WO2021107059A1

WO2021107059A1 - Absorbent article

Info

Publication number: WO2021107059A1
Application number: PCT/JP2020/044119
Authority: WO
Inventors: 丸山　貴史; 黒田　賢一郎; 野田　祐樹
Original assignee: ユニ・チャーム株式会社
Priority date: 2019-11-26
Filing date: 2020-11-26
Publication date: 2021-06-03
Also published as: JPWO2021107059A1; KR20220106759A; CN114727891B; CN114727891A; TW202133825A; CN116370204A

Abstract

Provided is an absorbent article (1) including an absorbent core (10) that has a longitudinal direction, a width direction, and a thickness direction perpendicular to one another and that has pulverized liquid-retaining fibers. The liquid-retaining fibers have broadleaf-tree liquid-retaining fibers made of broadleaf trees. The absorbent core (10) has a plurality of high-density sections (100) in each of which the liquid-retaining fibers are gathered. The absorbent core (100) has a low-density section that has a lower density of the liquid-retaining fibers than the high-density sections, at one side or the other side of at least one of the high-density sections (100) in the thickness direction.

Description

Absorbent article

The present invention relates to an absorbent article.

As an example of an absorbable article, a sanitary napkin that absorbs excrement such as menstrual blood is known. Such a sanitary napkin is provided with an absorbent body (absorbent core), and the absorbent core contains water-retaining (liquid-retaining) fibers. Usually, softwood pulp fiber having a long fiber length is used as the water-retaining fiber. Further, in Patent Document 1, in addition to the water-absorbent fiber 12F which is a water-retaining fiber, a fiber mass 11 which is an aggregate in which synthetic fibers are accumulated in a mass shape is included in the absorbable core 4, whereby the absorbable core The absorbent article having enhanced flexibility and cushioning property of No. 4 is disclosed.

JP-A-2019-98187

Such an absorbent article is required to have sufficient absorbency even when worn for a long time. However, with conventional absorbent articles, it has been difficult to increase the absorbency of excrement while forming the absorber softly so that the absorber does not twist or bend when worn for a long period of time. For example, in the absorbent article of Patent Document 1, in order to enhance the cushioning property of the absorber, a fiber mass of synthetic fibers having low water absorption is included, so that the water absorption performance may be deteriorated by that amount.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an absorbent article having both flexibility and absorbency.

The main invention for achieving the above object is an absorbent article having an absorbent core having a longitudinal direction, a width direction and a thickness direction orthogonal to each other and having crushed liquid-retaining fibers. The liquid-retaining fiber has a broad-leaved liquid-retaining fiber made of a broad-leaved tree, the absorbent core has a plurality of high-density portions in which the liquid-retaining fibers are aggregated, and the absorbent core has at least one. The absorbent article is characterized by having a low-density portion having a lower density of the liquid-retaining fibers than the high-density portion on one side or the other side of the high-density portion in the thickness direction.

Other features of the present invention will be clarified by the description in the present specification and the accompanying drawings.

According to the present invention, it is possible to provide an absorbent article having both flexibility and absorbency.

It is a schematic plan view which looked at the napkin 1 from the skin side in the thickness direction. It is a schematic cross section shown by the arrow AA in FIG. It is a figure which shows the distribution of the fiber length of the hardwood liquid-retaining fiber (hardwood pulp) and softwood liquid-retaining fiber (softwood pulp). It is a figure which shows the distribution of the average fiber width of hardwood pulp and softwood pulp. FIG. 4A is a diagram illustrating a method for producing pulverized pulp used in the absorber 10. FIG. 4B is a diagram illustrating a method for producing the absorber 10 using crushed pulp or the like. It is an enlarged photograph of a fiber mass 100 obtained when a pulp sheet containing hardwood pulp is pulverized. FIG. 6A is a schematic plan view of the fiber mass 100 when viewed from a predetermined direction. FIG. 6B is a view taken along the line BB of FIG. 6A. 7A to 7C are views for explaining the arrangement of the fiber mass 100 in the thickness direction of the absorber 10. FIG. 8A is a schematic cross-sectional view of the absorber 10 in the region where the squeezed portion 40 (linear squeezed portion 41) is provided. FIG. 8B is a schematic cross-sectional view of the absorber 10 in the region where the squeezing portion 40 (linear squeezing portion 41) having the high pressure squeezing portion 45 and the low pressure squeezing portion 46 is provided. It is the schematic sectional drawing which shows the modification of the absorber 10.

The description of this specification and the accompanying drawings will clarify at least the following matters.
An absorbent article having an absorbent core having a longitudinal direction, a width direction, and a thickness direction orthogonal to each other and having crushed liquid-retaining fibers, wherein the liquid-retaining fibers are broad-leaved tree holders made of broad-leaved trees. The absorbent core has a plurality of high-density portions in which the liquid-retaining fibers are aggregated, and the absorbent core has at least one of the high-density portions in the thickness direction. An absorbent article characterized by having a low-density portion on one side or the other side, which has a lower density of the liquid-retaining fibers than the high-density portion.

According to such an absorbent article, water such as menstrual blood absorbed by the absorbent core easily moves from the low density part to the high density part (fiber mass) in the thickness direction due to the capillary phenomenon. Therefore, it becomes easy to absorb and retain the water content of the absorbent core as a whole, and the absorbability can be enhanced. Further, since the area and volume of individual fibers of hardwood liquid-retaining fibers are smaller than those of softwood liquid-retaining fibers, there are few places where the fibers are entangled with each other, and the area (volume) of the entangled parts themselves is also small. Therefore, the movements of the fibers are less likely to interfere with each other, and the flexibility of the absorber can be increased. As a result, it is possible to realize an absorbent article having both flexibility and absorbency.

In such an absorbent article, in the high-density portion, the low-density portion is located in a central portion where the liquid-retaining fibers are concentrated and not entangled with the fibers in the low-density portion, and outside the central portion. The average density of the high-density portion is higher than the average density of the absorbent core, and the weight of the fiber contained in the central portion is the raised portion of the raised portion. It is desirable that it is greater than the weight of the fibers contained.

According to such an absorbent article, more water is easily drawn from the periphery of the high-density portion to the central portion via the raised portion due to the capillary phenomenon. This makes it possible to increase the total amount of water that can be retained by the absorbent core.

In such an absorbent article, in the high-density portion, the low-density portion is located in a central portion where the liquid-retaining fibers are concentrated and not entangled with the fibers in the low-density portion, and outside the central portion. The average density of the high-density portion is higher than the average density of the absorbent core, and the weight of the fiber contained in the central portion is the raised portion of the raised portion. It is desirable that it is less than or equal to the weight of the fibers contained.

