Absorbent articles

Abstract

The present invention provides an absorbent article equipped with a second sheet, which allows urine and other fluids to smoothly transfer to the absorbent material. [Solution] An absorbent article having a top sheet, a back sheet, and an absorbent disposed between them, with a second sheet disposed between the top sheet and the absorbent, wherein the second sheet 10 is composed of a laminate having a nonwoven fabric layer 11 and a plastic film layer 12 from the top sheet side, and a plurality of through holes 13 are formed in the second sheet 10, and the second sheet 10 has protrusions 14 that project toward the back sheet side along the outer edge of the through holes 13, and the protrusions 14 have a protruding base 14A and a protruding end 14B, the protruding base 14A extends toward the center 13C of the through hole 13 toward the back sheet side, and the protruding end 14B extends toward the back sheet side away from the center 13C of the through hole 13.

Description

Technical Field

[0001] The present disclosure relates to absorbent articles such as disposable diapers, urine pads (including incontinence pads), and menstrual pads.

Background Art

[0002] Conventionally, absorbent articles having a topsheet, a backsheet, and an absorber disposed therebetween, and a second sheet disposed between the topsheet and the absorber are known. The second sheet is provided to enhance the absorption performance of urine or the like in the absorbent article, and various second sheets are known. For example, Patent Document 1 discloses an absorbent article provided with a second sheet composed of a laminate having a nonwoven fabric layer and a plastic film layer from the topsheet side and having a plurality of through holes formed therein. Patent Document 2 discloses an absorbent article provided with a composite surface sheet having a formed film in which three-dimensional holes are formed and having small holes having a male side and a female side opposite thereto, and a fiber nonwoven fabric disposed closer to the wearer side than the formed film, and having a plurality of large holes formed therethrough the nonwoven fabric and the formed film. Patent Document 3 discloses an absorbent article provided with a second sheet made of a plastic film and having a large number of apertures provided with side walls protruding from the topsheet side to the backsheet side.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] While various sheets have been proposed for use in conventional absorbent articles, in a second sheet with multiple perforations as described above, it is desirable that urine, etc., that has permeated the top sheet and moved to the second sheet smoothly transfer to the absorbent material through the perforations. The problem to be solved by this disclosure is to provide an absorbent article having a second sheet, in which urine, etc., can smoothly transfer to the absorbent material. [Means for solving the problem]

[0005] The absorbable articles related to this disclosure that have been able to solve the aforementioned problems are as follows: [1] An absorbent article having a top sheet, a back sheet, and an absorbent material disposed between them, wherein a second sheet is disposed between the top sheet and the absorbent material, The second sheet is composed of a laminate having a nonwoven fabric layer and a plastic film layer from the top sheet side, and a plurality of through holes are formed in the second sheet. The second seat has a protrusion that extends toward the back seat side along the outer edge of the through hole, The aforementioned projection has a projection base and a projection end, the projection base extends toward the center of the through hole toward the backsheet side, and the projection end extends toward the backsheet side away from the center of the through hole, in an absorbent article. [2] The absorbent article according to [1], wherein in a cross-section of the second sheet in the thickness direction passing through the center of the through hole, the height of the protrusion is 0.3 times or more and 1.7 times or less the opening width of the through hole. [3] In a cross-section of the second sheet in the thickness direction passing through the center of the through hole, the average inclination angle of the protruding base with respect to the planar direction of the second sheet is smaller than the average inclination angle of the protruding end. [1] or [2] The absorbent article according to [1] or [2]. [4] In a cross-section of the second sheet in the thickness direction passing through the center of the through hole, the length of the base of the protrusion in the height direction of the protrusion is longer than the length of the end of the protrusion in the height direction of the protrusion, as described in any of [1] to [3]. [5] In a cross-section of the second sheet in the thickness direction passing through the center of the through hole, the edge of the protrusion is formed in a non-linear shape, as described in any of [1] to [4]. [6] The absorbent article according to any one of [1] to [5], wherein the aspect ratio of the planar shape of the through hole is 6.0 or less. [7] The absorbent article according to any one of [1] to [6], wherein the area ratio of the through holes in the second sheet is 1% or more and 10% or less. [8] The absorbent article according to any one of [1] to [7], wherein the second sheet has the nonwoven fabric layer penetrating the through hole. [9] The absorbent article according to any one of [1] to [8], wherein the absorbent article has a longitudinal direction and a width direction perpendicular to the longitudinal direction, the through hole is formed in a shape that is longer in the longitudinal direction than in the width direction in a plan view, and the protruding end of the protrusion extends toward the back sheet side toward the center of the through hole toward the back sheet side in a cross section in the width direction.

[10] The absorbent article according to [9], wherein at least a portion of the protruding end of the protrusion extends toward the backsheet side toward the center of the through hole in the longitudinal cross-section. [Effects of the Invention]

[0006] The absorbent article according to this disclosure is composed of a laminate having a nonwoven fabric layer and a plastic film layer from the top sheet side, and includes a second sheet with multiple through holes. As a result, urine and other substances absorbed by the top sheet by the nonwoven fabric layer are quickly drawn into the second sheet, and the urine and other substances that have moved to the second sheet can move to the absorbent body through the through holes. In this case, the second sheet has protruding portions that project towards the back sheet side along the outer edge of the through holes. The protruding portions have a protruding base and a protruding end. The protruding base extends toward the center of the through hole toward the back sheet side, and the protruding end extends toward the back sheet side away from the center of the through hole. Therefore, urine and other substances on the second sheet can easily move smoothly to the absorbent body via the protruding portions. Specifically, at the protruding base, urine and other substances on the second sheet tend to collect in the through holes, and at the protruding end, the through holes are formed to widen toward the back sheet side, so that urine and other substances that enter the through holes can easily move to the absorbent body without getting stuck at the protruding end. Therefore, urine and other substances that have permeated the top sheet and moved to the second sheet can easily move smoothly to the absorbent body through the through holes. [Brief explanation of the drawing]

