JP2019103714A - Absorbent article - Google Patents

Abstract

To provide an absorbent article capable of suppressing liquid leaks in a rear portion.SOLUTION: An absorbent article according to one aspect of the present invention includes a main body and a pair of adhesive portions. The main body includes a front core portion and a rear core portion located at both end sides in a longitudinal direction. The rear core portion has: an absorbent core having a structural surface on which a plurality of vertical grooves extending in the longitudinal direction to the center of a width direction orthogonal to the longitudinal direction are arranged symmetrically in the width direction; a front surface sheet covering one main surface of the absorbent core; and a back surface sheet covering the other main surface opposite the one main surface of the absorbent core. The pair of adhesive portions are arranged on the main body along the longitudinal direction, and are opposed, across the back surface sheet, to a pair of second vertical grooves arranged at both sides of the first vertical groove nearest to the center of the width direction among the plurality of vertical grooves.SELECTED DRAWING: Figure 4

Description

  The present invention relates to absorbent articles such as sanitary napkins.

BACKGROUND ART Absorbent articles of the type used by being disposed inside underwear, such as sanitary napkins, are known. In this type of absorbent article, in order to prevent displacement of the absorbent article during wearing, a slip stopper for fixing the absorbent article to the underwear is provided (for example, see Patent Document 1). .
Moreover, the absorbent article is equipped with the absorber which has a longitudinal direction for absorbing liquid substances, such as menstrual blood. The absorbent has an absorbent core and a core wrap sheet covering the absorbent core. The absorbent core is formed with a groove so as to be easily deformed along the skin of the wearer wearing the absorbent article (see, for example, Patent Document 2).

JP, 2015-97718, A JP, 2015-112235, A

  The sanitary napkin is worn with its rear part corresponding to the buttocks of the wearer. In particular, the sanitary napkin for the night is formed to have a long rear part in order to prevent liquid leakage in the rear part, and the rear part of the sanitary napkin is formed so as to substantially cover the buttocks. Since the buttocks portion has a shape in which the groin region is sharply depressed with respect to the swelling of the buttocks, a gap is easily generated between the groin and the sanitary napkin at the rear portion of the sanitary napkin. For this reason, a liquid substance such as menstrual blood excreted from the excretory part of the wearer may flow into the rear part with tearing, and liquid leakage may occur in the rear part.

  An object of the present invention relates to an absorbent article capable of suppressing liquid leakage in the rear portion.

The absorbent article which concerns on one form of this invention comprises a main body and a pair of adhesion part.
The main body includes a front core portion and a rear core portion positioned on both end sides in the longitudinal direction, and the rear core portion extends in a longitudinal direction with respect to a width direction central portion orthogonal to the longitudinal direction. An absorbent core having a structural surface arranged symmetrically in the width direction, a surface sheet covering one main surface of the absorbent core, and the other opposite to the one main surface of the absorbent core And a back sheet covering the main surface of
The pair of adhesive portions are provided on the main body along the longitudinal direction, and the pair of second adhesive portions arranged on both sides of the first longitudinal groove portion positioned at the center in the width direction among the plurality of longitudinal grooves. It opposes to a vertical groove part on both sides of the above-mentioned back sheet.

  As described above, according to the present invention, it is possible to suppress liquid leakage in the rear portion of the absorbent article.

BRIEF DESCRIPTION OF THE DRAWINGS It is a perspective view which shows the absorbent article of the 1st Embodiment of this invention. It is a schematic plan view of the above-mentioned absorptive article. It is sectional drawing cut | disconnected by the III-III line of FIG. It is a top view of the absorptive core of the above-mentioned absorptive article. It is a schematic diagram for demonstrating the deformation state of the back part of the napkin at the time of wearing the said absorbent article. It is a top view of the absorptive core of the absorptive article of a 2nd embodiment of the present invention. It is a top view of the absorptive core of the absorptive article of a 3rd embodiment of the present invention. It is a top view of the absorptive core of the absorptive article of a 4th embodiment of the present invention. It is a top view of the absorptive core as a comparative example.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In the drawings, an X axis, a Y axis, and a Z axis are shown.

First Embodiment
[Whole composition of the napkin]
FIG. 1 is a perspective view showing an absorbent article 1 according to an embodiment of the present invention. In FIG. 1, the X-axis direction corresponds to the front-rear direction, the Y-axis direction corresponds to the left-right direction, and the Z-axis direction corresponds to the vertical direction.
FIG. 2 is a plan view of the absorbent article 1 and shows a mode in which the absorbent article 1 shown in FIG. 1 is stretched along the XY plane. In the absorbent article 1 shown in FIG. 2, the X-axis direction corresponds to the longitudinal direction, the Y-axis direction corresponds to the width direction, and the Z-axis direction corresponds to the thickness direction. Hereinafter, the absorbent article 1 is demonstrated in the aspect shown in FIG.
The absorbent article 1 of the present embodiment is configured as a sanitary napkin and hereinafter referred to as a napkin 1.
The napkin 1 of the present embodiment may be used at bedtime, and may have a length of, for example, 30 cm or more along the X-axis direction, which is the longitudinal direction.

  In the present embodiment, the napkin 1 includes a napkin main body (hereinafter simply referred to as "main body") M, a pair of wing portions W, a pair of side guards G, and a pair of rear flap portions F.

The main body M extends in the longitudinal direction and is fixed to the inner surface (mounted surface) of the underwear of the wearer when worn. The main body M has an absorber, which will be described later, and has a function of absorbing a liquid such as menstrual blood of the wearer (hereinafter, also referred to as “liquid”).
The main body M has a front area M1, an intermediate area M2, and a rear area M3 sectioned along the longitudinal direction.
The front area M1 is an area disposed in front of the middle area M2 (ventral side of the wearer), and is configured to face the front of the excretory area of the wearer at the time of wearing.
The middle area M2 is configured to face the excretory area of the wearer at the time of wearing. In the case of a napkin having a wing, an area in the longitudinal direction (X-axis direction) overlapping with the entire length of the wing is an intermediate area M2. In the case of the napkin which does not have a wing, the central region when the total length of the napkin is divided into three equal parts is taken as an intermediate region M2. The intermediate region M2 may be located closer to the front of the main body M as illustrated, or may be located at the central portion in the longitudinal direction of the main body M.
The rear area M3 is an area disposed behind the intermediate area M2 (the back of the wearer), and is configured to face the rear of the wearer's excretion area when worn. In the present embodiment, the rear region M3 is formed to be longer in the longitudinal direction than each of the front region M1 and the middle region M2. Thereby, it is possible to effectively prevent the liquid leakage to the rear.

The wing portion W is configured to largely protrude outward in the width direction from the middle region M2.
The side guard G is arranged to extend in the longitudinal direction at the widthwise peripheral edge of the main body M including the intermediate region M2.
The rear flap portion F is configured to bulge outward in the width direction from the rear region M3 and can be fixed to the region facing the buttocks of the inner surface of the underwear of the wearer at the time of wearing. Thereby, the back flap part F can prevent position shift of back field M3 accompanying with operation of a wearer at the time of wearing, and can support a back leak prevention function by back field M3.
The napkin 1 may not have at least one of the wing portion W, the side guard G, and the rear flap portion F.

[Configuration of each part of the napkin]
3 is a cross-sectional view taken along line III-III of the napkin of FIG.
As shown in FIGS. 2 and 3, the napkin 1 includes an absorbent body 11, a top sheet 12, a back sheet 13, a pair of side sheets 14, an adhesive portion 15, and a pressing groove 16.
In addition, the main body M has the absorber 11, the surface sheet 12, and the back surface sheet 13, and has the structure on which these were laminated | stacked.

The absorber 11 has a longitudinal direction in the X-axis direction, and is disposed at the central portion in the thickness direction of the napkin 1. The absorber 11 absorbs the excreted liquid from the surface on the surface sheet 12 side, and diffuses the inside to hold the liquid.
The absorbent body 11 has an absorbent core 20 and a core wrap sheet 30.

