CN107847374B - Absorbent article - Google Patents

Abstract

The absorbent article (1) of the present invention comprises a front sheet (2), a back sheet (3), and an absorbent body (4) interposed between the two sheets (2, 3). The absorbent article (1) has a second sheet (9) between the topsheet (2) and the absorbent body (4). The front sheet (2) has a concavo-convex structure including a skin-side protruding portion (21) protruding toward the skin-facing side and having an internal space (S1), and a non-skin-side protruding portion (22) protruding toward the non-skin-facing side and having an internal space (S2). When the front sheet (2) is viewed in cross section, the grammage of the fibers of the wall portion (21W) is higher than the grammage of the fibers of the top portion (21T) of the skin-side protruding portion (21) and the top portion (22T) of the non-skin-side protruding portion (22). The absorber (4) is formed of a laminate of absorbent sheets and has slits (43). The slit (43) penetrates through the 1-layer laminate.

Description

Absorbent article

Technical Field

The present invention relates to an absorbent article such as a sanitary napkin.

Background

The present applicant has previously proposed an absorbent article in which a topsheet is disposed directly above an absorbent body, a plurality of slits are provided in a lower layer of the topsheet, and a plurality of solid protrusions are provided in an upper layer of the topsheet (see patent document 1). The applicant of the present invention has also previously proposed an absorbent article in which a plurality of slits are formed in an absorbent body, and a front sheet disposed above the absorbent body is provided with protrusions formed into blocks by forming depressions in a diagonal lattice shape by pressure bonding of constituent fibers (see patent document 2).

Unlike the absorbent article described above, patent document 3 describes an absorbent article having a topsheet directly above an absorbent body, the topsheet being provided with a plurality of projections, and a hollow structure being provided between the projections of the topsheet and the absorbent body.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2005-319043

Patent document 2: japanese laid-open patent publication (JP 2015-024002)

Patent document 3: japanese laid-open patent publication No. 2009-268559

Disclosure of Invention

The present invention relates to an absorbent article including an absorbent main body including: a liquid-permeable front sheet forming a skin-facing surface, a back sheet forming a non-skin-facing surface, and an absorbent body interposed between the sheets, the absorbent body comprising: the absorbent article includes a discharge portion facing portion disposed to face a discharge portion of a wearer when worn, a front portion disposed on a belly side of the wearer relative to the discharge portion facing portion, and a rear portion disposed on a back side of the wearer relative to the discharge portion facing portion, and has a longitudinal direction corresponding to a front-back direction of the wearer and a transverse direction perpendicular to the longitudinal direction. A second sheet made of nonwoven fabric is disposed between the topsheet and the absorbent body. The front sheet has an uneven structure including a plurality of skin-side protruding portions protruding toward the skin-facing surface and having an internal space, and a plurality of non-skin-side protruding portions protruding toward the non-skin-facing surface and having an internal space. The excretion portion opposing portion includes: a hollow portion having a hollow structure between the skin-side protruding portion and the second sheet, and a non-pressure-bonding portion in which the non-skin-side protruding portion and the absorbent body are not pressure-bonded. When the topsheet is viewed in cross section, the grammage of fibers in the wall portion between the top of the skin-side protrusion and the top of the non-skin-side protrusion is higher than the grammage of fibers in the top of the skin-side protrusion and the top of the non-skin-side protrusion. The absorbent body is formed of a laminate of absorbent sheets, and has a plurality of slits in the excretion portion-facing portion. The slit penetrates at least 1 layer of the laminate.

Drawings

Fig. 1 is a plan view showing a skin-facing surface side (topsheet side) of a sanitary napkin which is a preferred embodiment of the absorbent article of the present invention.

Fig. 2 is a cross-sectional view schematically showing a section taken along line II-II of fig. 1.

Fig. 3 is an enlarged perspective view of a main portion of a front sheet of the sanitary napkin shown in fig. 1.

Fig. 4 is an enlarged schematic sectional view of a main portion of the front sheet shown in fig. 3.

Fig. 5 is a plan view of an absorbent body included in the sanitary napkin shown in fig. 1.

Fig. 6(a) to 6(b) are partially enlarged plan views showing a preferable arrangement of the vertical slit in the excretion portion slit region of the absorbent body shown in fig. 5.

Fig. 7 is an enlarged perspective view of a main portion of a topsheet in another embodiment of the absorbent article of the present invention.

Fig. 8 is an enlarged perspective view of a main part of a front surface sheet included in the sanitary napkin of comparative example 1.

Detailed Description

Since the absorbent article described in patent document 1 has a plurality of slits in the lower layer of the topsheet, it can quickly absorb excreted body fluid and quickly transfer the body fluid to the absorbent body located therebelow. In addition, since the absorbent article described in patent document 2 has a plurality of slits in the longitudinal direction in the absorbent body, the topsheet is less likely to wrinkle, and the body fluid excreted can be quickly absorbed into the absorbent body. However, there is a demand for suppressing the spread of excreted body fluid on the surface of the topsheet and suppressing the rewet of body fluid absorbed into the absorbent body.

Since the absorbent article described in patent document 3 has a hollow structure between the convex portion of the topsheet and the absorbent body, the liquid return of the body fluid absorbed into the absorbent body can be suppressed. However, patent document 3 does not disclose any structure for rapidly absorbing excreted body fluid and suppressing diffusion of excreted body fluid on the surface of the topsheet.

Accordingly, an object of the present invention is to provide an absorbent article which can eliminate the above-described drawbacks of the prior art.

Hereinafter, a sanitary napkin 1 (hereinafter, also referred to as "sanitary napkin 1") according to a preferred embodiment of the absorbent article of the present invention will be described with reference to the drawings. Fig. 1 is a plan view of a sanitary napkin 1 according to the present embodiment as viewed from the front sheet side, and fig. 2 is a sectional view of the sanitary napkin 1 according to the present embodiment. As shown in fig. 1 and 2, the sanitary napkin 1 has an absorbent main body 10, and the absorbent main body 10 has a liquid-permeable topsheet 2 forming a skin-facing surface, a backsheet 3 forming a non-skin-facing surface, and an absorbent body 4 interposed between these two sheets 2, 3. In the sanitary napkin 1, a second sheet 9 made of nonwoven fabric is disposed between the topsheet 2 and the absorbent member 4. The second sheet 9 is a sheet independent of the topsheet 2 and the absorbent body 4, and is also referred to in the art as a sub-sheet (sub-sheet). The second sheet 9 is a sheet that functions to improve the permeability of liquid from the topsheet 2 to the absorbent body 4, or to reduce the liquid absorption into the absorbent body 4 from returning to the topsheet 2.

As shown in fig. 1, the absorbent main body 10 of the sanitary napkin 1 has: a excretory part facing portion B disposed to face an excretory part (vaginal opening or the like) of a wearer when worn, a front portion a disposed on the abdominal side (front side) of the wearer relative to the excretory part facing portion B, and a rear portion C disposed on the back side (rear side) of the wearer relative to the excretory part facing portion B. The sanitary napkin 1 and the absorbent main body 10 have a longitudinal direction X corresponding to the front-back direction of the wearer, and a transverse direction Y orthogonal to the longitudinal direction X. That is, the absorbent main body 10 is divided into a front portion a, a discharge portion facing portion B, and a rear portion C in this order in the longitudinal direction X.

In the present specification, the skin-facing surface is a surface of the sanitary napkin 1 or a component thereof (for example, the absorbent main body 10) that faces the skin side of the wearer when the sanitary napkin 1 is worn, and the non-skin-facing surface is a surface of the sanitary napkin 1 or a component thereof that faces the side opposite to the skin side (the dressing side) when the sanitary napkin 1 is worn. The longitudinal direction X coincides with the longitudinal direction of the sanitary napkin 1 and the absorbent main body 10, and the transverse direction Y coincides with the width direction (direction orthogonal to the longitudinal direction) of the sanitary napkin 1 and the absorbent main body 10.

In the present embodiment, as shown in fig. 1 and 2, the sanitary napkin 1 includes, in addition to the absorbent main body 10, a pair of flap portions 10W, and the pair of flap portions 10W, 10W extend outward in the transverse direction Y from both side portions along the longitudinal direction X of the excretion portion-facing portion B of the absorbent main body 10.

In the absorbent article of the present invention, when the flap portion 10W is provided as in the sanitary napkin 1 of the present embodiment, the excretion portion-facing portion B refers to a region having the flap portion 10W in the longitudinal direction of the absorbent article (the longitudinal direction of the absorbent article, the X direction in the drawing) (a region sandwiched by the root portion in the longitudinal direction X of one flap portion 10W and the root portion in the longitudinal direction X of the other flap portion 10W). The excretion portion facing portion in the absorbent article having no flap portion is a region surrounded by a first bending line and a second bending line from the front end in the longitudinal direction X of the absorbent article among 2 bending lines (not shown) crossing the absorbent article in the transverse direction (the width direction of the absorbent article, the Y direction in the drawing) generated when the absorbent article is folded into a single package form of three folds.

In the sanitary napkin 1, as shown in fig. 2, the topsheet 2 covers the entire skin-facing surface of the absorbent member 4 and extends outward in the transverse direction Y from both side edges of the absorbent member 4 in the longitudinal direction X. On the other hand, the back sheet 3 covers the entire region of the absorbent body 4 other than the skin-facing surface, and further extends outward in the lateral direction Y from both side edges of the absorbent body 4 in the longitudinal direction X, and forms a flap portion 10S together with the side sheet 5 described below. The back sheet 3 and the side sheet 5 are joined to each other by a known joining method such as adhesive, heat sealing, ultrasonic sealing, or the like at extending portions from both side edges of the absorbent body 4 in the longitudinal direction X.

In the sanitary napkin 1, as shown in fig. 1 and 2, the side sheets 5 are disposed on both side portions in the longitudinal direction X of the skin-facing surface of the absorbent main body 10 (the skin-facing surface of the topsheet 2). The side sheets 5 are preferably disposed over the entire length in the longitudinal direction X of the absorbent main body 10 so as to overlap with both side portions of the absorbent body 4 in the longitudinal direction X in plan view.

In the sanitary napkin 1, as shown in fig. 1, the pair of side sheets 5 and 5 are joined to the topsheet 2 by a linear first join line 61 located at the excretory part facing portion B and a linear second join line 62 located in the front and rear (front portion a and rear portion C) of the first join line 61 in the longitudinal direction X. The first join line 61 is curved so as to protrude outward in the lateral direction Y in a plan view, and the second join line 62 is linear (zigzag) so as to extend so as to intersect alternately in the longitudinal direction in a plan view. When the side sheet 5 is thus bonded to the topsheet 2 by the first bonding line 61 and the second bonding line 62 and fixed to the skin-facing surface of the absorbent main body 10, as shown in fig. 2, a space P defined by the side sheet 5 and the topsheet 2 is formed on the inner side in the lateral direction Y than the first bonding line 61 and the second bonding line 62. Since the space portion P opens to the center of the absorbent main body 10 in the lateral direction Y, body fluid such as menstrual blood flowing outward from the center of the lateral direction Y is contained in the space portion P, and as a result, leakage of body fluid can be effectively prevented.