[0007] [Figure 1] As an example of an absorbent article related to this disclosure, a plan view of a urine pad seen from the top sheet side is shown. [Figure 2] Figure 1 shows an example of a II-II cross-section of an absorbent material. [Figure 3] Figures 1 and 2 show enlarged perspective views of the second seat provided in the absorbent material. [Figure 4] This diagram shows a cross-sectional view of the area around the through-hole in the thickness direction of the second seat. [Modes for carrying out the invention]

[0008] The absorbent articles relating to this disclosure will be described with reference to the drawings. Figures 1 to 4 show an example of the configuration of a urine pad as an example of the absorbent articles relating to this disclosure. Figure 1 is a plan view of the absorbent article (urine pad) as seen from the top sheet side, and Figure 2 is an example of a II-II cross-section of the absorbent article shown in Figure 1. Figure 3 is an enlarged perspective view of the second sheet provided in the absorbent articles shown in Figures 1 and 2, and Figure 4 is a cross-sectional view of the through hole in the thickness direction of the second sheet. In the drawings, arrow x represents the width direction, arrow y represents the longitudinal direction, and the direction perpendicular to the plane formed by arrows x and y represents the thickness direction z. Note that the absorbent articles relating to this disclosure are not limited to the embodiments shown in the drawings.

[0009] The absorbent article 1 has a top sheet 2, a back sheet 3, and an absorbent material 4 placed between them, with a second sheet 10 placed between the top sheet 2 and the absorbent material 4. The absorbent article 1 can be used, for example, in disposable diapers, urine pads (including incontinence pads), sanitary napkins, etc.

[0010] The absorbent article 1 has a longitudinal direction y and a width direction x. The longitudinal direction y corresponds to the direction extending in the front-to-back direction between the wearer's legs when the absorbent article is worn by the wearer. The width direction x is the direction that lies on the same plane as the absorbent article and is perpendicular to the longitudinal direction y, and corresponds to the left-to-right direction of the wearer when the absorbent article is worn. Furthermore, the direction parallel to the plane formed by the longitudinal direction y and the width direction x is defined as the plane direction, and the direction perpendicular to it is defined as the thickness direction z.

[0011] The top sheet 2 is a sheet located on the wearer's side when the absorbent article is worn, and is preferably permeable to liquids. As the top sheet 2, for example, a nonwoven fabric made from hydrophilic fibers such as cellulose, rayon, or cotton; or a nonwoven fabric made from hydrophobic fibers such as polyolefin (e.g., polypropylene, polyethylene), polyester (e.g., PET), or polyamide (e.g., nylon), in which the surface of the hydrophobic fibers has been made hydrophilic with a hydrophilizing agent such as a surfactant can be used. Alternatively, woven fabric, knitted fabric, perforated plastic film, etc., may be used as the top sheet 2.

[0012] The backsheet 3 is a sheet that is located on the side opposite to the wearer, that is, the outside, when the absorbent article is worn, and is preferably liquid-impermeable. As the backsheet 3, a non-woven fabric formed from hydrophobic fibers such as polyolefin (for example, polypropylene, polyethylene), polyester (for example, PET), polyamide (for example, nylon), or a plastic film can be used. Further, a laminate of a non-woven fabric and a plastic film may be used. In the present disclosure, liquid impermeability also includes the meaning of water repellency.

[0013] The absorbent article 1 is preferably provided with rising flaps 5 on both sides in the width direction x on the skin side. By providing the rising flaps 5, lateral leakage of urine or the like is prevented. The rising flap 5 can be formed, for example, by joining side sheets 6 extending in the longitudinal direction y to both sides in the width direction x of the top sheet 2, and providing an elastic member 7 for rising in the inner portion in the width direction x of the side sheet 6. By providing the side sheet 6 and the elastic member 7 for rising in this way, the inner portion in the width direction x of the side sheet 6 rises toward the skin of the wearer due to the contracting force of the elastic member 7 for rising, and the rising flap 5 is formed. The rising flap 5 or the side sheet 6 is preferably composed of a liquid-impermeable plastic film, a liquid-impermeable non-woven fabric, or the like.

[0014] As the non-woven fabric constituting each of the sheets described above, a spunbond non-woven fabric, a point-bond non-woven fabric, an air-through non-woven fabric, a meltblown non-woven fabric, an airlaid non-woven fabric, a spunlace non-woven fabric, an SMS non-woven fabric, etc. can be used. The mass per unit area of each of these sheets is preferably 8 g / m 2 or more, more preferably 10 g / m 2 or more, and preferably 40 g / m 2 or less, more preferably 30 g / m 2 or less.

[0015] The absorbent body 4 is not particularly limited as long as it contains an absorbent material capable of absorbing excrement such as urine. As the absorbent body 4, for example, a molded body formed by molding an absorbent material into a predetermined shape can be used, or the molded body can be covered with a covering sheet such as a paper sheet (e.g., tissue paper or thin paper) or a liquid-permeable nonwoven fabric sheet. Examples of absorbent materials include hydrophilic fibers such as pulp fibers, and superabsorbent resins such as polyacrylic acid, polyaspartic acid, cellulose, and starch-acrylonitrile. The superabsorbent material may also include polyolefin fibers such as polyethylene and polypropylene, and heat-fusible fibers such as polyester fibers such as PET and polyamide fibers. These heat-fusible fibers may be hydrophilized with surfactants or the like to increase their affinity for urine, etc.