The absorbent core 20 has a function to absorb and hold a liquid. The absorbent core 20 may be formed of, for example, a fiber assembly composed of hydrophilic fibers such as pulp fibers, or may have a configuration in which a water absorbing polymer is held by the fiber assembly. . The detailed configuration of the absorbent core 20 will be described later.
The absorbent core 20 has a first surface 20 a as one main surface facing the surface sheet 12 and a second surface 20 b as the other main surface facing the back surface sheet 13. In the present embodiment, the first surface 20a is configured as a structured surface having a convex structure or a groove, and the second surface 20b is configured as a flat surface.

  The core wrap sheet 30 covers the absorbent core 20 and has, for example, a function of holding the shape of the absorbent core 20. The core wrap sheet 30 is formed of, for example, thin soft paper such as tissue paper, liquid-permeable non-woven fabric, or the like.

The surface sheet 12 is configured as a liquid-permeable sheet material and disposed on the absorber 11. The surface sheet 12 includes an outer surface 12 a which constitutes the surface (surface in the thickness direction) of the napkin 1 in the main body M.
The top sheet 12 covers the first surface 20 a of the absorbent core 20.

The back sheet 13 is disposed to face the top sheet 12 in the thickness direction with the absorber 11 interposed therebetween. The back surface sheet 13 includes the outer surface 13a which constitutes the back surface (surface under the thickness direction) of the napkin 1, and is disposed over the main body M, the wing portion W and the rear flap portion F.
The back sheet 13 covers the second surface 20 b of the absorbent core 20.

  The pair of side sheets 14 oppose each other in the width direction with the top sheet 12 interposed therebetween, and are disposed at the widthwise peripheral edge of the napkin 1.

  The adhesive portion 15 is a slip stopper that fixes the napkin 1 to the undergarment and suppresses the napkin 1 from being displaced from the undergarment, and is formed on the outer surface 13 a of the back sheet 13. The adhesive unit 15 includes, for example, a main unit adhesive unit 151 provided on the main body M, a wing adhesive unit 152 provided on the wing unit W, and a rear flap adhesive unit 153 provided on the rear flap unit F.

The squeeze groove 16 is configured as a linear groove formed by squeezing the absorber 11 and the top sheet 12. The pressing groove 16 is configured to go around the main body M as shown in FIGS.
The squeeze groove 16 can induce deformation to a shape that fits the wearer at the time of wearing, and can enhance the effect of preventing liquid leakage outward in the width direction and longitudinal direction of the napkin 1.

[Detailed configuration of absorbent core]
Next, the configuration of the absorbent core will be described in detail.
FIG. 2 is a plan view showing the positional relationship between the absorbent core 20 and the adhesive portion 15 in the napkin 1.
FIG. 3 is a cross-sectional view of the rear region M3 of the napkin 1 and shows the positional relationship between the longitudinal groove 27 and the main adhesive portion 151 arranged in the rear core portion 23 of the absorbent core 20. As shown in FIG.
FIG. 4 is a plan view of the absorbent core 20 that constitutes a part of the absorbent body 11. In FIG. 4, in order to explain the positional relationship between the longitudinal groove 27 arranged in the absorbent core 20 and the main adhesive portion 151 provided on the outer surface 13 a of the back sheet 13 when the napkin 1 is viewed in plan, The adhesive portion 151 is illustrated by a dashed line.

(Whole structure of absorbent core)
The absorbent core 20 has a front core portion 21 and a rear core portion 23 facing each other in the longitudinal direction (X-axis direction), and an intermediate core portion 22 located between the front core portion 21 and the rear core portion 23. . The absorbent core 20 has a planar shape narrowed at the intermediate core portion 22. The front core portion 21 of the absorbent core 20 covers only the front region M1, the middle core portion 22 extends from the front region M1 to the rear region M3 via the middle region M2, and the rear core portion 23 only the rear region M3, It is arranged respectively.

The front core portion 21 and the rear core portion 23 face each other in the longitudinal direction. The front core portion 21 and the rear core portion 23 may be respectively disposed in front of and behind the excretory area of the wearer at the time of wearing.
The middle core portion 22 is located between the front core portion 21 and the rear core portion 23 and has a narrower width than the front core portion 21 and the rear core portion 23.

  In the present embodiment, the front core portion 21 and the rear core portion 23 may have boundary portions 21 a and 23 a adjacent to the intermediate core portion 22 and decreasing in width toward the intermediate core portion 22. The boundaries 21a and 23a may be in a line symmetrical shape or an asymmetrical shape with respect to a symmetry axis parallel to the width direction. By providing the boundaries 21a and 23a, the deformation of the boundaries 21a and 23a with respect to the external force in the width direction can be suppressed, and the deformation of the intermediate core 22 can be effectively suppressed.

  The absorbent core 20 has a first surface 20a as one main surface and a second surface 20b as the other main surface facing each other along the thickness direction (Z-axis direction).

  The first surface 20 a is a surface on which the top sheet 12 is disposed via the core wrap sheet 30. The outer surface 12 a of the top sheet 12 is a skin contact surface. When the napkin 1 is worn by the wearer, the first surface 20a is located on the skin side of the wearer.

  The second surface 20 b is a surface on the side on which the back sheet 13 is disposed via the core wrap sheet 30. The adhesive portion 15 formed on the outer surface 13a of the back sheet 13 is configured to be able to fix the napkin 1 to the inner surface of the undergarment. When the napkin 1 is worn by the wearer, the second surface 20b is located on the inner side of the undergarment. The second surface 20 b is substantially flat.

The first surface 20 a has a plurality of longitudinal grooves 27 and lateral grooves 28 intersecting with each other.
In the absorbent core 20, the longitudinal grooves 27 and the lateral grooves 28 are provided symmetrically in the width direction with respect to the widthwise center of the absorbent core 20.
The plurality of transverse grooves 28 are arranged in the longitudinal direction and extend in the width direction orthogonal to the longitudinal direction.
The plurality of longitudinal grooves 27 are arranged in the width direction and extend in the longitudinal direction.

By providing the vertical groove 27 and the horizontal groove 28, the flexibility of the absorbent core 20 can be enhanced, and the liquid absorption speed can be increased by drawing the liquid into the groove. In addition, the absorbent core 20 is divided into a plurality of block portions 29 by the longitudinal grooves 27 and the lateral grooves 28, so that the surface area of the absorbent core 20 can be increased, and the liquid can be absorbed and held efficiently.
Each block portion has a four-sided shape, a substantially fan-like shape, or a shape in which a part of a rectangle is cut in a plan view of a top of the block portion. The top of each block 29 is substantially flat.

  The first surface 20 a has a plurality of convex block portions 29 defined by the longitudinal grooves 27 and the lateral grooves 28. The absorbent core 20 has a concavo-convex structure attributable to, for example, a basis weight distribution on the first surface 20a. Since the basis weight has a correlation with the rigidity, by adjusting the basis weight distribution, it is possible to control the deformation of the absorbent core 20 with respect to the external force applied at the time of mounting.

  The intermediate core portion 22 includes a high basis weight portion 24 and a pair of low basis weight portions 25. In FIG. 4, the high basis weight portion 24 is shown by a dense dot pattern, and the low basis weight portion 25 is shown by a rough dot pattern. The high basis weight portion 24 has a high basis weight relative to the low basis weight portion 25. The high basis weight portion 24 may be arranged to face the excretory area of the wearer at the time of wearing.

  As shown in FIG. 4, the first surface 20 a is a front structural surface 51 located at the front core portion 21, a liquid receiving surface 52 located at the intermediate core portion 22, and a rear structural surface located at the rear core portion 23. And 53. The front structural surface 51 is adjacent to the liquid receiving surface 52. The rear structural surface 53 is adjacent to the receiving surface 52.