According to such an absorbent article, since the region of the raised portion having a low density is larger than that of the central portion, many voids are formed between the liquid-retaining fibers, and the high-density portion is subjected to an external force. Is easily deformed. Therefore, the flexibility of the absorbent core is improved. In addition, since the number of voids in the raised portion increases, even a liquid containing a substance other than water, such as menstrual blood, easily permeates the raised portion and reaches the central portion. As a result, good absorbency can be realized while increasing the flexibility of the absorbent article.

In such an absorbent article, the shape of the high-density portion is planar, and the maximum width of the region occupied by the raised portion in the plane direction of the high-density portion is the raised portion in a direction orthogonal to the plane direction. It is longer than the maximum width of the region occupied by the portions, and among the plurality of high-density portions included in the absorbent core, the direction perpendicular to the plane direction with respect to the thickness direction of the absorbent core is along. The proportion of the high density portion arranged is larger than the proportion of the high density portion arranged so as to be perpendicular to the plane direction with respect to the longitudinal direction or the width direction of the absorbent core. Large is desirable.

According to such an absorbent article, the gradient of the fiber density in the thickness direction (Z direction) of the high density portion is larger than the gradient of the fiber density in the plane direction (X, Y direction). Therefore, the capillary phenomenon is likely to act in the thickness direction, and water is easily absorbed. Then, the water drawn into the central portion of the high-density portion is difficult to diffuse to the outside in the plane direction due to the raised portion spreading in the plane direction, and is easily retained in the high-density portion. Thereby, the absorbability of the absorbent article can be further enhanced.

In such an absorbent article, when the diameter of the circle circumscribing the central portion is Rc and the diameter of the circle circumscribing the raised portion is Ro in the plane direction of the high-density portion, (Ro-Rc). ) <Rc is desirable.

According to such an absorbent article, the ratio of the raised portion to the high-density portion becomes small, so that the number of entangled points between the fibers of the raised portion and the fibers of the low-density portion around the raised portion is reduced. Therefore, the bond between the high-density portion and the low-density portion is weakened, and the absorbent core becomes flexible as a whole. Thereby, the flexibility of the absorbent article can be further increased.

In such an absorbent article, when the diameter of the circle circumscribing the central portion is Rc and the diameter of the circle circumscribing the raised portion is Ro in the plane direction of the high-density portion, (Ro-Rc). ) ≧ Rc.

According to such an absorbent article, since the ratio of the raised portion to the high-density portion is large, the number of entangled points between the fibers of the raised portion and the fibers of the low-density portion around the raised portion increases. Therefore, the position of the high-density portion is easily fixed with respect to the density portion of the absorbent core, and the absorbent core is less likely to be twisted or deformed. As a result, it is possible to prevent the absorbent article from losing its shape.

It is desirable that at least a part of the high-density portion of the absorbent article is in contact with a sheet member adjacent to the skin side of the absorbent core in the thickness direction.

According to such an absorbent article, moisture such as menstrual blood is attracted from the sheet member adjacent to the skin side to the inside of the absorbent core and held in the high-density portion, so that the moisture is retained on the skin side sheet. It does not easily remain, and it is possible to prevent moisture from rewetting on the sheet on the skin side. As a result, it becomes difficult for moisture to come into contact with the wearer's skin when the absorbent article is worn, and it is possible to prevent skin troubles such as a rash and cause discomfort to the wearer.

It is desirable that at least a part of the high-density portion of the absorbent article is in contact with a sheet member adjacent to the non-skin side of the absorbent core in the thickness direction.

According to such an absorbent article, water such as menstrual blood permeates from the skin side to the non-skin side of the absorbent core and is held in a high-density portion provided on the non-skin side in the thickness direction. It will be easier. Therefore, moisture is less likely to remain on the skin side surface of the absorbent core, and rewetting is less likely to occur. As a result, it becomes difficult for moisture to come into contact with the wearer's skin when the absorbent article is worn, and it is possible to prevent skin troubles such as a rash and cause discomfort to the wearer.

In such an absorbent article, at least a part of the high-density portion in the thickness direction is a sheet member adjacent to the skin side of the absorbent core and a sheet member adjacent to the non-skin side of the absorbent core. It is desirable to be in contact with both.

According to such an absorbent article, the high-density portion occupies a high proportion in the thickness direction of the absorbent core, and it becomes easy to retain water over a wide range in the thickness direction. That is, the water retention capacity of the absorbent core can be increased as compared with the case where the high-density portion does not exist in the absorbent core.

Such an absorbent article has a top sheet arranged on the skin side in the thickness direction of the absorbent core, and the top sheet and the absorbent core are integrally pressed in the thickness direction. It is desirable that the squeezed portion is provided and the squeezed portion and the high-density portion are in contact with each other in the thickness direction.

According to such an absorbent article, a part of the water moving in the plane direction along the squeezed portion (linear squeezed portion) is attracted from the skin side to the non-skin side in the thickness direction by the high density portion. It is easily absorbed by the absorbent core. Therefore, it is possible to prevent the moisture from being excessively diffused in the plane direction of the absorbent core and to enhance the absorbency of the absorbent core.

In such an absorbent article, the squeezed portion has a low-pressure squeezed portion and a high-pressure squeezed portion in which the absorbent core is squeezed more densely than the low-pressure squeezed portion, and in the thickness direction. It is desirable that the low-pressure squeezed portion and the high-density portion are in contact with each other.

According to such an absorbent article, the provision of the low-pressure squeezing portion suppresses excessive deformation of the absorbent core during wearing, and makes it difficult for the absorbent core to break. Further, the moisture moving in the plane direction along the low-pressure squeezed portion can be easily drawn in the thickness direction of the absorbent core by the high-density portion, and both the flexibility and the absorbability of the absorbent core can be achieved at the same time.

In the longitudinal direction of such an absorbent article, the weight of the high-density portion included per unit area of the central region when the absorbent core is divided into three equal parts is the weight of the absorbent core in the longitudinal direction. It is desirable that the weight of the high-density portion is larger than the weight of the high-density portion included in the unit area of both end regions when divided into three equal parts.

According to such an absorbent article, in the longitudinal direction of the absorbent core, water such as menstrual blood is more likely to be retained in the central region than in both end regions, so that menstrual blood or the like leaks to the outside in the longitudinal direction. It becomes easier to suppress.

In the width direction, the weight of the high-density portion contained in the unit area of the central region when the absorbable core is divided into three equal parts is the weight of the absorbable core in the width direction. It is desirable that the weight of the high-density portion is larger than the weight of the high-density portion included in the unit area of both end regions when divided into three equal parts.

