JP2019209120A - Absorbent article - Google Patents

Abstract

To provide an absorbent article of high fitness.SOLUTION: An absorbent article includes: a liquid-permeable surface sheet; a rear surface sheet; and an absorber which has an absorbent core and is arranged between the surface sheet and the rear surface sheet. It has a vertical direction corresponding to the back and forth direction of a wearer and a horizontal direction orthogonal to the vertical direction. The absorbent core has a front core part and a rear core part positioned on both end parts side in the vertical direction and an intermediate core part positioned between the front core part and the rear core part and narrower than the front core part and the rear core part. The intermediate core part includes: a high basis weight part positioned in the center in the horizontal direction and protruding to the rear sheet side; and a low basis weight part which has lower basis weight than the high basis weight part and is formed on the horizontal direction side part of the high basis weight part.SELECTED DRAWING: Figure 5

Description

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

  An absorbent article of a type that is used inside an undergarment, such as a sanitary napkin, is provided with an absorber for absorbing a liquid material such as menstrual blood. An absorber has a core wrap sheet etc. which coat | cover the said absorptive core other than the absorptive core which absorbs and diffuses the said liquid substance. For example, Patent Literature 1 discloses an absorbent article in which a protruding portion for improving fit to the excretion region is provided in the central region of the absorbent core facing the excretion region of the wearer.

JP 2014-104093 A

  When the absorbent article is worn, various external forces are applied from the wearer to the absorbent article. For example, a lateral external force is applied to the middle part of the absorbent article from the left and right legs of the wearer. Moreover, the pressure of the thickness direction from a wearer is added to the surface sheet side of an absorbent article. Therefore, there is a need for an absorbent article that can maintain high fit even when subjected to these external forces.

  The subject of this invention is related with an absorbent article with high fitting property.

An absorbent article according to one aspect of the present invention is
A liquid permeable top sheet, a back sheet, and an absorbent body having an absorbent core and disposed between the top sheet and the back sheet, the longitudinal direction corresponding to the front-rear direction of the wearer and the above It has a horizontal direction orthogonal to the vertical direction.
The absorptive core is located between the front core portion and the rear core portion, which are located on both ends in the vertical direction, and the front core portion and the rear core portion. And an intermediate core portion having a narrow width.
The intermediate core portion is located in the center in the lateral direction, has a high basis weight portion protruding toward the back sheet side, and has a basis weight lower than the high basis weight portion, and the lateral side portion of the high basis weight portion. And a low basis weight part formed.

  According to the absorbent article of the present invention, it is possible to improve fit.

It is a perspective view showing an absorptive article of one embodiment of the present invention. It is a top view which shows the said absorbent article. It is sectional drawing cut | disconnected by the III-III line of FIG. It is a figure which shows the absorptive core of the said absorbent article, and is the back view seen from the lower surface side. It is sectional drawing which shows the structure of the intermediate | middle core part of the said absorptive core typically, FIG. 5A shows at the time of non-wearing, and FIG. 5B shows at the time of wearing. It is a reverse view of the absorber of the said absorbent article. It is a schematic diagram explaining the relationship between the crack of a wearer's buttocks at the time of wearing the said absorbent article, and the deformation | transformation state in the back core part of the said absorbent core. It is a top view of the said absorptive article which shows the positional relationship of the transverse groove part and solid guard in the above-mentioned back core part.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[Overall structure of napkin]
The absorbent article 1 shown in FIG.1 and FIG.2 is equipped with the main body M, a pair of wing part W, a pair of solid guard G, a pair of back flap part F, and the pressing groove part E. FIG. The absorbent article 1 is configured as a sanitary napkin and is hereinafter referred to as a napkin 1.
The napkin 1 has a vertical direction X corresponding to the wearer's front-rear direction and a horizontal direction Y corresponding to the wearer's left-right direction and orthogonal to the vertical direction X. Further, the napkin 1 has a thickness direction Z orthogonal to both the vertical direction X and the horizontal direction Y. In addition, in this specification, regarding the thickness direction Z, the side close to the wearer's skin may be referred to as “up” and the side close to the clothing may be referred to as “down”.
The napkin 1 may be used at bedtime, and may have a length of 30 cm or more along the longitudinal direction X, for example.

  The main body M extends along the vertical direction X, and is fixed to the inner surface of the wearer's underwear when worn. The main body M has an absorber 11 to be described later and has a function of absorbing a liquid material (hereinafter also referred to as “liquid”) such as menstrual blood of the wearer.

  The three-dimensional guard G is provided on the peripheral edge of the main body M in the horizontal direction Y and is disposed so as to extend in the vertical direction X. The three-dimensional guard G stands up in the thickness direction Z when worn, and can prevent leakage of liquid in the lateral direction Y. “Standing up in the thickness direction” means standing up toward the wearer.

The compressed groove portion E is formed by being compressed from the surface sheet 12 to be described later downward in the thickness direction Z, and is configured to surround the peripheral edge of the main body M, for example.
The wing portion W is configured to protrude greatly from the main body M outward in the lateral direction Y.
The rear flap portion F is configured to bulge outward in the lateral direction Y at the rear portion of the main body M.
In addition, the napkin 1 does not need to have at least one of the wing part W, the solid guard G, the pressing groove part E, and the back flap part F.

  As shown in FIG. 3, the napkin 1 includes an absorber 11, a top sheet 12, a back sheet 13, and a pair of side sheets 14. In the main body M, the napkin 1 has a configuration in which the back sheet 13, the absorber 11, and the top sheet 12 are laminated in the thickness direction Z. These structures are appropriately joined and integrated by, for example, joining by an adhesive, heat sealing, or the like, and embossing by the compressed groove E.

The absorber 11 extends along the vertical direction X and is disposed between the top sheet 12 and the back sheet 13. The absorber 11 absorbs the liquid from the top sheet 12 and diffuses it inside to hold the liquid.
The absorbent body 11 has an absorbent core 16 and a core wrap sheet 17.
The absorbent core 16 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 in the fiber assembly. .
The core wrap sheet 17 covers the absorbent core 16 and has, for example, a function of maintaining the shape of the absorbent core 16. The core wrap sheet 17 is formed of, for example, tissue paper-like thin and soft paper, liquid-permeable nonwoven fabric, or the like.
Details of the absorber 11 will be described later.

  The top sheet 12 is configured as a liquid-permeable sheet material, and is disposed above the thickness direction Z of the absorber 11. Let the outer surface (upper surface) of the surface sheet 12 be the liquid receiving surface 12a. In addition, between the surface sheet 12 and the absorber 11, the improvement of the permeability | transmittance of the liquid from the surface sheet 12 to the absorber 11, prevention of the liquid return to the surface sheet 12 of the liquid absorbed by the absorber 11, etc. From this point of view, a second sheet (sublayer sheet) may be disposed.

  The back sheet 13 is disposed below the thickness direction Z of the absorber 11. The back sheet 13 is joined to the top sheet 12 and the side sheet 14 by an adhesive, a heat seal, etc., for example in a peripheral part. The back sheet 13 may be joined to the absorber 11 by an adhesive or the like.

  In the back sheet 13, a main body adhesive portion 18 is provided on the outer surface of the main body M, and a wing adhesive portion 19 is provided on the outer surface of the wing portion W. The main body adhesive portion 18 and the wing adhesive portion 19 have a function as a displacement preventing material that fixes the napkin 1 to the clothes. These pressure-sensitive adhesive portions 18 and 19 are formed, for example, by applying a pressure-sensitive adhesive such as a hot-melt pressure-sensitive adhesive to the back sheet 13. Although not shown, the napkin 1 may further include a rear flap adhesive portion provided on the rear flap portion F.