The front structural surface 51 and the rear structural surface 53 have a shape in which a plurality of grooves are formed on a flat surface.
On the liquid receiving surface 52, the high basis weight portion 24 is shaped so as to protrude upward in the thickness direction from the low basis weight portion 25, the front core portion 21 and the rear core portion 23. Each of the high basis weight portion 24 and the low basis weight portion 25 has a shape in which a plurality of grooves are formed on a flat surface.
In addition, it may replace with the form of FIG. 3, and the form which the high basic weight part 24 protrudes below a Z direction may be sufficient. In that case, when sticking on underwear, the convex structure which protruded below via the back surface sheet 13 is pushed up, and it becomes the structure similar to the form of FIG.

In the absorbent core 20, the area in which the groove is formed, that is, the bottom forming the groove is relatively thinner than the area of the block 29 in which the groove is not formed.
The thickness and basis weight of the absorbent core 20 are in correlation. The bottom portion forming the groove portion has a relatively low basis weight as compared to the block portion. As a result, the bottom of the groove is less rigid than the block. Therefore, when an external force is applied to the absorbent core 20, the absorbent core 20 is easily deformed with the groove portion as the deformation starting point.
From the viewpoint of ease of deformation, it is desirable for each groove to have a basis weight of the absorbent material smaller than that of the surrounding block. Here, "low basis weight" is a concept including a form in which the material of the absorbent core is present as well as a form in which the material of the absorbent core is not present. However, in the form in which the material of the absorbent core is present, since the block-like portions of the absorbent core located on both sides are connected via the respective grooves, the absorbent core moves by swaying, breaking and breaking by thousand. It is more preferable because breakage and the like can be prevented and flexibility can be imparted.

  In the present embodiment, each groove is substantially the same as the groove width at the bottom forming the groove and the groove width at the opening of the groove. The bottom of the groove is located substantially parallel to the second surface 20b. The side of the groove forming the groove is substantially perpendicular to the bottom. The width of the groove (groove width) described below indicates the width at the opening of the groove.

  In addition, although a groove part demonstrates the example which the cross section orthogonal to the longitudinal direction of a groove part substantially rectangular shape here, it is not limited to this. For example, the V-shaped or trapezoidal groove may have a V-shaped or trapezoidal cross section having a tapered side surface whose width increases from the bottom toward the opening. Even in such a case, in the absorbent core, the area in which the grooves are formed has a lower basis weight and lower rigidity than the area in which the grooves are not formed. For example, in the case of a V-shaped or trapezoidal groove, the width of the groove indicates the width at the opening.

(Structure of rear structural surface)
Next, the vertical groove 27 disposed in the rear structural surface 53 will be described in detail.

The rear structural surface 53 has five longitudinal grooves 27 and lateral grooves 28.
In the rear structural surface 53, a plurality of longitudinal grooves 27 extending in the longitudinal direction are symmetrically arranged in the width direction with respect to a central portion in the width direction orthogonal to the longitudinal direction.
The five longitudinal grooves 27 are spaced apart from one another and arranged at equal pitches in the width direction. Here, the arrangement pitch is the distance between the centers of adjacent longitudinal grooves 27.

The five longitudinal groove portions 27 include one first longitudinal groove portion 271, a pair of second longitudinal groove portions 272, and a pair of third longitudinal groove portions 273. The first longitudinal groove 271, the second longitudinal groove 272, and the third longitudinal groove 273 are all referred to as the longitudinal groove 27 when it is not necessary to distinguish them.
The first longitudinal groove 271 is located at the center in the width direction of the five longitudinal grooves, and is located at the center in the width direction of the rear structural surface 53.
The pair of second longitudinal groove portions 272 is arranged adjacent to the first longitudinal groove portion 271 one on each side thereof.
The pair of third longitudinal groove portions 273 is arranged one by one on both sides of the first longitudinal groove portion 271 and the pair of second longitudinal groove portions 272.
The first longitudinal groove 271 and the second longitudinal groove 272 have the same groove width. The third longitudinal groove portion 273 has a groove width narrower than the groove widths of the first longitudinal groove portion 271 and the second longitudinal groove portion 272.

The rear structural surface 53 has a total of 36 block portions 29 divided into six rows in the longitudinal direction and six rows in the width direction by the lateral grooves 28 and the longitudinal grooves 27. The block portions 29 each have a quadrangular top portion in a plan view. Hereinafter, the dimension at the block portion 29 indicates the dimension at the top of the block portion 29.
Each block portion 29 has a width that is greater than the groove width a of the first longitudinal groove 271. Here, the width dimension of the block portion 29 indicates the dimension in the width direction (Y-axis direction).

  The lateral grooves 28 are arranged at equal intervals in the rear structural surface 53 so that the dimensions in the longitudinal direction (X-axis direction) of the respective block portions 29 of the rear structural surface 53 are the same.

The width dimension of each block portion 29 of the two row block portion groups located at the center in the width direction of the rear structural surface 53 is shorter than the width dimension of each block portion 29 of the block portions of the other rows.
The width dimension of each block portion 29 of the pair of block portions positioned immediately on both sides of the two rows of block portions positioned at the central portion in the width direction of rear structural surface 53 is the pair of the outermost portions located in the width direction. It is shorter than the width dimension of each block portion 29 of the block portion group.
As described above, in the rear structural surface 53, the width dimension of the block portion is gradually shortened from the side end side in the width direction toward the center.
In addition, "the center part of the width direction" is an area by the side of the center including the central line which bisects an absorptive article in the width direction, and in middle core part 22, a part which counters a wearer's excretion part. In the rear core portion 23, it refers to a region including a portion facing the groin 61.

[Positional relationship between the vertical groove and the adhesive part of the main body]
Next, the positional relationship between the longitudinal groove portion of the absorbent core and the main-body adhesive portion will be described with reference to FIGS. 2 to 4.
The pair of main body adhesive portions 151 includes a first main body adhesive portion 151a extending in the longitudinal direction which is spaced apart from each other and disposed substantially in parallel, and a second main body adhesive portion 151b. The first main adhesive portion 151a and the second main adhesive portion 151b have the same width (dimension in the Y-axis direction) and a rectangular shape having the same overall length, and are symmetrical at the widthwise center line of the napkin 1 .

The pair of main body adhesive portions 151 is provided along the longitudinal direction (X-axis direction). The pair of main body adhesive portions 151 have a total length that does not reach each of the front end portion and the rear end portion in the longitudinal direction of the absorbent core 20.
The pair of main body adhesive portions 151 is disposed in a region opposed in the thickness direction across the back sheet 13 with the pair of second longitudinal grooves 272 and the pair of third longitudinal grooves 273 of the main body M.
The adhesive portion 15 is made of, for example, a hot melt adhesive.

As shown in FIG. 4, when viewed in a plan view, the second longitudinal groove 272 and the third longitudinal groove 273 are located in the region where the main adhesive portion 151 is disposed in the width direction. The second longitudinal groove portion 272 and the third longitudinal groove portion 273 overlap the main body adhesive portion 151.
When viewed in a plan view, the first vertical groove 271 is not located in the area in which the main body adhesive portion 151 is disposed. The first vertical groove 271 and the main unit adhesive portion 151 do not overlap with each other.

The width e of the entire outer shape of the pair of main body adhesive portions 151 is narrower than the width D of the rear core portion 23. When viewed in plan, the rear core portion 23 has a region that does not overlap with the pair of main body adhesive portions 151 at both side ends in the width direction.
That is, as shown in FIG. 4, when seen in a plan view, each block portion 29 of the block portion group along the longitudinal direction located at the outermost side in the width direction of the rear core portion 23 partially includes the main adhesive portion 151. And other parts do not overlap with the main unit adhesive part 151.