According to such an absorbent article, in the width direction of the absorbent core, water such as menstrual blood is more likely to be retained in the central region than in both end regions, so that menstrual blood or the like leaks to the outside in the width direction. It becomes easier to suppress.

In such an absorbent article, the absorbent core contains a highly absorbent polymer, and the maximum outer diameter of the high density portion is larger than the maximum outer diameter of the highly absorbent polymer. desirable.

According to such an absorbent article, when the highly absorbent polymer (SAP) swells, there is a high possibility that a high-density portion is arranged between two adjacent SAPs, so that the SAPs come into contact with each other. It becomes difficult and gel blocking is suppressed. As a result, it is possible to suppress the decrease in the absorbability of SAP and enhance the absorbability of the absorbable core.

In such an absorbent article, the average fiber length of the hardwood liquid-retaining fiber is less than 2 mm, and the absorbent core is a liquid-retaining fiber made of a material other than hardwood, and is more than the hardwood liquid-retaining fiber. It is also desirable that it contains liquid-retaining fibers with a long average fiber length.

According to such an absorbent article, the hardwood liquid-retaining fiber having a short fiber length and the liquid-retaining fiber having a long fiber length are easily entangled, and the shape of the absorbent core is easily maintained. Therefore, the flexibility is higher than the case where the absorbent core is formed only by the liquid-retaining fibers having a long fiber length, and the distance between the fibers is shortened, so that the liquid is less likely to collect between the fibers and the liquid returns. Is improved. In addition, it is possible to prevent the shape from being lost as compared with the case where the absorbent core is formed only by the liquid-retaining fibers having a short fiber length.

In such an absorbent article, the average fiber length of the broadleaf tree liquid-retaining fiber is less than 2 mm, and the absorbent core has a longer average fiber length than the broadleaf tree liquid-retaining fiber and is hydrophobic thermoplastic. It is desirable that it contains fiber.

According to such an absorbent article, hardwood fibers having a short average fiber length and fibers having a long average fiber length are entangled and entangled, so that the shape of the absorbent core is less likely to be lost. In addition, the inclusion of hydrophobic fibers improves the diffusivity of water in the absorbent core. This facilitates the absorption and retention of water over a wide area of the absorbent core. Therefore, the absorbency of the absorbent article can be further improved.

In such an absorbent article, the average fiber width of the hardwood liquid-retaining fiber is 15 μm or less, and the number of the hardwood liquid-retaining fiber contained per unit area of the absorbent core is 300 fibers / mm ^2. It is desirable that the number is less than 2500 fibers / mm ² and that the hardwood liquid-retaining fibers have a highly absorbent polymer.

According to such an absorbent article, the fibers are hard to be entangled and the hardwood pulp having a short fiber width is densely packed, so that the probability of contact between the excrement liquid and the fibers is high. In addition, since the probability that multiple hardwood pulps come into contact with SAP is high, the excrement liquid contained in the hardwood pulp is easily drawn into the highly absorbent polymer between the hardwood pulps, and the excrement liquid is absorbed multiple times. It is also possible to reduce the liquid return.

In such an absorbent article, the standard deviation of the fiber length of the hardwood liquid-retaining fiber is 0.27 or less, and the standard deviation of the fiber width of the hardwood liquid-retaining fiber is 7.55 or less. desirable.

According to such an absorbent article, when the distribution width is narrow and the standard deviation is small, it is easy to maintain a uniform fiber density in the absorber, so that the fiber is less biased in the planar direction and the excrement is diffused concentrically. It will be easier to do.

In such an absorbent article, the value obtained by adding the standard deviation of the fiber length of the broad-leaved liquid-retaining fiber to the average fiber length of the broad-leaved liquid-retaining fiber is 2 of the average fiber length of the broad-leaved liquid-retaining fiber. The value obtained by subtracting the standard deviation of the fiber length of the broad-leaved liquid-retaining fiber from the average fiber length of the broad-leaved liquid-retaining fiber is the average fiber length of the broad-leaved liquid-retaining fiber. It is desirable that it is larger than the value of 1/2.

According to such an absorbent article, the fiber is less biased and the excrement liquid can be easily diffused evenly.

In such an absorbent article, the absorbent core contains a plurality of thermoplastic fibers and has a squeezing portion for integrally squeezing the absorbent core in the thickness direction. , It is desirable that the thermoplastic fibers are fused to each other.

According to such an absorbent article, the shape of the absorber can be easily stabilized by fusing the thermoplastic fibers to each other. As a result, even when the wearer moves his / her body significantly while wearing the absorbent article, it becomes easy to prevent the absorber from losing its shape or deteriorating the water absorption.
It gets better.

It is desirable that the absorbent article is at least one of a sanitary napkin, a vaginal discharge sheet, and a light incontinence pad.

According to such an absorbent article, it is possible to realize a sanitary napkin, a vaginal discharge sheet, and a light incontinence pad that have both flexibility and absorbency.

It is desirable that the absorbent article has a pair of wing portions extending from the central region in the longitudinal direction to both outer sides in the width direction.

According to such an absorbent article, when worn, the absorbent article can be easily attached to the underwear or the like by folding the wing portion from the outside to the inside (inseam side of the wearer's underwear) in the width direction.

It is desirable that the non-skin side surface of the absorbent article is provided with an adhesive portion for attaching the absorbent article to the wearer's underwear when worn.

According to such an absorbent article, the position of the absorbent article is fixed by attaching the adhesive portion to the skin side surface of the wearer's underwear or the like at the time of wearing, and it is possible to prevent misalignment.

It is desirable that the absorbent article is provided with a functional material in at least a part of the absorbent core.

According to such an absorbent article, the functional material is easily held in the high-density portion of the absorbent core, so that the effect of the functional material can be more effectively exerted in the absorbent article. For example, by retaining the antibacterial agent in the high-density portion of the absorbent core, it is possible to easily cause an antibacterial action in the portion where absorbed urine or menstrual blood is accumulated. Further, by retaining and accumulating fragrances, cooling sensations, warming agents and the like in the high-density portion, it is possible to easily maintain the effects of these functional materials for a long time.

When the fibers contained in the absorbent core are separated by using a sieve shaker conforming to the provisions of JJISK0069, the absorbent article remains on the 14-mesh sieve of the sieve shaker. The value obtained by dividing the weight of the fibers (Nots) obtained by the weight of the absorbent core before separation determines the weight of the fibers (Fine) that have passed through the 60-mesh sieve of the sieve shaker. It is desirable that it is larger than the value divided by the weight of the sex core.