The pair of side sheets 14 oppose each other in the lateral direction Y with the top sheet 12 interposed therebetween, and are disposed on the circumferential edge of the napkin 1 in the lateral direction Y. The side sheet 14 can be formed of a non-woven fabric or a resin film. The side sheet 14 preferably has functions such as liquid impermeability, water repellency, and moisture permeability, and may have a laminated structure or a single layer structure.
In the present embodiment, the side seat 14 is configured such that the lateral Y peripheral edge portion is folded outward to form the three-dimensional guard G. The side sheet 14 is joined to the top sheet 12 by the adhesive 15 at the base of the three-dimensional guard G. The detailed configuration of the three-dimensional guard G will be described later.

[Configuration of absorbent core]
As shown in FIG. 3, the absorbent core 16 has an upper surface 16a located above the thickness direction Z (on the top sheet 12 side) and a bottom surface 16b located below the thickness direction Z (on the back sheet 13 side). As for the absorptive core 16, an uneven structure is formed in the lower surface 16b, and the basic weight of each part mentioned later is adjusted. Moreover, although the upper surface 16a is comprised flat, for example, at the time of wear, it can deform | transform by applying the pressure of the thickness direction Z from a wearer. Details of the deformation will be described later.

  As shown in FIG. 4, the absorbent core 16 has a front core part 20, an intermediate core part 21, and a rear core part 22. The front core part 20, the intermediate core part 21, and the rear core part 22 are arranged along the vertical direction X. That is, the front core part 20 and the rear core part 22 are located on both ends in the longitudinal direction X, and the intermediate core part 21 is located between the front core part 20 and the rear core part 22. The intermediate core part 21 is an area | region which opposes a wearer's excretion area | region, and the front core part 20 and the back core part 22 are parts which oppose the front and back of a wearer's excretion area | region, respectively. The absorbent core 16 has a planar shape that is symmetrical in the lateral direction Y.

As shown in FIG. 4, the intermediate core part 21 has a width dimension D <b> 2 that is narrower than the width dimension D <b> 1 of the front core part 20 and the width dimension D <b> 3 of the rear core part 22. That is, the absorbent core 16 has a planar shape confined in the lateral direction Y in the intermediate core portion 21.
The width dimension D2 of the intermediate core portion 21 is the minimum width dimension in the lateral direction Y. The width dimension D1 of the front core part 20 and the width dimension D3 of the rear core part 22 shall mean the maximum width dimension in the horizontal direction Y.
Reducing the external force from the lateral direction Y applied to the intermediate core portion 21 when the wearer's legs are closed and the crotch width is reduced by the absorbent core 16 having the narrow intermediate core portion 21. Can do.

The width dimension D1 of the front core part 20 and the width dimension D3 of the rear core part 22 may be the same or different, and in the example shown in FIG.
In the example shown in FIG. 4, the width dimension D <b> 2 of the intermediate core portion 21 is formed constant along the vertical direction X. Further, the width dimension D1 of the front core portion 20 and the width dimension D3 of the rear core portion 22 are constant along the vertical direction X in regions other than the front taper region 20t and the rear taper region 22t described later, but are not limited thereto. Not.
Note that “the width dimension is constant” in a certain area means that the difference in the width dimension in the area is within 20% when the minimum width in the horizontal direction Y of the area is 100%. . In addition, in the front core part 20 and the back core part 22, it is preferable that the difference of the width dimension in each area | region is 10% or less when the minimum width in the horizontal direction Y is 100%.
The length dimension in the longitudinal direction X of the front core part 20 and the rear core part 22 may be the same or different. For example, the rear core part 22 is configured to be longer.

[Configuration of intermediate core]
The intermediate core portion 21 includes a high basis weight portion 23 and a low basis weight portion 24 having a lower basis weight than the high basis weight portion 23. In FIG. 4, the high basis weight portion 23 is indicated by a high-density dot pattern, and the low basis weight portion 24 is indicated by a low-density dot pattern.
The high basis weight part 23 is located at the center in the lateral direction Y and protrudes toward the back sheet 13.
The low basis weight portion 24 is formed on the lateral side portion of the high basis weight portion 23. In the example shown in FIG. 4, the low basis weight portion 24 is divided into left and right sides with the high basis weight portion 23 interposed therebetween.
The basis weight of the absorbent core 16 has a positive correlation with the thickness in a region other than the high-density compressed groove portion. For this reason, the high basis weight portion 23 protrudes downward in the thickness direction Z from the low basis weight portion 24 and is configured to be thicker than the low basis weight portion 24.
Further, the basis weight of the absorbent core 16 has a positive correlation with the rigidity. That is, the high basis weight part 23 has higher rigidity than the low basis weight part 24 and is not easily deformed by an external force. On the other hand, since the basic weight is relatively low, the low basic weight portion 24 has a configuration that is easily deformed with respect to an external force.

The shape at the time of non-wearing (FIG. 5A) and the time of wearing (FIG. 5B) in the intermediate core part 21 is demonstrated using typical sectional drawing of FIG.
As shown in FIG. 5A, the intermediate core portion 21 has a step formed between the high basis weight portion 23 and the low basis weight portion 24 on the lower surface 16b.
That is, the high basis weight part 23 includes a top surface region 23b and a side surface region 23e formed continuously from the top surface region 23b on the lower surface 16b.
The top surface region 23b is a surface facing downward in the thickness direction Z, and is configured to be flat as a whole.
The side surface region 23e constitutes a side surface of the high basis weight portion 23 protruding downward in the thickness direction Z, and is a surface facing the lateral direction Y, for example.
In the example shown in FIG. 5A, the side surface region 23e is configured to be perpendicular to the XY plane, and the area of the high basis weight portion 23 in plan view is configured to be the same as the area of the top surface region 23b. However, the present invention is not limited to this. For example, the side surface region 23e may be inclined with respect to the XY plane.
On the other hand, the upper surface 16a includes a flat central region 23a as compared with the lower surface 16b.
In addition, "the upper surface 16a or the lower surface 16b is flat" means that a region excluding the low basis weight groove portion and the compressed groove portion E, which will be described later, is substantially flat. Do not consider. Moreover, in FIG. 5, illustration of the said groove part and the pressing groove part E is abbreviate | omitted.

The low basis weight portion 24 includes a first peripheral region 24a on the upper surface 16a, and includes a second peripheral region 24b on the lower surface 16b.
The first peripheral region 24a is formed continuously and flat from the central region 23a, and is located on the same plane as the central region 23a when not worn as shown in FIG. 5A.
The second peripheral region 24b is a region that protrudes outward in the lateral direction Y from the end of the side surface region 23e.

  At the time of wearing shown in FIG. 5B, the intermediate core portion 21 is in a state where pressure is applied from the wearer downward in the thickness direction Z, that is, toward the clothing side. Since a step is formed on the lower surface 16b between the top surface region 23b that is the high basis weight portion 23 and the second peripheral region 24b that is the low basis weight portion 24, the second peripheral region 24b is a side region. 23e is pressed. Thereby, the upper surface 16a is bent between the central region 23a and the first peripheral region 24a, and the first peripheral region 24a is pushed down from the base connected to the central region 23a toward the end side. Therefore, the first peripheral region 24a is deformed into a slope shape.

That is, at the time of wearing, the low basic weight part 24 formed in the lateral direction Y side part of the high basic weight part 23 is pressed against the clothing side by the pressure applied from the wearer. Thereby, the high basic weight part 23 which protrudes in the back surface sheet 13 side is pushed up relatively toward the skin side, and it deform | transforms so that the intermediate | middle core part 21 may rise to a wearer side in the horizontal direction Y center part. Thereby, the high basic weight part 23 closely_contact | adheres to a wearer's excretion area | region.
Moreover, the absorptive core 16 does not have a level | step difference in the upper surface 16a side, but deform | transforms into the inclined surface form which the 1st peripheral area | region 24a continues from the center area | region 23a. Thereby, it becomes a structure with which it is hard to make a clearance gap between the upper surface 16a and an excretion area | region, and it becomes the napkin 1 with high fitting property to an excretion area | region and a feeling of mounting | wearing.

