JP2024058339A - Absorbent articles - Google Patents

Abstract

[Problem] To provide an absorbent article that is excellent in absorption speed and does not easily become thick when repeatedly absorbing body fluids. [Solution] The absorbent article 1 includes an absorbent core 9, the absorbent article 1 includes a widthwise centerline WC that passes through the center in the longitudinal direction L and extends in the widthwise direction W, the absorbent core 9 is partitioned by the widthwise centerline WC into a first absorbent core portion 21 having a relatively small mass and a second absorbent core portion 23 having a relatively large mass, the absorbent core 9 includes longitudinal grooves 31, 35 that extend in the longitudinal direction L and are arranged continuously from the first absorbent core portion 21 to the second absorbent core portion 23 across the widthwise centerline WC, and the longitudinal grooves 31, 35 include relatively narrow portions 31a, 35a arranged in the first absorbent core portion 21 and relatively wide portions 31b, 35b arranged in the second absorbent core portion 23. [Selected Figure] Figure 3

Description

This disclosure relates to absorbent articles.

In order to facilitate the diffusion of bodily fluids in the longitudinal direction of the absorbent core, absorbent articles having grooves in the absorbent core have been studied.
For example, Patent Document 1 discloses an absorbent article (claim 1) comprising an absorbent core containing superabsorbent polymer particles, the absorbent article having a longitudinal direction including a front and a rear, a width direction and a thickness direction, and being partitioned into a front body and a rear body, the absorbent core comprising a first layer and a second layer adjacent to each other in the thickness direction, the first layer comprising, disposed in the front body, (i) a groove portion extending along the longitudinal direction, penetrating through the thickness direction and having an end at the rear position, and (ii) a base portion disposed adjacent to the rear position of the groove portion with the end sandwiched therebetween, the second layer comprising a groove portion corresponding portion and a base portion corresponding portion, respectively, at positions overlapping the groove portion and the base portion in the thickness direction, and the average density of the superabsorbent polymer particles contained in the base and the average density of the superabsorbent polymer particles contained in the base portion corresponding portion are higher than the average density of the superabsorbent polymer particles contained in the groove portion corresponding portion.

JP 2019-118722 A

The absorbent article of Patent Document 1 has room for improvement in terms of the absorption speed, thickness of the absorbent article, and the like when repeatedly absorbing body fluids.
Therefore, an object of the present disclosure is to provide an absorbent article that has an excellent absorption rate and is less likely to become thick when repeatedly absorbing body fluids.

The present inventors have discovered an absorbent article having a longitudinal direction and a width direction and including an absorbent core, the absorbent article having a widthwise centerline passing through the longitudinal center of the absorbent article and extending in the width direction, the absorbent core being partitioned by the widthwise centerline into a first absorbent core portion having a relatively small mass and a second absorbent core portion having a relatively large mass, the absorbent core having vertical grooves extending in the longitudinal direction across the widthwise centerline and arranged continuously from the first absorbent core portion to the second absorbent core portion, the vertical grooves having a relatively narrow portion arranged in the first absorbent core portion and a relatively wide portion arranged in the second absorbent core portion.

The absorbent article of the present disclosure has excellent absorption speed and is less likely to become thick when repeatedly absorbing bodily fluids.

FIG. 1 is a diagram for illustrating a disposable diaper 1 according to a first embodiment. FIG. 2 is a diagram for illustrating the disposable diaper 1 according to the first embodiment. FIG. 3 is a diagram for illustrating the disposable diaper 1 according to the first embodiment. FIG. 4 is a diagram for illustrating the disposable diaper 1 according to the first embodiment. FIG. 5 is a diagram for explaining a disposable diaper according to the second embodiment. FIG. 6 is a diagram for explaining a disposable diaper according to the third embodiment. FIG. 7 is a diagram for explaining a disposable diaper according to the fourth embodiment. FIG. 8 is a diagram for explaining a disposable diaper according to the fifth embodiment.

Specifically, the present disclosure relates to the following aspects:
[Aspect 1]
1. An absorbent article having a longitudinal direction and a width direction and including an absorbent core,
The absorbent article has a widthwise centerline passing through a center of the absorbent article in the longitudinal direction and extending in the width direction,
the absorbent core is partitioned by the widthwise centerline into a first absorbent core portion having a relatively small mass and a second absorbent core portion having a relatively large mass,
the absorbent core has longitudinal grooves extending in the longitudinal direction, the longitudinal grooves being arranged continuously from the first absorbent core portion to the second absorbent core portion across the widthwise centerline,
The longitudinal grooves have a relatively narrow portion disposed in the first absorbent core portion and a relatively wide portion disposed in the second absorbent core portion.
The absorbent article as described above.

The absorbent article has vertical grooves that have narrow portions in the first absorbent core portion, where the mass of the absorbent core is relatively small, and wide portions in the second absorbent core portion, where the mass of the absorbent core is relatively large. Therefore, when bodily fluids (e.g., urine) reach the absorbent core, the wide portions of the vertical grooves tend to diffuse the bodily fluids relatively more easily into the second absorbent core portion, where the mass of the absorbent core is relatively large. Since the mass of the second absorbent core portion is relatively large, the second absorbent core portion has a large absorption capacity for bodily fluids and is excellent in repeated absorption and absorption speed of bodily fluids.

On the other hand, when body fluids reach the absorbent core, the narrow portion of the vertical groove makes it relatively difficult for the body fluids to diffuse into the first absorbent core portion, which has a relatively small mass, and therefore the first absorbent core portion is less likely to thicken when body fluids are repeatedly absorbed.
As described above, when the absorbent article repeatedly absorbs body fluids, it has a high absorption rate and the absorbent core is unlikely to become thick.
Furthermore, when the absorbent article repeatedly absorbs body fluids, it has a high absorption rate and the absorbent core is unlikely to become thick, so that the absorbent core can be made thinner, and therefore the absorbent article can be made thinner.

[Aspect 2]
2. The absorbent article of claim 1, wherein the first absorbent core portion and the second absorbent core portion are disposed at the front and rear, respectively.

In the above absorbent article, the first absorbent core portion and the second absorbent core portion are disposed in the front and rear, respectively, so that absorbed body fluids are preferentially diffused to the second absorbent core portion disposed in the rear, and are preferentially absorbed by the second absorbent core portion disposed in the rear. Therefore, the above absorbent article is unlikely to cause discomfort in the groin area of the wearer when repeatedly absorbing body fluids.

[Aspect 3]
2. The absorbent article of claim 1, wherein the first and second absorbent core portions are positioned at the rear and front, respectively.

In the above absorbent article, the first absorbent core portion and the second absorbent core portion are disposed at the rear and front, respectively, so that absorbed body fluids are preferentially diffused to the second absorbent core portion disposed at the front, and can be preferentially absorbed by the second absorbent core portion disposed at the front. Therefore, the above absorbent article is unlikely to cause discomfort in the buttocks of the wearer when repeatedly absorbing body fluids.

[Aspect 4]
the absorbent core having a longitudinal centerline extending through the widthwise center in the longitudinal direction;
The absorbent core has a region in the second absorbent core portion in which the wide portion of the longitudinal groove is disposed so as to move away from the longitudinal centerline as it approaches an end of the absorbent core.
The absorbent article according to any one of claims 1 to 3.

In the absorbent article, the wide portion of the vertical groove has a predetermined area, so that the second absorbent core portion can easily diffuse body fluids outward in the width direction of the second absorbent core portion, and the second absorbent core portion can easily absorb body fluids as a whole. As a result, when the absorbent article repeatedly absorbs body fluids, it has a superior absorption speed and the second absorbent core portion of the absorbent core is less likely to become thick locally.

[Aspect 5]
the absorbent core having a longitudinal centerline extending through the widthwise center in the longitudinal direction;
The absorbent core has a region in a first absorbent core portion in which the narrow portions of the longitudinal grooves are disposed so as to move away from the longitudinal centerline as they approach the end portions of the absorbent core.
The absorbent article according to any one of claims 1 to 4.

In the absorbent article, the narrow portion of the vertical groove has a predetermined area, so that the first absorbent core portion can easily diffuse body fluids outward in the width direction of the first absorbent core portion, and the first absorbent core portion can easily absorb body fluids as a whole. As a result, when the absorbent article repeatedly absorbs body fluids, it has a superior absorption speed and the first absorbent core portion of the absorbent core is less likely to become thick locally.

[Aspect 6]
the first absorbent core portion is divided into three equal parts in the longitudinal direction, and partitioned into a first absorbent core first portion, a first absorbent core second portion, and a first absorbent core third portion in that order from the end portion of the absorbent core;
The narrow portion is disposed in the third portion of the first absorbent core.
The absorbent article according to any one of claims 1 to 5.

Generally, in absorbent articles, bodily fluids tend to be excreted near the center line in the width direction.
In the above-mentioned absorbent article, since the narrow portion is disposed in the third portion of the first absorbent core, which is in contact with the widthwise center line of the first absorbent core portion, the narrow portion of the vertical groove makes it relatively difficult for bodily fluids to diffuse into the first absorbent core portion, which has a relatively small mass.
As a result, when body fluids are repeatedly absorbed, the first absorbent core portion is less likely to become thick, and the absorbent article is more likely to exhibit the effect of mode 1.

[Aspect 7]
the second absorbent core portion is divided into three equal parts in the longitudinal direction, and partitioned into a second absorbent core first portion, a second absorbent core second portion, and a second absorbent core third portion in this order from the widthwise center line;
The wide portion is disposed in the first portion of the second absorbent core.
The absorbent article according to any one of claims 1 to 6.

Generally, in absorbent articles, bodily fluids tend to be excreted near the center line in the width direction.
In the above-mentioned absorbent article, the wide portion is disposed in the second absorbent core first portion that is in contact with the widthwise center line of the second absorbent core portion, and therefore the wide portion of the vertical groove tends to diffuse bodily fluids relatively more easily toward the second absorbent core portion, which has a relatively larger mass.
As a result, when body fluids are repeatedly absorbed, the second absorbent core portion tends to have excellent repetitive absorbency and absorption speed of body fluids, and the absorbent article tends to exhibit the effect of mode 1 more easily.