According to such an absorbent article, since the content of the high-density portion where the fibers are aggregated is high, voids are formed inside the absorber and moisture such as body fluid easily passes through, so that the liquid permeability of the absorbent core is high. Can be enhanced. In addition, since the high-density portion itself easily holds the liquid, the water retention of the absorbent core is increased. Therefore, the water absorption of the absorbent core can be further improved.

=== Embodiment ===
<< Basic configuration of sanitary napkins >>
As an example of the absorbent article according to the present embodiment, a sanitary napkin 1 (hereinafter, also simply referred to as “napkin 1”) will be described. In the following description, a sanitary napkin will be described as an example of an absorbent article, but the absorbent article of the present embodiment also includes a so-called vaginal discharge sheet (for example, panty liner), a light incontinence pad, and the like. It is not limited to sanitary napkins.

FIG. 1 is a schematic plan view of the napkin 1 as viewed from the skin side in the thickness direction. FIG. 2 is a schematic cross section shown by arrow AA in FIG. Further, in the following description, each direction is defined as shown in FIGS. 1 and 2. That is, the "longitudinal direction" along the product longitudinal direction of the napkin 1, the "width direction" orthogonal to the longitudinal direction along the product short direction of the napkin 1, and the "thickness" orthogonal to the longitudinal direction and the width direction, respectively. "Direction" is defined. Of the longitudinal directions, the direction that is the ventral side of the wearer when the napkin 1 is used is defined as the "front side", and the direction that is the dorsal side of the wearer is defined as the "rear side". In the thickness direction, the side that comes into contact with the wearer's skin when the napkin 1 is worn is referred to as the "skin side (upper side)", and the opposite side is referred to as the "non-skin side (lower side)".

The napkin 1 is a vertically elongated sheet-like member in a plan view, and is a pair of side sheets 2, a top sheet 3, a second sheet 4, an absorber 10 (absorbent core), a cover sheet 6, and a back sheet 5. And are laminated in order from the skin side to the non-skin side in the thickness direction (see FIG. 2). Each of these members is joined to a member adjacent to each other in the thickness direction with an adhesive such as a hot melt adhesive (HMA). Examples of the adhesive application pattern include an Ω pattern, a spiral pattern, and a stripe pattern.

Further, the napkin 1 has a napkin main body 20 provided with an absorber 10 and a pair of wing portions 30 extending outward from the central region in the longitudinal direction of the napkin main body 20 in the width direction. The central region in the longitudinal direction in which the wing portion 30 is provided is a region that comes into contact with the wearer's excretion port (lower crotch) when the napkin 1 is used.

The top sheet 3 is a member that comes into contact with the wearer's skin when the napkin 1 is used, and allows liquids such as menstrual blood to permeate from the skin side to the non-skin side in the thickness direction and move to the absorber 10. Therefore, as the top sheet 3, an appropriate liquid-permeable flexible sheet such as an air-through non-woven fabric is used.

The second sheet 4 is a liquid permeable sheet, and the same air-through non-woven fabric as the top sheet 3 can be exemplified. The second sheet 4 is provided on the skin side surface of the absorber 10 and plays a role of preventing the reversion of excrement such as menstrual blood, improving the diffusion of excrement, and improving the cushioning property. However, the napkin 1 does not have to have the second sheet 4.

The cover sheet 6 may be a liquid-permeable sheet or a liquid-impermeable sheet, and examples thereof include tissue paper, SMS (spun bond / melt blown / spun bond) non-woven fabric, and the like. The cover sheet 6 is provided between the absorber 10 and the back sheet 5. However, the napkin 1 does not have to have the cover sheet 6.

The back sheet 5 prevents the liquid that has passed through the top sheet 3 and absorbed by the absorber 10 from seeping out to the clothing side (non-skin side) such as underwear when the napkin 1 is used. For the back sheet 5, an appropriate liquid-impermeable flexible sheet such as a polyethylene (PE) resin film is used. The plane size of the top sheet 3 and the back sheet 5 is larger than that of the absorber 10.

The side sheet 2 may be a liquid-permeable sheet or a liquid-impermeable sheet, and examples thereof include the same air-through non-woven fabric and SMS non-woven fabric as the top sheet 3.

Then, as shown in FIG. 1, the outer peripheral edges of the side sheet 2 and the top sheet 3 and the back sheet 5 are bonded to each other by adhesion or fusion, so that the absorber 10 is between the sheets. Is held. Further, the pair of side seats 2 extend from both side portions in the width direction of the top sheet 3 to the outside in the width direction, and form a pair of wing portions 30 together with the back seat 5. Further, as shown in FIG. 2, the surface of the napkin main body 20 on the non-skin side (non-skin side of the back sheet 5) is formed by applying an appropriate adhesive (for example, a hot melt adhesive). A plurality of adhesive parts (corresponding to slip prevention) are provided at intervals in the width direction. When the napkin 1 is used, the adhesive portion of the main body is attached to the side surface of the skin such as the wearer's underwear to fix the napkin 1 and prevent misalignment. Similarly, a wing adhesive portion (corresponding to slip prevention) formed by applying a hot melt adhesive or the like is provided on the most non-skin side surface of the wing portion 30 (non-skin side surface of the back sheet 5). (See Fig. 2).

Absorber 10 (corresponding to an absorbent core) is a vertically long member that is long along the longitudinal direction, and absorbs liquid (excrement) such as menstrual blood and holds it inside. Details of the absorber 10 will be described later. The second sheet 4, the absorber 10, and the cover sheet 6 have the same planar shape and are laminated in the thickness direction. In the present embodiment, the respective members are bonded to each other by a hot melt adhesive (HMA), but they may not be bonded to each other.

Further, the napkin 1 is provided with a plurality of squeezed portions 40 (recesses) (see FIG. 1). The squeezed portion 40 is a portion recessed from the skin side to the non-skin side in the thickness direction, and is a portion having a higher density of liquid-retaining fibers than an adjacent portion. In the squeezed portion 40, at least the entire area of the top sheet 3, the second sheet 4, and the absorber 10 in the thickness direction is squeezed (embossed) from the skin side in the thickness direction and joined and integrated. This makes it difficult for the napkin 1 to twist. However, not limited to the above, the squeezing portion 40 is provided only on the absorber 10, the squeezing portion 40 is provided only from the top sheet 3 to a part of the absorber 10 on the skin side in the thickness direction, or from the back sheet 5. The squeezing portion 40 may be provided on the absorber 10. Further, the arrangement pattern of the squeezing portion 40 is not limited to that shown in FIG.

<Specific configuration of absorber 10>
The absorber 10 has a liquid-retaining fiber that absorbs a liquid, and is formed into a vertically elongated shape in a plan view. Further, the absorber 10 may contain a material other than the liquid-retaining fiber (for example, a hydrophobic fiber such as a thermoplastic resin fiber). When it has a liquid-retaining fiber and a thermoplastic resin fiber (hydrophobic fiber), the absorber 10 is formed in a state where these fibers are mixed with each other.