[0016] The absorbent material preferably contains hydrophilic fibers to increase the absorption rate of urine and other fluids. Furthermore, the absorbent material preferably contains a water-absorbent resin to increase its absorption capacity. Therefore, the absorbent body 4 preferably contains hydrophilic fibers (especially pulp fibers) and a water-absorbent resin. In this case, for example, it is preferable to use a material in which a water-absorbent resin is mixed or scattered on an aggregate of hydrophilic fibers.

[0017] The absorbent material 4 may be a sheet-shaped absorbent material. Examples of sheet-shaped absorbent materials include those formed by having an absorbent resin between nonwoven fabrics and not having pulp fibers. Because such a sheet-shaped absorbent material has an absorbent resin between the nonwoven fabrics, it can achieve a high absorption capacity. Furthermore, because the sheet-shaped absorbent material does not have pulp fibers between the nonwoven fabrics, it can be formed into a thin, non-bulky form.

[0018] The absorbent material 4 may have multiple absorbent layers. For example, the absorbent material 4 may have a first absorbent layer on the second sheet 10 side and a second absorbent layer on the back sheet 3 side. The number of absorbent layers included in the absorbent material 4 can be appropriately determined depending on the application.

[0019] The shape (planar shape) of the absorbent 4 is not particularly limited. The shape of the absorbent 4 can be appropriately determined according to the application, and examples include a roughly rectangular shape, hourglass shape, gourd shape, shuttlecock shape, etc. If the absorbent 4 has multiple absorbent layers, the shapes (planar shapes) and / or sizes of the absorbent layers may differ from each other.

[0020] The second sheet 10 is a sheet placed between the top sheet 2 and the absorber 4. The second sheet 10 has a first surface 10A on the top sheet 2 side and a second surface 10B on the back sheet 3 side. As shown in Figure 3, the second sheet 10 is composed of a laminate having a nonwoven fabric layer 11 and a plastic film layer 12 from the top sheet 2 side, and a plurality of through holes 13 are formed in the second sheet 10. That is, the second sheet 10 is composed of a laminate of the nonwoven fabric layer 11 and the plastic film layer 12, with the nonwoven fabric layer 11 located on the top sheet 2 side and the plastic film layer 12 located on the back sheet 3 side, and the through holes 13 are formed to penetrate the second sheet 10 in the thickness direction z. The through holes 13 are formed to extend from the first surface 10A to the second surface 10B inside the second sheet 10.

[0021] In absorbent article 1, the second sheet 10 configured in this way is placed between the top sheet 2 and the absorbent core 4. This allows urine and other fluids excreted by the wearer and permeated through the top sheet 2 to be quickly drawn into the absorbent core 4, while also reducing the wettability of the top sheet 2. Specifically, because a nonwoven fabric layer 11 is present on the first surface 10A of the second sheet 10, the urine and other fluids absorbed by the top sheet 2 are drawn into the second sheet 10 by the nonwoven fabric layer 11. The urine and other fluids that have moved to the second sheet 10 can then pass through the through-holes 13 formed in the second sheet 10 and move to the absorbent core 4. On the other hand, the plastic film layer 12 of the second sheet 10 prevents the urine and other fluids that have moved to the absorbent core 4 from flowing back to the top sheet 2. As a result, absorbent article 1 has excellent urine absorption performance, and the wettability of the top sheet 2 is reduced, resulting in a comfortable wearing experience.

[0022] The type of nonwoven fabric constituting the nonwoven fabric layer 11 is not particularly limited, but it is preferable that the nonwoven fabric constituting the nonwoven fabric layer 11 is hydrophilic. As the nonwoven fabric constituting the nonwoven fabric layer 11, any nonwoven fabric usable for the top sheet 2 can be used, and point-bonded nonwoven fabrics, air-through nonwoven fabrics, spunbond nonwoven fabrics, meltblown nonwoven fabrics, airlaid nonwoven fabrics, spunlace nonwoven fabrics, etc., can be used. In order to enhance the effect of drawing in urine, etc., it is preferable that the nonwoven fabric constituting the nonwoven fabric layer 11 has a sufficiently large interfiber gap, and therefore it is preferable that the nonwoven fabric layer 11 is composed of point-bonded nonwoven fabric, air-through nonwoven fabric, spunbond nonwoven fabric, or spunlace nonwoven fabric. Since these nonwoven fabrics do not use adhesives for interfiber bonding, the drawing power of urine, etc. can be enhanced.

[0023] The nonwoven fabric constituting the nonwoven layer 11 is preferably composed of synthetic resin fibers such as polyolefin (e.g., polypropylene, polyethylene), polyester (e.g., PET), and polyamide (e.g., nylon), and the surface of the fibers is preferably treated with a hydrophilizing agent such as a surfactant. By constructing the nonwoven fabric of the nonwoven layer 11 in this way, the penetration of urine, etc., into the interior of the fibers constituting the nonwoven fabric is suppressed. As a result, the amount of urine, etc. that has moved from the top sheet 2 to the second sheet 10 that remains on the second sheet 10 is reduced, and more of the urine, etc., is able to pass through the through-holes 13 and through the second sheet 10.

[0024] The nonwoven fabric layer 11 is preferably composed of a long-fiber nonwoven fabric. If the nonwoven fabric layer 11 is composed of a long-fiber nonwoven fabric, urine and the like can easily diffuse widely in the nonwoven fabric layer 11 along the fiber orientation direction of the long fibers. As a result, the diffusion of urine and the like in the planar direction in the second sheet 10 is increased, and the absorbent material 4 can more easily contribute to the absorption of urine and the like over a wider area in the planar direction. In this case, it is preferable that the constituent fibers of the nonwoven fabric are oriented in the longitudinal direction y of the absorbent article 1. Therefore, it is preferable that the nonwoven fabric layer 11 is composed of a spunbond nonwoven fabric, and it is preferable that the constituent fibers of the spunbond nonwoven fabric are oriented in the longitudinal direction y of the absorbent article 1.