[Aspect 8]
Aspect 8. The absorbent article according to any one of aspects 1 to 7, wherein the narrow portion and the wide portion of the longitudinal groove are directly connected to each other.
In the absorbent article, the narrow portion and the wide portion have a connecting portion that directly connects them, and therefore the absorbent article is more likely to exhibit the effect of aspect 1.

[Aspect 9]
Aspect 9. The absorbent article of any one of aspects 1 to 8, wherein the absorbent core comprises a pair of waisted portions in the first absorbent core portion.

In general, in absorbent articles, the thigh-corresponding portion that corresponds to the wearer's thighs is pinched between the wearer's thighs when the absorbent article is in use, which tends to narrow the width (length in the width direction), and the thigh-corresponding portion tends to have poor absorbency for bodily fluids (especially instantaneous absorbency). In addition, when the thigh-corresponding portion absorbs bodily fluids and becomes thicker, the wearer is likely to feel uncomfortable.

In the above absorbent article, the absorbent core has a pair of narrowed portions in the first absorbent core portion that correspond to the thighs. In the above absorbent article, the narrow portions of the vertical grooves make it relatively difficult for bodily fluids to diffuse into the first absorbent core portion, which has a relatively small mass compared to the second absorbent core portion, and the first absorbent core portion is less likely to thicken when bodily fluids are repeatedly absorbed.

Therefore, even if the pair of constricted portions is compressed in the width direction when the absorbent article is in use, the absorbent article has an excellent absorption speed when repeatedly absorbing body fluids, and the absorbent core, especially the pair of constricted portions, is unlikely to become thick.

[Aspect 10]
the absorbent core comprises pulp fibers and a superabsorbent polymer;
The absorbent core has a skin side and a non-skin side,
the average density of the superabsorbent polymer on the skin-side surface of the absorbent core is higher than the average density of the superabsorbent polymer on the non-skin-side surface of the absorbent core;
The absorbent article according to any one of the preceding aspects.

In the above absorbent article, the average density of the superabsorbent polymer on the skin side of the absorbent core is higher than the average density of the superabsorbent polymer on the non-skin side of the absorbent core, so that when body fluids are repeatedly absorbed, the absorbent core can diffuse the body fluid on the non-skin side, providing excellent diffusion of body fluids and easily reducing free water on the skin side, making the wearer feel dry.
From the viewpoint of the effect, it is preferable that the above average density relationship is satisfied in the region in the thickness direction of the absorbent article where the longitudinal grooves of the absorbent core are not present.

[Aspect 11]
1. An absorbent article comprising an absorbent core having a longitudinal direction and a width direction,
the absorbent core is partitioned by a widthwise centerline that passes through the center of the absorbent article in the longitudinal direction and extends in the width direction into a front absorbent core portion that is relatively large in mass and disposed at the front side of the absorbent article, and a rear absorbent core portion that is relatively small in mass and disposed at the rear side of the absorbent article,
the absorbent core has longitudinal grooves extending in the longitudinal direction, the longitudinal grooves being arranged continuously from the front absorbent core portion to the rear absorbent core portion across the widthwise centerline,
the longitudinal grooves have a relatively narrow portion disposed in the front absorbent core portion and a relatively wide portion disposed in the rear absorbent core portion;
The absorbent article as described above.

In general, when an absorbent article is worn, the front absorbent core portion is pinched between the wearer's thighs, which tends to narrow its width (length in the width direction). In the narrowed portion, the area (area on the liquid-permeable sheet side) tends to be small, which tends to result in poor absorption of bodily fluids. In addition, if bodily fluids are absorbed, the absorbent core tends to become thicker, which tends to make the article less comfortable to wear.

The absorbent article has vertical grooves that have narrow portions in the front absorbent core portion where the mass of the absorbent core is relatively large, and wide portions in the rear absorbent core portion where the mass of the absorbent core is relatively small.

Therefore, in the early stages of bodily fluid absorption, when the bodily fluid (e.g., urine) reaches the absorbent core, the wide portions of the vertical grooves tend to preferentially diffuse the bodily fluid to the rear absorbent core portion. Therefore, the bodily fluid can be actively absorbed and retained in the rear absorbent core portion. Also, in the early stages of bodily fluid absorption, when the bodily fluid (e.g., urine) reaches the absorbent core, the narrow portions of the vertical grooves tend to relatively less diffuse the bodily fluid to the front absorbent core portion, making it less likely for the front absorbent core portion to thicken and less likely for the front absorbent core portion to become uncomfortable to wear.

Next, when body fluids are repeatedly absorbed, depending on the amount of body fluid, the rear absorbent core portion may have difficulty absorbing the body fluid. However, in such a case, since the mass of the front absorbent core portion of the absorbent article is relatively large, the front absorbent core portion can absorb the body fluid, and the absorbent article has a superior absorption rate of body fluids.
As a result, the absorbent article is less likely to have an increased thickness in the absorbent core, is less likely to be uncomfortable to wear, and has an excellent absorption rate even when it repeatedly absorbs body fluids.

[Aspect 12]
the absorbent core having a longitudinal centerline extending through the widthwise center in the longitudinal direction;
the absorbent core has a region in the front absorbent core portion in which the narrow portions of the longitudinal grooves are disposed so as to move away from the longitudinal centerline as they approach the end of the absorbent core;
12. The absorbent article of claim 11.

In the above absorbent article, the narrow portion of the vertical groove has a predetermined area, so that when body fluids are repeatedly absorbed, the front absorbent core portion is more likely to diffuse the body fluid outward in the width direction of the front absorbent core portion, making it easier for the entire front absorbent core portion to absorb the body fluid. As a result, when the above absorbent article repeatedly absorbs body fluids, it has a superior absorption speed and the front absorbent core portion of the absorbent core is less likely to become thick locally.

[Aspect 13]
the absorbent core having a longitudinal centerline extending through the widthwise center in the longitudinal direction;
the absorbent core has an area in the rear absorbent core portion where the wide portion of the longitudinal groove is disposed so as to move away from the longitudinal centerline as it approaches the end of the absorbent core,
13. The absorbent article according to claim 11 or 12.

In the absorbent article, the wide portion of the vertical groove has a predetermined area, so that the rear absorbent core portion can easily diffuse body fluids outward in the width direction of the rear absorbent core portion, and the entire rear absorbent core portion can easily absorb body fluids. As a result, the effect of aspect 11 can be more easily achieved.

[Aspect 14]
the front absorbent core portion is divided into three equal parts in the longitudinal direction, and is partitioned into a front absorbent core first part, a front absorbent core second part and a front absorbent core third part in this order from the end of the absorbent core,
The narrow portion is disposed at least in the front absorbent core third portion.
The absorbent article according to any one of aspects 11 to 13.

Generally, in absorbent articles, bodily fluids tend to be excreted near the center line in the width direction.
In the above-mentioned absorbent article, the narrow portion is disposed at least in the front absorbent core third portion that is in contact with the widthwise center line of the front absorbent core portion, so that when body fluids are repeatedly absorbed and the rear absorbent core portion has difficulty absorbing body fluids, the narrow portion of the vertical groove makes it easier for the front absorbent core portion to absorb the body fluids.

[Aspect 15]
Aspects 15. The absorbent article according to any one of aspects 11 to 14, wherein the narrow portion and the wide portion of the longitudinal groove are directly connected to each other.
In the absorbent article, the narrow portion and the wide portion have a connecting portion that directly connects them, and therefore the absorbent article is more likely to exhibit the effect of aspect 11.

[Definition]
・"Direction along a specified direction"
In this specification, the term "direction along a predetermined direction" refers to a direction having an intersecting angle of less than 45° with the predetermined direction. The above-mentioned direction along a predetermined direction refers to a direction having an intersecting angle of preferably 30° or less, more preferably 20° or less, and even more preferably 5° or less with the predetermined direction.

In this specification, the term "direction parallel to a predetermined direction" means a direction having an intersection angle of 5° or less with the predetermined direction. The direction parallel to the predetermined direction preferably has an intersection angle of 3° or less with the predetermined direction, more preferably 1° or less, and even more preferably 0°.
Examples of the predetermined direction include the longitudinal direction, the width direction, and the thickness direction.
In this specification, when something is simply referred to as extending in a certain direction, or (a length) in a certain direction, it means a direction having an intersecting angle of 0° with the certain direction.

The absorbent article according to the present disclosure will be described in detail below.
First Embodiment
Figures 1 to 4 are diagrams for explaining an absorbent article, specifically a disposable diaper 1, according to one embodiment of the present disclosure (hereinafter, may be referred to as the "first embodiment"). Specifically, Figure 1 is a plan view of the disposable diaper 1. Figure 2 is a plan view of the absorbent body 7 of the disposable diaper 1 (plan view of the non-skin side 13 of the absorbent core 9). Figure 3 is a plan view of the non-skin side 13 of the absorbent core 9 of the disposable diaper 1. Figure 4 is an end view taken along the line IV-IV of Figure 3.

The disposable diaper 1 has a longitudinal direction L including a front direction FD and a rear direction RD, which are perpendicular to each other, a width direction W, and a thickness direction T. The disposable diaper 1 also has a longitudinal centerline LC that passes through the center of the width direction W of the disposable diaper 1 and extends in the longitudinal direction L of the disposable diaper 1, and a widthwise centerline WC that passes through the center of the longitudinal direction L of the disposable diaper 1 and extends in the width direction W of the disposable diaper 1.
The disposable diaper 1 comprises a liquid-permeable sheet 3, a liquid-impermeable sheet 5, and an absorbent body 7 between the liquid-permeable sheet 3 and the liquid-impermeable sheet 5.

As shown in FIG. 1, the disposable diaper 1 has a pair of leak-proof walls 101 including elastic members 103, a fixing portion 105 for fixing the leak-proof walls 101 to the liquid-permeable sheet 3, elastic members 107, a tape fastener 109, etc., but these are well known in the art and therefore will not be described here.