In the sanitary napkin 1, as shown in fig. 1, the flap portion 10S largely projects outward in the transverse direction Y at the excretion portion facing portion B, and thus a pair of flap portions 10W, 10W extend on both the left and right sides of the absorbent main body 10 in the longitudinal direction X. As shown in fig. 1, the front sheet 2 and the back sheet 3 extend outward in the longitudinal direction X from the front end and the rear end of the absorbent body 4 in the longitudinal direction X, and are joined to each other at these extended portions by a known joining method such as an adhesive, heat sealing, or ultrasonic sealing, to form end seal portions.

The flap portion 10W is used by being folded back toward the non-skin-facing surface side of the crotch portion of clothing worn by shorts or the like. In the sanitary napkin 1, as shown in fig. 1, the flap portion 10W has a substantially trapezoidal shape with a lower base (a side longer than an upper base) located on the side portion of the absorbent main body 10 along the longitudinal direction X in plan view. As shown in fig. 2, a flap portion attaching portion 71 for fixing the flap portion 10W (sanitary napkin 1) to a garment (not shown) such as pants is formed on the non-skin-facing surface of the flap portion 10W, and the flap portion 10W folded back to the non-skin-facing surface (outer surface) side of the crotch portion of the garment to be worn can be attached and fixed to the crotch portion by the flap portion attaching portion 71 in use. As shown in fig. 2, a body attachment portion 72 (displacement prevention portion) for fixing the absorbent body 10 to clothing worn in shorts or the like is also formed on the non-skin-facing surface of the absorbent body 10.

As shown in fig. 1 and 2, in the sanitary napkin 1, linear compressed grooves 8 are formed in the skin-facing surface of the absorbent main body 10 (the skin-facing surface of the topsheet 2) so that the topsheet 2 and the second sheet 9 are integrally recessed toward the backsheet 3. The "linear shape" in the linear pressing groove 8 means: the shape of the groove (recessed portion) is not limited to a straight line in a plan view, and includes a curved line. Each line may be a continuous line or a discontinuous line such as a broken line. For example, the linear embossed groove 8 may include a row of discontinuous dots embossed therein. The linear compressed groove 8 has a first transverse compressed groove 81 extending in the transverse direction Y and longitudinal compressed grooves 82 extending in the longitudinal direction X on both side portions of the excretory part facing portion B in the front portion a and the rear portion C, respectively. In the sanitary napkin 1, the first transverse compressed grooves 81 in the front portion a and the rear portion C are curved so as to project outward in the longitudinal direction X, and the longitudinal compressed grooves 82 are curved so as to project inward in the transverse direction Y. In the sanitary napkin 1, the first transverse compressed groove 81 in the front portion a, one longitudinal compressed groove 82, the first transverse compressed groove 81 in the rear portion C, and the other longitudinal compressed groove 82 are connected to form a ring-shaped whole peripheral groove. In the sanitary napkin 1, the linear compressed groove 8 has second transverse compressed grooves 83, 83 extending in the transverse direction Y on the longitudinally inner side of the first transverse compressed groove 81 in the front portion a and the rear portion C, respectively. In the sanitary napkin 1, the second transverse compressed grooves 83, 83 of the front portion a and the rear portion C are curved so as to project outward in the longitudinal direction X. Further, as shown in fig. 1, the second transverse compressed grooves 83, 83 of the sanitary napkin 1 are not connected to the pair of longitudinal compressed grooves 82, but may be connected. The linear compressed grooves 8 formed in this manner can suppress the diffusion of body fluid in the planar direction of the absorbent body 4, and can effectively prevent the leakage of fluid from the periphery of the sanitary napkin 1.

As shown in fig. 3 and 4, the topsheet 2 of the sanitary napkin 1 has an uneven structure including a plurality of skin-side protrusions 21 protruding toward the skin-facing surface and having the internal space S1, and a plurality of non-skin-side protrusions 22 protruding toward the non-skin-facing surface and having the internal space S2. Preferably, the skin-side protrusions 21 and the non-skin-side protrusions 22 are alternately and continuously arranged in 2 different directions intersecting each other in a plan view of the topsheet 2. Here, the 2 different directions preferably intersect at an angle of 30 degrees or more and 90 degrees or less with respect to any first direction in the plane and a second direction intersecting therewith, for example, 90 degrees in the sanitary napkin 1. That is, for example, in the sanitary napkin 1, one of the 2 directions is the transverse direction Y, and the other of the 2 directions is the longitudinal direction X. Therefore, the skin-side protrusions 21 and the non-skin-side protrusions 22 are alternately and continuously arranged in the longitudinal direction X and the lateral direction Y when the topsheet 2 is viewed in plan. In the embodiment shown in fig. 4, the convex portion as viewed from the skin-facing surface side is the skin-side convex portion 21, and the concave portion is the non-skin-side convex portion 22. Conversely, the convex portion viewed from the non-skin-facing surface side is the non-skin-side convex portion 22, and the concave portion is the skin-side convex portion 21. Therefore, the skin-side protrusion 21 shares a part with the non-skin-side protrusion 22. The common portion is a wall portion 21W having an annular structure described below and a wall portion 22W having an annular structure described below.

In the sanitary napkin 1, as shown in fig. 3 and 4, the skin-side protrusion 21 has a wall portion 21W of an annular structure between the top portion 21T and the opening portion 21H of the internal space S1 of the front sheet 2. The non-skin-side protruding portion 22 has a wall portion 22W of an annular structure between the top portion 22T and the opening portion 22H of the internal space S2. In the sanitary napkin 1, the skin-side protrusion 21 and the non-skin-side protrusion 22 have a truncated cone shape or a hemispherical shape with a curved top 21T and 22T. The fibers of the top portion 22T of the plurality of non-skin-side protruding portions 22 have a lower grammage than the fibers of the peripheral portions thereof, and the top portion 22T may have a through hole 23. In the embodiment shown in fig. 3 and 4, the non-skin-side protruding portion 22 has a through hole 23 that penetrates the top portion 22T. When the non-skin-side protruding portions 22 have the through holes 23, a part of the top portions 22T of the plurality of non-skin-side protruding portions 22 may have the through holes 23, or all of the top portions 22T of the plurality of non-skin-side protruding portions 22 may have the through holes 23. The topsheet 2 may have the non-skin-side protruding portion 22 including both the top portion 22T having the through-hole 23 and the top portion 22T having no through-hole 23 and having a low fiber grammage, and the non-skin-side protruding portion 22.

When the skin-side protrusion 21 and the non-skin-side protrusion 22 of the front sheet of the sanitary napkin 1 are observed in more detail, the shape of the skin-side protrusion 21 is hemispherical, and the shape of the non-skin-side protrusion 22 is conical or truncated conical with a curvature at the top. The protruding shapes of the skin-side protruding portion 21 and the non-skin-side protruding portion 22 are not limited to the above shapes, and may be any protruding shapes. For example, the shape of the cone may be a cone, a truncated cone, a pyramid, a truncated pyramid, an oblique cone, or the like. In the sanitary napkin 1, the skin-side protrusion 21 and the non-skin-side protrusion 22 hold the truncated cone-shaped or hemispherical inner space S1 and the inner space S2 having a curvature at the top similar to the outer shape thereof.

When the topsheet 2 is viewed in plan from the skin-facing surface side, the wall portion 21W of the skin-side protrusion 21 has an annular structure centered on the top portion 21T of the skin-side protrusion 21. When the topsheet 2 is viewed in plan from the non-skin-facing surface side, the wall portion 22W of the non-skin-side protrusion 22 has an annular structure centered on the top portion 22T of the non-skin-side protrusion 22. As shown in fig. 4, the wall portion 21W of the skin-side protrusion 21 shares the same portion with the wall portion 22W of the non-skin-side protrusion 22. The "annular shape" is not particularly limited as long as the front sheet 2 has a series of shapes that are endless in plan view, and may have any shape such as a circle, an ellipse, a rectangle, and a polygon in plan view of the front sheet 2. From the viewpoint of preferably maintaining the continuous state of the dough sheet 2, a circular or elliptical ring-like configuration is preferable. Further, when the "ring shape" is regarded as a three-dimensional shape, any ring structure such as a cylindrical shape, an oblique cylindrical shape, an elliptical cylindrical shape, a truncated conical shape, a truncated oblique conical shape, a truncated elliptical conical shape, a truncated quadrangular pyramid shape, or a truncated oblique quadrangular pyramid shape may be mentioned, and from the viewpoint of realizing a continuous sheet state, a cylindrical shape, an elliptical cylindrical shape, a truncated conical shape, or a truncated elliptical conical shape is preferable.

The topsheet 2 having the skin-side protruding portion 21 and the non-skin-side protruding portion 22 provided as described above is configured to have a curved surface that is continuous as a whole without a bent portion. In this manner, the front sheet 2 preferably has a continuous structure in the planar direction. The term "continuous" as used herein means that there are no intermittent portions or small holes other than the through holes 23 formed in the top 22T of the non-skin-side protruding portion 22. The pores do not include fine pores such as gaps between fibers. The small hole including the through hole 23 may be defined as a hole having a diameter of 1.0mm or more in terms of a circle.

In the sanitary napkin 1, the front sheet 2 has different fiber weights in the thickness direction of the front sheet. Here, the grammage of the fibers means the amount of fibers per unit area of the front sheet 2, that is, the number of fibers. The high fiber grammage means that the amount of fibers existing per unit area of the front sheet 2 is large and the distance between fibers is small. The low grammage of the fibers means that the amount of the fibers existing per unit area of the front sheet 2 is small and the distance between the fibers is large. That is, the capillary force is high at a portion where the grammage of the fiber is high, and the capillary force is low at a portion where the grammage of the fiber is low.