[0025] The nonwoven fabric layer 11 may be made of a heat-embossed nonwoven fabric. That is, the nonwoven fabric constituting the nonwoven fabric layer 11 may have a heat-embossed portion. If the nonwoven fabric layer 11 is made of a heat-embossed nonwoven fabric, it is possible to reduce the amount of urine, etc. that remains in the nonwoven fabric layer 11 while ensuring the urine, etc. trapping effect of the nonwoven fabric layer 11, thereby reducing the bulk of the nonwoven fabric layer 11. As a result, it is possible to reduce the amount of urine, etc. that flows back from the second sheet 10 to the top sheet 2. A heat-embossed nonwoven fabric means a nonwoven fabric that has been heat-embossed on its own.

[0026] The shape and arrangement of the heat-embossed portions of the nonwoven fabric layer 11 are not particularly limited, but it is preferable that the heat-embossed portions be provided in a scattered pattern of any shape. The shape of each heat-embossed portion is not particularly limited, and can be circular, elliptical, oblong, polygonal, corrugated, star-shaped, etc., and these may be provided in a regular arrangement pattern or in a random arrangement pattern. When the heat-embossed portions are provided in a regular arrangement pattern, it is preferable that the heat-embossed portions be provided at each grid point of an arbitrary grid. The shape and arrangement of the heat-embossed portions are defined in a state in which the through holes 13 are not formed.

[0027] The plastic film layer 12 can be a film formed from a synthetic resin such as polyolefin (e.g., polypropylene, polyethylene), polyester (e.g., PET), or polyamide (e.g., nylon). The synthetic resin is preferably a thermoplastic resin. The plastic film layer 12 may be treated with a hydrophilizing agent such as a surfactant. The plastic film layer 12 is preferably not embossed, as this makes it less likely to break.

[0028] The plastic film layer 12 is positioned on the backsheet 3 side of the nonwoven fabric layer 11 and is laminated and integrated with the nonwoven fabric layer 11. Preferably, the nonwoven fabric layer 11 and the plastic film layer 12 are joined to each other, for example, by adhesive or by welding. Preferably, 80% or more of the area of ​​the nonwoven fabric layer 11 is joined to the plastic film layer 12, more preferably 90% or more, and even more preferably 95% or more.

[0029] When the nonwoven fabric layer 11 and the plastic film layer 12 are joined to each other by welding, the nonwoven fabric layer 11 may partially melt and be welded to the plastic film layer 12, the plastic film layer 12 may partially melt and be welded to the nonwoven fabric layer 11, or both the nonwoven fabric layer 11 and the plastic film layer 12 may partially melt and be welded to each other. However, from the viewpoint of enhancing the urine-absorbing effect of the nonwoven fabric layer 11, it is preferable that the adhesive does not enter the interfiber gaps of the constituent fibers of the nonwoven fabric layer 11, and that the nonwoven fabric layer 11 does not melt. In other words, it is preferable that the nonwoven fabric layer 11 and the plastic film layer 12 are not joined to each other by adhesive. Furthermore, it is preferable that the plastic film layer 12 partially melts and is welded to the nonwoven fabric layer 11 rather than the nonwoven fabric layer 11 partially melting and being welded to the plastic film layer 12.

[0030] In a plan view of the absorbent article 1, it is preferable that the entire second sheet 10 is positioned inward from the outer edge of the absorbent body 4. When the second sheet 10 is positioned in this manner, the entire second sheet 10 will be located on the top sheet 2 side of the absorbent body 4 without protruding from it. Therefore, urine and other substances on the second sheet 10 can easily transfer through the through-holes 13 of the second sheet 10 to the top sheet 2 side surface of the absorbent body 4, preventing them from transferring to areas other than the absorbent body 4.

[0031] As shown in Figure 4, the through-hole 13 of the second sheet 10 is formed to protrude toward the back sheet 3. The second sheet 10 has a protruding portion 14 that extends toward the back sheet 3 along the outer edge of the through-hole 13. Figure 4 shows a cross-sectional view of the second sheet 10 in the thickness direction z passing through the center 13C of the through-hole 13. The portion of the second sheet 10 along the outer edge of the through-hole 13 (the peripheral portion of the through-hole 13) protrudes toward the back sheet 3, and the portion of the second sheet 10 that protrudes toward the back sheet 3 from the peripheral portion of the through-hole 13 becomes the protruding portion 14. With the second sheet 10 formed in this way, urine and other fluids on the first surface 10A of the second sheet 10 tend to collect in the through-hole 13, and the urine and other fluids on the first surface 10A of the second sheet 10 tend to move toward the absorbent material 4 through the through-hole 13. As a result, the wettability of the top sheet 2 can be reduced.

[0032] The protruding portion 14 has a protruding base portion 14A and a protruding end portion 14B. The protruding base portion 14A is a part of the protruding portion 14 that includes the starting point where the protruding portion 14 protrudes toward the backsheet 3 side, and the protruding end portion 14B is a part of the protruding portion 14 that includes the tip of the protruding portion 14 that protrudes toward the backsheet 3 side. The protruding portion 14 is formed such that the protruding base portion 14A extends toward the center 13C of the through hole 13 toward the backsheet 3 side, and the protruding end portion 14B extends toward the backsheet 3 side away from the center 13C of the through hole 13. Preferably, the protruding portion 14 has a constricted portion between the protruding base portion 14A and the protruding end portion 14B where the cross-sectional area of ​​the through hole 13 is narrowed.