The absorbent body 7 has the same longitudinal direction L, width direction W, and thickness direction T as the disposable diaper 1, which are perpendicular to each other, and is composed of an absorbent core 9 having a skin side 11 on the liquid permeable sheet 3 side and a non-skin side 13 on the liquid impermeable sheet 5 side, and a core wrap 15 made of tissue that covers the skin side 11 and non-skin side 13 of the absorbent core 9.

The absorbent core 9 contains pulp fibers 17 and superabsorbent polymer 19 .
The absorbent core 9 is partitioned into a first absorbent core portion 21 disposed forward FD of the widthwise centerline WC, and a second absorbent core portion 23 disposed rearward RD of the widthwise centerline WC. The first absorbent core portion 21 has a relatively smaller mass than the second absorbent core portion 23. By disposing the first absorbent core portion 21 in the front FD and the second absorbent core portion 23 in the rear RD, the disposable diaper 1 is less likely to cause discomfort in the wearer's groin area when it repeatedly absorbs body fluids.

The first absorbent core portion 21 is divided into three equal parts in the longitudinal direction L, and is partitioned into a first absorbent core first part 21F, a first absorbent core second part 21S, and a first absorbent core third part 21T, in order from the end on the front FD side of the absorbent core 9. The second absorbent core portion 23 is divided into three equal parts in the longitudinal direction L, and is partitioned into a second absorbent core first part 23F, a second absorbent core second part 23S, and a second absorbent core third part 23T, in order from the widthwise center line WC.

The absorbent core 9 has three longitudinal grooves extending along the longitudinal direction L, namely, a right longitudinal groove 31, a central longitudinal groove 33, and a left longitudinal groove 35, which are arranged continuously from the first absorbent core portion 21 to the second absorbent core portion 23 across the widthwise centerline WC. The right longitudinal groove 31, the central longitudinal groove 33, and the left longitudinal groove 35 are arranged in order from the right to the left of the wearer. The right longitudinal groove 31, the central longitudinal groove 33, and the left longitudinal groove 35 are arranged on the non-skin side surface 13 of the absorbent core 9. In other words, the right longitudinal groove 31, the central longitudinal groove 33, and the left longitudinal groove 35 are recessed from the non-skin side surface 13 of the absorbent core 9 toward the skin side surface 11 of the absorbent core 9.

The right vertical groove 31 is composed of a right vertical groove first narrow portion 31a arranged continuously from the first absorbent core portion 21 to the second absorbent core portion 23, a right vertical groove second wide portion 31b arranged in the second absorbent core portion 23, and a right vertical groove third narrow portion 31c arranged in the second absorbent core portion 23.
Each of the right vertical groove first narrow portion 31a, the right vertical groove second wide portion 31b, and the right vertical groove third narrow portion 31c has a plurality of lateral grooves (not indicated with reference numerals) extending in the width direction W.

The right vertical groove first narrow portion 31a and the right vertical groove second wide portion 31b are arranged to extend in the longitudinal direction L (longitudinal centerline LC), and the right vertical groove third narrow portion 31c is arranged to be farther from the longitudinal centerline LC the further rearward RD.

The first narrow right vertical groove portion 31a, the second wide right vertical groove portion 31b, and the third narrow right vertical groove portion 31c have a connecting portion (not shown) that directly connects them, and the relationship between the width W31a in the width direction W of the first narrow right vertical groove portion _31a , the width W31b in the width direction W of the second wide right vertical groove portion _31b , and the width _{W31c in the width direction W of the third narrow right vertical groove portion 31c} is as follows:
Width _W31b > Width _W31a = Width _W31c

The left vertical groove 35 is composed of a left vertical groove first narrow portion 35a arranged continuously from the first absorbent core portion 21 to the second absorbent core portion 23, a left vertical groove second wide portion 35b arranged in the second absorbent core portion 23, and a left vertical groove third narrow portion 35c arranged in the second absorbent core portion 23.
Each of the left vertical groove first narrow portion 35a, the left vertical groove second wide portion 35b, and the left vertical groove third narrow portion 35c has a plurality of lateral grooves (not indicated with reference numerals) extending in the width direction W.

The first narrow portion 35a of the left vertical groove and the second wide portion 35b of the left vertical groove are arranged to extend in the longitudinal direction L (longitudinal centerline LC), and the third narrow portion 35c of the left vertical groove is arranged to be farther from the longitudinal centerline LC the further rearward RD.

The first left vertical groove narrow portion 35a, the second left vertical groove wide portion 35b, and the third left vertical groove narrow portion 35c have a connecting portion (not shown) that directly connects them, and the relationship between the width _W35a in the width direction W of the first right vertical groove narrow portion 31a, the width _W35b in the width direction W of the second right vertical groove wide portion 31b, and the width _W35c in the width direction W of the third right vertical groove narrow portion 31c is as follows:
Width W _35b > Width W _35a = Width W _35c

Since the right vertical groove first narrow portion 31a and the right vertical groove second wide portion _31b satisfy the relationship of width _W31b > width W31a, and the left vertical groove first narrow portion 35a and the left vertical groove second wide portion 35b satisfy the relationship of width _W35b > width _W35a , the disposable diaper 1 tends to have an excellent absorption rate when repeatedly absorbing body fluids, and the absorbent core 9 is less likely to become thick.

As shown in FIG. 4, the average density of the superabsorbent polymer 19 on the skin side 11 of the absorbent core 9 is higher than the average density of the superabsorbent polymer 19 on the non-skin side 13 of the absorbent core 9. As a result, when body fluids are repeatedly absorbed, the absorbent core 9 can diffuse the body fluid on the non-skin side 13 side, providing excellent diffusion of body fluids and making it easier to reduce free water on the skin side 11 side, making the wearer feel more dry.

The right and left first narrow portions 31a, 35a are disposed in the first absorbent core third portion 21T, so that the first absorbent core portion 21 is less likely to become thick when it absorbs body fluids repeatedly.
The right vertical groove second wide portion 31b and the left vertical groove second wide portion 35b are disposed in the second absorbent core first portion 23F, so that when body fluids are repeatedly absorbed, the second absorbent core portion 23 tends to have excellent repetitive body fluid absorption properties and absorption speed.

The absorbent core 9 has an hourglass shape, and the first absorbent core portion 21 has a pair of constricted portions 37 recessed toward the longitudinal center line LC. This allows the disposable diaper 1 to have a high absorption rate when repeatedly absorbing body fluids, and prevents the absorbent core 9, and in particular the pair of constricted portions 37, from becoming thick.

The right vertical groove first narrow portion 31a and the right vertical groove second wide portion 31b have a connecting portion (not shown) that directly connects them, and the left vertical groove first narrow portion 35a and the left vertical groove second wide portion 35b have a connecting portion (not shown) that directly connects them. This allows the disposable diaper 1 to have a high absorption rate and prevent the absorbent core 9 from becoming thick when it repeatedly absorbs body fluids.

The absorbent core 9 has, in the first absorbent core portion 21, six vertical grooves 51 arranged on the non-skin side 13 and an aperture portion 55 which is a through hole that penetrates from the skin side 11 to the non-skin side 13. The absorbent core 9 also has, in the second absorbent core portion 23, eight vertical grooves 53 arranged on the non-skin side 13 and an aperture portion 57 which is a through hole that penetrates from the skin side 11 to the non-skin side 13, but a description of these will be omitted.

Second Embodiment
Fig. 5 is a diagram for explaining a disposable diaper (not shown) according to another embodiment of the present disclosure (hereinafter, may be referred to as a "second embodiment"). Specifically, Fig. 5 is a plan view of the non-skin side surface 13 of an absorbent core 9 included in the disposable diaper.
The disposable diaper according to the second embodiment is the same as the disposable diaper 1 according to the first embodiment except for the absorbent core 9, and therefore a description of the parts other than the absorbent core 9 will be omitted. Also, with regard to the absorbent core 9 according to the second embodiment, a description of the same parts as those of the absorbent core 9 according to the first embodiment will be omitted.

The absorbent core 9 has four vertical grooves extending along the longitudinal direction L, which are arranged continuously from the first absorbent core part 21 to the second absorbent core part 23 across the widthwise center line WC: the rightmost vertical groove 201, the right vertical groove 203, the left vertical groove 205, and the leftmost vertical groove 207. The rightmost vertical groove 201, the right vertical groove 203, the left vertical groove 205, and the leftmost vertical groove 207 are arranged in order from the right to the left of the wearer. The rightmost vertical groove 201, the right vertical groove 203, the left vertical groove 205, and the leftmost vertical groove 207 are arranged on the non-skin side surface 13 of the absorbent core 9. In other words, the rightmost vertical groove 201, the right vertical groove 203, the left vertical groove 205, and the leftmost vertical groove 207 are recessed from the non-skin side surface 13 of the absorbent core 9 toward the skin side surface 11 of the absorbent core 9.

The right vertical groove 203 is composed of a right vertical groove first narrow portion 203a arranged continuously from the first absorbent core portion 21 to the second absorbent core portion 23, a right vertical groove second wide portion 203b arranged in the second absorbent core portion 23, and a right vertical groove third narrow portion 203c arranged in the second absorbent core portion 23.
Each of the right vertical groove first narrow portion 203a, the right vertical groove second wide portion 203b, and the right vertical groove third narrow portion 203c has a plurality of lateral grooves (not indicated with reference numerals) extending in the width direction W.

The right vertical groove first narrow portion 203a and the right vertical groove third narrow portion 203c are arranged to extend in the longitudinal direction L (longitudinal centerline LC), and the right vertical groove second wide portion 203b is arranged to be farther from the longitudinal centerline LC the further rearward RD.