The above-mentioned absorbent core 20 is typically a mixed-stack fiber body obtained by mixing and stacking pulp fibers and an absorbent polymer.
Examples of hydrophilic fibers contained in the absorbent core 20 include pulp fibers, rayon fibers, cotton fibers, cellulose-based hydrophilic fibers such as cellulose acetate, polyolefin fibers such as polyethylene and polypropylene, condensation of polyesters, polyamides, etc. It is possible to use one or two or more selected from the group fibers and the like.
As the water absorbing polymer contained in the absorbent core 20, for example, sodium polyacrylate, acrylic acid-vinyl alcohol copolymer, sodium polyacrylate cross-linked product, starch-acrylic acid graft copolymer, isobutylene-maleic anhydride One or more selected from copolymers and saponified products thereof, polyaspartic acid and the like can be used.

  The absorptive core 20 which has an uneven structure in the above-mentioned back structure surface 53 can be manufactured, for example using the fiber-stacking apparatus provided with the fiber-stacking drum which has the recessed part for accumulation | storage in an outer peripheral surface. In the fiber stacking apparatus, the core material is deposited in the accumulation recess by supplying the core material such as pulp fiber to the outer peripheral surface of the fiber stacking drum. An absorbent core can be obtained by releasing the deposited fiber body from the accumulation recess.

[Operation and effect of this embodiment]
FIG. 5 is a schematic view for explaining the relationship between the groin 61 of the collar 60 of the wearer and the deformed state of the rear core 23 in the rear region M3 of the napkin 1 when the napkin 1 of the present embodiment is worn. In FIG. 5, in order to make a drawing intelligible, the one part structure of the napkin 1 is abbreviate | omitted and shown in figure, and only the absorptive core 20 and the main body adhesion part 151 are shown in figure.

In the present embodiment, a plurality of longitudinal grooves 27 extending in the longitudinal direction are arranged in the rear core portion 23 of the absorbent core 20 so that the longitudinal grooves 27 are easily deformed in the width direction with the longitudinal grooves 27 as a deformation starting point. .
Furthermore, in the napkin 1 having such an absorbent core 20, the main adhesive portion 151 is not disposed opposite to the first longitudinal groove 271 positioned on the central side in the width direction among the plurality of longitudinal grooves. The main adhesive portion 151 is disposed opposite to the second longitudinal groove portion 272 located on both sides of the longitudinal groove portion 271.
Therefore, the deformation of the bottom of the first vertical groove 271 is less likely to be inhibited by the main adhesive portion 151, and the deformation of the bottom of the second vertical groove 272 is more likely to be inhibited by the main adhesive portion 151.

  Thereby, as shown in FIG. 5, the first vertical groove 271 in which deformation of the bottom is not easily inhibited by the main body adhesive portion 151 is a pair of second longitudinal grooves 272 in which deformation of the bottom is easily inhibited by the main body adhesive portion 151. When the napkin 1 is attached, the area facing the ridge 60, especially the crease 61, in the rear area M3 of the napkin 1 is placed at an acute angle with the bottom of the first longitudinal groove 271 as the deformation starting point. It is easy to be deformed so as to project to the side 20 a of 1 side. By deforming the napkin 1 so that the protruding portion enters the cleft, the gap between the cleft of the wearer and the napkin 1 is reduced. Thereby, even if a liquid substance such as menstrual blood or the like excreted from the excretory area of the wearer flows out to the rear part, the liquid is quickly absorbed by the absorbent core 20, and liquid leakage in the rear part is suppressed.

  Thus, at least the first longitudinal groove 271 and the pair of second longitudinal grooves 272 which are three longitudinal grooves are arranged in the rear core portion 23 in the rear area M3 of the napkin 1, and the centers of the three longitudinal grooves are arranged. The main adhesive portion 151 is not disposed opposite to the first longitudinal groove 271 and the second adhesive portion 151 positioned opposite to the first longitudinal groove 271 is disposed opposite to the first longitudinal groove 271. This promotes preferential deformation of the bottom of the first vertical groove 271 during mounting.

Further, in the rear region M3 of the napkin 1, the main adhesive portion 151 is disposed to be opposed to the second longitudinal groove 272, so that the deformation of the bottom of the second longitudinal groove 272 is inhibited by the main adhesive portion 151. The ease of deformation is reduced compared to the bottom of the vertical groove 271 of
Therefore, the area in which the second longitudinal grooves 272 of the napkin 1 of the present embodiment are arranged and the main adhesive portion 151 is provided follows the area in which the first longitudinal grooves 271 that are deformed at an acute angle are arranged. It is easy to deform gently along the shape of. As a result, the gap between the vicinity of the groin and the napkin 1 is reduced, the fit is improved, and the lateral leakage of the rear portion is suppressed.

  Thus, in the napkin 1 of the present embodiment, the rear region M3 is easily deformed along the shape of the buttocks including the torso. Thereby, even if liquid material such as menstrual blood of the wearer flows out to the rear core portion 23 of the napkin 1, it is absorbed quickly by the absorber 11 deformed along the crease 61, and liquid leakage in the rear portion is suppressed. . In particular, when the napkin is worn in a supine position by the wearer at bedtime, the liquid easily flows to the back on the back side, so the napkin 1 of the present embodiment is effective in suppressing liquid leakage at night in the rear. is there.

Further, in the present embodiment, at the position where the rear core portion 23 is present in the rear region M3, in the region where the main body adhesive portion 151 is disposed, the thick longitudinal groove portions are in order from the center portion side in the width direction toward the side portions. Two vertical grooves 272 and a third vertical groove 273 which is a thin vertical groove are arranged. The region in which the thick vertical groove portions are arranged is lower in rigidity than the region in which the thin vertical groove portions are arranged, and it becomes easy to deform.
As a result, in the rear region M3, the central portion in the width direction in which the main adhesive portion 151 is not disposed and the first longitudinal groove portions 271 are arranged is most likely to be deformed, and stepwise from the central portion to the side portions The ease of change changes. As a result, the deformation of the main body M corresponding to the area from the groin to the swelling of the buttocks becomes gentle, and the fit property is improved. Accordingly, the gap between the buttocks and the napkin 1 is reduced, the fit is improved, and the lateral leakage of the rear portion is suppressed.

Further, in the present embodiment, the block portion 29 of the rear core portion 23 has a width that is greater than the groove width of the first longitudinal groove 271.
As a result, the first longitudinal groove 271 easily becomes a deformation starting point, and when the napkin 1 is attached, the napkin 1 is easily deformed into an ideal shape along the groin.
For example, when the first vertical groove 271 has a groove width equal to or wider than the width of the block 29, the range serving as the deformation starting point is broadened, and the position of the deformation starting point is largely deviated Cheap.
On the other hand, by making the groove width of the first vertical groove 271 narrower than the width of the block 29 as in the present embodiment, the deformation starting point is less likely to deviate, and the napkin 1 is deformed into a desired shape. Cheap.

Further, in the present embodiment, all the longitudinal groove portions 27 other than the first longitudinal groove portion 271 are disposed opposite to the pair of main body adhesive portions 151 in the thickness direction at the rear core portion 23 existing position of the rear region M3.
For example, in the case where there is a region in which the main adhesion portion 151 is not arranged and the longitudinal grooves are arrayed on both sides in the width direction of the rear region M3, the rear flap portion F is the first starting from the longitudinal groove at the time of mounting. It may be deformed so as to fold into the surface 20a side.
On the other hand, in the present embodiment, all of the longitudinal groove portions 27 other than the first longitudinal groove portion 271 are disposed to face the pair of main body adhesive portions 151 in the thickness direction, so that the longitudinal groove portions 27 arranged in both side portions The deformation of the bottom portion is inhibited by the main-body adhesive portion 151, and the deformation of the rear flap portion F so as to be broken toward the first surface 20a is suppressed.