[0033] In Figure 4, the boundary between the protruding base 14A and the protruding end 14B of the protruding portion 14 is shown by a dotted line, and the protruding end 14B is provided on the backsheet 3 side of the protruding base 14A. In one embodiment of the second sheet 10, there is a gap between the protruding base 14A and the protruding end 14B, and the protruding base 14A and the protruding end 14B are indirectly connected. In another embodiment of the second sheet 10, the protruding end 14B is directly connected to the protruding base 14A. In the cross-section of the second sheet 10 in the thickness direction z, the protruding base 14A and the protruding end 14B are directly or indirectly connected and may extend in a straight line, in a curved line, or in a multi-stage bend.

[0034] In a cross-section of the second sheet 10 in the thickness direction z, passing through the center 13C of the through hole 13, the protruding base 14A extends toward the center 13C of the through hole 13 toward the back sheet 3, and the protruding end 14B extends toward the back sheet 3 toward the center 13C of the through hole 13. The center 13C of the through hole 13 refers to the centroid of the through hole 13 in a plan view of the second sheet 10. The formation of the protruding portion 14 in this manner makes it easier for urine, etc., that has permeated the top sheet 2 and moved to the second sheet 10 to smoothly move through the through hole 13 to the absorbent material 4. In other words, urine and other fluids on the first surface 10A of the second sheet 10 can easily transfer to the absorbent material 4 via the protruding portion 14 that protrudes toward the back sheet 3. At this time, at the protruding base portion 14A, urine and other fluids on the first surface 10A of the second sheet 10 tend to collect in the through-hole 13, and at the protruding end portion 14B, the through-hole 13 is formed to widen toward the back sheet 3, so that urine and other fluids are less likely to clog at the protruding end portion 14B and can easily transfer to the absorbent material 4.

[0035] The protrusions 14 formed as described above also act to separate the second sheet 10 from the surface of the absorbent 4 on the top sheet 2 side. Since the protrusions 14 are formed such that the protruding end 14B extends away from the center 13C of the through hole 13 toward the back sheet 3 side, the protrusions 14 are more easily and stably maintained in an upright position on the surface of the absorbent 4 on the top sheet 2 side, and it is easier to ensure the height of the protrusions 14. As a result, the part of the second sheet 10 other than the protrusions 14 is more likely to be positioned away from the surface of the absorbent 4 on the top sheet 2 side, and the distance between the first surface 10A of the second sheet 10 and the surface of the absorbent 4 on the top sheet 2 side is more easily ensured. Therefore, it is less likely that urine etc. that has moved to the absorbent 4 will flow back to the top sheet 2 side through the through hole 13 of the second sheet 10.

[0036] In an embodiment of the absorbent article 1 according to this disclosure, the protruding portion 14 only needs to have a protruding base 14A and a protruding end 14B formed as described above in at least a portion of the circumferential direction of the through hole 13. That is, the protruding base 14A and the protruding end 14B only need to be formed as described above in any cross section in the thickness direction z of the second sheet 10 passing through the center 13C of the through hole 13. For example, the protruding portion 14 may have a protruding base 14A and a protruding end 14B formed as described above in a cross section in the thickness direction z along the width direction x passing through the center 13C of the through hole 13, but at least one of the protruding base 14A and the protruding end 14B may not be formed as described above in a cross section in the thickness direction z along the longitudinal direction y passing through the center 13C of the through hole 13. Furthermore, in order to facilitate the smooth collection of urine and other fluids on the second seat 10 into the through-hole 13, it is preferable that the protruding base 14A is formed to extend along the entire circumferential direction of the through-hole 13 toward the back seat 3 side, which is the thickness direction z, and toward the center 13C of the through-hole 13. The circumferential direction of the through-hole 13 refers to the direction surrounding the through-hole 13 and corresponds to the direction in which the outer edge of the through-hole 13 extends.

[0037] In the cross-section of the second sheet 10 in the thickness direction z passing through the center 13C of the through hole 13, the height H (length in the thickness direction z) of the protrusion 14 is preferably 0.3 times or more the opening width W of the through hole 13, more preferably 0.4 times or more, even more preferably 0.5 times or more, and preferably 1.7 times or less, more preferably 1.5 times or less, and even more preferably 1.3 times or less. When the protrusion 14 is formed in this manner, it is easier for the protrusion 14 to be held stably without being crushed, and it is easier to ensure a sufficient distance between the first surface 10A of the second sheet 10 and the surface of the absorber 4 on the top sheet 2 side. The opening width W of the through hole 13 refers to the narrowest length of the opening width (length in the vertical direction z of the thickness direction) of the through hole 13, and in the case of the protrusion 14 formed as described above, it is the opening width at the constricted part of the protrusion 14. If the planar shape of the through-hole 13 is not circular, the opening width W of the through-hole 13 is defined as the average of the opening width W in the cross-section along the long axis and the opening width W in the cross-section along the short axis of the planar shape of the through-hole 13.

[0038] The height H of the protrusion 14 is preferably 0.1 mm or more, more preferably 0.2 mm or more, preferably 1.0 mm or less, and more preferably 0.7 mm or less. When the protrusion 14 is formed in this manner, it becomes easier to stably form the protrusion 14 having a protrusion base 14A and a protrusion end 14B, and the thickness of the second sheet 10 does not become too thick, making it easier to form the absorbent article 1 with a thin thickness.