As shown in fig. 4, in the sanitary napkin 1, when the topsheet 2 is viewed in cross section, the grammage of the wall portions 21W, 22W between the top portion 21T of the skin-side protrusion 21 and the top portion 22T of the non-skin-side protrusion 22 is higher than the grammage of the top portion 21T of the skin-side protrusion 21 and the top portion 22T of the non-skin-side protrusion 22. In the sanitary napkin 1, the grammage of the fibers of the wall portion 21W of the skin-side protrusion 21 (the wall portion 22W of the non-skin-side protrusion 22) is preferably higher than the grammage of the fibers of both the top portion 21T of the skin-side protrusion 21 and the top portion 22T of the non-skin-side protrusion 22. In particular, in the sanitary napkin 1, the grammage of the fibers increases in the order of top portion 22T < top portion 21T of the skin-side protruding portion 21 < wall portion 21W of the skin-side protruding portion 21 (wall portion 22W of the non-skin-side protruding portion 22). Therefore, the capillary force also increases in the order of the top portion 22T < the top portion 21T of the skin-side protruding portion 21 < the wall portion 21W of the skin-side protruding portion 21 (the wall portion 22W of the non-skin-side protruding portion 22). In this case, the grammage and capillary force may be gradually increased continuously in the order of the top portion 22T < the top portion 21T of the skin-side protrusion 21 < the wall portion 21W of the skin-side protrusion 21 (the wall portion 22W of the non-skin-side protrusion 22), or may be increased stepwise. In this way, due to the difference in capillary force caused by the change in density between the skin-side protruding portion 21 and the non-skin-side protruding portion 22 of the topsheet 2, the excreta such as menstrual blood absorbed from the skin-side surface of the topsheet 2 can be easily transferred to the non-skin-side surface, and the residual excretory fluid or the amount of rewet on the skin-side surface of the topsheet 2 can be reduced. Further, since the basis weight of the top portion 22T is made low, the excretory fluid is easily transferred to the absorbent body 4, and the absorption rate of the excretory fluid is increased.

As described below, the grammage value of the fibers of the topsheet 2 is expressed as a value obtained by converting the number of fibers in the field of view of the measurement site per unit area. The grammage of the fibers is preferably 2 fibers/mm at the top 22T of the non-skin-side protrusion 22²Above, 10 roots/mm is particularly preferable²Above, and preferably 100 pieces/mm²Particularly preferably 80 roots/mm²Hereinafter, specifically, 2 roots/mm are preferable²Above 100 pieces/mm²The number of the cells is preferably 10/mm or less²Above 80 roots/mm²The following. The top 21T of the skin-side protrusion 21 is preferably 30 pieces/mm²More than, particularly preferably 50 pieces/mm²Above, and preferably 130 pieces/mm²The number of the cells is preferably 120/mm or less²Hereinafter, specifically, 30 roots/mm are preferable²130 or more/mm²Less, more preferably 50 pieces/mm²Above 120 pieces/mm²The following. The wall portion 21W of the skin-side protruding portion 21 (the wall portion 22W of the non-skin-side protruding portion 22) is preferably 30 pieces/mm²More than, particularly preferably 50 pieces/mm²Above, and preferably 200 pieces/mm²The number of the carbon atoms is preferably 150/mm²Hereinafter, specifically, 30 roots/mm are preferable²Above and 200 pieces/mm²In the following, furtherPreferably 50 roots/mm²Above 150 pieces/mm²The following. The top 21T of the skin-side protrusion 21 has a fiber weight larger than the layer thickness T of the top 21T_L1Is measured at a position near the center of (1). The weight of the fibers at the top 22T of the non-skin-side protrusion 22 is set to be equal to the layer thickness T of the top 22T_L2Is measured at a position near the center of (1). The grammage of the fibers of the wall portion 21W of the skin-side protruding portion 21 (the wall portion 22W of the non-skin-side protruding portion 22) is within the sheet thickness T_sOf the wall portion 21W near the middle_L3The entire thickness was measured at a position near the center of (a). The determination of the grammage of the fibers is as follows.

< method for measuring gram weight of fiber >

The cut surface of the front sheet 2 was observed under magnification (adjusted to a magnification of about 30 to 60 fiber sections; 150 to 500 times) using a scanning electron microscope, and counted as passing through each fixed area (0.5 mm)²Left and right) of the cut surfaces. Then, it is converted to 1mm per unit²The number of cross sections of the fiber (2) is defined as the fiber weight. The measurement was performed at 3 sites, and the weight of the fiber of the sample was determined by averaging.

Scanning electron microscope: JCM-5100 (trade name) manufactured by Japan electronic Co., Ltd

In addition, from the viewpoint of recovering the shape of the protruding portions 21 to the original shape even when the skin-side protruding portions 21 are crushed by the body pressure during wearing and the inward pressing force generated by the thighs of the wearer, rapidly absorbing the excreted body fluid into the absorbent body, suppressing the diffusion of the excreted body fluid on the surface of the topsheet 2, and suppressing the rewet of the body fluid absorbed into the absorbent body 4, the compressibility of the topsheet 2 is preferably 40% or more, particularly preferably 60% or more, and preferably 95% or less, particularly preferably 90% or less, specifically preferably 40% or more and 95% or less, and further preferably 60% or more and 90% or less. The compressibility of the face sheet 2 can be measured using a KES compression tester. The greater the value measured using the KES compression tester, the more excellent the cushioning property can be evaluated. The compression ratio of the front sheet 2 measured by the KES compression tester is defined by interpretation of registration と at value of feng and い (2 nd edition) (translation: standardization and interpretation of evaluation of texture (second edition)), (published by the japan society of japan fiber mechanics institute of china, japan research council (7/10/1980)), which is a physical property relating to the compression characteristics of cloth. The method of measuring the compressibility of the front sheet 2 by the KES compression tester is as follows.

< method for measuring compressibility >

As the measuring apparatus, a KES-FB3 compression tester manufactured by Kato Tech was used. Using this tester, the area to be compressed was 2cm²The measurement specimen (dough sheet 2) was at 0.5gf/cm²Thickness under load T₀. Next, the sample was compressed at a pressurizing speed of 10 μm/sec. The load gradually increases with compression. The compression was carried out until the load reached 50gf/cm². Then, 50gf/cm was measured²Thickness under load T_m. Thickness T₀Minus the thickness T_mThe resulting value is divided by the thickness T₀The compression rate (%) of the front sheet 2 measured by the compression tester is calculated by multiplying it by 100. That is, the compression ratio (%) is based on (T)₀－T_m)/T₀X 100.

In addition, the compression energy of the front sheet 2 is preferably 0.98mN · m/cm from the viewpoints of the satisfactory level of the skin touch feeling when the skin-side protrusions 21 are brought into contact with the skin by the body pressure during wearing and the inward pressing force generated by the thighs of the wearer, and the movement of the skin-side protrusions 21 following the body²Above, 3.43mN · m/cm is particularly preferable²Above, and preferably 9.8mN · m/cm²The concentration is preferably 6.86mN · m/cm or less²More specifically, it is preferably 0.98mN · m/cm²Above and 9.8mN · m/cm²More preferably 3.43mN · m/cm²Above and 6.86mN · m/cm²The following. The compression energy of the face sheet 2 can be measured using a KES compression tester. The larger the WC value measured by the KES compression tester, the softer the front sheet 2 can be evaluated. The method of measuring the compression energy of the face sheet 2 by the KES compression tester is as follows.

< method for measuring compression energy >

As the measuring apparatus, a KES-G5 portable compression tester manufactured by Kato Tech was used. Using this tester, a sample (front sheet 2) of 5cm × 10cm was prepared and mounted on a test bed. Secondly, in a plane having an area of 2cm²The test specimen is compressed between the circular planar steel plates. The compression speed was set at 20 μm/sec, and the compression maximum load was set at 4.9 kPa. The recovery process was also measured at the same rate. The compression energy (WC) of the front sheet 2 is represented by the following equation. T is_m、T₀And P respectively represent 4.9kPa (50 gf/cm)²) Thickness under load, 49Pa (0.5 gf/cm)²) Thickness at the time of loading and load at the time of measurement.

The thickness of the front sheet 2 is defined as the sheet thickness T, which is the total thickness of the front sheet 2 when viewed from the side as shown in fig. 4_sThe local thickness of the front sheet 2 bent into unevenness is set as a layer thickness T_L. Sheet thickness T_sCan be suitably adjusted depending on the use, and when used as a topsheet for an absorbent article such as a sanitary product, it is preferably 1mm or more and 3.5mm or less, more preferably 1.2mm or more and 2.5mm or less. By setting the range, the body fluid absorption rate at the time of use is high, and the liquid can be suppressed from flowing back from the absorbent body, and further, appropriate cushioning properties can be achieved.

Layer thickness T_LThe front sheet 2 may be different in each portion and may be adjusted as appropriate depending on the purpose. When used as a topsheet for an absorbent article such as a sanitary product, the thickness T of the top portion 21T of the skin-side protrusion 21 is preferably set to the layer thickness T_L1Layer thickness T of wall portion 21W of the skin-side projecting portion 21 (wall portion 22W of the non-skin-side projecting portion 22)_L3Layer thickness T > Top 22T of non-skin-side protrusion 22_L2The order of (a) becomes smaller. Thus, the top 21T of the skin-side protrusion 21 has a low fiber grammage, particularly on the skin-facing surface side, and can achieve a good skin feel. On the other hand, the wall portion 21W of the skin-side protrusion 21 (the wall portion 22W of the non-skin-side protrusion 22) has a high fiber grammage and is less likely to be crushed, and thus can be formedA front sheet 2 which is free from deformation, has good cushioning properties, and has an excellent liquid absorption rate.

Sheet thickness T_sSum layer thickness T_LThe measurement was carried out by the following method.

Sheet thickness T_sThe measurement method (2) was carried out by using a thickness measuring device under a load of 0.05kPa applied to the dough sheet 2. The thickness measuring device used was a laser displacement meter manufactured by OMRON corporation. Thickness measurement 10 points were measured, and the average value of these was calculated as the thickness. In addition, the layer thickness T_LThe assay of (a) is as follows: the front sheet 2 was cut in the thickness direction using a feater razor (model number FAS-10, manufactured by feater safety razor). Then, the thickness of each layer was measured by enlarging the cross section of the cut piece by about 20 times using a digital microscope VHX-900 manufactured by KEYENCE.

The distance between the top 21T of the skin-side protrusion 21 and the top 22T of the non-skin-side protrusion 22, which are located closest to each other when the topsheet 2 is viewed in plan view, may be appropriately adjusted depending on the application, and when the topsheet is used as an absorbent article topsheet such as a sanitary product, the distance is preferably 1mm or more and 15mm or less, and more preferably 3mm or more and 10mm or less. The distance L21 (see fig. 4) between the top portions 21T, 21T of the skin-side protrusions 21 adjacent to each other in the lateral direction Y of the topsheet 2 is preferably 2mm or more and 30mm or less, and more preferably 3mm or more and 15mm or less. The distance between the top portions 21T, 21T of the skin-side protruding portions 21 adjacent to each other in the longitudinal direction X of the topsheet 2 is preferably 2mm or more and 30mm or less, and more preferably 3mm or more and 15mm or less. The grammage of the topsheet 2 may be appropriately selected depending on the application, and when used as a topsheet for an absorbent article such as a sanitary product, the average value of the sheet as a whole is preferably 15g/m²Above and 50g/m²Hereinafter, more preferably 20g/m²Above and 40g/m²The following.