Furthermore, in the said structure, the intermediate core part 21 is comprised narrowly. Thereby, in the napkin 1, the external force from the horizontal direction Y added by a wearer's both legs is relieve | moderated.
Further, the low basis weight portion 24 functions as an easily deformable region in the intermediate core portion 21. That is, when a large external force is applied from the lateral direction Y, the low-rigidity low basis weight portion 24 is compressed and deformed, and energy of the external force is consumed. Thereby, a deformation | transformation of the high basic weight part 23 is suppressed and adhesiveness with an excretion area | region is maintained.
Furthermore, since the intermediate core portion 21 is configured to be narrow, the compression deformation of the low basis weight portion 24 is difficult to propagate to the rear core portion 22 and the front core portion 20. Therefore, generation | occurrence | production of the clearance gap between the napkin 1 and a wearer is suppressed not only in a wearer's excretion area | region but the back and front, and fitting property is improved.

[Planar shape of high basis weight section]
As shown in FIG. 4, the high basis weight portion 23 extends along the longitudinal direction X, but the shape of the front and rear ends thereof can alleviate the propagation of compression deformation of the low basis weight portion 24 in the longitudinal direction X. . In addition, the planar shape of the high basic weight part 23 means the shape in XY plane, and shall use synonymous with the planar shape of the top surface area | region 23b here.

  The high basis weight portion 23 includes a rear end portion 23d whose width dimension gradually decreases toward the front end in the vertical direction X. That is, in the rear portion of the intermediate core portion 21, the width of the high basis weight portion 23 gradually decreases toward the rear core portion 22, and the width of the low basis weight portion 24 gradually increases.

  In the absorbent core 16 having the above-described configuration, the easily deformable region gradually widens from the intermediate core portion 21 toward the rear core portion 22. Thereby, when the low basic weight part 24 is compressed and deformed by an external force from the lateral direction Y, the degree of compression is gradually relaxed toward the rear core part 22, and propagation of the influence of the deformation to the rear core part 22 is effective. Is suppressed. Therefore, the fit property behind the excretion region is further improved.

Moreover, in the high basic weight part 23, the front end part 23c located ahead in the vertical direction X may also have a configuration in which the width gradually decreases toward the front end in the vertical direction X.
Thereby, as above-mentioned, an easily deformable area | region gradually spreads toward the front core part 20 from the intermediate | middle core part 21, and the influence of the compressive deformation of the low basic weight part 24 becomes difficult to be propagated to the front core part 20. Therefore, the fit is further enhanced in front of the excretion region.

  In FIG. 4, the front end portion 23c and the rear end portion 23d have an arc shape or an elliptic arc shape. Thereby, since the width | variety in the front-end | tip part 23c and the front-end | tip of the back end part 23d becomes 0, the low basic weight part 24 in the area | region adjacent to the back core part 22 can be comprised more widely. Therefore, the compression deformation in the low basis weight portion 24 is sufficiently relaxed, and the compression deformation can be effectively suppressed from propagating to the rear core portion 22.

The shapes of the front end portion 23c and the rear end portion 23d of the high basis weight portion 23 are not limited to the above shapes.
For example, the front end portion 23c and the rear end portion 23d may have a triangular shape with a sharp tip. Also by this, the front end portion 23c and the rear end portion 23d have a shape in which the width gradually decreases toward the tip, and the width at the front end of the front end portion 23c and the rear end portion 23d becomes zero. Therefore, the same effect as the front end part 23c and the rear end part 23d of FIG. 4 can be obtained.
Alternatively, the front end portion 23c and the rear end portion 23d may have a trapezoidal shape including a side along the horizontal direction Y at the tip, or may have a rectangular shape with rounded corners. Also by these, the front end portion 23c and the rear end portion 23d have a shape in which the width gradually decreases toward the tip, and the external force buffering action by the low basis weight portion 24 can be enhanced.
Note that the front end portion 23c and the rear end portion 23d do not have a shape in which the width gradually decreases toward the tip, and may be configured in a rectangular shape having substantially the same width as a whole.

The length dimension in the vertical direction X of the high basis weight portion 23 is not particularly limited, and may be formed over the entire length of the intermediate core portion 21 or may be formed in a part of the intermediate core portion 21.
In particular, the high basis weight portion 23 is formed over the entire length of the intermediate core portion 21, so that the fit to the wearer and the liquid absorbability are enhanced over the entire excretion region.
When the rear end portion 23d of the high basis weight portion 23 is adjacent to the rear core portion 22 as described above, the following taper region (rear taper region 22t) is provided in the rear core portion 22. Thus, the propagation of compression deformation to the rear core portion 22 is further suppressed.

[Configuration of taper area]
As shown in FIG. 4, the rear core portion 22 includes a rear taper region 22 t that is formed adjacent to the intermediate core portion 21 and gradually increases in width dimension toward the rear in the vertical direction X.

Since the rear core portion 22 has a smaller basis weight than the high basis weight portion 23, it is relatively easily deformed as compared with the high basis weight portion 23.
That is, in the absorbent core 16 having the above-described configuration, the easily deformable region gradually expands further in the longitudinal direction X from the boundary portion P2 where the rear end portion 23d of the high basis weight portion 23 contacts. Thereby, when the low basis weight part 24 is compressively deformed by an external force from the lateral direction Y, the compressive deformation is gradually relieved also in the rear core part 22. Therefore, propagation of the compression deformation to the rear core portion 22 is further suppressed, and the fit property behind the excretion region is further enhanced.

  Moreover, the front core part 20 may also have the same taper area | region. That is, the front core portion 20 may be formed adjacent to the intermediate core portion 21 and include a front tapered region 20t whose width dimension gradually increases toward the front in the longitudinal direction X. This also suppresses the propagation of the compressive deformation from the lateral direction Y to the front core portion 20 and improves the fit in the front of the excretion region.

  The outer edges of the rear taper region 22t and the front taper region 20t are not limited to a linear shape, and may be a curved shape. The shapes of the rear taper region 22t and the front taper region 20t may be symmetric in the front-rear direction or asymmetric in the front-rear direction.

[Configuration of core wrap sheet]
As shown in FIG. 3, the absorbent body 11 has a core wrap sheet 17 in addition to the absorbent core 16. The core wrap sheet 17 is wound in the lateral direction Y of the absorbent core 16 so as to cover the front and back of the absorbent core 16. By providing the core wrap sheet 17, it is possible to protect the structure of the absorbent core 16 at the time of distribution and wearing, and also has an effect of enhancing the buffering action against the above-described external force. Details will be described below.

  The core wrap sheet 17 is formed of paper, nonwoven fabric, or the like as described above. That is, the core wrap sheet 17 is made of a sheet material having sufficiently lower rigidity than the absorbent core 16. The core wrap sheet 17 may be composed of one sheet material or a plurality of sheet materials. The core wrap sheet 17 may be bonded to the top sheet 12 and the back sheet 13 by, for example, an adhesive applied in a predetermined pattern.

The width dimension along the horizontal direction Y of the core wrap sheet 17 is configured to be constant along the vertical direction X, for example, but is not limited thereto, and has a small or large width dimension at the middle portion in the vertical direction X. It may be configured.
The length dimension along the longitudinal direction X of the core wrap sheet 17 is formed to be equal to the length dimension (full length) of the absorbent core 16 in the longitudinal direction X, but is not limited thereto, and the full length of the absorbent core 16 is not limited thereto. It may be longer or shorter.

As shown in FIG. 6, the core wrap sheet 17 includes a core covering portion 17 c that covers each portion of the absorbent core 16, and an extending portion 17 s that extends outward in the lateral direction Y of the low basis weight portion 24. Have. In FIG. 6, the outline of the absorbent core 16, the high basis weight portion 23, and the low basis weight portion 24 is indicated by broken lines.
Since the core wrap sheet 17 is made of a sheet material having sufficiently lower rigidity than the absorbent core 16, the core wrap sheet 17 covers the absorbent core 16 with a shape corresponding to the shape of the absorbent core 16.

