheet is made of a nonwoven fabric.

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