The first narrow portion 203a, the second wide portion 203b, and the third narrow portion 203c are directly connected to each other through a connecting portion (not shown), and the relationship between the width _W203a in the width direction W of the first narrow portion 203a, the width _W203b in the width direction W of the second wide portion 203b, and the width _W203c in the width direction W of the third narrow portion 203c is as follows:
Width W _203b > Width W _203a = Width W _203c

The left vertical groove 205 is composed of a left vertical groove first narrow portion 205a arranged continuously from the first absorbent core portion 21 to the second absorbent core portion 23, a left vertical groove second wide portion 205b arranged in the second absorbent core portion 23, and a left vertical groove third narrow portion 205c arranged in the second absorbent core portion 23.
Each of the left vertical groove first narrow portion 205a, the left vertical groove second wide portion 205b, and the left vertical groove third narrow portion 205c has a plurality of lateral grooves (not indicated with reference numerals) extending in the width direction W.

The left vertical groove first narrow portion 205a and the left vertical groove third narrow portion 205c are arranged to extend in the longitudinal direction L (longitudinal centerline LC), and the left vertical groove second wide portion 205b is arranged to be farther from the longitudinal centerline LC the further rearward RD.

The first narrow portion 205a, the second wide portion 205b, and the third narrow portion 205c are directly connected to each other via a connecting portion (not shown), and the relationship between the width _W205a of the first narrow portion 205a in the width direction W, the width _W205b of the second wide portion 205b in the width direction W, and the width _W205c of the third narrow portion 205c in the width direction W is as follows:
Width _W205b > Width _W205a = Width _W205c

When the right vertical groove first narrow portion 203a and the right vertical groove second wide portion 203b satisfy the relationship of width _W205b > width _W205a , and when the left vertical groove first narrow portion 205a and the left vertical groove second wide portion 205b satisfy the relationship of width _W205b > width _W205a , the disposable diaper tends to have a superior absorption rate when repeatedly absorbing body fluids, and the absorbent core 9 is less likely to become thick.

In the absorbent core 9, the right vertical groove second wide portion 203b and the left vertical groove second wide portion 205b are arranged in the second absorbent core portion 23 so that they are farther away from the longitudinal centerline LC the closer they are to the end of the absorbent core 9, i.e., the further rearward RD. This makes it easier for the second absorbent core portion 23 to diffuse bodily fluids to the outside in the width direction W of the second absorbent core portion 23, making it easier for the entire second absorbent core portion 23 to absorb bodily fluids.

The right and left first narrow portions 203a, 205a are disposed in the first absorbent core third portion 21T, so that the first absorbent core portion 21 is less likely to become thick when it absorbs body fluids repeatedly.
The right vertical groove second wide portion 203b and the left vertical groove second wide portion 205b are disposed in the second absorbent core first portion 23F, so that when body fluids are repeatedly absorbed, the second absorbent core portion 23 tends to have excellent repetitive body fluid absorption properties and absorption speed.

The right vertical groove first narrow portion 203a and the right vertical groove second wide portion 203b have a connecting portion (not shown) that directly connects them, and the left vertical groove first narrow portion 205a and the left vertical groove second wide portion 205b have a connecting portion (not shown) that directly connects them. This provides a high absorption rate and prevents the absorbent core 9 from becoming thick when the disposable diaper repeatedly absorbs bodily fluids.

The absorbent core 9 has, in the first absorbent core portion 21, six vertical grooves 221 arranged on the non-skin side 13 and an aperture portion 225 which is a through hole that penetrates from the skin side 11 to the non-skin side 13. The absorbent core 9 also has, in the second absorbent core portion 23, eight vertical grooves 223 arranged on the non-skin side 13 and an aperture portion 227 which is a through hole that penetrates from the skin side 11 to the non-skin side 13, but a description of these will be omitted.

Third Embodiment
Fig. 6 is a diagram for explaining a disposable diaper (not shown) according to still another embodiment (hereinafter, may be referred to as a "third embodiment") of the present disclosure. Specifically, Fig. 6 is a plan view of the skin side surface 11 of an absorbent core 9 included in the disposable diaper.
The disposable diaper according to the third embodiment is the same as the disposable diaper 1 according to the first embodiment except for the absorbent core 9, and therefore a description of the parts other than the absorbent core 9 will be omitted. Also, with regard to the absorbent core 9 according to the third embodiment, a description of the same parts as those of the absorbent core 9 according to the first embodiment will be omitted.

The absorbent core 9 has two longitudinal grooves, a right longitudinal groove 301 and a left longitudinal groove 303, which are arranged continuously from the first absorbent core portion 21 to the second absorbent core portion 23 across the widthwise center line WC and extend in the longitudinal direction L. The right longitudinal groove 301 and the left longitudinal groove 303 are arranged in order from the right to the left of the wearer. The right longitudinal groove 301 and the left longitudinal groove 303 are arranged on the skin side surface 11 of the absorbent core 9. In other words, the right longitudinal groove 301 and the left longitudinal groove 303 are recessed from the skin side surface 11 of the absorbent core 9 toward the non-skin side surface 13 of the absorbent core 9.

The right vertical groove 301 is composed of a right vertical groove first narrow portion 301a arranged in the first absorbent core portion 21 and a right vertical groove second wide portion 301b arranged continuously from the first absorbent core portion 21 to the second absorbent core portion 23.
Each of the right vertical groove first narrow portion 301a and the right vertical groove second wide portion 301b includes a plurality of lateral grooves (not indicated with reference numerals) extending in the width direction W.

The right vertical groove first narrow portion 301a and the right vertical groove second wide portion 301b are directly connected to each other via a connecting portion (not shown), and the relationship between the width _W301a in the width direction W of the right vertical groove first narrow portion 301a and the width _{W301b in the width direction W of the right vertical groove second wide portion 301b} is as follows:
Width W _301b > Width W _301a

The left vertical groove 303 is composed of a left vertical groove first narrow portion 303a arranged in the first absorbent core portion 21 and a left vertical groove second wide portion 303b arranged continuously from the first absorbent core portion 21 to the second absorbent core portion 23.
Each of the left longitudinal groove first narrow portion 303a and the left longitudinal groove second wide portion 303b includes a plurality of lateral grooves (not indicated with reference numerals) extending in the width direction W.

The first narrow portion 303a and the second wide portion 303b of the left vertical groove have a connecting portion (not shown) that directly connects them, and the relationship between the width _W303a of the first narrow portion 303a in the width direction W and the width _W303b of the second wide portion 303b in the width direction W is as follows:
Width W _303b > Width W _303a

When the right vertical groove first narrow portion 301a and the right vertical groove second wide portion 301b satisfy the relationship of width _W301b > width _W301a , and when the left vertical groove first narrow portion 303a and the left vertical groove second wide portion 303b satisfy the relationship of width _W303b > width _W303a , the disposable diaper tends to have a superior absorption rate when repeatedly absorbing body fluids, and the absorbent core 9 is less likely to become thick.

The right and left first narrow portions 301a, 303a are disposed in the first absorbent core third portion 21T, so that the first absorbent core portion 21 is less likely to become thick when it absorbs body fluids repeatedly.
The right vertical groove second wide portion 301b and the left vertical groove second wide portion 303b are disposed in the second absorbent core first portion 23F, so that when body fluids are repeatedly absorbed, the second absorbent core portion 23 tends to have excellent repetitive body fluid absorption properties and absorption speed.

The right vertical groove first narrow portion 301a and the right vertical groove second wide portion 301b have a connecting portion (not shown) that directly connects them, and the left vertical groove first narrow portion 303a and the left vertical groove second wide portion 303b have a connecting portion (not shown) that directly connects them. This provides the disposable diaper with excellent absorption speed and prevents the absorbent core 9 from becoming thick when the disposable diaper repeatedly absorbs bodily fluids.

The absorbent core 9 has four vertical grooves 321 arranged only in the first absorbent core portion 21 and two vertical grooves 323 arranged only in the second absorbent core portion 23 on the skin side 11, but a description of these will be omitted.

Fourth Embodiment
Fig. 7 is a diagram for explaining a disposable diaper (not shown) according to still another embodiment (hereinafter, may be referred to as a "fourth embodiment") of the present disclosure. Specifically, Fig. 7 is a plan view of the skin side surface 11 of an absorbent core 9 included in the disposable diaper.
The disposable diaper according to the fourth embodiment is the same as the disposable diaper 1 according to the first embodiment except for the absorbent core 9, and therefore a description of the parts other than the absorbent core 9 will be omitted. Also, with regard to the absorbent core 9 according to the fourth embodiment, a description of the same parts as those of the absorbent core 9 according to the first embodiment will be omitted.

The absorbent core 9 contains pulp fibers (not shown) and a superabsorbent polymer (not shown).
The absorbent core 9 is partitioned into a first absorbent core portion 401 disposed rearward RD of the widthwise centerline WC and a second absorbent core portion 403 disposed forward FD of the widthwise centerline WC. By disposing the first absorbent core portion 401 in the rear RD and the second absorbent core portion 403 in the front FD, the disposable diaper is less likely to cause discomfort in the buttocks of the wearer when it repeatedly absorbs body fluids.

The first absorbent core portion 401 has a relatively smaller mass than the second absorbent core portion 403. The first absorbent core portion 401 is divided into three equal parts in the longitudinal direction L, and is partitioned into a first absorbent core first portion 401F, a first absorbent core second portion 401S, and a first absorbent core third portion 401T, in order from the end portion on the rear RD side of the absorbent core 9. The second absorbent core portion 403 is also divided into three equal parts in the longitudinal direction L, and is partitioned into a second absorbent core first portion 403F, a second absorbent core second portion 403S, and a second absorbent core third portion 403T, in order from the widthwise center line WC.
The absorbent core 9 has a skin side 11 on the liquid permeable sheet 3 side and a non-skin side 13 on the liquid impermeable sheet 5 side.

The absorbent core 9 has two longitudinal grooves, a right longitudinal groove 411 and a left longitudinal groove 413, which are arranged continuously from the first absorbent core part 401 to the second absorbent core part 403 across the widthwise center line WC and extend in the longitudinal direction L. The right longitudinal groove 411 and the left longitudinal groove 413 are arranged in order from the right to the left of the wearer. The right longitudinal groove 411 and the left longitudinal groove 413 are arranged on the skin side surface 11 of the absorbent core 9. In other words, the right longitudinal groove 411 and the left longitudinal groove 413 are recessed from the skin side surface 11 of the absorbent core 9 toward the non-skin side surface 13 of the absorbent core 9.