As shown in FIG. 5, the extending portion 17 s is configured to partition the space region S that forms the constricted shape of the intermediate core portion 21. That is, the core material which comprises the absorptive core 16 does not exist in the extension part 17s. However, in the space region S, the main body of the core material does not exist, but there are some fibers protruding outward from the periphery of the absorbent core 16 and a part of the core material separated from the absorbent core 16. May be.
In the absorbent body 11, the extending portion 17 s is configured with a basis weight lower than that of the low basis weight portion 24 and is configured to be more easily deformed.

  As shown in FIG. 5, at the time of wearing, the extending part 17s of the core wrap sheet 17 receives pressure from the wearer in the thickness direction Z downward (clothing side). Since the core wrap sheet 17 has sufficiently lower rigidity than the absorbent core 16, the extended portion 17s is maintained in a state of being pressed along the clothes by the pressure. That is, the extension portion 17s of the core wrap sheet 17 is pressed downward in the thickness direction Z, so that the low basis weight portion 24 located inside the core wrap sheet 17 is also pressed downward in the thickness direction Z. Maintained.

  Thus, the low basis weight part 24 returns to the shape before wearing by own elastic force because the extension part 17s of the core wrap sheet 17 exists further in the lateral direction Y outward of the low basis weight part 24. Can be prevented. Thereby, the high basic weight part 23 is maintained in the state where the thickness direction Z was raised relatively. Therefore, even during the wearer's movement, the adhesion between the high basis weight portion 23 and the excretion region is maintained, and the napkin 1 maintains a high fit.

[Configuration of groove]
As shown in FIG. 4, the absorbent core 16 is divided into blocks by a low basis weight longitudinal groove portion 26, boundary groove portions 27 c and 27 d, an annular groove portion 28, and a lateral groove portion 29. These groove portions open to the lower surface 16b of the absorbent core 16, have grooves formed upward in the thickness direction Z, and have a basis weight lower than the surroundings.
By these groove portions, the deformation of the absorbent core 16 at the time of wearing can be controlled more effectively. Hereinafter, the configuration and operation of each groove will be described.

(Vertical groove)
As shown in FIG. 4, the absorbent core 16 includes a low basis weight vertical groove portion 26 c formed in the horizontal direction Y center portion 22 c of the rear core portion 22 and extending in the vertical direction X. Since the basis weight and the rigidity have a correlation, the longitudinal groove portion 26c is a portion that is easily deformed as compared with a region other than the groove portion.
The center part 22c in the lateral direction of the rear core part 22 refers to a central part of the rear core part 22 divided into three equal parts in the lateral direction Y. On the other hand, the portions on both sides in the lateral direction Y of the rear core portion 22 are defined as side portions 22d.
In the example shown in FIG. 4, the longitudinal groove portion 26 c is formed over the entire length of the rear core portion 22 in the longitudinal direction X, but may be formed in a part of the rear core portion 22.

The effect | action at the time of wear of the vertical groove part 26c is demonstrated using FIG.
As shown in the figure, the rear core portion 22 can face the wearer's buttocks H when worn. Moreover, the heel part H has the crack H1, and has the shape divided into right and left.
In the rear core portion 22, the longitudinal groove portion 26c having low rigidity is likely to be a starting point of deformation. For this reason, as schematically shown in FIG. 7, in the rear core portion 22, the lateral direction Y center portion 22 c where the longitudinal groove portion 26 c is positioned during wearing protrudes upward in the thickness direction Z and deforms along the crack H <b> 1. . Therefore, the clearance gap between a wearer's crack H1 and the napkin 1 becomes small, and the fitting property of the napkin 1 in the back of an excretion area | region can be improved. Thereby, in the napkin 1, the liquid transmission leak resulting from the clearance in the back is suppressed.

  In addition, the absorptive core 16 may have the other longitudinal groove part formed in the back core part 22 other than the longitudinal groove part 26c. The vertical groove portions formed in the absorbent core 16 are collectively referred to as “vertical groove portions 26”. These longitudinal groove portions 26 can impart flexibility to the absorbent core 16 and can enhance fit to the wearer's body. The configuration of the vertical groove portion 26 other than the vertical groove portion 26c will be described later.

(Boundary groove)
The absorbent core 16 further includes a low basis weight boundary groove portion 27d formed in the boundary portion between the intermediate core portion 21 and the rear core portion 22 and extending in the lateral direction Y. In the example shown in FIG. 4, the boundary groove portion 27 d is formed adjacent to the rear end portion 23 d of the high basis weight portion 23.
In the following description, the boundary portion P <b> 2 refers to a portion that does not belong to either the rear core portion 22 or the intermediate core portion 21. Similarly, the boundary portion P <b> 1 refers to a portion that does not belong to any of the front core portion 20 and the intermediate core portion 21.

  As explained in FIG. 5, at the time of wearing, the high basis weight portion 23 is deformed so as to rise upward in the thickness direction Z with respect to the rear core portion 22 having a low basis weight. By forming the boundary groove portion 27, it is possible to suppress the internal stress (tension) resulting from the deformation of the intermediate core portion 21 from propagating to the rear core portion 22 across the boundary portion P2. Thereby, the deformation | transformation of the back core part 22 which followed the deformation | transformation of the high basic weight part 23 is suppressed, and the preferable deformation | transformation along the collar part of the back core part 22 becomes easy to be induced | guided | derived (refer FIG. 7). Therefore, the fit is also improved behind the napkin 1.

  Further, the absorbent core 16 may further include a low basis weight boundary groove portion 27c formed in the boundary portion P1 between the intermediate core portion 21 and the front core portion 20 and extending in the lateral direction Y. The boundary groove 27c is formed adjacent to the front end 23c of the high basis weight portion 23, for example. Also by such a boundary groove part 27c, similarly to the boundary groove part 27d, the internal stress based on the deformation of the intermediate core part 21 is suppressed from propagating to the front core part 20, and follows the deformation of the high basis weight part 23. The deformation of the front core portion 20 is prevented.

(Annular groove)
Furthermore, the absorptive core 16 may have the annular groove part 28 formed along the outer edge of the high basic weight part 23 so that the circumference | surroundings of the high basic weight part 23 may be enclosed annularly. By providing the annular groove 28, when pressure is applied downward from the wearer in the thickness direction Z, the annular groove 28 can be a starting point of bending, and the deformation of the low basis weight portion 24 in the thickness direction Z is easier. .

(Horizontal groove)
The absorptive core 16 is further formed in the back core part 22, and has the some horizontal groove part 29 of the low basic weight which cross | intersects the vertical groove part 26c and each extends in a horizontal direction. In the rear core portion 22 shown in FIG. 4, five lateral groove portions 29 are arranged at equal intervals, but the number and arrangement are not limited thereto.

  The absorbent core 16 may further include a lateral groove portion 29 formed in the front core portion 20 and the intermediate core portion 21 in addition to the lateral groove portion 29. These lateral groove portions 29 can impart flexibility to the absorbent core 16 and can enhance fit to the wearer's body. The configuration of these lateral groove portions 29 will be described later.

As described above, since the basis weight and the rigidity have a correlation, the lateral groove portion 29 can impart deformability to the absorbent core 16. On the other hand, a three-dimensional guard G is formed on the peripheral edge Y in the lateral direction of the napkin 1. In the napkin 1, a curved shape that further enhances the fitting property is induced by using the elastic force of the elastic member 143 disposed on the three-dimensional guard G and the deformability of each lateral groove portion 29.
Hereinafter, the configuration and the like of the three-dimensional guard G will be described.