The liquid-retaining fiber includes pulp, for example, wood pulp obtained from coniferous or broadleaf tree, non-wood pulp such as bagas, kenaf, bamboo, hemp, cotton (for example, cotton linter); recycled cellulose fiber such as rayon fiber. Examples include semi-synthetic fibers such as acetate fibers.

In the absorber provided in the conventional absorbent article, softwood liquid-retaining fiber (also referred to as softwood pulp), which is a liquid-retaining fiber made of softwood, was often used. On the other hand, in the absorber 10 of the present embodiment, at least a part of the liquid-retaining fibers contains hardwood liquid-retaining fibers (also referred to as hardwood pulp) which are liquid-retaining fibers made of hardwood. This hardwood liquid-retaining fiber (broad-leaved pulp) is characterized in that the fiber length is shorter than that of the softwood liquid-retaining fiber (coniferous pulp).

FIG. 3A is a diagram showing the distribution of fiber lengths of hardwood liquid-retaining fibers (hardwood pulp) and softwood liquid-retaining fibers (softwood pulp). The horizontal axis shows the fiber length (mm), and the vertical axis shows the frequency (%). As shown in the figure, the average fiber length of softwood pulp is 2.5 mm, and the distribution width of the fiber length is wide (fibers of 3 mm or more are included. The standard deviation is 1.6). On the other hand, the average fiber length of hardwood pulp is 0.79 mm, and the distribution width of the fiber length is narrow (standard deviation is 0.27). In the napkin 1 of the present embodiment, since the absorber 10 uses hardwood pulp, the average fiber length of the liquid-retaining fibers is short (specifically, less than 2 mm).

The average fiber length of the pulp fiber means the length-weighted average fiber length L (l) as measured by the center line fiber length (Cont). The length-weighted average fiber length is measured as an L (l) value by Kajaani FiberLab Fiber Properties (offline) [kajaaniFiberLab fiber products (off-line)] manufactured by metso automation. This is also the method recommended by JIS P 8226-2 (a method for measuring fiber length by pulp-engineering automatic analysis method, which conforms to the non-polarized method). Further, the average fiber width of the pulp fibers described below is measured as Fiber Width.

The average fiber length and average fiber width are measured excluding fiber lumps as described in the JIS evaluation method. Therefore, the data of the average fiber length and the average fiber width shown in the present specification are the results measured excluding the fiber mass 100 described later.

The average fiber length of fibers other than pulp fibers is the glass with the scale of "A7.1.1 A method (standard method)" in "A7.1 Fiber length measurement" of Annex A of JIS L 1015: 2010. Measure according to "Method of measuring the length of individual fibers on a plate". The above method is a test method corresponding to ISO 6989 published in 1981.

Examples of the thermoplastic resin fiber include a single fiber made of polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), etc., a fiber obtained by polymerizing PP and PE, or PP and PE. Examples thereof include composite fibers having a core-sheath structure composed of. Further, with the thermoplastic resin fiber, the degree of crimping can be adjusted. For example, the fiber can be crimped by using a core-sheath type or eccentric type composite fiber composed of two synthetic fiber components having different melting points as the thermoplastic resin fiber. In the present embodiment, the average fiber length of the thermoplastic resin fiber is about 30 mm. Further, the average number of crimps per unit length of the thermoplastic resin fiber is set to be smaller than the average number of crimps per unit length of the liquid-retaining fiber. As a result, the entanglement between the thermoplastic resin fiber and the liquid-retaining fiber is reduced, and the crease is less likely to remain. Therefore, even when the thermoplastic resin fiber is contained, the wearing feeling can be improved and the leakage prevention property can be improved. As a method for measuring the average number of crimps, for example, a plurality of test pieces (for example, 5 cm square test pieces) are sampled in the width direction, and a Keyence microscope VH-Z450 or the like is used in the test pieces. The number of crimps per inch (2.54 cm) may be measured several times with no load applied to the fibers. The number of crimps (average number of crimps per unit length) can be calculated from the average value.

FIG. 3B is a diagram showing the distribution of the average fiber width of hardwood pulp and softwood pulp. The horizontal axis shows the fiber width (μm), and the vertical axis shows the frequency (%). As shown in FIG. 3B, the average fiber width of softwood pulp is about 30 μmm (upper figure), and the distribution width of the fiber width is wide (standard deviation is 11.9). On the other hand, the average fiber width of hardwood pulp is about 15 μm (see the figure below), and the distribution width of the fiber width is narrow (standard deviation is 7.55). In the napkin 1 of the present embodiment, since the absorber 10 uses hardwood pulp, the average fiber width of the liquid-retaining fibers is shorter than that in the case where only softwood pulp is used.

The average fiber width of the hardwood pulp is 15 μm or less, the number of fiber densities is 300 / mm ² or more and less than 2500 / mm ² (details will be described later), and the highly absorbent polymer between the hardwood pulps. It is desirable to have liquid-absorbing granules such as (so-called SAP). Then, since the fibers are short and the fibers are thin, the absolute fiber area is small, so that the fibers are difficult to entangle, and the broadleaf pulp, which is characterized by a short fiber width, is densely packed, so that the excrement fluid and the fibers come into contact with each other. Is increased, and the excrement liquid contained in the broadleaf tree pulp is easily drawn into the highly absorbent polymer between the broadleaf tree pulps, so that the liquid return can be reduced even in the absorption of the excrement liquid a plurality of times.

Looking at the distribution width, hardwood pulp has a narrower fiber length and fiber width distribution width than softwood pulp. That is, the standard deviation of the fiber length of hardwood pulp is 0.27 or less, and the standard deviation of the fiber width of hardwood pulp is 7.55 or less. Furthermore, the value obtained by adding the standard deviation of the fiber length of the broad-leaved pulp to the average fiber length of the broad-leaved pulp (0.79 + 0.27 = 1.06) is twice the average fiber length of the broad-leaved pulp (1.58). Smaller than, the value obtained by subtracting the standard deviation of the fiber length of the broadleaf pulp from the average fiber length of the broadleaf pulp (0.79-0.27 = 0.52) is 1/2 of the average fiber length of the broadleaf pulp. Greater than (0.395).

When the distribution width is narrow and the standard deviation is small in this way, it is easy to maintain a uniform fiber density in the absorber, so that there is little bias in the plane direction and it is easy to diffuse concentrically.

Further, the absorber 10 may contain fibers other than the above, and may contain natural fibers such as cellulose, regenerated cellulose fibers such as rayon, and the like.