The right vertical groove 411 is composed of a right vertical groove first narrow portion 411a arranged continuously from the first absorbent core portion 401 to the second absorbent core portion 403, and a right vertical groove second wide portion 411b arranged in the second absorbent core portion 403.
Each of the right vertical groove first narrow portion 411a and the right vertical groove second wide portion 411b includes a plurality of lateral grooves (not indicated with reference numerals) extending in the width direction W.

The right vertical groove first narrow portion 411a and the right vertical groove second wide portion 411b have a connecting portion (not shown) that directly connects them, and the relationship between the width _W411a of the right vertical groove first narrow portion 411a in the width direction W and the width _W411b of the right vertical groove second wide portion 411b in the width direction W is as follows.
Width W _411b ＞ Width W _411a

The left vertical groove 413 is composed of a left vertical groove first narrow portion 413a arranged continuously from the first absorbent core portion 401 to the second absorbent core portion 403, and a left vertical groove second wide portion 413b arranged in the second absorbent core portion 403.
Each of the left vertical groove first narrow portion 413a and the left vertical groove second wide portion 413b includes a plurality of lateral grooves (not indicated with reference numerals) extending in the width direction W.

The absorbent core 9 has an hourglass shape, and the first absorbent core portion 401 has a pair of constricted portions 37 that are recessed toward the longitudinal center line LC. This allows the disposable diaper to have a high absorption rate when repeatedly absorbing body fluids, and also prevents the absorbent core 9, and in particular the pair of constricted portions 37, from becoming thick.

The first narrow portion 413a and the second wide portion 413b of the left vertical groove have a connecting portion (not shown) that directly connects them, and the relationship between the width _W413a of the first narrow portion 413a in the width direction W and the width _W413b of the second wide portion 413b in the width direction W is as follows:
Width W _413b ＞ Width W _413a

By the right vertical groove first narrow portion 411a and the right vertical groove second wide portion 411b satisfying the relationship of width _W411b > width _W411a , and by the left vertical groove first narrow portion 413a and the left vertical groove second wide portion 413b satisfying the relationship of width _W413b > width _W413a , the disposable diaper becomes more likely to have an excellent absorption rate when repeatedly absorbing body fluids, and the absorbent core 9 is less likely to become thick.

The right and left first narrow portions 411a, 413a are disposed in the first absorbent core third portion 401T, so that the first absorbent core portion 401 is less likely to become thick when it absorbs body fluids repeatedly.
The right vertical groove second wide portion 411b and the left vertical groove second wide portion 413b are each disposed across the second absorbent core first portion 403F to the second absorbent core third portion 403T, so that when body fluids are repeatedly absorbed, the second absorbent core portion 403 tends to have excellent repetitive body fluid absorption properties and absorption speed.

The right vertical groove first narrow portion 411a and the right vertical groove second wide portion 411b have a connecting portion (not shown) that directly connects them, and the left vertical groove first narrow portion 413a and the left vertical groove second wide portion 413b have a connecting portion (not shown) that directly connects them. This provides the disposable diaper with excellent absorption speed and prevents the absorbent core 9 from becoming thick when the disposable diaper repeatedly absorbs bodily fluids.

The absorbent core 9 has four vertical grooves 431 arranged only in the first absorbent core portion 401 and two vertical grooves 433 arranged only in the second absorbent core portion 403 on the skin side 11, but a description of these will be omitted.

Fifth Embodiment
Fig. 8 is a diagram for explaining a disposable diaper (not shown) according to still another embodiment (hereinafter, may be referred to as a "fifth embodiment") of the present disclosure. Specifically, Fig. 8 is a plan view of the skin side surface 11 of an absorbent core 9 included in the disposable diaper.
The disposable diaper according to the fifth embodiment is the same as the disposable diaper 1 according to the first embodiment except for the absorbent core 9, and therefore a description of the parts other than the absorbent core 9 will be omitted. Also, with regard to the absorbent core 9 according to the fifth embodiment, a description of the same parts as those of the absorbent core 9 according to the first embodiment will be omitted.

The absorbent core 9 contains pulp fibers (not shown) and a superabsorbent polymer (not shown).
The absorbent core 9 is divided into a front absorbent core part 501 disposed forward FD from the widthwise centerline WC, and a rear absorbent core part 503 disposed rearward RD from the widthwise centerline WC. The front absorbent core part 501 has a relatively larger mass than the rear absorbent core part 503. The front absorbent core part 501 is divided into three equal parts in the longitudinal direction L, and is divided into a front absorbent core first part 501F, a front absorbent core second part 501S, and a front absorbent core third part 501T in order from the end of the front FD side of the absorbent core 9. The rear absorbent core part 503 is also divided into three equal parts in the longitudinal direction L, and is divided into a rear absorbent core first part 503F, a rear absorbent core second part 503S, and a rear absorbent core third part 503T in order from the widthwise centerline WC.
The absorbent core 9 has a skin side 11 on the liquid permeable sheet 3 side and a non-skin side 13 on the liquid impermeable sheet 5 side.

The absorbent core 9 has two vertical grooves, a right vertical groove 505 and a left vertical groove 507, which are arranged from the front absorbent core part 501 to the rear absorbent core part 503 across the widthwise centerline WC and extend along the longitudinal direction L. The right vertical groove 505 and the left vertical groove 507 are arranged in order from the right to the left of the wearer. The right vertical groove 505 and the left vertical groove 507 are arranged on the skin side surface 11 of the absorbent core 9. In other words, the right vertical groove 505 and the left vertical groove 507 are recessed from the skin side surface 11 of the absorbent core 9 toward the non-skin side surface 13 of the absorbent core 9.

The right vertical groove 505 is composed of a right vertical groove first narrow portion 505a arranged in the front absorbent core portion 501 and a right vertical groove second wide portion 505b arranged continuously from the front absorbent core portion 501 to the rear absorbent core portion 503.
Each of the right vertical groove first narrow portion 505a and the right vertical groove second wide portion 505b includes a plurality of lateral grooves (not indicated with reference numerals) extending in the width direction W.

The right vertical groove first narrow portion 505a and the right vertical groove second wide portion 505b have a connecting portion (not shown) that directly connects them, and the relationship between the width _W505a of the right vertical groove first narrow portion 505a in the width direction W and the width _W505b of the right vertical groove second wide portion 505b in the width direction W is as follows:
Width W _505b ＞ Width W _505a

The left vertical groove 507 is composed of a left vertical groove first narrow portion 507a arranged in the front absorbent core portion 501 and a left vertical groove second wide portion 507b arranged continuously from the front absorbent core portion 501 to the rear absorbent core portion 503.
Each of the left longitudinal groove first narrow portion 507a and the left longitudinal groove second wide portion 507b includes a plurality of lateral grooves (not indicated with reference numerals) extending in the width direction W.

The first narrow portion 507a and the second wide portion 507b of the left vertical groove have a connecting portion (not shown) that directly connects them, and the relationship between the width _W507a of the first narrow portion 507a in the width direction W and the width _W507b of the second wide portion 507b in the width direction W is as follows:
Width W _507b ＞ Width W _507a

By the right vertical groove first narrow portion 505a and the right vertical groove second wide portion 505b satisfying the relationship of width _W505b > width _W505a , and by the left vertical groove first narrow portion 507a and the left vertical groove second wide portion 507b satisfying the relationship of width _W507b > width _W507a , the disposable diaper becomes more likely to have an excellent absorption rate when repeatedly absorbing body fluids, and the absorbent core 9 becomes less likely to become thick.

The first narrow portion 505a of the right vertical groove and the first narrow portion 507a of the left vertical groove are disposed in the second portion 501S of the front absorbent core and the third portion 501T of the front absorbent core, respectively, so that the front absorbent core portion 501 is less likely to become thick when repeatedly absorbing body fluids.
The right vertical groove second wide portion 505b and the left vertical groove second wide portion 507b are each continuously disposed from the front absorbent core third portion 501T to the rear absorbent core third portion 503T, so that when body fluids are repeatedly absorbed, the rear absorbent core portion 503 tends to have excellent repetitive body fluid absorption properties and absorption speed.

The right vertical groove first narrow portion 505a and the right vertical groove second wide portion 505b have a connecting portion (not shown) that directly connects them, and the left vertical groove first narrow portion 507a and the left vertical groove second wide portion 507b have a connecting portion (not shown) that directly connects them. This provides a high absorption rate and prevents the absorbent core 9 from becoming thick when the disposable diaper repeatedly absorbs bodily fluids.

In the absorbent core 9, the front absorbent core portion 501 has a region (not shown) in which the right vertical groove first narrow portion 505a and the left vertical groove first narrow portion 507a are each arranged so as to be farther from the longitudinal centerline LC the closer they are to the end on the front FD side of the absorbent core 9. This makes it easier for the front absorbent core portion 501 to diffuse bodily fluids outward in the width direction W of the front absorbent core portion 501, making it easier for the entire front absorbent core portion 501 to absorb bodily fluids.

The absorbent core 9 has six vertical grooves 521 arranged only in the front absorbent core portion 501 and two vertical grooves 523 arranged only in the rear absorbent core portion 503 on the skin side 11, but a description of these will be omitted.

The absorbent article according to the present disclosure (hereinafter, sometimes referred to as "First Disclosure") is not particularly limited, and examples thereof include disposable diapers, urine absorption pads, incontinence pads, incontinence liners, and the like.
In the present disclosure, the longitudinal direction and the width direction respectively refer to the longitudinal direction and the width direction of the absorbent article, unless otherwise specified. Note that the absorbent core according to the present disclosure often has the same longitudinal direction and width direction as the longitudinal direction and the width direction of the absorbent article, respectively.