[Structure of 3D guard]
As illustrated in FIGS. 2 and 3, the three-dimensional guard G includes a folded region 141, a fixed end 142, and an elastic member 143. The three-dimensional guard G is configured by the side sheet 14 in the present embodiment, but may be formed by a sheet material different from the side sheet 14.

The folded region 141 is a portion of the side seat 14 that is folded outward in the lateral direction Y.
The fixed end portion 142 is an end portion on the inner side in the lateral direction Y of the three-dimensional guard G, and is a base portion of the three-dimensional guard G joined to the liquid receiving surface 12 a of the topsheet 12. The fixed end 142 is joined to the topsheet 12 using the adhesive 15 in this embodiment.

  The elastic member 143 includes a plurality of thread-like elastic members that are disposed in the folded region 141 and can be expanded and contracted in the longitudinal direction X. The elastic member 143 is attached to the side sheet 14 in a state of being stretched in the XY plane in a state of being stretched in the vertical direction X. Thereby, at the time of wearing, the elastic member 143 contracts in the vertical direction X, and the main body M is curved so that the liquid receiving surface 12a is gently dented, and the folded region 141 can stand up in the thickness direction Z. The skin-side surface of the raised folded region 141 is a surface that can come into contact with the wearer's skin, and liquid leakage in the lateral direction Y is prevented.

As shown in FIG. 2, the three-dimensional guard G is disposed over the entire length in the longitudinal direction X of the main body M in the present embodiment, and at least a part thereof is configured to be able to stand up.
The three-dimensional guard G has a standing region G1 and a non-standing region G2.
The standing region G1 is configured to be able to stand in the thickness direction Z. The standing region G <b> 1 is disposed up to a part of the front core portion 20 and the rear core portion 22 across the intermediate core portion 21.
The non-standing area G2 is formed at the back and front of the standing area G1, respectively. For example, the non-standing region G2 is joined to the outer surface of the side sheet 14 in the thickness direction Z in a state where the side sheet 14 is folded. Accordingly, the folded region 141 is configured not to stand in the non-standing region G2.

  The elastic member 143 is actually disposed over the entire three-dimensional guard G including the non-standing region G2, but it is sufficient that the elastic member 143 is disposed at least in the standing region G1. In FIG. 2, the illustration of the elastic member 143 in the non-standing region G2 is omitted.

[Positional relationship between lateral groove and solid guard]
As described above, the rear core portion 22 has five lateral groove portions 29 formed therein. In FIG. 8, other groove portions are omitted.
Referring to FIG. 8, among these lateral groove portions 29, a front lateral groove portion 29 (hereinafter referred to as a first lateral groove portion 29 c) extends to a region opposite to the standing region G <b> 1 of each of the pair of three-dimensional guards G, The rear lateral groove portion 29 (hereinafter referred to as the second lateral groove portion 29d) extends to a region opposite to the non-standing region G2 of each of the pair of solid guards G. Note that “the lateral groove portion extends to the region opposite to the standing region or the non-standing region” means that each lateral groove portion 29 is a part or the whole of the region between the pair of standing regions G1 or non-standing regions G2 in the napkin 1. Extending in the horizontal direction Y, and includes an aspect extending below the three-dimensional guard G or outward in the horizontal direction Y.

  The napkin 1 shown in FIG. 8 will be described more specifically. Of the horizontal groove portions 29 formed in the rear core portion 22, the horizontal groove portion 29 located closest to the front end side of the napkin 1 is the first horizontal groove portion 29c. Also, all the lateral groove portions 29 located on the rear end side of the napkin 1 are second lateral groove portions 29d. In the napkin 1, in the rear core portion 22, three of the five lateral groove portions 29 are located in the front, and two are located in the rear. Therefore, when the rear core portion 22 is divided into two in the vertical direction X, one of the horizontal groove portions 29 located in the front half region of the rear core 22 is the first horizontal groove portion 29c, and the remaining is the second horizontal groove portion 29d. It has become. Of course, the present invention is not limited to this, and all the lateral groove portions 29 located in the front half region of the rear core 22 may be the first lateral groove portions 29c. Further, only the lateral groove 29c located on the rear end side of the napkin in the rear half region of the rear core 22 may be the second lateral groove 29d.

  In the napkin 1 shown in FIG. 8, in the standing region G1, the elastic member 143 contracts along the vertical direction X and stands up in the thickness direction Z when worn. Since the first lateral groove portion 29 c is less rigid than the region other than the groove portion of the absorbent core 16, the first lateral groove portion 29 c bends from the bottom of the groove as the elastic member 143 contracts. Thereby, the absorptive core 16 can curve upwards behind the excretion area | region where the 1st horizontal groove part 29c exists. Therefore, the napkin 1 is curved so as to wrap around the excretion area, and the adhesion to the wearer's excretion area can be secured.

On the other hand, the elastic force is not exhibited in the non-standing region G2. For this reason, each 2nd horizontal groove part 29d can raise the softness | flexibility of the back core part 22 using the easy deformability, and can curve the back core part 22 gently so that it may fit a collar part. .
Further, as described with reference to FIG. 7, the rear core portion 22 can be deformed so as to protrude along the crack by the longitudinal groove portion 26c. Since the second lateral groove portion 29d is provided in the region facing the non-standing region G2, the second lateral groove portion 29d is unlikely to be bent along the longitudinal direction X, and the deformation that fits the crack of the rear core portion 22 is prevented. I can't interfere. Therefore, the adhesiveness in the heel part of the napkin 1 can be improved.
That is, the lateral groove portion 29 and the three-dimensional guard configured as described above can achieve both fit in the excretion region of the absorbent core 16 and fit in the buttocks behind the excretion region.

  From the viewpoint of the above-described adhesion to the wearer's excretion region and the buttocks, it is preferable that all the lateral groove portions 29 located in the rear half region of the rear core portion 22 are the second lateral groove portions 29d. From the same viewpoint, among the horizontal groove portions 29 located in the front half region of the rear core portion 22, with respect to the vertical direction X, the horizontal groove portion 29 located in the front end side half region in the front half region is the first. It is preferable that the lateral groove portion 29 c located in the region of the lateral groove portion 29 c on the rear end side ½ is the second lateral groove portion 29 d.

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

(Width of each part of absorbent core)
The width dimensions D1 and D3 of the front core part 20 and the rear core part 22 are preferably 60 mm or more and 100 mm or less, and more preferably 70 mm or more and 90 mm or less.
The width D2 of the narrowest portion of the intermediate core portion 21 is preferably 40 mm or greater and 75 mm or less, and more preferably 50 mm or greater and 70 mm or less.

(Basis weight of absorbent core)
The basis weight of the absorbent core 16 excluding the longitudinal groove part 26, boundary groove parts 27c and 27d, the annular groove part 28 and the transverse groove part 29 is preferably 100 g / m ² or more and 1000 g / m ² or less, more preferably 150 g / m ^2. It is 900 g / m ² or more.
The basis weight of the high basis weight portion 23 preferably being 400 g / ^{m 2} or more 1000 g / ^{m 2} or less, more preferably 500 g / ^{m 2} or more 900 g / ^{m 2} or less.

(Measurement method of the basis weight of the absorbent core)
The measurement object area | region of the absorptive core 16 is cut | disconnected using the feather blade made from a feather company, and a small piece is obtained so that it may become a predetermined area. The weights of these pieces are measured using an electronic balance (Electronic balance GR-300 manufactured by A & D, accuracy: 4 digits after the decimal point). The basis weight of the small piece is calculated by dividing the obtained weight by the area of the small piece of each part. About each of each part, let the average of the basic weight of five small pieces be a basic weight.

(Thickness dimension of the intermediate core)
The thickness dimensions of the high basis weight portion 23 and the low basis weight portion 24 can be set in consideration of the basis weight.
The dimension in the thickness direction Z of the high basis weight portion 23 is, for example, 3 mm or more and 15 mm or less, and preferably 5 mm or more and 13 mm or less.
The dimension of the thickness direction Z of the low basic weight part 24 is 2 mm or more and 12 mm or less, for example, Preferably, it is 3 mm or more and 10 mm or less.