As described above, in the sanitary napkin 1, as shown in fig. 1 and 2, the second sheet 9 is disposed between the topsheet 2 and the absorbent body 4. The second sheet 9 may be disposed on the skin-facing surface of the absorbent body 4, but in the sanitary napkin 1, the second sheet 9 covers the entire skin-facing surface of the auxiliary absorbent body 41, which is the multi-layer portion 42, in the absorbent body 4 described below, and extends outward in the transverse direction Y from both side edges of the auxiliary absorbent body 41 in the longitudinal direction X. In the sanitary napkin 1, the side edge along the longitudinal direction X of the second sheet 9 is positioned between the side edge along the longitudinal direction X of the below-described auxiliary absorber 41 and the side edge along the longitudinal direction X of the main absorber 40. The front and rear end edges in the longitudinal direction X of the second sheet 9 are located at the front and rear end edges in the longitudinal direction X of the sanitary napkin 1 and extend over the entire region in the longitudinal direction X of the sanitary napkin 1.

The second sheet 9 preferably contains a hydrophilic nonwoven fabric or a hydrophilic fiber aggregate. Examples of the nonwoven fabric include a through-air nonwoven fabric, a point-bond nonwoven fabric, a resin-bond nonwoven fabric, a spunlace nonwoven fabric, and an air-laid nonwoven fabric. As the fibers constituting the nonwoven fabric body, natural fibers, semisynthetic fibers, and synthetic fibers can be used. Examples of natural fibers include pulp, cotton, and hemp. Examples of the semi-synthetic fibers include triacetate fibers and diacetate fibers. As the synthetic fiber, single fibers of polyethylene, polyethylene terephthalate, polypropylene, polyvinyl alcohol, and composite fibers containing 2 or more of these resins can be cited. Examples of the composite fiber include a core-sheath type, a side-by-side type, and an eccentric type.

The gram weight of the second sheet 9 is preferably 10g/m²Above and 50g/m²The amount of the surfactant is preferably 15g/m or less²Above and 40g/m²The following. The thickness of the second sheet 9 is preferably 0.1mm to 5 mm.

In the excretion portion-facing portion B, the sanitary napkin 1 has a hollow portion having a hollow structure between the skin-side protruding portion 21 of the topsheet 2 and the second sheet 9, and a non-pressure-bonding portion in which the non-skin-side protruding portion 22 of the topsheet 2 and the absorbent body 4 are not pressure-bonded. Hereinafter, the portion of the drainage part facing portion B having the hollow portion and the non-pressure-bonding part is referred to as a hollow maintaining portion. Specifically, the topsheet 2 and the second sheet 9 are not pressed against each other in the portion other than the linear compressed groove 8 in the excretory part facing portion B of the sanitary napkin 1, and a hollow portion having a hollow structure is formed between each skin-side protrusion 21 of the topsheet 2 and the second sheet 9. In addition, in the sanitary napkin 1, the front sheet 2 and the second sheet 9 are not pressed against each other in the portion other than the linear compressed groove 8 in the excretion portion-facing portion B, and a non-pressure-contact portion is formed in which the non-skin-side protruding portion 22 of the front sheet 2 and the absorbent body 4 are not pressed against each other. That is, the hollow maintaining portion in the excretion portion-corresponding portion B refers to a portion other than the linear compressed groove 8 in the excretion portion-corresponding portion B in the sanitary napkin 1. Further, it is preferable that the front sheet 2 and the second sheet 9 are not subjected to thermocompression bonding among the compression bonding. Here, "thermocompression bonding" is different from thermal bonding in which constituent fibers constituting the front sheet 2 are fixed to each other to form a nonwoven fabric shape, and means that the front sheet 2 and the second sheet 9 are pressed and depressed by embossing or the like while applying heat to the front sheet 2 and the second sheet 9, thereby bonding the front sheet 2 and the second sheet 9.

The hollow maintaining portions of the front sheet 2 and the second sheet 9 in the excretion portion-corresponding portion B need not be provided over the entire area of the excretion portion-corresponding portion B, as long as they are present in the central area of the excretion portion-corresponding portion B in the lateral direction Y. Here, the central region is a region that is positioned midway of the discharge portion facing portion B in the lateral direction Y. If the hollow maintaining portion is present in this region, rapid absorption of body fluid is easily achieved.

The hollow maintaining portion may be present in an area of 50% or more, preferably 70% or more, with respect to the total area of the drainage portion facing portion B. Within this range, the excellent texture of the hollow structure can be easily maintained.

In the portion other than the linear compressed groove 8 in the excretion portion-facing portion B of the sanitary napkin 1, when the topsheet 2 is viewed in cross section in one of the 2 different directions intersecting each other, the hollow-structured internal spaces S1 between the plurality of skin-side protrusions 21 of the topsheet 2 and the second sheet 9 are connected to each other. In the sanitary napkin 1, it is preferable that the respective internal spaces S1 are not partitioned (not separated), and as shown in fig. 4, for example, when the topsheet 2 is viewed in cross section in the transverse direction Y in one of the 2 directions, the internal spaces S1, S1 of the plurality of skin-side protrusions 21 adjacent obliquely upward between the longitudinal direction X and the transverse direction Y are connected to each other, and the connection of the internal spaces S1, S1 to each other is expanded in the plane direction formed by the longitudinal direction X and the transverse direction Y.

In the sanitary napkin 1, the absorbent member 4 is formed of a laminate of absorbent sheets 411 to 413, and has a plurality of slits 43 in the excretion portion-facing portion B. As shown in fig. 5, the absorbent body 4 preferably includes a main absorbent body 40 that forms the outer shape of the absorbent body 4, and an auxiliary absorbent body 41 that is smaller than the main absorbent body 40 and is disposed in the excretion portion-corresponding portion B, when the absorbent body 4 is viewed in plan.

In the sanitary napkin 1, as shown in fig. 2, the main absorber 40 is formed of 2 absorbent sheets 411 and 412 having the same shape and the same size, each of which has a substantially rectangular shape with rounded corners in plan view and extends from the front portion a to the rear portion C through the excretion portion-corresponding portion B. In the sanitary napkin 1, as shown in fig. 2, the auxiliary absorbent body 41 has a substantially rectangular shape in plan view and is disposed in the excretion portion-facing portion B. The auxiliary absorber 41 has a 2-layer structure in which 1 absorbent sheet 413 is folded, and is disposed between the 2 absorbent sheets 411 and 412 constituting the main absorber 40. As described above, in the sanitary napkin 1, the auxiliary absorbent body 41 having the 2-layer structure formed of the absorbent sheet 413 is wrapped in the main absorbent body 40 formed of the 2-piece absorbent sheets 411 and 412.

As shown in FIG. 2, the absorbent body 4 formed of the absorbent sheets 411 to 413 has a multi-layer portion 42 of a 4-layer structure formed of a main absorbent body 40 of a 2-layer structure and an auxiliary absorbent body 41 of a 2-layer structure at the excretion portion-facing portion B. In addition, the absorber 4 has a 2-layer structure laminated structure formed of the 2-layer main absorber 40, except for the multi-layer portion 42. Here, the multi-layer portion 42 refers to a portion where the number of laminated sheets of the absorbent sheet constituting the absorbent body 4 is larger than that of the portion located around the absorbent sheet, as shown in fig. 2. In the sanitary napkin 1, the multi-layer portion 42 is thicker than the portion located around it, and a raised portion that rises toward the topsheet 2 (the skin-facing surface side of the sanitary napkin 1) is formed in the excretion portion-facing portion B. By disposing the auxiliary absorber 41 having a 2-layer structure in a part of the main absorber 40, the local absorption capacity of the absorber 4 can be easily and effectively increased. The absorbent sheets may be joined together by a loosely spread adhesive or the like without being joined.

The thickness of the absorbent body 4 of the sanitary napkin 1 in the multi-layer portion 42 is preferably 0.7mm or more, more preferably 1mm or more, and further preferably 5mm or less, more preferably 4mm or less, more specifically preferably 0.7mm or more and 5mm or less, and further preferably 1mm or more and 4mm or less. By setting the thickness of the multi-layer portion 42 in such a range, it is easy to achieve both a good wearing feeling and a high absorption performance in the excretion portion-corresponding portion B in which the multi-layer portion 42 is formed. In addition, when the absorbent article includes the flap portion as in the sanitary napkin 1 of the present embodiment, the absorbent body 4 is easily prevented from being wrinkled at the excretion portion-corresponding portion B when worn. The thickness of the absorbent body 4 in the portion other than the multi-layer portion 42 is preferably 0.3mm or more, more preferably 0.5mm or more, and further preferably 3mm or less, more preferably 2.5mm or less, more specifically preferably 0.3mm or more and 3mm or less, and further preferably 0.5mm or more and 2.5mm or less. This range is preferable from the viewpoint of high absorption performance and improved followability to the wearer's motion.

In the absorbent body 4 of the sanitary napkin 1, the difference in thickness (step difference) between the boundary between the multi-layer portion 42 and the peripheral portion thereof or between the two adjacent to the boundary is preferably 2mm or less, and more preferably 1.5mm or less. The purpose is as follows: in the excretion portion-facing portion B, wrinkles are suppressed from occurring in the vicinity of the boundary between the multi-layer portion 42 and the region of the peripheral portion thereof where only the main absorber 40 is present. If the step difference is large, the following may occur: when the sanitary napkin 1 is worn to follow the movement of the wearer, the gap caused by the step difference is filled, and as a result, wrinkles are likely to be generated due to the influence of the step difference. The thickness of each part of the absorbent body 4 is measured by the following method.

< method for measuring thickness of absorbent >

An absorber as an object to be measured was left standing at a horizontal position without wrinkles or folds, and 5cN/cm was measured²Thickness under load. Thickness was measured using a DIAL gauge thickness gauge (PEACOCK DIAL UPRIGHT GAUGES R5-C (OZAKI MFG. CO. LTD.). At this time, a plate (acrylic plate having a thickness of about 5 mm) which is circular or square in plan view is disposed between the distal end portion of the thickness gauge and the measurement portion of the object to be measured so that the load becomes 5cN/cm²The size of the plate is adjusted.