The absorbent article according to the present disclosure has a widthwise centerline passing through a center in a longitudinal direction of the absorbent article and extending in a width direction of the absorbent article. The absorbent article according to the present disclosure also has a longitudinal centerline passing through a center in a width direction of the absorbent article and extending in a longitudinal direction of the absorbent article.
In the present disclosure, the above-mentioned widthwise centerline and longitudinal centerline respectively refer to the widthwise centerline and longitudinal centerline of the absorbent article. In particular, it should be noted that the widthwise centerline that defines the first absorbent core portion and the second absorbent core portion of the absorbent core is the above-mentioned widthwise centerline of the absorbent article.

In the absorbent core according to the present disclosure, the first absorbent core portion can be divided into three equal parts in the longitudinal direction, and can be partitioned into a first absorbent core first portion, a first absorbent core second portion, and a first absorbent core third portion, in that order from the end of the absorbent core. Note that the end means the front end when the first absorbent core portion is disposed in the front, and means the rear end when the first absorbent core portion is disposed in the rear.

In addition, in the absorbent core according to the present disclosure, the second absorbent core portion can be divided into three equal parts in the longitudinal direction, and partitioned in order from the widthwise centerline into a second absorbent core first portion, a second absorbent core second portion, and a second absorbent core third portion.

In the absorbent article according to the present disclosure, the absorbent core may contain pulp fibers, superabsorbent polymer particles, etc. The absorbent core may be arranged as an absorbent body including the absorbent core and a core wrap covering the absorbent core from the skin side and/or the non-skin side. The core wrap may be any of those known in the art, such as tissue, nonwoven fabric (e.g., spunbond nonwoven fabric, SMS nonwoven fabric, spunlace nonwoven fabric, etc.), etc.
The manufacturing method of the absorbent core is not particularly limited, but examples thereof include an integrally molded absorbent core.

The pulp fibers may be any known pulp fiber in the art, and may include, for example, wood pulp fibers and non-wood pulp fibers. The wood pulp fibers may include, for example, softwood pulp fibers and hardwood pulp fibers. The non-wood pulp fibers may include, for example, straw pulp fibers, bagasse pulp fibers, reed pulp fibers, kenaf pulp fibers, mulberry pulp fibers, bamboo pulp fibers, hemp pulp fibers, cotton pulp fibers (for example, cotton linters), etc.

As the superabsorbent polymer particles, those known in the art may be used without any particular restrictions, and examples thereof include superabsorbent polymer particles such as polyacrylate-based, polysulfonate-based, maleic anhydride-based, polyacrylamide-based, polyvinyl alcohol-based, polyethylene oxide-based, polyaspartate-based, polyglutamate-based, polyalginate-based, starch-based, and cellulose-based particles; starch-based or cellulose-based superabsorbent polymer particles such as starch-acrylic acid (salt) graft copolymer, saponified starch-acrylonitrile copolymer, and crosslinked product of sodium carboxymethylcellulose.

The absorbent core according to the present disclosure may further include other materials known in the art, such as fibers other than pulp fibers, such as natural fibers, synthetic fibers, semi-synthetic fibers, etc. The natural fibers include regenerated cellulose fibers. The regenerated cellulose fibers include rayon fibers, such as viscose rayon, polynosic, and modal obtained from viscose, cuprammonium rayon fibers (also called "cupra") obtained from a cuprammonium salt solution of cellulose, and lyocell and tencel obtained by an organic solvent spinning method using an organic solvent that is a mixed solution of an organic compound and water, without going through a cellulose derivative. The semi-synthetic fibers include semi-synthetic cellulose fibers, such as acetate fibers, such as triacetate fibers and diacetate fibers.

When the absorbent core according to the present disclosure comprises pulp fibers, the absorbent core comprises pulp fibers in a basis weight of preferably 50 to 400 g/m ² , and more preferably 100 to 350 g/m ² . Also, when the absorbent core according to the present disclosure comprises superabsorbent polymer particles, the absorbent core comprises superabsorbent polymer particles in a basis weight of preferably 50 to 400 g/m ² , and more preferably 100 to 350 g/m ² . In view of the present disclosure.

In the present disclosure, the basis weight of the absorbent core and the superabsorbent polymer particles is measured as follows.
(1) The absorbent core is removed from the absorbent article by a method known in the art, and a sample A of a predetermined size (e.g., 5 cm x 5 cm) is cut out. After drying in an atmosphere of 100°C or higher, the mass: m _A (g) and area: S _A (m ² ) of sample A are measured.
(2) The basis weight of sample A: bs _A (g/m ² ) is calculated using the following formula:
_bsA (g/ ^m2 ) = _mA / _SA
It is calculated as follows.

(3) The same measurement is repeated ten times, and the average of the basis weights: bs _A (g/m ² ) of the ten samples A is taken as the basis weight: BS _A (g/m ² ) of the absorbent core.
(4) A sample B of a predetermined size (for example, 4 mm×4 mm) is cut out from the absorbent core, and after drying in an atmosphere of 100° C. or higher, the mass m _B (g) of the sample B is measured.
(5) The pulp fibers and superabsorbent polymer particles contained in sample B are separated, and the mass of the pulp fibers: m _pf (g) and the mass of the superabsorbent polymer particles: m _sap (g) are measured.

(6) The basis weight of the pulp fiber in sample B: bs _pf (g/m ² ) was calculated using the following formula:
bs _pf (g/m ² ) = BS _A × m _pf /m _B
It is calculated as follows.
(7) The same measurement is repeated ten times, and the average of the basis weights of the ten pulp fibers: bs _pf (g/m ² ) is taken as the basis weight of the pulp fiber: BS _pf (g/m ² ).
(8) The basis weight of the superabsorbent polymer particles in sample B: bs _sap (g/m ² ) was calculated using the following formula:
bs _sap (g/ ^m2 ) = BS _A × m _sap /m _B
It is calculated as follows.
(9) The same measurement is repeated 10 times, and the average of the basis weights: bs _sap (g/m ² ) of the 10 superabsorbent polymer particles is taken as the basis weight: BS _sap (g/m ² ) of the superabsorbent polymer particles.

In the absorbent article according to the present disclosure, the absorbent core is divided by the widthwise centerline into a first absorbent core portion having a relatively small mass and a second absorbent core portion having a relatively large mass (i.e., the second absorbent core portion having a larger mass than the first absorbent core portion).

In the absorbent article according to the present disclosure, the second absorbent core portion has a mass greater than that of the first absorbent core portion, preferably by 1 to 60% by mass, more preferably by 5 to 50% by mass, and even more preferably by 15 to 45% by mass. As a result, when bodily fluids (e.g., urine) reach the absorbent core, the wide portions of the vertical grooves make it easier for the bodily fluids to diffuse into the second absorbent core portion, which has a relatively large mass, and the narrow portions of the vertical grooves make it harder for the bodily fluids to diffuse into the first absorbent core portion, which has a relatively small mass.

In this specification, the mass of the first absorbent core portion and the mass of the second absorbent core portion can be compared by removing the absorbent core from the absorbent article by methods known in the art and directly measuring the mass of the first absorbent core portion and the mass of the second absorbent core portion.

The first and second absorbent core portions can be disposed at the front and rear of the absorbent article, respectively, such that the absorbent article is less likely to cause discomfort in the groin area of the wearer when repeatedly absorbing body fluids.
The first and second absorbent core portions can be disposed at the rear and front of the absorbent article, respectively, so that the absorbent article is less likely to cause discomfort to the wearer's buttocks when repeatedly absorbing body fluids.

In the absorbent article according to the present disclosure, the absorbent core has longitudinal grooves extending in the longitudinal direction, straddling the widthwise centerline and arranged continuously from the first absorbent core portion to the second absorbent core portion.
The longitudinal groove may be one or more, and may be arranged symmetrically with respect to the longitudinal center line.
The longitudinal grooves may be disposed on either the skin side or the non-skin side of the absorbent core, in view of the effects of the present disclosure.

The longitudinal groove may further include one or more lateral grooves extending in a direction along the width direction. When the longitudinal groove, which is a main groove, further includes a lateral groove, which is a secondary groove, the body fluid can be diffused in the width direction.
The width of the lateral grooves, which are the minor grooves (the length in the longitudinal direction of the absorbent article), is preferably narrower than the width of the longitudinal grooves, which are the major grooves (the length in the width direction of the absorbent article), in order to diffuse bodily fluids in the longitudinal direction.

The lateral grooves may be lateral grooves with ends (lateral grooves that are not connected to other longitudinal grooves), and may not have ends and may connect multiple longitudinal grooves, but lateral grooves with ends are preferred. This is to preferentially diffuse bodily fluids in the longitudinal direction.

The fact that the vertical grooves have the horizontal grooves does not affect the fact that the vertical grooves are arranged continuously from the first absorbent core portion to the second absorbent core portion. This is because even if the vertical grooves further have horizontal grooves, the vertical grooves can still allow the body fluid absorbed by the absorbent article to flow in the longitudinal direction along the vertical grooves.

The longitudinal grooves have a relatively narrow portion located in the first absorbent core portion and a relatively wide portion (i.e., a wide portion wider than the narrow portion) located in the second absorbent core portion. This allows the absorbent article to have a high absorption rate and prevent the absorbent core from becoming thick when repeatedly absorbing bodily fluids.

The widths of the narrow and wide portions refer to the lengths in the width direction, similar to the width of the longitudinal grooves.
In the case where the absorbent core according to the present disclosure has a plurality of longitudinal grooves, it is sufficient that some of the plurality of longitudinal grooves have the narrow portion and the wide portion, from the viewpoint of the effect of the present disclosure.

The wide portion preferably has a width of 4.0 to 8.0 mm, more preferably 4.5 to 7.5 mm, and even more preferably 5.0 to 7.0 mm. The narrow portion, assuming a smaller width than the wide portion, preferably has a width of 2.0 to 6.0 mm, more preferably 2.5 to 5.5 mm, and even more preferably 3.0 to 6.0 mm. The wide portion also has a larger width than the narrow portion, preferably 1.0 to 3.0 mm, more preferably 1.3 to 2.7 mm, and even more preferably 1.5 to 2.5 mm, which is larger than the narrow portion. As a result, when the absorbent article repeatedly absorbs bodily fluids, it has a superior absorption rate and the absorbent core is less likely to become thick.