(Configuration of vertical groove, horizontal groove and annular groove)
The absorbent core 16 may be formed with a longitudinal groove portion 26 extending in the longitudinal direction X in addition to the longitudinal groove portion 26 c located in the lateral Y center portion 22 c of the rear core portion 22. In the following description, the vertical groove portion 26 in the central portion in the horizontal direction Y is referred to as a first vertical groove portion 26c, and the vertical groove portions 26 formed on both sides in the horizontal direction Y are referred to as a second vertical groove portion 26d and a third vertical groove portion 26e. To do.
In the rear core portion 22 shown in FIG. 4, the second vertical groove portion 26d is formed at the boundary between the central portion 22c and the side portion 22d, and the third vertical groove portion 26e is formed in the side portion 22d. For example, the second vertical groove portion 26d may be formed in the central portion 22c, or may be formed in the side portion 22d. Although the 1st vertical groove part 26c, the 2nd vertical groove part 26d, and the 3rd vertical groove part 26e are arrange | positioned at equal intervals in the horizontal direction Y, they may not be equal intervals.
Furthermore, the groove widths of the first vertical groove portion 26c, the second vertical groove portion 26d, and the third vertical groove portion 26e may be different or the same. For example, the groove width of the first longitudinal groove portion 26c is larger than the groove width of the longitudinal groove portion located in the side portion 22d, that is, the third longitudinal groove portion 26e in the present embodiment, and thus along the flange portion of the central portion 22c. It becomes easier to promote deformation. In particular, by configuring the groove width of the first vertical groove portion 26c and the second vertical groove portion 26d to be larger than the groove width of the third vertical groove portion 26e, the deformation along the crack of the central portion 22c described in FIG. It becomes easier to encourage.

  Further, the longitudinal groove portion 26 may be formed not only in the rear core portion 22 but also in the intermediate core portion 21 and the front core portion 20. In the example shown in FIG. 4, the first vertical groove portion 26 c extends over the entire length in the vertical direction X of the absorbent core 16. The second vertical groove portion 26 d and the third vertical groove portion 26 e extend over the entire length in the vertical direction X of the rear core portion 22 and the front core portion 20. The configuration of the vertical groove portions 26 is not limited, and may be formed in a part of the vertical direction X of each portion, and the groove width may not be constant.

  As described above, the lateral groove portion 29 extending along the lateral direction Y may be formed not only on the rear core portion 22 but also on the intermediate core portion 21 and the front core portion 20, for example. The arrangement interval of the lateral groove portions 29 is not limited to an equal interval and may be different. Moreover, although each horizontal groove part 29 is formed over the horizontal direction Y full length of the absorptive core 16, you may be formed only in a part of the horizontal direction Y. Moreover, the groove width of each horizontal groove part 29 may be the same, and may differ.

  The groove widths of the vertical groove part 26, the horizontal groove part 29, and the annular groove part 28 are preferably 0.5 mm or more and 10 mm or less, and more preferably 1 mm or more and 5 mm or less. The depth of the annular groove part 28 is 0.5 mm or more and 10 mm or less, for example, and the depth of the vertical groove part 26 and the horizontal groove part 29 is 0.5 mm or more and 10 mm or less, for example.

  In addition to those described above, the configuration of the longitudinal groove portion 26, the boundary groove portions 27c and 27d, the annular groove portion 28, and the lateral groove portion 29 is not limited to the configuration described in FIG. It can be set as appropriate based on the shape of the device, the required function, and the like. In the napkin 1, the absorbent core 16 may not have at least one of the longitudinal groove portion 26, the boundary groove portions 27 c and 27 d, the annular groove portion 28, and the lateral groove portion 29.

  The “low basis weight” of each of the grooves 26 to 29 is a concept including a form in which the material of the absorbent core 16 is present, in addition to a form in which the material of the absorbent core 16 is present. In the form in which the material of the absorbent core 16 is present in each of the groove portions 26 to 29, the block-shaped portions of the absorbent core 16 located on both sides thereof are connected via the respective groove portions 26 to 29. However, it is more preferable because it is difficult to cause twist, breakage, tearing, etc. due to movement and can impart flexibility.

  The embodiment of the present invention has been described above, but the present invention is not limited to the above-described embodiment, and it is needless to say that various modifications can be made without departing from the gist of the present invention.

  Although the example of the sanitary napkin was shown as an absorbent article in the above embodiment, it is not limited to this. The absorbent article of the present invention may be, for example, a urine pad, a cage sheet, or a disposable diaper. In particular, the present invention is useful for pad-like absorbent articles such as sanitary napkins, urine pads, and cage sheets.