  Thus, the width e of the entire outer shape of the pair of main body adhesive portions 151 is such that, in the rear core portion 23, the longitudinal groove portions 27 other than the first longitudinal groove 271 and the main body adhesive portions 151 overlap in plan view. It may be set to

  Further, in the present embodiment, since the lateral groove portion 28 is disposed in addition to the longitudinal groove portion 27, in the longitudinal direction of the napkin 1, it is easily deformed along the shape of the wearing target portion of the wearer, and the fit property is improved.

[Additional explanation of this embodiment]
Hereinafter, the description of the present embodiment will be supplemented.

(Measurement method of groove width)
The width of the groove is determined by measuring the width at the opening of the groove. The absorbent core is placed horizontally, the measurement magnification is adjusted with a microscope (VHX-1000 manufactured by KEYENCE Corporation), and the first surface 20 a is enlarged to measure the opening width.
Alternatively, the absorbent core 20 is cut using a feather blade razor and the cross section of the cut sample is observed at a magnification of 20 to 100 times using a microscope (VHEX-1000 manufactured by KEYENCE Corporation), The groove width may be measured.

(Method of measuring thickness of each part of absorbent core)
The thickness of the absorbent core 20 to be measured is measured by measuring the thickness of small pieces cut out to measure the basis weight for each part. The small pieces cut out from the absorbent core are pressurized at a pressure of 5 kPa for 10 minutes, and measurement is carried out immediately after weight removal. Place an acrylic plate with a size of 20 mm × 20 mm and a thickness of 3 mm in the central area of the sample after weight removal, and use the KEYENCE non-contact laser displacement meter (laser head LK-G30, displacement meter LK-GD500) to sample Measure the thickness of When the size of the cut-out piece is small and difficult to measure by a non-contact laser displacement meter, the section of the cut sample is, for example, 20 to 100 using a microscope (VHX-1000 manufactured by KEYENCE Corporation). It may be observed at double magnification and measured.

(Example of each configuration)
The numerical example of the said absorptive core 20 and the main body adhesion part 151 is demonstrated. In addition, it is not limited to the numerical value described here.
The groove width of the longitudinal groove 27, the width of the main adhesive portion 151, and the like are appropriately set according to the width of the absorbent core 20, the depth of the longitudinal groove 27, and the thickness of the bottom of the longitudinal groove 27 and the block 29.
The total length dimension of the main body adhesive portion 151 is appropriately set in accordance with the total length of the absorbent core 20 and the total length of the napkin 1.
The distance between the pair of main body adhesive portions 151 is appropriately set according to the width of the first longitudinal groove 271.
The thickness of the bottom of the grooves 27 and 28 and the thickness of the block 29 are correlated with the basis weight. The thickness and basis weight of the bottoms of the groove portions 27 and 28 and the block portion 29 are appropriately set such that a sufficient absorption amount can be obtained while providing a comfortable wearing feeling with an appropriate thickness that does not make the wearer feel uncomfortable.

The width of the first longitudinal groove 271 and the second longitudinal groove 272, which are large longitudinal grooves, is preferably 2.5 mm or more so that the central portion easily bends along the buttocks and has sufficient strength. .5 mm or less, more preferably 3 mm or more and 5 mm or less, and 4 mm in this embodiment.
The width a of the third vertical groove 273 which is a thin vertical groove is preferably 0.5 mm or more and 2.5 mm or less, more preferably 1 mm or more and 2 mm or less, in order to make the rear portion soft and easy to deform along the buttocks. In the present embodiment, it is 1.5 mm.
The wiring pitch of the vertical groove portions 27 arranged in the rear core portion 23 is, for example, 11 mm or more and 15 mm or less, and is 13 mm in the present embodiment.

  The groove depth d1 of the first vertical groove 271, the second vertical groove 272, the third vertical groove 273, and the horizontal groove 28 is 1.5 mm or more and 6 mm or less, and is 4 mm in the present embodiment. The groove depth indicates the distance from the opening to the bottom of the groove located on the same plane as the top of the block 29.

As shown in FIG. 4, the width c (dimension in the Y-axis direction) of each of the first main adhesive portion 151 a and the second main adhesive portion 151 b constituting the pair of main adhesive portions 151 is, for example, 15 mm or more and 30 mm or less In the present embodiment, it is 25 mm.
The space | interval b of a pair of main body adhesion part 151 is 3 mm or more and 20 mm or less, for example, and was 10 mm in this embodiment.
The total length of the pair of main body adhesive portions 151, that is, the dimension in the X-axis direction can be, for example, a length less than the total length of the absorbent core 20.

The distance b between the pair of main body adhesive portions 151 is appropriately adjusted according to the width a of the first longitudinal groove 271. The distance between the pair of main body adhesive portions 151 is the distance between the first main body adhesive portion 151 a and the second main body adhesive portion 151 b.
The distance b between the pair of main body adhesive portions 151 is, for example, equal to or larger than the width a of the first longitudinal groove 271 and is preferably smaller than the distance between the pair of second longitudinal grooves 272. That is, the main unit adhesive portion 151 and the second vertical groove portion 272 may be overlapped so that the second longitudinal groove portion 272 is positioned at least in the region where the main body adhesive portion 151 is provided in plan view.
When the napkin 1 is viewed in a plan view, the distance b between the pair of main body adhesive portions 151 is a groove of the first longitudinal groove portion 271 so that the first longitudinal groove 271 is arranged between the pair of main body adhesive portions 151. It is set, for example, in anticipation of margins such as positional deviation in the width direction at the time of application to the back sheet 13 of the hot melt adhesive to be the width and the main adhesive portion 151 and positional deviation in the width direction at the time of assembling the napkin 1.

The width e of the entire outer shape of the pair of main body adhesive portions 151 in the rear core portion 23 is, for example, 45 mm or more and 70 mm or less, and is 60 mm in the present embodiment.
The width e is appropriately set in accordance with the width D of the rear core portion 23 and the position of the longitudinal groove 27 arranged at the outermost side in the width direction arranged in the rear core portion 23.
The width e of the pair of main body adhesive portions 151 is set so that the pair of main body adhesive portions 151 is opposed to the longitudinal groove portions 27 other than the first longitudinal groove portion 271 in the thickness direction in the rear core portion 23.

The thickness of the bottom portion of the horizontal groove portion 28 and the vertical groove portion 27 in the rear core portion 23 is, for example, 0.5 mm or more and 6 mm or less. The basis weight of the bottom surface of the horizontal groove portion 28 and the vertical groove portion 27 is, for example, 25 g / m ² or more and 300 g / m ² or less.
The thickness of the block portion 29 of the rear core portion 23 is, for example, 2 mm or more and 10 mm or less.

The dimension in the width direction of the block portion 29 of the block portion group in the center 2 rows of the rear core portion 23 is, for example, 8.5 mm or more and 10.5 mm or less, and is 10 mm in the present embodiment.
The dimension in the width direction of each block portion 29 of a pair of block portion groups adjacent to the central two rows of block portion groups of the rear core portion 23 and opposed via the central two rows of block portion groups is, for example, 10 mm or more It is 11.5 mm or less, and was 11 mm in this embodiment.
The dimension in the width direction of each block portion 29 of the pair of block portion groups positioned on the outermost side of the rear core portion 23 is, for example, 10.7 mm or more and 12.3 mm or less, and is 11.5 mm in this embodiment.

  The width D of the rear core portion 23 is preferably 60 mm to 100 mm, more preferably 70 mm to 90 mm, and 80 mm in this embodiment.

Other Embodiments
The form of the grooves arranged on the rear structural surface of the rear core portion is not limited to the first embodiment.
Hereinafter, second to fourth embodiments will be described as examples of other embodiments.

  The absorbent core shown in each of the following embodiments differs from the absorbent core 20 of the first embodiment only in the form of the grooves arranged on the rear structural surface.

As in the case of the absorbent core 20 of the first embodiment, each of the absorbent cores shown in the following embodiments has the first surface and the second surface facing each other along the thickness direction. When the absorbent core is incorporated into a napkin, it has a groove on the first surface on which the top sheet is disposed.
The plan view of the absorbent core used in the description of each embodiment corresponds to the plan view on the first surface side where the grooves are arranged.