Further, it is desirable that the thickness of the absorber 10 is 2 mm or more and 10 mm or more. If the thickness of the absorber 10 is less than 2 mm, it is too thin and twisted, and if it exceeds 10 mm, it is too hard and the wearer may feel uncomfortable.

Further, since hardwood pulp is thinner than softwood pulp and the interfiber distance is short, the fiber number density of hardwood pulp is larger than that of softwood pulp when compared under the same density condition. The fiber number density corresponds to the average number of fibers per unit area, and is a value obtained by calculating the number of fibers included per unit area in the case of a finely packed structure by the fiber thickness + the average distance between fibers. .. Looking at these estimated values, the fiber number density of hardwood pulp is 1182.2 fibers / mm ^2, which is about 6 times the fiber number density of softwood pulp (200.3 fibers / mm ^2). Therefore, when hardwood pulp is used, the density can be increased as compared with the case where softwood pulp is used.

Fiber number density is desirably 2500 lines / mm less than ² 300 lines / mm ² or more. If the fiber number density is ^{less than 300 fibers / mm 2} , folding habits are less likely to remain, but the absorber 10 becomes faint and twists during use, resulting in a decrease in the absorber area and easy leakage. .. If the fiber density is 2500 fibers / mm ² or more, the absorber 10 will be too hard and the finish will be too hard, and the feeling of discomfort during use will increase. If the number of fibers density 300 lines / mm ² or more 2,500 / mm ² under a, it is possible to enhance the capillary effect, also it allows thinner and softening, it is possible to enhance the absorbency.

<Manufacturing method of absorber 10>
As a method for producing the absorber 10, a method of accumulating crushed pulp, a highly absorbent polymer, or the like is known. FIG. 4A is a diagram illustrating a method for producing pulverized pulp used in the absorber 10. FIG. 4B is a diagram illustrating a method for producing the absorber 10 using crushed pulp or the like. Here, a case where the absorber 10 includes a liquid-retaining fiber, a thermoplastic resin fiber, and a highly absorbent polymer (SAP) will be described.

First, crushed pulp, which is a raw material for the absorber 10, is produced. The crushed pulp is produced by crushing the pulp sheet PS as a raw material using a transport mechanism 61 and a saw mill 62. The transport mechanism 61 transports the pulp sheet PS unwound from the raw fabric roll in a predetermined direction. The saw mill 62 is a rotating body provided with a plurality of blades on the outer peripheral surface of the columnar roll, and as shown in FIG. 4A, rotates so as to scrape the pulp sheet PS on the downstream side in the transport direction. As a result, the pulp sheet PS is finely pulverized to produce pulverized pulp as a raw material for the absorber 10. A hammer mill may be used instead of the saw mill 62 to crush the pulp sheet PS by hitting it.

Conventionally, when a pulp sheet made of softwood is crushed, the fibers of softwood pulp are decomposed one by one to form long filamentous softwood liquid-retaining fibers (average fiber length of about 2.5 mm). On the other hand, in this embodiment, a pulp sheet PS containing hardwood pulp is used. As described above, since the average fiber length of hardwood pulp (hardwood liquid-retaining fiber) is short (the average fiber length is less than 2 mm), the fibers are less likely to be entangled with each other as compared with softwood pulp. Therefore, the pulp sheet PS containing hardwood pulp has few places where the fibers are entangled with each other, and is brittle and easily crumbles. When such pulp sheet PS is crushed by the saw mill 62, the fibers of the hardwood pulp are not decomposed one by one, but a fiber mass 100 (also referred to as so-called "notts") in which a plurality of fibers are aggregated in a fluff shape is formed. It is separated from the pulp sheet PS so as to collapse.

Further, as described above, the average fiber width of hardwood pulp is about 15 μm. That is, hardwood pulp is characterized not only by having a short fiber length but also by being thin. Therefore, hardwood pulp has a small cross-sectional area and volume of each fiber, fibers are more likely to be aggregated in a pill shape, and the amount of fibers contained in the pill is larger than that of softwood. When trying to form such a fiber mass with conventional air-laid pulp, it is not preferable because the adhesive contained between the pulps tends to hinder the drawing of water and the fiber mass itself becomes hard. Moreover, since pulp is cellulose, it is difficult to heat-seal. Therefore, it is also difficult to form a fiber mass by using a method such as heat fusion.

FIG. 5 is an enlarged photograph of a fiber mass 100 obtained when a pulp sheet containing hardwood pulp is crushed. As shown in FIG. 5, the fiber mass 100 obtained in this step has a lower density than that of the central portion 101 in the central portion 101 in which the hardwood liquid-retaining fibers are gathered at a high density and around the central portion 101. It has a raised portion 102. The raised portion 102 is formed by peeling off the portion of the pulp sheet PS in which the fibers are entangled with each other. That is, the pulp sheet PS is formed by densely gathering a plurality of such fiber lumps 100, and when the pulp sheet PS is scraped by the saw mill 62, the entangled portions of the adjacent fiber lumps 100, 100 are peeled off, whereby The portion separated into the individual fiber lumps 100 and the entanglement is peeled off becomes the raised portion 102.

In the present embodiment, a sample obtained by crushing the pulp sheet PS by the method shown in FIG. 4A is subjected to a sieving machine according to a test method specified in JIS K0069 (for example, a sieving machine manufactured by AS ONE Corporation). SS-HK60) was used to separate each fiber size, and those satisfying the following conditions were designated as "fiber mass 100". First, the sample is placed on a 14-mesh sieve provided in a sieve shaker. The "mesh" is a standard sieving wire mesh specified in JIS Z8801. For example, 14 mesh is a wire mesh having an opening of 1.18 mm, a wire diameter of 0.63 mm, and an opening area of 42.3%. is there. In addition, a cylinder with the same diameter as the sieve is installed on the lower side of the mesh, and a hole is made on the side surface of the cylinder at a height of 70 mm below the mesh so that there is no gap (for example, a wonder gun manufactured by Osawa & Company). W101: A suction minimum inner diameter of 22 mm and a pressure of 0.5 Mpa) are installed. Further, an air ejection device (for example, Air Duster Gun AG-101 manufactured by TONE Co., Ltd .: nozzle length 95 mm, nozzle inner diameter 4 mm, pressure 0.5 Mpa) is installed at a height of 50 mm above the mesh. Next, while shaking for 15 minutes under the condition of an amplitude of 70 mm and 60 times / minute, the air ejection device is evenly ejected, and the fibers are sucked by the suction device to separate the fibers from the sample. Then, what remains on the sieve (14 mesh) after 15 minutes has passed is referred to as "fiber mass 100 (notts)".