(1) A liquid-permeable top sheet, a back sheet, and an absorbent body having an absorbent core and disposed between the top sheet and the back sheet, and corresponding to the longitudinal direction of the wearer The absorbent article has a transverse direction perpendicular to the direction and the longitudinal direction, and the absorbent core includes a front core portion and a rear core portion located on both end sides in the longitudinal direction, the front core portion, and the An intermediate core portion that is positioned between the rear core portion and narrower than the front core portion and the rear core portion, and the intermediate core portion is located in the center in the lateral direction and is on the back sheet side An absorbent article comprising: a high basis weight portion protruding into a portion; and a low basis weight portion having a basis weight lower than that of the high basis weight portion and formed on the lateral side portion of the high basis weight portion.
(2) The absorbent article according to (1), wherein the high basis weight portion includes a rear end portion whose width gradually decreases toward the front end in the longitudinal direction.
(3) The high basis weight portion is formed over the entire length of the intermediate core portion, the rear core portion is formed adjacent to the intermediate core portion, and a taper whose width dimension gradually increases toward the rear in the vertical direction. The absorbent article as described in (1) or (2) containing an area | region.
(4) The absorbent body further includes a core wrap sheet including a core covering portion that covers the absorbent core and an extending portion that extends outward in the lateral direction of the low basis weight portion (1) ) To (3) any one of the absorbent articles.
(5) In any one of (1) to (4), the absorbent core further includes a low-basis-weight vertical groove portion that is formed in the horizontal center portion of the rear core portion and extends in the vertical direction. The absorbent article as described.
(6) The absorbent core according to any one of (1) to (5), further including a low-basis weight boundary groove portion formed in a boundary portion between the intermediate core portion and the rear core portion and extending in the lateral direction. The absorbent article as described in one.
(7) The absorbent article further includes a pair of three-dimensional guards provided at the lateral peripheral edge and extending in the vertical direction, and the pair of three-dimensional guards are configured to be able to stand in the thickness direction of the absorbent article. And a non-standing region formed at the rear of the standing region, and the absorbent core is formed at the rear core portion and intersects the longitudinal groove portion in the lateral direction. It further has a plurality of lateral groove portions with a low basis weight that extend, and the plurality of lateral groove portions each include a front lateral groove portion that extends to a region opposite to the upright region of each of the pair of solid guards, and each of the pair of solid guards. The absorbent article according to (5) or (6), wherein the absorbent article is divided into a rear lateral groove portion extending to a region opposite to the non-standing region.
(8) When the rear core portion is divided into two in the longitudinal direction, the front lateral groove portion is at the foremost side of the lateral groove portion located in the front half region of the rear core, and the rest is the rear lateral groove portion. The absorbent article according to (7), wherein
(9) The absorbent article according to (8), wherein all the lateral groove portions located in the rear half region of the rear core portion are rear lateral groove portions.
(10) Among the horizontal groove portions positioned in the front half region of the rear core portion, the horizontal groove portion positioned in a further front end half region in the front half region with respect to the vertical direction is the front groove portion. The absorptive article according to (8) or (9), wherein the lateral groove portion located in the rear end side half region is the rear lateral groove portion.
(11) The width dimension of each of the front core part, the intermediate core part, and the rear core part is different in the width dimension in each region when the minimum width in the horizontal direction of each region is 100%. The absorbent article according to any one of (1) to (10), which is within 20% or less.
(12) In any one of the above (11), in the front core portion and the rear core portion, a difference in width dimension in each region is 10% or less when the minimum width in the lateral direction is 100%. Absorbent article as described in 1.
(13) The absorbent core according to (1) to (12), wherein the absorbent core has an annular groove formed along an outer edge of the high basis weight portion so as to surround the high basis weight portion in an annular shape. The absorbent article as described in any one.
(14) The absorbent article further includes a pair of side sheets disposed around the lateral direction with the top sheet interposed therebetween, and the three-dimensional guard has an elastic member at a folded portion in the lateral direction of the side sheet. The absorbent article according to any one of (1) to (13), which is arranged and configured to be stretchable in the longitudinal direction.
(15) The width dimension of the said front core part and the said back core part is 60 mm or more and 100 mm or less, Preferably it is 70 mm or more and 90 mm or less, The absorbent article as described in any one of said (1)-(14). .
(16) The absorbent article according to any one of (1) to (15), wherein a width dimension of a narrowest portion of the intermediate core portion is 40 mm to 75 mm, preferably 50 mm to 70 mm. .
(17) The basis weight of the high basis weight part of the absorbent core is 400 g / m ² or more and 1000 g / m ² or less, more preferably 500 g / m ² or more and 900 g / m ² or less. The absorbent article as described in any one of (16).
(18) The absorbent article according to any one of (1) to (17), wherein a dimension in a thickness direction of the high basis weight part is 3 mm to 15 mm, preferably 5 mm to 13 mm. .
(19) The absorbent article according to any one of (1) to (18), wherein a dimension in a thickness direction of the low basis weight part is 2 mm to 12 mm, preferably 3 mm to 10 mm.
(20) The absorbent article according to any one of (7) to (10), wherein a groove width of the lateral groove portion is 0.5 mm to 10 mm, preferably 1 mm to 5 mm.
(21) The absorbent article according to (13), wherein a groove width of the annular groove portion is 0.5 mm or more and 10 mm or less, preferably 1 mm or more and 5 mm or less.
(22) The absorbent article according to (13), wherein the depth of the annular groove is 0.5 mm or more and 10 mm or less.
(23) The absorbent article according to (5), wherein the depth of the longitudinal groove is 0.5 mm or more and 10 mm or less.
(24) The absorbent article according to any one of (7) to (10) and (20), wherein the depth of the lateral groove is 0.5 mm or more and 10 mm or less.
(25) The absorbent core includes a plurality of vertical groove portions located in the rear core portion, and the vertical groove portion located in the lateral center portion is grooved more than the vertical groove portion located in the lateral side portion. The absorbent article according to any one of (1) to (24), wherein the width is large.
(26) The vertical groove portion at the central portion in the horizontal direction is a first vertical groove portion, and the vertical groove portions formed on both sides of the horizontal direction are the second vertical groove portion and the third vertical groove portion in order from the side closer to the first vertical groove portion. The absorbent article according to (25), wherein the width of the first vertical groove portion and the second vertical groove portion is larger than the width of the third vertical groove portion when the groove portion is used.
(27) The absorbent article according to any one of (1) to (26), wherein the absorbent article is a sanitary napkin.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited to this.

[Preparation of sanitary napkin for evaluation]
(Example 1)
The sanitary napkin (napkin) shown in FIG. 2 provided with the absorber shown in FIGS.
The entire outer surface of the absorbent core composed of pulp fibers as hydrophilic fibers and a water-absorbing polymer was coated with a paper core wrap sheet having a basis weight of 16 g / m ² to prepare an absorbent body. Softwood bleached kraft pulp (NBKP) was used as the pulp fiber. As the water-absorbing polymer, an acrylic acid polymer partial sodium salt (manufactured by Nippon Shokubai Co., Ltd., Aquaric CAW) was used, and the basis weight was 24 g / m ² .
The total length of the absorbent core was 324 mm, the front core part was 50 mm, the intermediate core part was 130 mm, and the rear core part was 144 mm.
The width of the absorbent core was 65 mm at the intermediate core portion and 80 mm at the front core portion and the rear core portion. The basis weight of the pulp fibers, 700 g / ^{m 2} in the high basis weight portion of the intermediate core section, and 200 g / ^{m 2} by the low basis weight portion, a front core portion and a rear core portion was 200 g / ^{m 2.}
The width of the longitudinal groove portion of the absorbent core was 1.5 mm at the intermediate core portion. In the front core part and the rear core part, the first vertical groove part located in the central part in the horizontal direction and the second vertical groove parts on both sides thereof are 4 mm, and the third vertical groove part located in the lateral side parts on both sides is 1.5 mm. there were. Moreover, the width | variety of all the horizontal groove parts was 2 mm, and the width | variety of the annular groove part was 1.5 mm.

(Example 2)
A napkin of Example 2 was created in the same manner as Example 1 except that the width of the longitudinal groove part of the rear core part was all 1.5 mm.

(Comparative example)
A napkin of a comparative example was prepared in the same manner as in Example 2 except that the width of the absorbent core was uniformed to 80 mm over the entire length.

[Evaluation test]
About the napkin of Example 1 and 2 and a comparative example, the fit property with respect to a wearer's crotch part and a buttocks in a sleeping posture was evaluated by each method.

(Measurement method of napkin deflection rate and liquid flow distance)
The napkins of each of the examples and comparative examples were attached to a lower body model capable of walking operation for wearing a napkin that reproduced the waist of an adult woman. Prior to mounting, the width A of the napkin at the position corresponding to the intermediate core portion was measured in advance. The walking motion was controlled by a motor linked to the leg.
The lower body model has a hollow structure and has a hole through which liquid can be discharged from the crotch corresponding to the female vagina. A tube through which liquid can pass is connected to the hole, and it is designed so that a desired liquid can be conducted from outside the lower body model and discharged from the hole.
The napkin was attached to the lower body model by fixing the sanitary napkin on the side facing the lower body model of the sanitary shorts ("Lorier Active Guard (firm mode)", L size, manufactured by Kao Corporation).
The operation of injecting 3g of equine defibrinated blood into the napkin over 4 seconds with the napkin attached is performed 4 times at intervals of 3 minutes (0 minutes after measurement, 3 minutes, 6 minutes, and 9 minutes later). A total of 12 g of equine defibrinated blood was injected into each napkin. In addition, after the start of measurement, both legs of the lower body model were moved at a speed of 100 steps per minute for the first 5 minutes, and both legs of the lower body model were fixed in an open leg state with a crotch width of 42 mm for the subsequent 4 minutes.
The horse defibrinated blood has a viscosity of 8 mPa · s measured using a B-type viscometer (model number TVB-10M, manufactured by Toki Sangyo Co., Ltd., measurement conditions: rotor No. 19, 30 rpm, 25 ° C., 60 seconds). Thus, the blood cell / plasma ratio of defibrinated horse blood (manufactured by Nippon Biotest Co., Ltd.) was prepared.
After walking, the attached napkin was removed from the model while maintaining the deformed state, the width B of the napkin at the position corresponding to the intermediate core portion was measured, and the deflection rate of the napkin was calculated by the following equation.
Twist rate = {(width A−width B) / width A} × 100
Moreover, the liquid diffusion distance in the vertical direction on the surface sheet of the napkin was measured using a metal ruler, and was defined as the liquid flow distance of the napkin.
These measurement results are shown in Table 1.