  In all of the absorbent cores shown in the following embodiments, a plurality of longitudinal grooves extending in the longitudinal direction are symmetrically arranged in the width direction in the rear core portion, and among the plurality of longitudinal grooves are positioned at the center in the width direction The second longitudinal groove is arranged on both sides of the first longitudinal groove, the pair of main body adhesive portions are provided along the longitudinal direction in the main body, and the pair of main body adhesive portions is the back sheet in the second longitudinal groove In the first embodiment, the first longitudinal groove is not arranged in the area where the pair of main adhesive portions are opposed in the thickness direction across the back sheet of the rear structure surface, the point being oppositely disposed in the thickness direction across the In common with the absorbent core 20 of

Each absorbent core of each embodiment has five flutes 27 arranged at equal intervals similarly to the absorbent core 20 of the first embodiment. The five longitudinal groove portions 27 include one first longitudinal groove portion 271, a pair of second longitudinal groove portions 272, and a pair of third longitudinal groove portions 273.
The first vertical groove portion 271 is located at the center in the width direction among the five vertical groove portions.
The pair of second longitudinal groove portions 272 are arranged one by one on both sides of the first longitudinal groove portion 271.
The pair of third longitudinal groove portions 273 is arranged one by one on both sides of the first longitudinal groove portion 271 and the pair of second longitudinal groove portions 272.

Of the plurality of longitudinal grooves 27 arrayed in the rear core portion 23, the main adhesive portion 151 disposed opposite to the first longitudinal groove 271 disposed at the center in the width direction is disposed across the back sheet 13. not exist. The main adhesive portion 151 is disposed opposite to the second longitudinal groove 272 arranged on both sides of the first longitudinal groove 271 with the back sheet 13 interposed therebetween. Furthermore, the main unit adhesive portion 151 is disposed to face the third longitudinal groove 273 with the back sheet 13 interposed therebetween.
That is, when viewed in a plan view, the second longitudinal groove portion 272 and the third longitudinal groove portion 273 overlap the main body adhesive portion 151, but the first longitudinal groove portion 271 and the main body adhesive portion 151 do not overlap.

  In the napkin in which such an absorbent core is incorporated, as in the first embodiment, at the time of wearing, the first longitudinal groove 271 becomes a deformation starting point, and the bottom of the first longitudinal groove 271 is the other It is a structure which deforms preferentially so as to project to the first surface side, preferentially to the part.

  Therefore, as shown in FIG. 5, the central portion of the rear core portion 23 is deformed so as to project toward the skin with the first longitudinal groove 271 as a deformation starting point, and the napkin is easily deformed so as to enter the crease 61. Become. This makes it possible to reduce the gap between the torn 61 and the napkin and to suppress liquid leakage at the rear of the napkin.

Further, in the napkin provided with the absorbent core of each of the following embodiments, the main adhesive portion 151 is disposed opposite to the second longitudinal groove 272 in the rear region M3, so that the second longitudinal groove 272 is formed by the main adhesive portion 151. The deformation of the bottom of the groove is inhibited, and the ease of deformation is reduced compared to the bottom of the first flute 271.
Therefore, the area in which the second longitudinal grooves 272 of the napkin are arranged and the main adhesive portion 151 is provided follows the area in which the first longitudinal grooves 271 which are preferentially deformed at an acute angle are arranged, It is easy to deform gently along the As a result, the gap between the vicinity of the groin and the napkin is reduced, the fit is improved, and the lateral leakage of the rear portion is suppressed.

Moreover, in the napkin provided with the absorbent core of each of the following embodiments, each block portion 29 disposed on the rear structural surface 53 has a width that is greater than the groove width of the first longitudinal groove 271. That is, each block portion 29 of the block portion group located in the central two rows of the rear core portion 23 has a width dimension wider than the groove width of the first longitudinal groove 271 arranged between the two row block portions. Have.
Thus, as in the first embodiment, the first longitudinal groove 271 easily becomes a deformation starting point, and when the napkin 1 is attached, the napkin 1 is easily deformed into an ideal shape along the groin.

Moreover, in the napkin provided with the absorbent core of each of the following embodiments, all of the longitudinal groove portions 27 other than the first longitudinal groove portions 271 are disposed opposite to the pair of main body adhesive portions 151 in the thickness direction in the rear region M3.
For example, in the case where there is a region in which the main adhesion portion 151 is not arranged and the longitudinal grooves are arrayed on both sides in the width direction of the rear region M3, the rear flap portion F is the first starting from the longitudinal groove at the time of mounting. It may be deformed so as to fold into the surface 20a side.
On the other hand, in the napkin provided with the absorbent core of each embodiment described below, all of the longitudinal groove portions 27 other than the first longitudinal groove portion 271 are disposed to face the pair of main body adhesive portions 151 in the thickness direction. The deformation of the bottom of the longitudinal groove 27 arranged in the portion is inhibited by the main adhesive portion 151, and the deformation of the rear flap F so as to be broken toward the first surface 20a is suppressed.

  Hereinafter, in each embodiment, the configuration different from that of the first embodiment will be mainly described, and the same configuration will be denoted by the same reference numeral, and the description thereof will be omitted.

Second Embodiment
In the absorbent core 20 according to the first embodiment, the longitudinal groove portions 27 having different groove widths are arranged, but in the absorbent core 120 according to the second embodiment, the groove widths of the plurality of longitudinal groove portions 27 are the same. Configured
FIG. 6 is a plan view of the absorbent core 120 and shows the positional relationship between the longitudinal grooves 27 arranged in the rear core portion 23 and the main body adhesive portion 151. As shown in FIG. In FIG. 6, the main unit adhesive portion 151 is indicated by a chain line.

  In the absorbent core 120 of the present embodiment, the widths of the five longitudinal grooves 27 arranged in the rear core portion 23 are all the same, and the longitudinal grooves 27 are arranged at an equal arrangement pitch. The groove width of the five longitudinal grooves 27 is, for example, 1.5 mm, which is the same as the groove width of the third longitudinal groove 273 of the first embodiment. The arrangement pitch is, for example, 13 mm.

  Each block portion 29 disposed on the rear structural surface 53 has the same width dimension (dimension in the Y-axis direction). Each block portion 29 has a width that is greater than the groove width of the first longitudinal groove 271. For example, the width dimension of the block portion 29 is 11.5 mm.

Third Embodiment
In the absorbent core 20 of the first embodiment, the groove widths of the first longitudinal groove 271 and the second longitudinal groove 272 arranged in the central portion in the width direction are wide, and the third longitudinal arranged in both side portions. The groove width of the vertical groove 273 is configured to be narrow. On the other hand, in the absorbent core 220 of the third embodiment, the groove width is wide only in the first vertical groove 271 arranged at the center in the width direction, and the second vertical groove 272 and the third vertical groove The groove width 273 is configured to be narrower than the first longitudinal groove 271.

  FIG. 7 is a plan view of the absorbent core 220 and shows the positional relationship between the longitudinal grooves 27 arranged in the rear core portion 23 and the main body adhesive portion 151. As shown in FIG. In FIG. 7, the main adhesive unit 151 is indicated by a chain line.

In the absorbent core 220 of the present embodiment, the widths of the five vertical groove portions 27 are arranged in the rear core portion 23 at an equal arrangement pitch.
The first vertical groove 271 has a groove width wider than the second vertical groove 272 and the third vertical groove 273, and has, for example, the same 4 mm groove width as the first vertical groove 271 of the first embodiment. Have.
The second longitudinal groove portion 272 and the third longitudinal groove portion 273 both have the same groove width, and for example, have the same groove width of 1.5 mm as the groove width of the second longitudinal groove portion 272 of the first embodiment.
The arrangement pitch is, for example, 13 mm.