In the sanitary napkin 1, as shown in fig. 1 and 5, the slits 43 are arranged parallel to the longitudinal direction X. That is, each slit 43 is a longitudinal slit along the longitudinal direction X. The sanitary napkin 1 has slits (longitudinal slits) 43 formed along the longitudinal direction X in the discharge portion slit region 4S in both the longitudinal direction X and the transverse direction Y in a distributed state.

In the sanitary napkin 1, the slit 43 penetrates at least 1 layer of the laminate of the absorbent sheets 411 to 413 forming the absorbent member 4. In the sanitary napkin 1, as shown in fig. 2, when the absorbent body 4 is viewed in a transverse Y-section, slits (vertical slits) 43 penetrate not only 1 layer of the absorbent body 4 having the multi-layer portion 42 having a 4-layer structure but also all layers of the laminate. That is, the slits (longitudinal slits) 43 penetrate all layers of the absorbent body 4 in the thickness direction of the absorbent body 4. The slits 43 are preferably formed by cutting slits that penetrate the absorbent body 4 in the thickness direction at the portions of the excretion portion-corresponding portion B other than the multilayer portion 42 and the multilayer portion 42. As shown in fig. 5, the drain slit region 4S in which the plurality of slits 43 are arranged extends not only over the drain facing portion B but also over a part of the front portion a and a part of the rear portion C. That is, the slit 43 is present at least in the drainage portion facing portion B, and a region including the slit 43 located in the drainage portion facing portion B is referred to as a drainage slit region 4S. Therefore, the drain slit region 4S does not refer to a portion in which a slit is formed in the region of the drain-facing portion B. The vertical slits 43 form minute spaces, so that the excretory fluid from the front surface sheet 2 is easily introduced, and the cut portions of the vertical slits 43 are slightly compressed during the slitting process, so that the absorption rate is further improved. Further, by making the slits 43 completely penetrate the absorbent body 4, the liquid that has reached the absorbent body 4 can easily reach the non-skin-facing surface side of the absorbent body 4, and can be absorbed effectively by the absorbent body 4.

In the sanitary napkin 1, as shown in fig. 1, the width W43 (see fig. 5), which is the lateral length of each slit 43, is formed narrower than the interval L21 (see fig. 4) between the top portions 21T, 21T of the skin-side protrusions 21 adjacent to each other in the lateral direction Y in the topsheet 2. Further, the interval L21 between the top portions 21T, 21T is formed narrower than the interval L43 between the longitudinal slits 43 in the same slit row extending in the lateral direction Y (see fig. 5). Here, the width W43 of the slit means the length of the slit in the direction orthogonal to the extending direction of the slit. Here, the width of the slit is the maximum width of the widths in a natural state where no tension is applied before the absorbent article is fixed to the crotch portion of the clothing or the like, and is the width before the absorbent body 4 absorbs body fluid. Specifically, the width W43 of the slit (vertical slit) 43 in a plan view of each slit (vertical slit) 43 is preferably 0.1mm or more, more preferably 0.3mm or more, and further preferably 1mm or less, further preferably 0.8mm or less, and further preferably 0.1mm or more and 1mm or less, further preferably 0.3mm or more and 0.8mm or less.

In order to minimize the occurrence of bending of the top portion 21T during movement during wearing by overlapping the position of the longitudinal slits 43 with the position of the top portion 21T of the skin-side protrusion 21, and to maintain the fit of the product and the good feel of the skin of the topsheet 2 during wearing, the ratio ((L21/L43) × 100) of the interval L21 (see fig. 4) between the top portions 21T of the skin-side protrusion 21 to the interval L43 (see fig. 5) between the longitudinal slits 43 is preferably 10% or more, more preferably 30% or more, and preferably 70% or less, and even more preferably 55% or less, and thus preferably 10% or more and 70% or less, and even more preferably 30% or more and 55% or less.

Specifically, in the sanitary napkin 1, the interval L43 (see fig. 5) between the slits 43 is preferably 3mm or more, more preferably 7mm or more, and further preferably 20mm or less, more preferably 15mm or less, and further preferably 3mm or more and 20mm or less, and further preferably 7mm or more and 15mm or less.

In the sanitary napkin 1, the slits in the excretion portion slit region 4S are not particularly limited as long as the slits are arranged so as to be distributed in both the longitudinal direction X and the transverse direction Y, and in the case where there are longitudinal slits 43 along the longitudinal direction X as in the embodiment shown in fig. 5, it is preferable that the longitudinal rows L including the plurality of longitudinal slits 43 arranged in series along the longitudinal direction X of the sanitary napkin 1 are formed in a plurality of rows in the transverse direction Y. In the sanitary napkin 1, it is preferable that the longitudinal slits 43 in the longitudinal rows L, L adjacent in the transverse direction Y are not arranged at the same position in the longitudinal direction X.

In the sanitary napkin 1, as shown in fig. 5, the excretion portion slit region 4S is formed so as to include the multi-layer portion 42. In the multilayer portion 42, 2 or more rows of slits including 2 or more longitudinal slits 43 spaced apart in the lateral direction Y are preferably formed in the longitudinal direction X, more preferably 3 or more rows, and particularly preferably 4 or more rows. The number of vertical slits 43 included in each slit row and spaced apart in the lateral direction X is preferably 2 or more, and more preferably 3 or more. In the vertical direction X of the excretion portion slit region 4S, it is preferable that the more layer portion 42 has 1 or 2 or more rows of slits in front of or behind or in both front and behind the vertical direction X, in addition to the rows of slits included in the more layer portion 42.

Fig. 6 shows an example of a preferable arrangement of the vertical slit 43 in the drain slit region 4S. In the arrangement shown in these figures, slit rows R1, R2 including a plurality of longitudinal slits 43 spaced apart in the transverse direction Y of the sanitary napkin 1 are alternately formed in a plurality of rows in the longitudinal direction X of the sanitary napkin 1. In the configuration example shown in fig. 6, a slit row R1 including 2 longitudinal slits 43 spaced apart in the lateral direction Y and a slit row R2 including 3 longitudinal slits 43 spaced apart in the lateral direction Y are alternately formed in the longitudinal direction X.

In the example of the preferred arrangement of the longitudinal slits 43 shown in fig. 6, as shown in fig. 6(a) and 6(b), with respect to the longitudinal slits 43 in the 2 slit rows R1, R2 adjacent in the longitudinal direction X, the longitudinal slit 43 of one slit row R1 is arranged in the central portion between the longitudinal slits 43, 43 adjacent in the lateral direction Y of the other slit row R2. Further, the slit rows R1, R2 adjacent in the longitudinal direction X of the sanitary napkin 1 do not have a space therebetween. That is, no space is provided between the 2 slit rows R1, R2 adjacent in the longitudinal direction X. The behavior of no spacing between adjacent rows of slots includes: as shown in fig. 6(a), the positions of the end portions of the longitudinal slits 43 in the adjacent slit rows R1 and R2 are matched; and the case where the ends of the longitudinal slits 43 of the adjacent slit rows R1, R2 overlap each other in the longitudinal direction X as shown in fig. 6 (b). When the longitudinal slits 43 of 2 slit rows R1 and R2 are arranged in the longitudinal direction X with their ends overlapping each other as shown in fig. 6(b), the overlapping length L1 is preferably 20% or less, more preferably 10% or less, of the length L2 of the longitudinal slits 43 constituting the slit row in the direction X. In the sanitary napkin 1, the length L2 (see fig. 6) of the longitudinal slit 43 is preferably formed to be greater than the interval between the top portions 21T, 21T of the skin-side protrusions 21 adjacent in the longitudinal direction X in the front sheet 2, preferably 10mm or more, more preferably 15mm or more, further preferably 35mm or less, further preferably 25mm or less, further preferably 10mm or more and 35mm or less, further preferably 15mm or more and 25mm or less.

In the sanitary napkin 1, the adhesive is applied and fixed between the topsheet 2 and the second sheet 9 and between the second sheet 9 and the absorbent body 4. The adhesive can be applied by a known mechanism such as a slit coating gun, a spiral spray gun, a spray gun, or a dot spray gun (dot gun), and the sanitary napkin 1 is preferably applied spirally by a spiral spray gun. As the adhesive to be applied, for example, a hot melt adhesive is preferably used. The coating amount of the hot-melt adhesive is preferably 1.5g/m²Above and 10g/m²The following. The absorbent body 4 and the back sheet 3 may be bonded to each other with an adhesive.

The materials for forming the components of the sanitary napkin 1 of the present embodiment will be described.

The following sheets can be used as the top sheet 2: the sheet is suitably produced by using a hot-air nonwoven fabric having a single-layer structure or a multilayer structure in which a plurality of layers are laminated as a raw material nonwoven fabric, for example, by the method described in japanese patent application laid-open No. 2013-133574. The topsheet 2 manufactured by the method described in japanese patent application laid-open No. 2013-133574 is configured such that there is no thermally fused portion for forming the sheet shape having the skin-side protruding portion 21 and the non-skin-side protruding portion 22.

As the back sheet 3, various sheets conventionally used as back sheets of absorbent articles can be used without particular limitation, and for example, a liquid impermeable or water repellent resin film, a moisture permeable film, a laminate of a resin film and a nonwoven fabric, or the like can be used.

As the absorbent sheets 411 to 413 constituting the absorbent body 4, sheets in which constituent fibers or constituent fibers and a water-absorbent polymer are bonded to each other to form a sheet or the like can be preferably used, the sheets being bonded to each other via a bonding force of the water-absorbent polymer in a wet state or a separately added adhesive or an adhesive such as an adhesive fiber. As the absorbent sheet, there can be used: an absorbent sheet produced by the method described in Japanese patent application laid-open No. 8-246395; a dry sheet in which pulverized pulp and a water-absorbent polymer supplied with an air flow are accumulated and then consolidated with an adhesive (for example, a vinyl acetate adhesive, PVA (polyvinyl alcohol), or the like); an absorbent sheet obtained by applying a hot-melt adhesive or the like between paper or nonwoven fabric and then spreading a water-absorbent polymer; an absorbent sheet obtained by blending a water-absorbent polymer in a spun-bonded or melt-blown nonwoven fabric production step, and the like. These absorbent sheets can be used as a sheet-like absorbent body by cutting one sheet into a specific shape.

In addition, when a slit is formed in the absorbent body 4 as in the sanitary napkin 1, the stacked body of absorbent sheets may be partially cut by a known cutting mechanism, and for example, a cutting device having: a cutter roll having a plurality of circumferentially extending cutters formed on a circumferential surface of the roll in a manner dispersed in a circumferential direction and an axial length direction of the roll; and an anvil roll that receives the knife of the cutter roll.