Further, in the photograph of FIG. 5, a white fiber mass 100 is displayed on a black background, but the hardwood liquid-retaining fiber is dense in the region where the black background cannot be seen through in the center of the fiber mass 100. It is a central portion 101 gathered in. On the other hand, the raised portion 102 is a portion around the central portion 101 that allows the black color of the background to be visually recognized through the fiber mass 100.

Subsequently, the absorber 10 is manufactured using the fiber mass 100. As shown in FIG. 4B, the rotary drum 70 is a hollow cylindrical drum, and a plurality of recesses 71 are formed at a predetermined pitch on the peripheral surface as a mold for filling the absorber material. When the rotary drum 70 rotates and the recess 71 enters the material supply section 80, the absorber material supplied from the material supply section 80 is deposited (accumulated) in the recess 71 by the suction of the suction section 72.

The material supply unit 80 with the hood 80a is formed so as to cover the upper part of the rotary drum 70, and the material supply unit 80 is a crushed pulp (at least broadleaf pulp) obtained by crushing the pulp sheet PS with a crusher (see FIG. 4A). And the fiber mass 100) and the thermoplastic resin are supplied to the recess 71 by air transportation. Further, the material supply unit 80 includes a particle supply unit 81 for supplying highly absorbent polymer particles (SAP), and supplies the highly absorbent polymer particles to the recess 71. The mixture of the water-absorbent fiber and the thermoplastic fiber and the highly absorbent polymer particles are deposited in the recess 71 in a mixed state, and the absorber 10 is formed in the recess 71.

When the recess 71 accommodating the absorber 10 reaches the bottom of the drum due to the further rotation of the rotating drum 70, the absorber 10 is disengaged from the recess 71, and the base material (cover sheet 6, etc.) conveyed by the conveyor. It will be placed on top and handed over to the next process.

The formed absorber 10 contains a plurality of fiber lumps 100 in which liquid-retaining fibers are densely packed. That is, high-density portions made of fiber lumps 100 are scattered in the absorber 10. Therefore, in the region of the absorber 10 where the fiber lumps 100 (high-density portions) are scattered, unlike the squeezed portion 40, the liquid-retaining fiber is located in the central portion in the thickness direction rather than the end portion in the thickness direction. The density is high. In other words, the absorber 10 has a low-density portion having a lower density of liquid-retaining fibers than the high-density portion on one side or the other side in the thickness direction of at least one high-density portion (fiber mass 100). ing.

The density of the fiber mass 100 (high density part) can be measured as follows. First, the weight of the fiber mass 100 is measured using an electronic balance or the like. At this time, if the weight of the fiber mass 100 is less than the minimum measured weight of the electronic balance, a plurality of the fiber mass 100 are collectively measured up to the measurable weight, and the average value is taken as the average weight of the fiber mass 100. To do. Next, the thickness of the fiber mass 100 (the length in the Z direction of FIG. 6B described later) is measured with a microscope. When a plurality of fiber masses 100 are collectively weighed as described above, the thicknesses of all the fiber masses 100 used for the weight measurement are measured and the average value is taken as the average thickness of the fiber masses 100. Similarly, the area of the fiber mass 100 (the area in the XY plane of FIG. 6A, which will be described later) is measured from the measurement of the microscope. At that time, the areas of all the fiber masses 100 that have been weighed are measured, and the average value is taken as the average area of the fiber masses 100. Based on these measured values (calculated values), the density of the fiber mass 100 can be calculated by average weight / (average thickness × average area).

<About the performance of absorber 10>
In the absorber 10 (absorbent core) of the present embodiment, since a plurality of fiber lumps 100 are provided in a scattered manner, liquid absorbability and flexibility are improved as compared with the absorber of the conventional product. There is.

As described above, since the liquid-retaining fibers are gathered at a high density in the fiber mass 100, the portion of the absorber 10 where the fiber mass 100 (high density portion) is arranged is higher than the other portions. The density of liquid-retaining fibers is high. That is, the absorber 10 has a fiber mass 100, which is a high-density portion, and a low-density portion, which has a lower density of liquid-retaining fibers than the high-density portion (fiber mass 100), inside the absorber 10. Then, in the thickness direction of the absorber 10, the fiber mass 100 (high density portion) and the low density portion are arranged adjacent to each other. In other words, the absorber 10 of the present embodiment has a high-density portion, a fiber mass 100, and a low density adjacent to one side (skin side) or the other side (non-skin side) of the high-density portion in the thickness direction. Has a part. Since the high-density portion and the low-density portion are provided in the thickness direction of the absorber 10, the high-density portion is continuous in the thickness direction as in the squeezed portion 40, for example, as compared with the case where the high-density portion is continuous in the thickness direction. The bulk (thickness) of the absorber 10 is easily maintained, and the absorber 10 which is soft and has a high cushioning property can be realized.

When water such as menstrual blood adheres to the skin side in the thickness direction of the absorber 10, the water is absorbed in the thickness direction of the absorber 10 and is absorbed from the low density portion to the high density portion by the capillary phenomenon. It becomes easy to move to (fiber mass 100). That is, in the thickness direction of the absorber 10, the low-density portion and the high-density portion (fiber mass 100) are arranged adjacent to each other, so that the absorbed water can be guided to the fiber mass 100 and retained. it can. Therefore, it becomes easy to absorb and retain the water content of the absorber 10 (absorbable core) as a whole, and the absorbability of the absorber 10 can be enhanced.

Further, since the liquid-retaining fibers contained in the absorber 10 (absorbable core) of the present embodiment are formed from hardwood liquid-retaining fibers, they are averaged as compared with the liquid-retaining fibers made of coniferous trees. Since the fiber length is short and the fiber diameter is small, the cross-sectional area and volume per fiber are small. Therefore, the number of entangled points where one hardwood liquid-retaining fiber is entangled with other hardwood liquor-retaining fibers is small, and the area (volume) of the entangled points is small, so that the fibers are compared with the softwood water-retaining fibers. It is hard to get entangled with each other. Therefore, the movements of the liquid-retaining fibers are less likely to interfere with each other, and the flexibility of the absorber 10 is increased, so that it is difficult for the user of the napkin 1 to feel the hardness.

In addition, since the fiber width is shorter than that of the liquid-retaining fiber composed only of softwood fibers, the number of entangled points when viewed in the plane direction is reduced. Further, the thickness of the fiber is thinner than that of the liquid-retaining fiber composed only of softwood fiber. Therefore, if the density and thickness of the absorbers are equal, it is possible to contain more hardwood fibers in the thickness direction as compared with the case of using only softwood fibers, but the rigidity can be equal to or less than that. Therefore, it is possible to make it difficult for the wearer to feel the hardness of the absorber 10.