[0039] In a cross-section of the second sheet 10 in the thickness direction z passing through the center 13C of the through hole 13, it is preferable that the average inclination angle of the protruding base 14A with respect to the planar direction of the second sheet 10 is smaller than the average inclination angle of the protruding end 14B. If the protrusion 14 is formed in this manner, urine and the like on the second sheet 10 can be collected over a wide area at the protruding base 14A, and the protruding end 14B will not be easily crushed even if a force in the thickness direction z is applied to the second sheet 10.

[0040] The average inclination angle of the protruding base 14A and the average inclination angle of the protruding end 14B are determined as follows: In the cross section of the second sheet 10 passing through the center 13C of the through hole 13 in the thickness direction z, the plane direction, i.e., the direction perpendicular to the thickness direction z, is set to 0° and this is used as the reference angle. The angular range that the direction toward the center 13C of the through hole 13 toward the back sheet 3 can take is set to 0° to +90°. In the protruding base 14A, a line segment is drawn connecting the point where the extension direction of the second sheet 10 transitions from 0° (or less than or equal to 0°) to greater than 0° and the point where it transitions from less than 90° to 90° (or greater than or equal to 90°), and the angle between the extension direction of this line segment and the plane direction is set to the average inclination angle of the protruding base 14A. At the protruding end 14B, a line segment is drawn connecting the point where the extending direction of the second sheet 10 transitions from 90° (or less than 90°) to more than 90° with the tip of the protruding part 14, and the angle between the extending direction of this line segment and the planar direction is defined as the average inclination angle of the protruding end 14B. The extending direction of the second sheet 10 is determined from the extending direction of the midpoint of the thickness of the laminate of the nonwoven fabric layer 11 and the plastic film layer 12. The average inclination angle of the protruding base 14A and the average inclination angle of the protruding end 14B are both the angle between the extending direction of each line segment and the planar direction determined above, and therefore take a range of 0° to 90°.

[0041] In a cross-section of the second sheet 10 in the thickness direction z passing through the center 13C of the through hole 13, it is preferable that the length H1 of the protruding base 14A in the height direction of the protruding portion 14 is longer than the length H2 of the protruding end 14B in the height direction of the protruding portion 14. If the protruding portion 14 is formed in this manner, it becomes possible to collect urine and other substances on the second sheet 10 into the through hole 13 more efficiently. Note that the length H1 of the protruding base 14A in the height direction of the protruding portion 14 means the length obtained by projecting the protruding base 14A in the height direction of the protruding portion 14. The same applies to the length H2 of the protruding end 14B in the height direction of the protruding portion 14.

[0042] In a cross-section of the second sheet 10 in the thickness direction z passing through the center 13C of the through hole 13, it is preferable that the edge 14E of the protruding portion 14 is formed in a non-linear shape. The edge 14E of the protruding portion 14 can also be said to be the edge on the tip side of the protruding end 14B. If the edge 14E of the protruding portion 14 is formed in this way, the tip of the protruding portion 14 does not adhere closely to the surface of the absorbent body 4 on the top sheet 2 side, and a gap is easily formed between the tip of the protruding portion 14 and the surface of the absorbent body 4 on the top sheet 2 side. Therefore, when the absorbent body 4 absorbs urine, etc. and its absorbency is saturated in the portion that overlaps with the through hole 13, the urine, etc. that entered the through hole 13 does not get stuck at the tip of the protruding portion 14, but rather spreads easily through the gap between the tip of the protruding portion 14 and the surface of the absorbent body 4 on the top sheet 2 side. As a result, even after the absorbent body 4 has absorbed urine, etc., urine, etc. can easily be transferred smoothly from the second sheet 10 to the absorbent body 4.

[0043] The height H of the protrusion 14 is preferably 0.1 times or more, more preferably 0.2 times or more, preferably 0.5 times or less, and more preferably 0.4 times or less, the distance between the centers 13C of the through holes 13 formed by adjacent protrusions 14. In other words, it is preferable that the height H of adjacent protrusions 14 and the distance between the centers 13C of the through holes 13 formed by these protrusions 14 have this relationship. When the protrusions 14 are formed in this way, they are more likely to be held stably without being crushed, and a sufficient distance is more likely to be secured between the first surface 10A of the second sheet 10 and the surface of the absorber 4 on the top sheet 2 side.

[0044] In the second sheet 10, it is preferable that the nonwoven fabric layer 11 penetrates the through-holes 13. That is, in the second sheet 10, it is preferable that the nonwoven fabric layer 11 is inserted into the through-holes 13 of the plastic film layer 12. If the through-holes 13 are formed in this way, the inner surface of the through-holes 13 is covered with nonwoven fabric, making it easier for urine, etc., to smoothly transfer from the nonwoven fabric layer 11 to the through-holes 13. As a result, it is easier for urine, etc., to smoothly transfer through the through-holes 13 to the absorbent material 4.

[0045] The planar shape of the through-hole 13 is not particularly limited and can be circular, elliptical, oblong, polygonal, irregular, etc. Preferably, the planar shape of the through-hole 13 has a certain length in different directions in the planar direction. For example, in a planar view of the second sheet 10 as seen from the first surface 10A side, the aspect ratio of the planar shape of the through-hole 13 may be 6.0 or less, 5.0 or less, 4.0 or less, or 3.0 or less. If the through-hole 13 is formed with such a planar shape, urine and the like on the second sheet 10 will pass through the through-hole 13 more smoothly.

[0046] The planar shape of the through-hole 13 refers to the shape of the through-hole 13 in a plan view of the second sheet 10. The aspect ratio of the planar shape of the through-hole 13 can be determined by dividing the length in the major axis direction of the planar shape of the through-hole 13 by the length in the minor axis direction. The major axis direction of the planar shape of the through-hole 13 refers to the direction that gives the longest length of the planar shape of the through-hole 13. The minor axis direction refers to the direction perpendicular to the major axis direction, and the length in the minor axis direction of the planar shape of the through-hole 13 refers to the longest length in the minor axis direction of the planar shape of the through-hole 13.