The width dimension of each block portion 29 of the two rows of block portion groups located at the center in the width direction of the rear structural surface 53 is shorter than the width dimension of each block portion 29 of the block portions of the other rows.
The width dimension of each block portion 29 of the two rows of block portions located at the center is, for example, 10.25 mm.
The width dimension of each block portion 29 of the four rows of block portions other than the two rows of block portions positioned at the center of the rear structural surface 53 is, for example, 11.5 mm.

Fourth Embodiment
Similar to the absorbent core 120 of the second embodiment, the absorbent core 320 of the fourth embodiment is configured such that the groove widths of the plurality of longitudinal grooves 27 are the same. In the absorbent core 120 of the second embodiment, the longitudinal groove 27 is a fine longitudinal groove, but in the absorbent core 320 of the fourth embodiment, the longitudinal groove 27 is a large longitudinal groove.

  FIG. 8 is a plan view of the absorbent core 320 and shows the positional relationship between the longitudinal grooves 27 arranged in the rear core portion 23 and the main body adhesive portion 151. As shown in FIG. In FIG. 8, the main body adhesive portion 151 is indicated by a dashed line.

  In the absorbent core 320 of the present embodiment, the widths of the five longitudinal grooves 27 arranged in the rear core portion 23 are all the same, and the longitudinal grooves 27 are arranged at an equal arrangement pitch. The groove width of the vertical groove 27 is, for example, 4 mm, which is the same as the groove width of the first vertical groove 271 of the first embodiment. The arrangement pitch is, for example, 13 mm.

  Each block part 29 of the block part group of the center four rows of the rear structural surface 53 has the same width dimension (dimension in the Y-axis direction), for example, 9 mm. Further, the width dimension of each block portion 29 of the two rows of block portion groups located on the outermost side is, for example, 10.25 mm wider than the width dimension of each block portion 29 of the central four rows of block portion groups.

<Liquid flow evaluation>
Similar liquid flow for a total of five types of samples: the napkin 1 of the first embodiment described above, the napkins provided with the absorbent cores 120, 220, and 320 of the second to fourth embodiments, and the comparison napkin. The sex test was done and evaluated.

  FIG. 9 is a plan view of the absorbent core 1020 of the comparative napkin, showing the positional relationship between the main adhesive portion 1151 and the longitudinal groove 27. As shown in FIG. The main adhesive unit 1151 is illustrated by a dotted line. The comparative napkin is a napkin that differs from the napkin 1 of the first embodiment only in the shape of the main-body adhesive portion. The main adhesive portion 1151 of the comparative napkin has a predetermined width in the width direction (Y-axis direction) so as to be oppositely disposed in the thickness direction across the back sheet 13 with respect to all the longitudinal grooves 27 arranged in the rear core portion 23 And extends along the longitudinal direction (X-axis direction).

In each sample, an air through nonwoven fabric with a basis weight of 30 g / m ² was used as the top sheet 12.
Mixed core of mixed fibers of pulp fiber ("NB 416" (trade name), manufactured by Wafer Weather) and absorbent polymer ("CAW 151" (trade name), manufactured by Nippon Shokubai Co., Ltd.) in the absorbent core 20 A fiber was used. In the block portion 29 of the rear core portion 23, the basis weight of the pulp fiber is 240 g / m ^2, and the basis weight of the absorbent polymer is 16 g / m ² .
For the core wrap sheet 30, absorbent paper (manufactured by Ino Paper Co., Ltd.) having a basis weight of 16 g / m ² was used.
For the back sheet 13, a 25 μm thick polyethylene film was used.

The flowability test was conducted as follows.
A sample of the above-mentioned sanitary napkin is made of a transparent model made of acrylic resin that reproduces the lumbar region of a woman wearing, a sample of the above-mentioned sanitary napkin, a sanitary shorts (Kao Co., product name Laurier Active Guard (firm mode), L size) It mounted falsely using). A transparent model equipped with this napkin was placed in a posture of lying on the evaluation table.

As described above, 6 g of horse-defibrillated blood is injected at a rate of 2 g / 15 seconds at a position on the rear side of about 30 to 50 mm from the crotch of the model placed on the evaluation table, and then the napkin rear side from the injected position. The liquid flow distance to was measured. Three measurements were carried out for each sample, and the average value of the liquid flow distance obtained by these three measurements was evaluated. The evaluation results are described in Table 1.
The evaluation criteria for the liquid flow properties were: ○ less than 50 mm, Δ greater than or equal to 50 mm and less than 80 mm, and x greater than or equal to 80 mm.

As shown in Table 1, also in any of the napkins of the first to fourth embodiments, the liquid flow distance was short and the liquid flowability was good as compared with the comparative example.
In the napkins according to the first to fourth embodiments, compared to the napkin of the comparative example, the first longitudinal groove 271 is arranged at the center in the width direction of the rear region of the napkin, and the back sheet of the first longitudinal groove 271 The main body adhesive portion 151 does not exist in the area facing through 13. Therefore, the deformation of the bottom of the first vertical groove 271 is not inhibited by the main adhesive portion 151.
As a result, in the napkins according to the first to fourth embodiments, the first longitudinal groove 271 arranged at the center in the width direction in the rear area M3 serves as a deformation starting point toward the torso when the napkin is worn. It is a structure which is easy to deform | transform so that the back area | region M3 may protrude.

  On the other hand, in the napkin of the comparative example, since the main adhesive portion 1151 is provided on almost the entire surface of the rear region M3, the main adhesive portion 1151 acts so as to inhibit the deformation of the bottom of the first longitudinal groove 271. . Therefore, in the region corresponding to the first longitudinal groove 271, the napkin of the comparative example has high rigidity and is less likely to be deformed as compared with the napkins of the first to fourth embodiments. For this reason, in the napkin of the comparative example, the gap between the tear and the napkin is likely to be large.

  Therefore, in the napkins of the first to fourth embodiments, compared with the napkin of the comparative example, the gap between the torn and the napkin can be made smaller, and the result that the liquid flowability becomes good was obtained.

  As described above, in the napkin provided with the absorbent core provided with the longitudinal groove, the block portion is not provided in the region facing the first longitudinal groove located at the center in the width direction of the napkin. The bottom of the first longitudinal groove, which is thinner than the first longitudinal groove, becomes a deformation starting point, and the napkin is easily deformed along the groin, and liquid leakage can be suppressed.

Further, as shown in Table 1, the first embodiment was particularly good in liquid flowability as compared with the other second to fourth embodiments.
In the napkin 1 of the first embodiment, in the region where the pair of main body adhesive portions 151 of the rear structural surface 53 is disposed opposite to each other, the wide longitudinal groove (second The longitudinal groove portion 272) and the thin longitudinal groove portion (third longitudinal groove portion 273) are arranged. The region in which the thick vertical groove portions are arranged is lower in rigidity than the region in which the thin vertical groove portions are arranged, and it becomes easy to deform. Thereby, in the area | region where a pair of main body adhesion part 151 of the napkin 1 is arrange | positioned, the deformation | transformation ease is changing to the width direction.

  On the other hand, in the napkins of the second to fourth embodiments, the plurality of longitudinal groove portions 27 arranged in the area where the pair of main body adhesive portions 151 of the rear structural surface 53 are arranged to face each other have the same groove width There is. Thereby, in the area | region where a pair of main body adhesion part 151 of the napkin 1 is arrange | positioned, the deformation | transformation easiness by presence of a vertical groove does not change in the width direction.

Thus, in the napkin 1 of the first embodiment, in the rear region M3 of the main body M, the central portion in the width direction is most likely to be deformed, and the region where the main adhesive portion 151 is provided from the central portion toward the side portion It is difficult to deform in stages.
As a result, the deformation of the main body M corresponding to the area from the groin to the swelling of the buttocks becomes gentle, and the fit property is improved.
For this reason, in the napkin of the first embodiment, the gap between the buttocks and the napkin tends to be small, and the fit is further improved as compared with the napkins of the second to fourth embodiments, and the liquid flow is improved. Particularly good results were obtained.