In this disclosure, the width of the flutes (narrow and wide portions) is measured as follows.
(1) After the absorbent article is immersed in liquid nitrogen and frozen, the absorbent article is cut with a razor or the like at multiple locations passing through the longitudinal grooves to obtain multiple cross-sectional samples. The multiple cross-sectional samples are formed in the width direction and the thickness direction.
(2) Return the multiple cross-sectional samples to room temperature, and use an electron microscope (e.g., Keyence VE7800) to obtain cross-sectional images at a magnification of 50. From the multiple cross-sectional images, the width of the vertical grooves on the surface (skin side or non-skin side) is determined.
(3) The average width of the longitudinal grooves for the ten samples is taken as the width of the longitudinal grooves.
(4) For optional transverse grooves, measurements are similarly performed, except that a plurality of cross-sectional samples (formed in the longitudinal and thickness directions) are obtained at a plurality of locations of the absorbent article passing through the transverse grooves.

The narrow portion of the longitudinal groove and the wide portion of the longitudinal groove may have the same depth (depth in the thickness direction of the absorbent article), which makes it easier to achieve the effects of the present invention.
The narrow portion of the longitudinal groove and the wide portion of the longitudinal groove may have a depth greater than a depth of the narrow portion, which makes it easier to achieve the effects of the present invention.

The absorbent article has an excretory opening contact area that contacts the wearer's excretory opening, and the absorbent core has an excretory opening contact area equivalent area that corresponds to the excretory opening contact area. The excretory opening contact area equivalent area completely overlaps with the excretory opening contact area in the thickness direction of the absorbent article.

In the vertical groove, the narrow and wide portions do not have to be directly connected as long as they are connected via the area equivalent to the excretory opening contact area. This is because the bodily fluid excreted from the wearer's excretory opening reaches the area equivalent to the excretory opening contact area of the absorbent core from the excretory opening contact area of the absorbent article, and the effect of the present disclosure can be achieved as long as the narrow and wide portions are connected via the area equivalent to the excretory opening contact area.

In the vertical groove according to the present disclosure, when the narrow portion and the wide portion are connected via a region corresponding to the excretion opening contact area, the vertical groove may be narrower than the narrow portion in the region corresponding to the excretion opening contact area, or may be wider than the narrow portion and narrower than the wide portion, or may be wider than the wide portion.

In the absorbent core according to the present disclosure, it is preferable that the longitudinal grooves have connecting portions that directly connect the narrow portions and the wide portions. This allows the absorbent article to have a high absorption rate and prevent the absorbent core from becoming thick when repeatedly absorbing bodily fluids.

In the absorbent core according to the present disclosure, when the narrow portion and the wide portion have the connection point, it is preferable that the connection point is present in the third portion of the first absorbent core, the widthwise centerline, or the first portion of the second absorbent core. This allows the absorbent article to have a high absorption rate and prevent the absorbent core from becoming thick when the absorbent article repeatedly absorbs body fluids.

In addition, when the longitudinal groove further includes a transverse groove, and the width of the longitudinal groove changes in front and behind the transverse groove (i.e., there is a narrow portion in front or behind the transverse groove, and a wide portion in front or behind the transverse groove), the narrow portion and the wide portion start in the center of the transverse groove in the longitudinal direction.

In the absorbent core according to the present disclosure, the absorbent core may have an area in the second absorbent core portion where the wide portion of the longitudinal groove is disposed so as to move away from the longitudinal centerline as it approaches the end of the absorbent core. This makes it easier for the second absorbent core portion to diffuse bodily fluids to the outside in the width direction of the second absorbent core portion, making it easier for the entire second absorbent core portion to absorb bodily fluids.

In the absorbent core according to the present disclosure, the absorbent core may have an area in the first absorbent core portion where the narrow portions of the longitudinal grooves are arranged so as to move away from the longitudinal centerline as they approach the ends of the absorbent core. This makes it easier for the first absorbent core portion to diffuse bodily fluids outward in the width direction of the first absorbent core portion, making it easier for the entire first absorbent core portion to absorb bodily fluids.

The narrow portion is disposed at least in the third portion of the first absorbent core, so that the narrow portion of the longitudinal groove makes it difficult for bodily fluids to diffuse into the first absorbent core portion having a relatively small mass.
From the above viewpoint, the end of the narrow portion on the first absorbent core first portion side can be arranged in the first absorbent core first portion, the first absorbent core second portion or the first absorbent core third portion, and the end of the narrow portion on the second absorbent core third portion side can be arranged in the first absorbent core third portion or the second absorbent core first portion.

From this viewpoint, the narrow portion can be arranged, for example, only in the first absorbent core third portion, can be arranged from the second absorbent core first portion to the first absorbent core third portion, can be arranged from the first absorbent core third portion to the first absorbent core second portion, and can be arranged from the first absorbent core third portion to the first absorbent core first portion via the first absorbent core second portion.

The narrow portion has a length in the longitudinal direction of preferably 5% or more, more preferably 20% or more, even more preferably 50% or more, even more preferably 70% or more, and even more preferably 100% or more of the length in the longitudinal direction of the third portion of the first absorbent core. The narrow portion also has a length in the longitudinal direction of preferably 300% or less, more preferably 250% or less, even more preferably 200% or less, and even more preferably 150% or less of the length in the longitudinal direction of the third portion of the first absorbent core. This allows the narrow portion of the vertical groove to diffuse body fluid to a certain extent in the first absorbent core portion, which has a relatively small mass of the absorbent core, while making it relatively more difficult for the body fluid to diffuse in the second absorbent core portion.

The wide portion is disposed at least in the first portion of the second absorbent core, so that the wide portion of the longitudinal groove can spread bodily fluids more easily toward the second absorbent core portion having a relatively large mass.
From the above viewpoint, the end of the wide portion on the first absorbent core first portion side can be arranged in the first absorbent core third portion or the second absorbent core first portion. Also, the end of the wide portion on the second absorbent core third portion side can be arranged in the second absorbent core first portion, the second absorbent core second portion or the second absorbent core third portion.

From this viewpoint, the wide portion can be arranged, for example, only in the second absorbent core first part, can be arranged from the first absorbent core third part to the second absorbent core first part, can be arranged from the second absorbent core first part to the second absorbent core second part, and can be arranged from the second absorbent core first part to the second absorbent core third part via the second absorbent core second part.

The wide portion has a length in the longitudinal direction of preferably 5% or more, more preferably 20% or more, even more preferably 50% or more, even more preferably 70% or more, and even more preferably 100% or more of the length in the longitudinal direction of the first part of the second absorbent core. The wide portion also has a length in the longitudinal direction of preferably 300% or less, more preferably 250% or less, even more preferably 200% or less, and even more preferably 150% or less of the length in the longitudinal direction of the first part of the second absorbent core. This makes it easier for the wide portion of the longitudinal groove to diffuse bodily fluids relative to the second absorbent core part, which has a relatively large mass of the absorbent core.

The absorbent core may have any outer shape commonly used in the art, for example, a rectangular shape or an hourglass shape having a pair of waisted portions.
When the absorbent core has an hourglass shape with a pair of waisted portions, the pair of waisted portions are preferably located in the first absorbent core portion, so that when the absorbent article repeatedly absorbs body fluids, the absorbent core, particularly the pair of waisted portions, is prevented from becoming thicker while providing a superior absorption rate.

In the absorbent article according to the present disclosure, when the absorbent core contains pulp fibers and a superabsorbent polymer, it is preferable that the average density of the superabsorbent polymer on the skin side of the absorbent core is higher than the average density of the superabsorbent polymer on the non-skin side of the absorbent core, so that when the absorbent article repeatedly absorbs body fluids, the absorbent core can diffuse the body fluid on the non-skin side, providing excellent diffusion of body fluids and easily reducing free water on the skin side, making the wearer feel dry.
It is preferable that the above average density relationship is satisfied in the thickness direction of the absorbent article in an area where the absorbent core does not have longitudinal grooves.

In the present disclosure, the average density of a superabsorbent polymer can be evaluated, for example, as follows.
After the absorbent article is immersed in liquid nitrogen and frozen, the absorbent article is cut in the thickness direction using a razor or the like to obtain a cross-sectional sample at a plane intersecting the direction in which the longitudinal grooves extend. The sample is then returned to room temperature, and a cross-sectional image is obtained at a magnification of 50 times using an electron microscope (e.g., Keyence VE7800). The average density of the superabsorbent polymer particles in the cross-sectional image is then visually evaluated.

In an absorbent article according to another disclosure of the present disclosure (hereinafter, sometimes referred to as the "second disclosure"), the absorbent core can be partitioned by a front absorbent core portion and a rear absorbent core portion, instead of the partition by the first absorbent core portion and the second absorbent core portion described above. The front absorbent core portion is disposed on the front side of the absorbent article by the widthwise center line, and has a relatively larger mass than the rear absorbent core portion. The rear absorbent core portion is disposed on the rear side of the absorbent article by the widthwise center line, and has a relatively smaller mass than the front absorbent core portion.

In the second disclosure, the absorbent core has longitudinal grooves extending in the longitudinal direction, which are arranged continuously from the front absorbent core portion to the rear absorbent core portion across the widthwise centerline, and the longitudinal grooves have a relatively narrow portion arranged in the front absorbent core portion and a relatively wide portion arranged in the rear absorbent core portion. As a result, the absorbent article is less likely to have a thick absorbent core, is less likely to be uncomfortable to wear, and has an excellent absorption speed even when repeatedly absorbing bodily fluids.

In the second disclosure, the portions other than the front absorbent core portion and the rear absorbent core portion are the same as those in the first disclosure. In particular, the narrow and wide portions in the second disclosure have the same preferred ranges as those in the first disclosure, and therefore will not be described here. In the first disclosure, the first and second absorbent core portions can be read as the front and rear absorbent core portions, respectively.

The absorbent article, particularly the absorbent core, according to the present disclosure can be manufactured based on the disclosure of Patent Document 1, etc.