[0047] As one embodiment of the absorbent article 1 according to this disclosure, the absorbent article 1 has a longitudinal direction y and a width direction x perpendicular to the longitudinal direction y, and the through-hole 13 of the second sheet 10 may be formed in a shape that is longer in the longitudinal direction y than in the width direction x of the absorbent article 1 when viewed from the first surface 10A side of the second sheet 10 (also called the planar shape). Furthermore, the protruding end 14B of the protruding portion 14 may extend toward the back sheet 3 side toward the center 13C of the through-hole 13 in the cross section in the width direction x. With such a configuration, urine and the like can be efficiently diffused not only in the thickness direction z of the absorbent article 1 but also in the longitudinal direction y and the width direction x through the through-hole 13 of the second sheet 10.

[0048] As described above, the planar shape of the through-hole 13 may have a long axis direction and a short axis direction. In this case, the aspect ratio of the planar shape of the through-hole 13 is not particularly limited as long as it is greater than 1.0, and may be 1.1 or greater, 1.2 or greater, or 1.3 or greater. If the planar shape of the through-hole 13 is formed to have a long axis direction and a short axis direction, urine, etc. will diffuse more easily along the long axis direction of the through-hole 13 on the second sheet 10. Therefore, it becomes easier to control the diffusion direction of urine, etc. on the second sheet 10.

[0049] The planar shape of the through-hole 13 has a long axis direction and a short axis direction. In a cross-section along the thickness direction and the short axis direction passing through the center 13C of the through-hole 13, the protruding end 14B of the protruding portion 14 may extend away from the center 13C of the through-hole 13 toward the backsheet 3, and in a cross-section along the thickness direction and the long axis direction passing through the center 13C of the through-hole 13, the protruding end 14B may extend toward the center 13C of the through-hole 13 toward the backsheet 3. When the planar shape of the through-hole 13 has a long axis direction and a short axis direction, there is a concern that the through-hole 13 may be formed narrow in the short axis direction, making it difficult for urine, etc., to pass through the through-hole 13. However, by forming the protruding end 14B to extend away from the center 13C of the through-hole 13 toward the backsheet 3 in the short axis direction, smooth passage of urine, etc., through the through-hole 13 is ensured. Furthermore, if the protruding end 14B is formed to extend toward the center 13C of the through hole 13 toward the backsheet 3 in the longitudinal direction, the rate of change of the area of ​​the through hole 13 in the thickness direction z will be small at the protruding end 14B, making it less likely for urine, etc., to remain between the protruding base 14A and the protruding end 14B when passing through the through hole 13. It is preferable that the protruding base 14A extends toward the center 13C of the through hole 13 toward the backsheet 3 in both the longitudinal and short axis directions.

[0050] In this embodiment, it is preferable that the long axis direction of the through-hole 13 substantially coincides with the longitudinal direction y of the absorbent article 1. That is, it is preferable that the through-hole 13 is longer in the longitudinal direction y than in the width direction x of the absorbent article 1. With such a configuration, urine, etc., can diffuse more easily in the longitudinal direction y than in the width direction x on the second sheet 10, and the entire absorbent material 4 can contribute more easily to the absorption of urine, etc.

[0051] Furthermore, as a modification of this embodiment, at least a portion of the protruding end 14B of the protruding portion 14 may extend toward the backsheet 3 side toward the center 13C of the through hole 13 in the cross-section in the longitudinal direction y. This configuration ensures the smooth passage of urine and other liquids through the through hole 13. It is preferable that the protruding base 14A of the protruding portion 14 extends toward the backsheet 3 side toward the center 13C of the through hole 13 in both the width direction x and the longitudinal direction y.

[0052] The area ratio of the through-holes 13 in the second sheet 10 is preferably 1% or more and 10% or less. With the through-holes 13 formed in this way, urine, etc. can be quickly drawn from the top sheet 2 to the second sheet 10, and the urine, etc. that has moved to the second sheet 10 can easily move smoothly to the absorbent material 4 through the through-holes 13. The area ratio of the through-holes 13 in the second sheet 10 is more preferably 2% or more, even more preferably 3% or more, even more preferably 8% or less, and even more preferably 6% or less.

[0053] The area ratio of the through-hole 13 in the second sheet 10 can be determined by dividing the area of ​​the through-hole 13 by the area of ​​the second sheet 10, with the area of ​​the second sheet 10 including the through-hole 13 as the numerator and the area of ​​the through-hole 13 as the denominator, when viewed from the first surface 10A side of the second sheet 10. The area of ​​the through-hole 13 is the area of ​​the part of the through-hole 13 that is not visible from the second sheet 10 (i.e., the part where the other side of the second sheet 10 is visible) when viewed from the first surface 10A side of the second sheet 10.

[0054] It is preferable that multiple through-holes 13 are arranged in a row in the planar direction of the second sheet 10. The spacing between adjacent through-holes 13 is preferably, for example, 0.5 mm or more, more preferably 0.8 mm or more, even more preferably 1 mm or more, and preferably 10 mm or less, more preferably 7 mm or less, and even more preferably 4 mm or less. The area of ​​the through-hole 13 is, for example, 0.05 mm². 2 ~3mm 2 It is preferable that it be of a certain degree.