Examples of the water-absorbent polymer constituting the absorbent member 4 include sodium polyacrylate, acrylic acid-vinyl alcohol copolymer, crosslinked sodium polyacrylate, (starch-acrylic acid) graft copolymer, (isobutylene-maleic anhydride) copolymer and saponified product thereof, and polyaspartic acid. The absorbent sheets constituting the absorbent member 4 are preferably all water-absorbent sheets containing a water-absorbent polymer, and a laminate of water-absorbent sheets constituting the absorbent member may be formed by combining a water-absorbent sheet containing a water-absorbent polymer with a water-absorbent sheet containing no water-absorbent polymer.

The side sheet 5 can be any of various sheets conventionally used in the art without particular limitation, and for example, a liquid impermeable or water repellent resin film, a laminate of a resin film and a nonwoven fabric, or the like can be used. Examples of the other materials include water repellent (hydrophobic) nonwoven fabrics such as spunbond nonwoven fabrics, sheets obtained by combining spunbond nonwoven fabrics (S) and meltblown nonwoven fabrics (M) (for example, SM, SMs, SMMS, and the like), hot-rolled nonwoven fabrics, and hot-air nonwoven fabrics. In particular, a water repellent hot air nonwoven fabric is preferably used in terms of the degree of satisfactory touch to the skin and the prevention of side leakage.

As a method of forming the flap part attaching part 71 and the main body attaching part 72 (offset preventing part), a conventionally used method of fixing to a garment such as underwear and using an absorbent article can be used without particular limitation. For example, the adhesive may be formed by directly applying the adhesive to the back sheet 3, or may be formed by bonding the other surface side of the adhesive tape applied with the adhesive to the back sheet. Examples of the adhesive agent for forming the adhesive portion include emulsion-based, aqueous, and solvent-based adhesive agents. In addition, from the viewpoint of obtaining excellent dislocation prevention performance and stable productivity, the displacement prevention section is preferably formed by applying an adhesive agent such as a hot melt adhesive. As such an adhesive, an adhesive generally used for such articles can be used without limitation, and it is preferable to mainly use a synthetic rubber-based block copolymer having a basic structure similar to natural rubber. Examples of such block copolymers include styrene-isoprene-styrene block copolymers (SIS), styrene-ethylene-propylene-styrene copolymers (SEPS), styrene-butadiene-styrene block copolymers (SBS), and styrene-ethylene-butylene-styrene copolymers (SEBS). The adhesive patch preferably contains 10 to 65 wt%, particularly preferably 30 to 50 wt%, of one or more base polymers selected from these block copolymers. The misalignment preventing portion may not have adhesiveness as long as it can prevent misalignment between the absorbent main body and the garment to which it is fixed.

The linear grooves 8 (the first transverse grooves 81, the longitudinal grooves 82, and the second transverse grooves 83) can be formed by extrusion with or without heat (so-called embossing), or embossing such as ultrasonic embossing, according to a conventional method.

The operation and effect of the sanitary napkin 1 will be described.

In the sanitary napkin 1, as shown in fig. 3, the front sheet 2 is a sheet having an uneven structure including the plurality of skin-side protrusions 21 having the internal space S1 and the plurality of non-skin-side protrusions 22 having the internal space S2, and the slit 43 of the absorbent body 4 improves the fit of the product, thereby making it easier for the skin-side protrusions 21 to follow the movement of the wearer during wearing. In the sanitary napkin 1, the grammage of the fibers of the wall portions 21W, 22W is higher than the grammage of the fibers of the top portion 21T of the skin-side protruding portion 21 and the top portion 22T of the non-skin-side protruding portion 22, and therefore, the top portion 21T of the skin-side protruding portion 21 quickly absorbs excreted body fluid or body fluid adhering to the skin, and the top portion is pressed against the second sheet 9 during movement during wearing, thereby quickly transferring the fluid. At the same time, the slit 43 of the absorbent body 4 allows the body fluid excreted to be quickly absorbed into the absorbent body 4, and diffusion of the body fluid on the surface of the topsheet 2 can be suppressed. Further, by the hollow structure between each skin-side protrusion 21 of the topsheet 2 and the second sheet 9 and the arrangement of the second sheet 9, the liquid return of the body fluid absorbed into the absorbent body 4 can be suppressed. In particular, in the sanitary napkin 1, in the portion other than the linear compressed groove 8 in the excretion portion-facing portion B, the hollow-structured internal spaces S1, S1 formed between the plurality of skin-side protrusions 21 of the topsheet 2 and the second sheet 9 are connected to each other and the connection between the internal spaces S1, S1 is expanded in the plane direction formed by the longitudinal direction X and the transverse direction Y, as seen in a cross-sectional view as shown in fig. 4, so that the excreted body fluid can be absorbed into the absorbent body 4 more quickly, diffusion of the body fluid can be further suppressed, and the return of the body fluid absorbed into the absorbent body 4 can be further suppressed.

As shown in fig. 4, in the topsheet 2 of the sanitary napkin 1, the grammage of the fibers of the wall portions 21W, 22W of the skin-side protrusion 21 is higher than the grammage of the fibers of the top portion 21T of the skin-side protrusion 21. The top 22T of the non-skin-side protrusion 22 has a lower fiber weight than the wall portions 21W and 22W. Therefore, the body fluid can be quickly absorbed by the capillary force, and the body fluid can be transferred to the absorbent body 4 through the through-holes 23 of the top portions 22T of the non-skin-side protrusions 22. In particular, in the sanitary napkin 1, the through-holes 23 are formed in the top portion 22T, and therefore this effect is remarkable.

In addition, as shown in fig. 1, in the sanitary napkin 1, the front sheet 2 is a sheet in which the skin-side protrusions 21 and the non-skin-side protrusions 22 are alternately and continuously arranged in 2 different directions intersecting each other in a plan view, and therefore the skin-side protrusions 21 easily follow the movement of the wearer in all directions, and the fit when worn is improved. The slits 43 of the absorber 4 are vertical slits, and as shown in fig. 5, the discharge portion slit region 4S in which the plurality of vertical slits 43 are arranged extends not only over the discharge portion facing portion B but also over a part of the front portion a and a part of the rear portion C. Therefore, the longitudinal slit 43 is easily bent from the starting point, and the fit at the time of wearing is improved. In particular, since the interval L21 between the top portions 21T and 21T is formed narrower than the interval L43 between the vertical slits 43 in the same slit row extending in the lateral direction Y, when viewed in cross section as shown in fig. 2, a portion where the positions of the slits 43 overlap the positions of the top portions 21T of the skin-side protrusions 21 is not easily formed, and the folded slits 43 do not easily enter the internal space S1 of the skin-side protrusions 21, and the skin feel of the front sheet 2 itself is not easily impaired.

As shown in fig. 2, in the sanitary napkin 1, slits (longitudinal slits) 43 penetrate through all the layers of the absorbent body 4 having the multi-layer portion 42 having a 4-layer structure, and the second sheet 9 and the absorbent body 4 are fixed by applying an adhesive. Therefore, it is possible to prevent the slits (longitudinal slits) 43 from being opened excessively by the movement of the wearer during wearing, and to prevent the sanitary napkin 1 from being wrinkled or liquid from being accumulated due to the excessively opened slits (longitudinal slits) 43, thereby improving the wearing feeling.

The present invention has been described above based on preferred embodiments thereof, but the absorbent article of the present invention is not limited to the sanitary napkin 1 of the above-described embodiments and can be modified as appropriate.

For example, as shown in fig. 3, the front sheet 2 of the sanitary napkin 1 includes a plurality of skin-side protrusions 21 having the internal space S1 and a plurality of non-skin-side protrusions 22 having the internal space S2, and the front sheet 2 is a sheet in which the skin-side protrusions 21 and the non-skin-side protrusions 22 are alternately and continuously arranged in 2 different directions intersecting each other in a plan view, but may include a plurality of skin-side protrusions 21 having the internal space S1 and a plurality of non-skin-side protrusions 22 having the internal space S2. For example, as shown in fig. 7, the sheet may have an uneven structure in which the skin-side protrusions 24 having the strip-shaped internal spaces S3 extending in the longitudinal direction X and the non-skin-side protrusions 25 having the strip-shaped internal spaces S4 extending in the longitudinal direction X are alternately arranged in the lateral direction Y. The sheet may have a concavo-convex structure in which the skin-side protruding portion 24 having the strip-shaped internal space S3 extending in the lateral direction Y and the non-skin-side protruding portion 25 having the strip-shaped internal space S4 extending in the lateral direction Y are alternately arranged in the longitudinal direction X. In the uneven structure sheet shown in fig. 7, the uneven structure is formed by stretching the nonwoven fabric sheet by a pair of uneven rollers capable of meshing with each other, and the grammage of fibers in the side region between the top region of the skin-side protruding portion 24 and the bottom region of the non-skin-side protruding portion may be made lower than the grammage of fibers in the top region and the bottom region on the skin side in a cross-sectional view.

In the sanitary napkin 1, as shown in fig. 1 and 2, the front sheet 2 and the absorbent body 4 are integrally recessed toward the back sheet 3 side to form the linear pressing grooves 8 on the skin-facing surface of the absorbent main body 10 (the skin-facing surface of the front sheet 2), but the linear pressing grooves 8 may not be formed.

In the sanitary napkin 1, the absorbent member 4 is formed of a laminate of folded absorbent sheets 411 to 413, but a plurality of individual absorbent sheets may be laminated. In addition, various folding methods can be employed for the folding method of the absorbent sheet.

As shown in fig. 1 and 5, the plurality of slits 43 in the absorbent body 4 of the sanitary napkin 1 are longitudinal slits, but may be transverse slits extending in the transverse direction of the sanitary napkin 1, may be slits extending obliquely at an angle to both the longitudinal direction X and the transverse direction Y, or may be a mixture of longitudinal slits and transverse slits. As shown in fig. 2, the slits 43 of the absorbent body 4 of the sanitary napkin 1 penetrate all layers of the absorbent body 4 in the thickness direction of the absorbent body 4, but may penetrate at least 1 layer. From the viewpoint of further improving the fit of the topsheet 2, it is preferable that at least one layer is penetrated through the non-skin surface side, the slit 43 is bent to be convex toward the skin side, and when the auxiliary absorbent body 41 is provided in the multi-layer portion 42, it is more preferable that the auxiliary absorbent body 41 is also penetrated.

The excretory part slit region 4S of the absorbent body 4 of the sanitary napkin 1 may be formed only in the excretory part facing portion B, may extend from the excretory part facing portion B to a part of the rear portion C, or may extend from the excretory part facing portion B to a part of the front portion a and a part of the rear portion C. The number of absorbent sheets stacked in the multi-layer portion 42 may be 2 or 3 instead of 4, or may be 5 or more. The difference in the number of stacked multi-layer portions 42 and the absorbent sheets in the other portions may be 1 sheet or 3 sheets or more.