(Measurement method of napkin compression force)
The napkins of each of the examples and comparative examples were fixed to the inside of sanitary shorts (“Lorier Active Guard (solid mode)”, L size, manufactured by Kao Corporation) and attached to the lower body model described above.
Before the measurement, between the hole where the tube is connected and the base of the leg in the crotch part of the lower body model in advance, the pressure sensor (“Technical Co., Ltd.“ Small 3-axis force sensor USL06-H5-50N ”) Arranged.
The leg angle was set to 20 ° on both the left and right sides, a napkin was attached, the angle was changed to 5 °, and the pressure sensor value at the leg angle of 5 ° was read. Three measurements were carried out for each sample, and the average value was taken as the compressive force of the napkin.
The measurement results are shown in Table 1.

(Measurement method of rigidity at the back of the napkin)
Cut the napkin of each example and comparative example at the boundary corresponding to the intermediate core part (width 80 mm x length 100 mm) and the rear core part (width 80 mm x length 90 mm), and measure the side including the rear core part Used as a sample.
Each measurement sample was stored in a test room at a temperature of 23 ° C. and a humidity of 50% for 24 hours, and then the rigidity value of the measurement sample was measured according to the handle ohm method (JIS L-1096). As the handle ohmmeter, model: HOM-200 manufactured by Daiei Kagaku Seiki Seisakusho was used.
The measurement sample was placed on the handle ohmmeter so that the back sheet side of the measurement sample was directed upward and the longitudinal direction of the napkin was parallel to the slit having a width of 40 mm. The blade of the penetrator was lowered at a constant speed of 200 mm / min to a position corresponding to the first longitudinal groove of the absorbent core, and the maximum value indicated by the indicator (load meter) was read. The measurement was performed three times for each measurement sample, and the average value thereof was defined as the bending rigidity of the rear part of the napkin.
The measurement results are shown in Table 1.

(Measurement method of gap between napkin rear part and wearer)
The napkin of each example and comparative example is attached to the inside of a sanitary shorts ("Laurier Active Guard (solid mode)", L size, manufactured by Kao Corporation), and a napkin that reproduces the waist of an adult woman at bedtime Attached to the transparent model.
After wearing the napkin, the distance between the model skin surface and the napkin surface was measured using a metal ruler, and was defined as a gap with the wearer. The measurement position was the position where the buttocks skin surface and the napkin surface of the model were most separated when seen from the side, with the buttocks of the transparent model in contact with the floor surface (upward-facing state).
The measurement results are shown in Table 1.

(Measurement result of compressive force and deflection rate of napkin)
As shown in Table 1, in the comparative example, the compressive force was 1.30 N, but in Examples 1 and 2, the compressive force was 0.71 N and 0.72 N, respectively, which was smaller than the comparative example. there were. Thereby, in the napkin of Examples 1 and 2 in which the intermediate core portion is constricted, the compressive force (drag) against the external force in the direction of compression from the lateral direction is smaller than that of the napkin of Comparative Example 1 without constriction. It was confirmed. Therefore, in the napkins of Examples 1 and 2, it was presumed that the gap between the crotch narrowed and the twist when receiving external force from both legs was reduced.
Actually, the results of calculating the deflection rate of the napkin were also 5.6% in Examples 1 and 2, but 15.0% in the comparative example, which is a larger value. It was.
From these results, it was confirmed that the napkins of Examples 1 and 2 can prevent the middle core portion from being twisted and can improve the fit in the wearer's crotch portion.

(Measurement results of rigidity and gap at the back of the napkin)
As shown in Table 1, with respect to the rigidity of the central portion in the lateral direction of the napkin rear portion, the gap between the napkin rear portion and the wearer is a comparative example although Example 2 and the comparative example were both 70 gf. In Example 2, it was 5.7 mm in contrast to 10 mm. Furthermore, in Example 1, the gap between the napkin rear part and the wearer was 3.3 mm. Thereby, in the napkin of Example 1 and 2, it was confirmed that generation | occurrence | production of the clearance gap between the wearer of a sleeping posture and a napkin rear part can be suppressed. Moreover, in the napkin of Example 2, although the structure of the back core part was substantially the same as a comparative example, it was confirmed that a clearance gap can be reduced significantly. From this result, it was confirmed that a preferable deformation can be induced in the rear core portion by providing a constriction in the intermediate core portion.
Further, in Example 1 in which the first vertical groove part in the central portion in the horizontal direction and the second vertical groove parts on both sides thereof are thicker than the third vertical groove part in the side part, the vertical groove parts are all compared with Example 2 having the same width. The gap could be further reduced. Thus, in the rear core portion, the lateral center portion and the first longitudinal groove portion and the second longitudinal groove portion on both sides thereof are configured to be thicker than the third longitudinal groove portion on the lateral side portion, so that the fit at the collar portion of the napkin is achieved. It was confirmed that the sex can be further enhanced.

(Measurement result of liquid flow distance)
As shown in Table 1, the liquid flow distance was 111 mm in the comparative example, whereas it was 67 mm in Example 1 and 76 mm in Example 2. From this result, it was confirmed that in the napkins of Examples 1 and 2, the liquid flow in the sleeping posture can be suppressed and the liquid leakage can be effectively prevented. From the above results, it was confirmed that in the napkins of Examples 1 and 2, the fit property of the entire napkin can be improved.

1 ... Napkin (absorbent article)
DESCRIPTION OF SYMBOLS 11 ... Absorber 12 ... Top sheet 13 ... Back sheet 16 ... Absorbent core 20 ... Front core part 21 ... Middle core part 22 ... Back core part 23 ... High basic weight part 24 ... Low basic weight part

Claims (7)

A liquid permeable top sheet, a back sheet, and an absorbent body having an absorbent core and disposed between the top sheet and the back sheet, the longitudinal direction corresponding to the front-rear direction of the wearer and the An absorbent article having a transverse direction orthogonal to the longitudinal direction,
The absorbent core is
A front core portion and a rear core portion located on both ends in the longitudinal direction;
An intermediate core portion that is located between the front core portion and the rear core portion and is narrower than the front core portion and the rear core portion, and
The intermediate core part is
A high basis weight portion located at the center in the lateral direction and protruding toward the back sheet;
A low basis weight part having a basis weight lower than that of the high basis weight part and formed on the lateral side part of the high basis weight part. The high basis weight part is
The absorbent article according to claim 1, comprising a rear end portion whose width gradually decreases toward the longitudinal tip. The high basis weight portion is formed over the entire length of the intermediate core portion,
The absorbent article according to claim 1, wherein the rear core portion includes a tapered region that is formed adjacent to the intermediate core portion and has a width dimension that gradually increases toward the rear in the longitudinal direction. The absorber is
The core wrap sheet | seat further including the core coating | coated part which coat | covers the said absorptive core, and the extension part extended to the said horizontal direction outward of the said low basic weight part, It is any one of Claim 1 thru | or 3. Absorbent article as described in 1. The absorbent core is
The absorptive article according to any one of claims 1 to 4 which further has a low-basis weight vertical groove part which is formed in said horizontal direction central part of said back core part, and extends in said vertical direction. The absorbent core is
The absorbent article as described in any one of Claims 1 thru | or 5 which further has a low basic weight boundary groove part formed in the boundary part of the said intermediate | middle core part and the said back core part, and extending in the said horizontal direction. The absorbent article is
A pair of three-dimensional guards provided on the lateral peripheral edge and extending in the longitudinal direction;
The pair of three-dimensional guards are
A standing region configured to be able to stand in the thickness direction of the absorbent article;
A non-standing area formed behind the standing area,
The absorbent core is
A plurality of low-basis weight horizontal groove portions that are formed in the rear core portion and extend in the horizontal direction across the vertical groove portions;
The plurality of lateral grooves are
A front lateral groove portion extending to a region opposite to the standing region of each of the pair of solid guards;
The absorbent article according to claim 5 or 6, wherein each of the pair of three-dimensional guards is divided into a rear lateral groove portion extending to a region opposite to the non-standing region.

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