[0055] The nonwoven fabric layer 11 is made of heat-embossed nonwoven fabric, and each through-hole 13 may be formed in an area smaller than the heat-embossed portion of the heat-embossed nonwoven fabric. If heat-embossed portions are formed in this manner, the size of each heat-embossed portion will be larger, making it easier for urine, etc., to move on the first surface 10A of the second sheet 10, and as a result, urine, etc., will be more likely to collect in the through-holes 13.

[0056] The through-hole 13 described above can be formed, for example, as follows: A laminate of a nonwoven fabric layer and a plastic film layer is inserted between a pin roll and an anvil roll having recesses on its surface. Numerous pins protrude from the surface of the pin roll, and numerous recesses corresponding to the pins are formed on the surface of the anvil roll. When the pin roll and the anvil roll are rotated, the pins of the pin roll enter the recesses of the anvil roll. The pin has a straight body and a tip. The straight body has a constant outer diameter, while the tip has a diameter that decreases towards the tip, and the base end of the tip is formed to match the outer diameter of the straight body. When inserting the pin into the laminate of the nonwoven fabric layer and the plastic film layer, the pin is inserted up to the straight body. This allows the tip of the through-hole to be expanded. The anvil roll is configured to heat the inside of the recesses, and when the pin is inserted into the laminate of the nonwoven fabric layer and the plastic film layer, the portion of the plastic film layer near where the pin is inserted is heated. As a result, the plastic film layer in the vicinity shrinks due to heat, causing the tip of the through-hole to widen towards the tip, thereby forming the through-hole described above.

[0057] The absorbent articles relating to this disclosure have been described above with reference to the drawings, but the absorbent articles relating to this disclosure are not limited to urine pads as shown in the drawings, and may also be disposable diapers, light incontinence pads, or sanitary napkins.

[0058] When the absorbent item is a disposable diaper, the disposable diaper is composed of, for example, an anterior abdominal section, a posterior back section, and a crotch section located between these sections and equipped with an absorbent material. The anterior abdominal section corresponds to the part that comes into contact with the wearer's abdomen when wearing the disposable diaper, and the posterior back section corresponds to the part that comes into contact with the wearer's back when wearing the disposable diaper. The crotch section is located between the anterior abdominal section and the posterior back section and corresponds to the part that comes into contact with the wearer's crotch.

[0059] Disposable diapers may be tape-type or pant-type. Tape-type disposable diapers are constructed, for example, with fastening members provided at both ends in the width direction of the back, and by fastening these fastening members to the front of the abdomen, they can be formed into a pant shape when worn. Pant-type disposable diapers have a pant shape with a waist opening and a pair of leg openings, and are formed into a pant shape before being worn.

[0060] If the absorbent item is a disposable diaper, the disposable diaper is formed such that, for example, a laminate in which an absorbent material is placed between a top sheet and a back sheet has an abdominal area, a posterior area, and a crotch area located between them. The disposable diaper can also be constructed by providing an absorbent body in the crotch area of ​​an outer material having an abdominal area, a posterior area, and a crotch area located between them, with an absorbent material placed between a top sheet and a back sheet. In the latter case, the outer material can be formed into a pant shape to make a pant-type disposable diaper. [Explanation of symbols]

[0061] 1: Absorbent items (urinary pads) 2: Top sheet 3: Back seat 4: Absorbent material 10: Second seat, 10A: First side, 10B: Second side 11: Non-woven layer 12: Plastic film layer 13: Through hole, 13C: Center (of the through hole) 14:Protrusion, 14A:Protrusion base, 14B:Protrusion end, 14E: Edge

Claims

1. An absorbent article having a top sheet, a back sheet, and an absorbent material disposed between them, wherein a second sheet is disposed between the top sheet and the absorbent material, The second sheet is composed of a laminate having a nonwoven fabric layer and a plastic film layer from the top sheet side, and a plurality of through holes are formed in the second sheet. The second seat has a protrusion that extends toward the back seat side along the outer edge of the through hole, The aforementioned projection has a projection base and a projection end, the projection base extends toward the center of the through hole toward the backsheet side, and the projection end extends toward the backsheet side away from the center of the through hole, in an absorbent article.

2. The absorbent article according to claim 1, wherein in a cross-section of the second sheet in the thickness direction passing through the center of the through hole, the height of the protrusion is 0.3 times or more and 1.7 times or less the opening width of the through hole.

3. The absorbent article according to claim 1, wherein in a cross-section of the second sheet in the thickness direction passing through the center of the through hole, the average inclination angle of the protruding base with respect to the planar direction of the second sheet is smaller than the average inclination angle of the protruding end.

4. The absorbent article according to claim 1, wherein in a cross-section of the second sheet in the thickness direction passing through the center of the through hole, the length of the protruding base in the height direction of the protrusion is longer than the length of the protruding end in the height direction of the protrusion.

5. The absorbent article according to claim 1, wherein in a cross-section of the second sheet in the thickness direction passing through the center of the through hole, the edge of the protruding portion is formed in a non-linear shape.

6. The absorbent article according to claim 1, wherein the aspect ratio of the planar shape of the through hole is 6.0 or less.

7. The absorbent article according to claim 1, wherein the area ratio of the through-holes in the second sheet is 1% or more and 10% or less.

8. The absorbent article according to claim 1, wherein the second sheet has the nonwoven fabric layer penetrating the through hole.

9. The absorbent article has a longitudinal direction and a width direction perpendicular to the longitudinal direction. The absorbent article according to claim 1, wherein the through hole is formed in a shape that is longer in the longitudinal direction than in the width direction when viewed from above, and the protruding end of the protruding portion extends toward the back sheet side toward the center of the through hole in a cross section in the width direction.

10. The absorbent article according to claim 9, wherein at least a portion of the protruding end of the protruding portion extends toward the backsheet side toward the center of the through hole in the longitudinal cross-section.

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