The absorbent article of the present invention may be a sanitary napkin, a panty liner (vaginal secretion pad), an incontinence pad, or the like.

The following absorbent article is further disclosed with respect to the above-described embodiment of the present invention.

< 1 > an absorbent article comprising an absorbent main body including: a liquid-permeable front sheet forming a skin-facing surface, a back sheet forming a non-skin-facing surface, and an absorbent body interposed between the sheets, the absorbent body comprising: a discharge portion facing portion disposed to face a discharge portion of a wearer when the absorbent article is worn, a front portion disposed on a ventral side of the wearer with respect to the discharge portion facing portion, and a rear portion disposed on a back side of the wearer with respect to the discharge portion facing portion, the absorbent article having a longitudinal direction corresponding to a front-back direction of the wearer and a lateral direction orthogonal to the longitudinal direction, a second sheet formed of a nonwoven fabric being disposed between the front sheet and the absorbent body, the front sheet being a sheet having a concavo-convex structure including a plurality of skin-side projecting portions projecting toward a skin-facing surface and having an internal space, and a plurality of non-skin-side projecting portions projecting toward a non-skin-facing surface and having an internal space, the discharge portion facing portion including a hollow portion having a hollow structure between the skin-side projecting portion and the second sheet, and a non-pressure-bonding portion in which the non-skin-side projecting portions and the absorbent body are not pressure-bonded, when the topsheet is viewed in cross section, the grammage of fibers at the wall between the top of the skin-side protrusion and the top of the non-skin-side protrusion is higher than the grammage of fibers at the top of the skin-side protrusion and the top of the non-skin-side protrusion, the absorbent body is formed of a laminate of absorbent sheets, and the excretion portion-facing portion has a plurality of slits that penetrate through at least 1 layer of the laminate.

< 2 > the absorbent article according to < 1 >, wherein the hollow maintaining portion including the hollow portion and the non-pressure-bonded portion in the excretion portion-corresponding portion is present at least in a central region in the lateral direction in the excretion portion-corresponding portion.

< 3 > the absorbent article according to < 2 >, wherein the hollow maintaining part is present in an area of 50% or more with respect to the total area of the excretion part-facing part.

The absorbent article according to any one of < 4 > and < 1 > to < 3 >, wherein linear compressed grooves are formed in the skin-facing surface of the absorbent body so that the front sheet and the second sheet are integrally recessed toward the back sheet side, and the front sheet and the second sheet are not pressed against each other in the excretion portion-facing portion except for the linear compressed grooves.

The absorbent article according to any one of < 5 > such as < 1 > to < 4 >, wherein the skin-side protrusions and the non-skin-side protrusions are alternately arranged in the lateral direction.

The absorbent article according to any one of < 6 > such as < 1 > to < 5 >, wherein the skin-side protrusions and the non-skin-side protrusions are alternately and continuously arranged in 2 different directions intersecting each other in a plan view of the topsheet.

[ 7 ] the absorbent article according to any one of the above < 5 > or < 6 >, wherein the top portions of the skin-side protrusions adjacent in the transverse direction of the top sheet are spaced from each other by 2mm to 30 mm.

The absorbent article according to any one of < 8 > and < 5 > to < 7 >, wherein the slits are longitudinal slits extending in the longitudinal direction, and are distributed in both the longitudinal direction and the transverse direction, and the interval between the tops of the skin-side protrusions adjacent in the transverse direction in the front sheet is narrower than the interval between the slits adjacent in the transverse direction.

< 9 > the absorbent article according to < 8 >, wherein the longitudinal slits are formed to have a length longer than the interval between the tops of the skin-side protrusions adjacent to each other in the longitudinal direction of the front sheet.

The absorbent article according to < 10 > such as < 8 > or < 9 >, wherein the length of the longitudinal slit is 10mm or more and 35mm or less.

The absorbent article according to < 11 > or < 10 >, wherein the longitudinal slit has a length of 15mm to 25 mm.

The absorbent article according to any one of < 12 > such as < 1 > to < 11 >, wherein the second sheet and the absorbent body are fixed with an adhesive, and the slit penetrates all layers of the laminate.

< 13 > the absorbent article according to < 12 >, wherein the interval between the top portions of the skin-side protrusions or the interval between the top portions of the non-skin-side protrusions is 3mm to 15 mm.

The absorbent article according to any one of < 14 > such as < 1 > to < 13 >, wherein the grammage of the fibers of the wall portion of the skin-side protrusion is higher than the grammage of the fibers of the top portion of the skin-side protrusion.

The absorbent article according to any one of < 15 > such as < 1 > to < 14 >, wherein the density of the fibers at the top of the non-skin-side protrusion is lower than the density of the fibers at the periphery thereof.

The absorbent article according to < 16 > or < 15 >, wherein the top portions of the plurality of non-skin-side protrusions have through holes.

The absorbent article according to < 17 > such as < 15 > or < 16 >, wherein the relationship of the basis weight of the fibers is that the top of the non-skin-side protrusion < the top of the skin-side protrusion < the wall of the skin-side protrusion.

The absorbent article according to any one of < 18 > such as < 1 > to < 17 >, wherein the protruding shape of the skin-side protrusion is a hemispherical shape or a conical shape.

< 19 > and < 18 > wherein the protruding shape of the skin-side protruding part is a hemisphere, a cone, a truncated cone, a pyramid, a truncated pyramid, or an oblique cone.

The absorbent article according to any one of < 20 > such as < 1 > to < 19 >, wherein the protruding shape of the non-skin-side protrusion is a cone or a truncated cone having a curvature at the top.

The absorbent article according to any one of < 21 > and < 1 > to < 20 >, wherein the compression ratio of the top sheet is 40 to 95%.

< 22 > the absorbent article according to any one of the above < 1 > to < 21 >, wherein the compression energy of the front sheet is 0.98mN · m/cm²Above and 9.8mN · m/cm²The following.

The absorbent article according to any one of < 23 > and < 1 > to < 22 >, wherein the sheet thickness of the top sheet is 1mm or more and 3.5mm or less.

The absorbent article of < 24 > such as < 1 > to < 23 >, wherein the grammage of the second sheet is 10g/m²Above and 50g/m²The following.

The absorbent article according to < 25 > or < 24 >, wherein the grammage of the second sheet is 15g/m²Above and 40g/m²The following.

The absorbent article according to < 26 > such as any one of < 1 > to < 25 >, wherein the second sheet has a thickness of 0.1mm or more and 5mm or less.

< 27 > the absorbent article according to any one of < 1 > to < 26 >, wherein the slits are longitudinal slits extending in the longitudinal direction and are dispersed in both the longitudinal direction and the transverse direction,

the ratio of the distance between the top portions of the skin-side protrusions to the distance between the longitudinal slits in the transverse direction is 10% to 70%.

The absorbent article according to < 28 > or < 27 >, wherein the ratio is 30% or more and 55% or less.

An absorbent article as described in any of < 29 > such as < 1 > to < 28 > which is a sanitary napkin.

Examples

Hereinafter, the absorbent article of the present invention will be described in further detail with reference to examples. The scope of the present invention is not limited in any way by this example.

< example 1 >

A sanitary napkin having the same basic configuration as the sanitary napkin 1 shown in fig. 1 and 2 including the topsheet shown in fig. 3 and 4 was produced, and this was the sample of example 1. As the front surface sheet, a sheet manufactured by the method described in japanese patent application laid-open No. 2013-133574 is used. The top sheet was adjusted to a total grammage of 25g/m in such a manner that the upper layer had a grammage of 10gsm formed from 2.4dtex with a core comprising polyethylene terephthalate and a sheath comprising polyethylene, and the lower layer had a grammage of 15gsm formed from 2.9dtex fibers with a core comprising polyethylene terephthalate and a sheath comprising polyethylene²The thickness T of the whole surface sheet_sAdjusted to 1.7 mm. The grammage of the fibers at the top 22T of the non-skin-side protrusion was 32 fibers/mm²The grammage of the fibers at the top 21T of the skin side protrusion was 39 fibers/mm²The grammage of the fibers of the wall 21W of the skin-side protruding portion was 46 threads/mm². The interval L21 between the top portions 21T and 21T of the skin-side protrusions adjacent to each other in the lateral direction Y of the topsheet is 5mm, and the interval between the top portions 21T and 21T of the skin-side protrusions adjacent to each other in the longitudinal direction X is 7 mm. As the second sheet, a sheet having a grammage of 25g/m was used²The hot air non-woven fabric of (1). The absorbent body formed of the absorbent sheet had longitudinal slits having a width W43 of 0.3mm, which is the transverse length, a length L2 of 20mm, and a gap L43 of 10mm between the longitudinal slits.

< example 2 >

A sanitary napkin was produced in the same manner as in example 1, except that the following sheet was used as the top sheet. For the topsheet, the upper layer was formed with 2.4dtex with a core comprising polyethylene terephthalate and a sheath comprising polyethyleneThe lower layer was adjusted to a total grammage of 25g/m in such a way that a 2.9dtex fiber with a core comprising polyethylene terephthalate and a sheath comprising polyethylene formed a grammage of 15gsm²The thickness T of the whole surface sheet_sThe thickness was adjusted to 1.6mm, and a through hole portion was provided near the bottom. The grammage of the fibers at the top 22T of the non-skin-side protrusion was 29 fibers/mm²The grammage of the fibers at the top 21T of the skin side protrusion was 40 fibers/mm²The grammage of the fibers of the wall 21W of the skin-side protruding portion was 45 threads/mm²

< comparative example 1 >

A sample of comparative example 1 was produced in the same manner as in example 1, except that the top sheet of the sample of example 1 was replaced with the top sheet 200 shown in fig. 8. The front sheet 200 includes a fiber sheet having a single-layer structure, and the concave portions 201 formed by pressure-bonding the constituent fibers are arranged in a diagonal lattice shape. The front surface sheet 200 is formed with a plurality of divided regions 202 partitioned into oblique lattice-shaped concave portions 201. Each of the divided regions 202 is a convex portion that is raised relative to the concave portion 201. Therefore, the front sheet 200 is a sheet having a plurality of concave-convex shapes each having a plurality of concave portions 201 formed in a diagonal lattice shape and a dividing region 202 which is a convex portion surrounded by the concave portions 201. The dividing regions 202, which are convex portions, are filled with the fibers constituting the front sheet 200. The gram weight of the top sheet 200 was 25g/m²The width of the recess 201 was 0.5mm, and the area of the dividing region 202 was 0.45cm²。

[ evaluation ]

With respect to the samples (sanitary napkins) of example 1 and comparative example 1, the liquid absorption time, the amount of residual absorption, the amount of return liquid, and the spreading area were evaluated by the following methods, respectively. These results are shown in table 1 below.