Further, as shown in Table 1, in the first, third, and fourth embodiments in which the thick longitudinal groove portions are arranged as the first longitudinal groove portions 271 in which the main body adhesive portion 151 is not disposed opposite to each other, the first longitudinal groove portions 271 are used. As compared with the second embodiment in which the fine longitudinal grooves are arranged, the liquid flowability is good.
This is because, by making the groove width of the first longitudinal groove 271 wider, the deformation area in the first longitudinal groove 271 becomes wider in the width direction, and the degree of deformation of the central portion in the width direction behind the napkin increases. This is because the napkin was deformed so that the protruding part of the napkin due to the deformation became more acute and entered into the tear, and the result that the liquid flowability became better was obtained.

  As mentioned above, although each embodiment of the present invention was described, the present invention is not limited only to the above-mentioned embodiment, and it is needless to say that various change can be added in the range which does not deviate from the gist of the present invention.

  For example, although the external shape of the whole of the pair of main body adhesive parts 151 is rectangular, the shape of the pair of main body adhesive parts 151 is not limited to this.

In the embodiment described above, the pair of main body adhesive portions 151 has a shape in which the width e is constant over substantially the entire length of the absorbent core 20 from the front area M1 through the middle area M2 to the rear area M3.
On the other hand, for example, similar to the flat outer shape of the narrowing shape of the absorbent core 20, the outer shape of the entire pair of main body adhesive portions is narrow in the region corresponding to the intermediate core portion 22, The width may be changed over the entire length in the longitudinal direction so that the width becomes wider in the region corresponding to 23.

  At least the pair of main body adhesive portions 151 has a shape extending in the longitudinal direction, and the first longitudinal groove 271 and the main body adhesive portions 151 do not overlap in the rear region M3 when the napkin 1 is viewed in plan. The second longitudinal groove portion 272 and the main body adhesive portion 151 arranged on both sides of the longitudinal groove portion 271 may be overlapped with each other.

Also, for example, in the absorbent core of each of the embodiments described above, the absorbent core may have only the longitudinal groove without providing the lateral groove.
Moreover, the absorbent core of each of the above-mentioned embodiments had a flat planar shape in which the intermediate core portion 22 is narrower than the front core portion 21 and the rear core portion 23. On the other hand, it may be a flat, non-bindered absorbent core in which the width dimension does not change in the longitudinal direction of the absorbent core.

Further, in the first embodiment, the widths of the longitudinal groove portions 27 positioned on the same straight line along the longitudinal direction are the same in the front core portion 21 and the rear core portion 23, but the second to the third In each embodiment of No. 4, the widths of the longitudinal groove portions 27 located on the same straight line are different between the front core portion 21 and the rear core portion 23.
In the second to fourth embodiments, the groove width of the longitudinal groove 27 arranged in the front core portion 21 is the same as the groove width of the longitudinal groove 27 positioned on the same straight line arranged in the rear core portion 23 It may be

  In the above embodiment, the rear structural surface 53 of the absorbent core is provided on the top sheet 12 side, but instead, the rear structural surface 53 of the absorbent core is provided on the back sheet 13 side, A flat surface may be directed to the top sheet 12 side. In this case, the main body adhesive portion 151 overlaps the opening of the second longitudinal groove 272, preferably over the entire width of the opening of the second longitudinal groove 272 when viewed in plan. As a result, the opening of the longitudinal groove 272 is less likely to move, and the same effect as that of the above-described embodiment can be obtained.

Moreover, in the above-mentioned embodiment, although the vertical groove part of two types of groove widths was arranged, it is not limited to this, the vertical groove part of three types of groove widths may be arranged.
In the case where vertical grooves having three groove widths are arranged in the order of wide width: thick vertical grooves, medium thick vertical grooves, and narrow vertical grooves, for example, the first vertical groove located at the center in the width direction is thick vertical groove The second longitudinal grooves located on both sides of the first longitudinal groove may be arranged as a thick longitudinal groove, and the third longitudinal groove located on the outermost side may be arranged as a fine longitudinal groove.
Alternatively, the first longitudinal groove located at the center in the width direction is a thick longitudinal groove, the second longitudinal groove located on both sides of the first longitudinal groove is a narrow longitudinal groove, and the third longitudinal groove located at the outermost Can be arranged as medium thick vertical grooves.
When longitudinal grooves having three or more groove widths are arranged, it is desirable that the widest longitudinal groove having the widest width be arranged at the center in the width direction of the rear core portion, which tends to be a deformation starting point.

  Moreover, although the number of the vertical groove parts 27 in the back core part 23 was all five in the above-mentioned embodiment, it is not limited to this, Three, seven odd numbers etc. may be sufficient.

  Moreover, in the back core part of the absorptive core of each above-mentioned embodiment, although the case where the basis weight of a block part and the bottom part of a groove part differs was mentioned as an example and demonstrated, it is not limited to this, for example The basis weight of the bottom of the groove may be equal. The thickness of at least the bottom of the groove may be thinner than the thickness of the block, whereby the region in which the grooves are arranged is more likely to be deformed than the region in which the block is located.

  Moreover, in the above-mentioned embodiment, although the example which manufactures the absorptive core which has an uneven structure in a back structure surface was raised using the fiber laying apparatus, it is not limited to this. For example, a groove may be formed by partially pressing on one side of an absorbent core having a substantially flat surface having a substantially uniform thickness in the plane, and an absorbent core having a concavo-convex structure may be manufactured.

  Moreover, in the above each embodiment, although the example of the sanitary napkin was shown as an absorbent article, it is not limited to this. The absorbent article of the present invention may be, for example, an incontinence pad, a cage sheet, a disposable diaper or the like.

1 ... Napkins (napkins, absorbent articles)
12: Top sheet 13: Back sheet 20, 120, 220, 320: Absorbent core 20a: First surface (one main surface)
20b second surface (other main surface)
27: longitudinal groove portion 28: lateral groove portion 29: block portion 53: rear structural surface (structural surface)
151 ··· Body adhesive part (adhesive part)
271 ... 1st vertical groove part 272 ... 2nd vertical groove part 273 ... 3rd vertical groove part M ... main part

Claims (5)

A plurality of longitudinal grooves extending in the longitudinal direction with respect to a width direction central portion orthogonal to the longitudinal direction include the front core portion and the rear core portion positioned on both end sides in the longitudinal direction, and the rear core portion has the width An absorbent core having a structural surface arranged symmetrically in a direction, a surface sheet covering one main surface of the absorbent core, and the other main surface opposite to the one main surface of the absorbent core A body having a back sheet covering the
The back sheet is provided on a pair of second longitudinal groove portions provided on the main body along the longitudinal direction and arranged on both sides of a first longitudinal groove portion positioned at the center side in the width direction among the plurality of longitudinal groove portions. An absorbent article comprising: a pair of adhesive parts opposed to each other across. An absorbent article according to claim 1, wherein
An absorbent article, wherein the first longitudinal groove has the same groove width as the pair of second longitudinal grooves or a groove width wider than the pair of second longitudinal grooves. The absorbent article according to claim 1 or 2, wherein
The plurality of longitudinal groove portions further have a plurality of third longitudinal groove portions having a groove width narrower than the first longitudinal groove portion. Absorbent article. The absorbent article according to claim 3, wherein
An absorbent article, wherein the pair of second longitudinal groove portions has a groove width wider than the plurality of third longitudinal groove portions. The absorbent article according to any one of claims 1 to 4, wherein
The structural surface further includes a plurality of lateral grooves arranged in the longitudinal direction and orthogonal to the plurality of longitudinal grooves.
An absorbent article, wherein each block section partitioned by the plurality of longitudinal grooves and the plurality of lateral grooves has a width that is greater than the groove width of the first longitudinal groove.

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