[Example]
The present disclosure will be described below with reference to examples, but the present disclosure is not limited to these examples.
[Production Example 1]
The absorbent core No. 1 shown in Fig. 3 was manufactured with reference to Patent Document 1, and a disposable diaper No. 1 including the absorbent core No. 1 was manufactured.
Absorbent core No. 1 had an average basis weight of 580 g/m ² (pulp fiber: 300 g/m ² , superabsorbent polymer: 280 g/m ² ), a first absorbent core portion weight of 13.8 g, and a second absorbent core portion weight of 18.5 g.
W _31a = W _31c = W _35a = W _35c = 4.0 mm, and W _31b = W _35b = 6.0 mm.
The thickness of the disposable diaper No. 1 was measured using a Peacock dial gauge manufactured by Ozaki Seisakusho Co., Ltd., with the intersection of the longitudinal centerline and the widthwise centerline as the center, and was found to be 3.5 mm.

[Comparative Production Example 1]
A disposable diaper No. 2 including an absorbent core No. 2 was produced in the same manner as in Production Example 1, except that W _31b = W _35b = 4.0 mm.

[Production Example 2]
The absorbent core No. 3 shown in Fig. 8 was manufactured with reference to Patent Document 1, and a disposable diaper No. 3 including the absorbent core No. 3 was manufactured.
Absorbent core No. 3 had an average basis weight of 540 g/m ² (pulp fiber: 300 g/m ² , superabsorbent polymer: 240 g/m ² ), a mass of the first absorbent core portion: 10.1 g, and a mass of the second absorbent core portion: 7.9 g.
W _505a =W _507a =4.0 mm, and W _505b =W _507b =6.0 mm.
The thickness of the disposable diaper No. 2 was measured with a Peacock dial gauge manufactured by Ozaki Seisakusho Co., Ltd., with the intersection of the longitudinal centerline and the widthwise centerline as the center, and was found to be 3.0 mm.

[Comparative Production Example 2]
Disposable diaper No. 4 having absorbent core No. 4 was produced in the same manner as in Production Example 2, except that W _505b = W _507b = 4.0 mm.

[Example 1 and Comparative Example 1, and Example 2 and Comparative Example 2]
The disposable diapers No. 1 to No. 4 were subjected to the absorbency test specified below to evaluate the absorption time. The results are shown in Tables 1 and 2.

[Absorbency test]
(1) A disposable diaper is set in a U-shaped device that is substantially U-shaped in side view. The disposable diaper is set in the U-shaped device such that the longitudinal center line of the disposable diaper is aligned with the center of the U-shaped device (the position with the lowest height).

<First Cycle>
(2) 120 mL (or 80 mL) of artificial urine (first injection) is injected from the burette into the central position of the absorbent body at a rate of 100 mL/10 seconds.
(3) The time from the start of the first injection of the artificial urine to when the artificial urine on the liquid-permeable sheet disappears is recorded as the absorption time (120 mL or 80 mL).
(4) Three minutes after the start of the first injection of artificial urine, the diffusion length (120 mL or 80 mL) of the artificial urine on the ventral and dorsal sides is recorded from the longitudinal center position of the absorbent body, from both the liquid-permeable sheet (TS) side and the liquid-impermeable sheet (BS) side.

<Second Cycle>
(5) 10 minutes after the start of the first injection of artificial urine, 120 mL (or 80 mL) of artificial urine (second injection) is injected from the burette into the center position of the absorbent body at a rate of 100 mL/10 seconds.
(6) The time from the start of the second injection of the artificial urine to when the artificial urine on the liquid-permeable sheet disappears is recorded as the absorption time (240 mL or 160 mL).
(7) Three minutes after the start of the second injection of artificial urine, the diffusion length (240 mL or 160 mL) of the artificial urine on the ventral and dorsal sides is recorded from the longitudinal center position of the absorbent body, from both the liquid-permeable sheet (TS) side and the liquid-impermeable sheet (BS) side.
(8) Four minutes after the start of the second injection of the artificial urine, the thickness of the disposable diaper No. 1 is measured using a Peacock dial gauge manufactured by Ozaki Seisakusho Co., Ltd., with the intersection of the longitudinal center line and the widthwise center line as the center.

<Third Cycle>
(9) 10 minutes after the start of the second injection of artificial urine, 120 mL (or 80 mL) of artificial urine (third time) is injected from the burette into the center position of the absorbent body at a rate of 100 mL/10 seconds.
(10) The time from the start of the third injection of the artificial urine to when the artificial urine on the liquid-permeable sheet disappears is recorded as the absorption time (360 mL or 240 mL).
(11) Three minutes after the start of the third injection of artificial urine, record the diffusion length (360 mL or 240 mL) of the artificial urine on the ventral and dorsal sides from the longitudinal center position of the absorbent body, from both the liquid-permeable sheet (TS) side and the liquid-impermeable sheet (BS) side.

(12) Four minutes after the start of the third injection of artificial urine, the disposable diaper is removed from the U-shaped device and left to stand in a spread-out state on a horizontal surface, and five minutes after the start of the third injection of artificial urine, about 75 g of 100 mm x 100 mm filter paper is placed on the liquid-permeable sheet of the disposable diaper with the artificial urine injection point as the center. In addition, a 3.5 kg weight of 100 mm x 100 mm x 50 mm (height) is placed on top of the filter paper. The mass of the filter paper is measured in advance before the test.
(13) Eight minutes after the start of the third injection of artificial urine, the weight is removed, the mass of the filter paper is measured, and the mass of the filter paper before the test is subtracted from it. The difference is the rewet (g).

The artificial urine was prepared by dissolving 200 g of urea, 80 g of sodium chloride, 8 g of magnesium sulfate, 3 g of calcium chloride, and approximately 1 g of dye: Blue No. 1 in 10 L of ion-exchanged water.

REFERENCE SIGNS LIST 1 disposable diaper 3 liquid permeable sheet 5 liquid impermeable sheet 7 absorbent body 9 absorbent core 11 skin side 13 non-skin side 15 core wrap 17 pulp fibre 19 superabsorbent polymer 21 first absorbent core part 23 second absorbent core part 31 right longitudinal groove 33 central longitudinal groove 35 left longitudinal groove L longitudinal direction W width direction T thickness direction FD front RD rear LC longitudinal centre line WC width centre line

Claims (12)

1. An absorbent article having a longitudinal direction and a width direction and including an absorbent core,
The absorbent article has a widthwise centerline passing through a center of the absorbent article in the longitudinal direction and extending in the width direction,
the absorbent core is partitioned by the widthwise centerline into a first absorbent core portion having a relatively small mass and a second absorbent core portion having a relatively large mass;
The absorbent core has longitudinal grooves extending in the longitudinal direction, the longitudinal grooves being arranged continuously from the first absorbent core portion to the second absorbent core portion across the widthwise centerline,
The longitudinal grooves have a relatively narrow portion disposed in the first absorbent core portion and a relatively wide portion disposed in the second absorbent core portion.
The absorbent article. The absorbent article of claim 1, wherein the first absorbent core portion and the second absorbent core portion are disposed at the front and rear, respectively. The absorbent article of claim 1, wherein the first absorbent core portion and the second absorbent core portion are disposed at the rear and the front, respectively. the absorbent core having a longitudinal centerline extending in the longitudinal direction through a center in the width direction;
The absorbent core has a region in the second absorbent core portion in which the wide portion of the longitudinal groove is disposed so as to be farther from the longitudinal centerline as it approaches the end of the absorbent core.
The absorbent article according to any one of claims 1 to 3. the absorbent core having a longitudinal centerline extending in the longitudinal direction through a center in the width direction;
The absorbent core has a region in a first absorbent core portion in which the narrow portions of the longitudinal grooves are disposed so as to move away from the longitudinal centerline as they approach an end of the absorbent core.
The absorbent article according to any one of claims 1 to 3. the first absorbent core portion is divided into three equal parts in the longitudinal direction, and partitioned into a first absorbent core first portion, a first absorbent core second portion, and a first absorbent core third portion in that order from the end portion of the absorbent core;
The narrow portion is disposed in the third portion of the first absorbent core.
The absorbent article according to any one of claims 1 to 3. the second absorbent core portion is divided into three equal parts in the longitudinal direction, and partitioned into a second absorbent core first portion, a second absorbent core second portion, and a second absorbent core third portion in this order from the center line in the width direction;
The wide portion is disposed in the first portion of the second absorbent core.
The absorbent article according to any one of claims 1 to 3. The absorbent article according to any one of claims 1 to 3, wherein the narrow portion and the wide portion of the longitudinal groove are directly connected. The absorbent article according to any one of claims 1 to 3, wherein the absorbent core has a pair of constricted portions in the first absorbent core portion. the absorbent core comprises pulp fibers and a superabsorbent polymer;
the absorbent core having a skin side and a non-skin side;
The average density of the superabsorbent polymer on the skin side of the absorbent core is higher than the average density of the superabsorbent polymer on the non-skin side of the absorbent core.
The absorbent article according to any one of claims 1 to 3. 1. An absorbent article comprising an absorbent core having a longitudinal direction and a width direction,
the absorbent core is partitioned by a widthwise centerline that passes through the center of the longitudinal direction of the absorbent article and extends in the width direction into a front absorbent core portion that is relatively large in mass and disposed at the front side of the absorbent article, and a rear absorbent core portion that is relatively small in mass and disposed at the rear side of the absorbent article,
the absorbent core has longitudinal grooves extending in the longitudinal direction, the longitudinal grooves being arranged continuously from the front absorbent core portion to the rear absorbent core portion across the widthwise centerline,
the longitudinal grooves have a relatively narrow portion disposed in the front absorbent core portion and a relatively wide portion disposed in the rear absorbent core portion;
The absorbent article. the absorbent core having a longitudinal centerline extending in the longitudinal direction through a center in the width direction;
the absorbent core has a region in the front absorbent core portion in which the narrow portions of the longitudinal grooves are disposed so as to move away from the longitudinal centerline as they approach the end of the absorbent core;
The absorbent article of claim 11.

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