< liquid absorption time >

Each of the samples of examples and comparative examples was developed and placed on a laboratory bench, and an acrylic acid injection plate having an elliptic cylinder with a major axis of 50mm and a minor axis of 22.5mm and an acrylic acid cylinder height of 30mm was integrally molded in the elliptic cylinder portion, and the injection hole thereof was positioned in the portion of the sample facing the excretory part on the skin-facing surface (front sheet side)The weight plates are placed in a central manner in a superposed manner, and the load is adjusted to 5g/m (including the liquid injection plate itself) by placing an appropriate weight plate². Horse defibrinated blood manufactured by NIPPON BIO-TEST, Inc. was preliminarily adjusted at room temperature (23 ℃), and 6g of the blood was measured and placed in a 10cc injection beaker. The blood was injected into the cylinder of the liquid injection plate at one time, and the time (seconds) from the moment the injection was completed until the blood in the cylinder disappeared and the front piece of the sample was exposed was measured. Each sample was subjected to 3 measurements, and the average value thereof was taken as the liquid absorption time of the sample.

< residual absorption amount >

1g of defibrinated horse blood (manufactured by NIPPON BIO-TEST Co., Ltd.) was dropped onto a horizontally placed glass plate having a smooth surface. On which a sanitary napkin is placed so that the topsheet faces downward. After keeping this state for 1 minute, the sanitary napkin was removed, and the amount of the defibered horse blood remaining on the plate was measured. Each sample was measured 3 times, and the average value thereof was taken as the absorption residual amount of the sample.

< amount of returned liquid after standing for 2 minutes >

After the liquid absorption time was measured, the sample was left to stand in a pressurized state for 2 minutes, the liquid injection plate was removed together with the weight, and 10 pieces of previously weighed absorbent paper (length 170mm, width 70mm, grammage 30g/cm, and weight) were stacked on the liquid absorption portion of the sample (the portion into which the liquid was injected in the measurement of the liquid absorption time)²) Overlaid on the surface of the sample, the sample was quickly fitted to the crotch of a pair of shorts and put on a dynamic walking model, and allowed to walk for 1 minute. After the running, the movement of the model was stopped, and the absorbent paper was taken out and weighed, and the amount (g) of liquid absorbed by the absorbent paper was calculated. Each sample was measured 3 times, and the average value was used as the amount of the returned liquid of the sample.

< liquid diffusion area >

Immediately after the measurement of the amount of the return liquid was completed, an OHP (Over Head Projector) film was placed on the front sheet, and the outline of the portion of the front sheet where red color was diffused was drawn. The liquid spreading area was determined by inputting an Image drawn on the OHP membrane to a personal computer with a scanner using dedicated software (Image-pro plus, (stock) NIPPON roller) capable of measuring the area of the inner side of the outline. Each sample was measured 3 times, and the average value was taken as the liquid spreading area of the sample.

[ Table 1]

	Unit of	Example 1	Example 2	Comparative example 1
					Time of liquid absorption	Second(s)	12	10	12
Residual absorption amount	mg	6.5	7	9
					Amount of liquid returned after standing for 2 minutes	mg	330	370	400
Area of liquid diffusion	cm2	15	16	17

From the results in table 1, it is understood that the sanitary napkin according to example 1 has a smaller residual absorption amount than the sanitary napkin according to comparative example 1, although the liquid absorption time is the same. It is understood that the sanitary napkin according to example 2 has a shorter liquid absorption time and a smaller amount of residual liquid than the sanitary napkin according to comparative example 1. Therefore, the sanitary napkins of examples 1 and 2 are expected to absorb excreted body fluids into the absorbent member more quickly than the sanitary napkin of comparative example 1. In addition, it is understood that the sanitary napkins of examples 1 and 2 have a smaller amount of rewet after standing for 2 minutes and a smaller liquid spreading area than the sanitary napkin of comparative example 1. Therefore, the sanitary napkins of examples 1 and 2 are expected to suppress the spread of excreted body fluid on the surface of the topsheet and suppress the return of body fluid absorbed into the absorbent body, compared with the sanitary napkin of comparative example 1.

Industrial applicability

According to the absorbent article of the present invention, the body fluid discharged can be quickly absorbed into the absorbent body, the body fluid discharged can be suppressed from spreading on the surface of the topsheet, and the body fluid absorbed into the absorbent body can be suppressed from returning.

Claims (25)

1. An absorbent article comprising an absorbent body, the absorbent body comprising: a liquid-permeable front sheet forming a skin-facing surface, a back sheet forming a non-skin-facing surface, and an absorbent body interposed between the sheets, the absorbent body comprising: an absorbent article having a discharge part facing portion disposed to face a discharge part of a wearer when worn, a front portion disposed on a belly side of the wearer with respect to the discharge part facing portion, and a rear portion disposed on a back side of the wearer with respect to the discharge part facing portion, the absorbent article having a longitudinal direction corresponding to a front-back direction of the wearer and a transverse direction orthogonal to the longitudinal direction, the absorbent article characterized in that:

a second sheet made of a nonwoven fabric is disposed between the top sheet and the absorbent body,

the front sheet has a concavo-convex structure including a plurality of skin-side protrusions protruding toward the skin-facing surface and having an internal space, and a plurality of non-skin-side protrusions protruding toward the non-skin-facing surface and having an internal space, the skin-side protrusions and the non-skin-side protrusions being alternately arranged in the lateral direction,

the drain opposite part includes: a hollow portion having a hollow structure between the skin-side protruding portion and the second sheet, and a non-pressure-bonding portion in which the non-skin-side protruding portion and the absorbent body are not pressure-bonded,

the grammage of fibers of a wall portion between the top of the skin-side protrusion and the top of the non-skin-side protrusion is higher than the grammage of fibers of the top of the skin-side protrusion and the top of the non-skin-side protrusion when the topsheet is viewed in cross section,

the absorbent body is formed of a laminate of absorbent sheets, and has a plurality of slits at the excretion portion-facing portion,

the slits penetrate through at least 1 layer of the laminate, the slits being longitudinal slits extending in the longitudinal direction and dispersed in both the longitudinal direction and the transverse direction,

the gap between the top portions of the skin-side protruding portions adjacent in the transverse direction in the front surface sheet is formed narrower than the gap between the adjacent slits in the transverse direction, a hollow maintaining portion including the hollow portion and the non-pressure-bonding portion in the discharge portion opposing portion is present at least in a transverse central region in the discharge portion opposing portion, and the hollow maintaining portion is present in an area of 50% or more with respect to a total area of the discharge portion opposing portion.

2. The absorbent article of claim 1, wherein:

a linear pressing groove formed by integrally recessing the front sheet and the second sheet toward the back sheet is formed on the skin-facing surface of the absorbent main body,

in the excretion portion-facing portion, the front surface sheet and the second sheet are not pressed at portions other than the linear pressing grooves.

3. The absorbent article of claim 1 or 2, wherein:

the skin-side protruding portion and the non-skin-side protruding portion are alternately and continuously arranged in 2 different directions intersecting each other in a plan view of the top sheet.

4. The absorbent article of claim 1 or 2, wherein:

the top portions of the skin-side protrusions adjacent to each other in the transverse direction of the front sheet are spaced apart from each other by 2mm to 30 mm.

5. The absorbent article of claim 1 or 2, wherein:

the longitudinal slits are formed to have a length longer than the interval between the tops of the skin-side protrusions adjacent to each other in the longitudinal direction in the front sheet.

6. The absorbent article of claim 1 or 2, wherein:

the length of the longitudinal slit is 10mm to 35 mm.

7. The absorbent article of claim 6, wherein:

the length of the longitudinal slit is 15mm to 25 mm.

8. The absorbent article of claim 1 or 2, wherein:

the second sheet and the absorber are fixed to each other with an adhesive, and the slit penetrates all layers of the laminate.

9. The absorbent article of claim 8, wherein:

the distance between the top portions of the skin-side protruding portions or the distance between the top portions of the non-skin-side protruding portions is 3mm to 15 mm.

10. The absorbent article of claim 1 or 2, wherein:

the grammage of the fibers of the wall portion of the skin-side protrusion is higher than the grammage of the fibers of the top portion of the skin-side protrusion.

11. The absorbent article of claim 1 or 2, wherein:

the density of fibers at the top of the non-skin-side protrusion is lower than the density of fibers at the periphery thereof.

12. The absorbent article of claim 11, wherein:

the top of the plurality of non-skin-side protrusions has a through hole.

13. The absorbent article of claim 11, wherein:

the relationship of the gram weight of the fiber is as follows: the top of the non-skin-side protrusion < the top of the skin-side protrusion < the wall of the skin-side protrusion.

14. The absorbent article of claim 1 or 2, wherein:

the protruding shape of the skin-side protruding part is a hemispherical shape or a conical shape.

15. The absorbent article of claim 14, wherein:

the protruding shape of the skin side protruding part is a hemisphere or a cone, a cone frustum, a pyramid frustum or an oblique cone.

16. The absorbent article of claim 1 or 2, wherein:

the protruding shape of the non-skin-side protruding portion is a cone or a truncated cone shape having a curvature at the top.

17. The absorbent article of claim 1 or 2, wherein:

the compression rate of the front surface piece is 40-95%.

18. The absorbent article of claim 1 or 2, wherein:

the compression energy of the front surface sheet is 0.98 mN.m/cm²Above and 9.8mN · m/cm²The following.

19. The absorbent article of claim 1 or 2, wherein: the sheet thickness of the front sheet is 1mm to 3.5 mm.

20. The absorbent article of claim 1 or 2, wherein:

the gram weight of the second sheet is 10g/m²Above and 50g/m²The following.

21. The absorbent article of claim 20, wherein:

the gram weight of the second sheet is 15g/m²Above and 40g/m²The following.

22. The absorbent article of claim 1 or 2, wherein:

the second sheet has a thickness of 0.1mm to 5 mm.

23. The absorbent article of claim 1 or 2, wherein:

the slits are longitudinal slits extending in the longitudinal direction, dispersed in both the longitudinal direction and the transverse direction,

the ratio of the interval between the top portions of the skin-side protrusions to the interval between the longitudinal slits in the transverse direction is 10% to 70%.

24. The absorbent article of claim 23, wherein:

the ratio is 30% or more and 55% or less.

25. The absorbent article of claim 1 or 2, wherein:

the absorbent article is a sanitary napkin.

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