In particular, the absorber 10 of the napkin 1 contains a plurality of fiber lumps 100 (high-density portion) in which liquid-retaining fibers are densely packed. If the high-density portion is formed by a softwood water-retaining fiber having a long fiber length, the number of entangled points of the fibers increases and the high-density portion becomes harder by that amount. There is a risk of causing a sense of discomfort. On the other hand, in the present embodiment, the fiber length of the liquid-retaining fibers constituting the fiber mass 100 (high-density portion) is short and the number of entangled points is small, so that the fiber mass 100 (high-density portion) itself The flexibility is also high, and it is difficult for the wearer to feel stiff or uncomfortable.

As described above, in the absorber 10 (absorbent core) of the present embodiment, high-density portions (fiber lumps 100) in which liquid-retaining fibers are densely provided are scattered from the hardwood, which is good. Both absorbency and flexibility can be achieved. Highly absorbent polymer particles (SAP) may be contained in the high-density portion (fiber mass 100). In this case, since the ratio of the SAP and the liquid-retaining fiber in contact with each other increases, it is possible to improve the absorption performance when the absorber 10 repeatedly absorbs water a plurality of times.

Further, as described with reference to FIG. 5, in the fiber mass 100, the central portion 101 in which the liquid-retaining fibers are gathered at a high density and the raised fibers on the outside of the central portion 101 having a lower density of the liquid-retaining fibers than the central portion 101. It has a unit 102. The central portion 101 is surrounded by the raised portion 102, and the raised portion 102 is surrounded by fibers other than the fiber mass 100 (that is, fibers constituting the low-density portion of the absorber 10). That is, the raised portion 102 is entangled with the fibers constituting the low-density portion of the absorber 10, and the central portion 101 is not entangled with the fibers constituting the low-density portion, but is entangled with the raised portion 102. Therefore, when the absorber 10 absorbs water such as excrement liquid, the liquid-retaining fibers constituting the low-density portion first absorb the water, and the water absorbed in the low-density portion is raised by the capillary phenomenon. It moves to the central portion 101 of the fiber mass 100 via the portion 102. In this way, the water absorbed by the absorber 10 is drawn from the outside to the center of the fiber mass 100.

In such a fiber mass 100, if the total amount (weight) of the liquid-retaining fibers contained in the central portion 101 is larger than the total amount (weight) of the liquid-retaining fibers contained in the raised portion 102, the central portion 101 has moisture. Since the amount of water that can be retained is increased, the water absorption of the absorber 10 can be increased. That is, more water can be easily drawn into the central portion 101 of the fiber mass 100 (high-density portion) from the surroundings, and the total amount of water retained by the absorber 10 can be increased.

On the other hand, the total amount (weight) of the liquid-retaining fibers contained in the central portion 101 may be equal to or less than the total amount (weight) of the liquid-retaining fibers contained in the raised portion 102. In this case, the region of the raised portion 102 surrounding the central portion 101 becomes large, but since the raised portion 102 has a lower density than the central portion 101, many voids are formed between the liquid-retaining fibers, and an external force is applied. It easily deforms when it is received. Therefore, the absorber 10 containing such a fiber mass 100 has high flexibility and is soft to the touch when the napkin 1 is worn, so that it is less likely to cause discomfort to the wearer. Further, since the raised portion 102 has many voids, even a liquid containing a substance other than water such as menstrual blood can easily permeate the raised portion 102 to reach the central portion 101. Therefore, it is possible to secure good absorbability while increasing flexibility.

FIG. 6A is a schematic plan view of the fiber mass 100 when viewed from a predetermined direction. FIG. 6B is a view taken along the line BB of FIG. 6A. In FIGS. 6A and 6B, when "X direction", "Y direction", and "Z direction" are defined as three directions orthogonal to each other, FIG. 6A represents an example of the shape of the fiber mass 100 in the XY plane. FIG. 6B shows an example of the shape of the fiber mass 100 in the XZ plane. Hereinafter, the "XY direction" in FIG. 6A is also referred to as the "planar direction" of the fiber mass 100, and the "XZ direction" in FIG. 6B is also referred to as the "thickness direction" of the fiber mass 100.

As shown in FIGS. 6A and 6B, the shape of the fiber mass 100 (high density portion) is planar, and the length in the Z direction is shorter than the length in the X and Y directions. Specifically, the diameter of the circle circumscribing the central portion 101 of the fiber mass 100 in the XY plane of FIG. 6A is Rc, the diameter of the circle circumscribing the raised portion 102 is Ro, and the fiber mass 100 is in the XZ plane of FIG. 6B. When the length (width) in the Z direction is Ho, Ho is shorter than Ro (Ro> Ho). That is, the maximum width (Ro) of the region occupied by the raised portion 102 in the X and Y directions is larger than the maximum width Ho of the region occupied by the raised portion 102 in the Z direction. Since the shape of the fiber mass 100 is not constant, the maximum length of the raised portion 102 in the X direction and the maximum length in the Y direction do not always match, but in the present specification, for convenience of explanation, the raised portion 102 of the raised portion 102. The diameter Ro of the circumscribed circle is defined as the maximum length of the fiber mass 100 in the X direction and the Y direction (planar direction).

Further, in the fiber mass 100 shown in FIGS. 6A and 6B, when the fiber density in the raised portion 102 is not significantly biased, the total amount (weight) of the fibers in the raised portion 102 in the plane direction (XY direction) of the fiber mass 100 is , It is larger than the total amount (weight) of the fibers of the raised portion 102 in the thickness direction (Z direction) of the fiber mass 100. When such a fiber mass 100 (high density portion) is arranged adjacent to the low density portion inside the absorber 10, the gradient of the fiber density in the thickness direction (Z direction) of the fiber mass 100 is flat. It is larger than the gradient of fiber density in the direction (X, Y direction). Therefore, in the fiber mass 100, the capillary phenomenon tends to act more strongly in the thickness direction, and water is easily absorbed in the thickness direction. Further, when the fiber mass 100 absorbs water, the water drawn and retained in the central portion 101 is less likely to diffuse from the center in the plane direction to the outside. This is because the raised portion radiating from the central portion 101 in the plane direction suppresses the movement of water from the center to the outside in the plane direction.

The gradient of fiber density in the plane direction and the thickness direction can be obtained by, for example, the following method. First, using a microscope, the area Sh1 of the high-density portion in the plane direction is set, and the area Sh2 of the entire (high-density portion + low-density portion) in the plane direction is measured. Then, Sh1 / Sh2 is calculated and used as the density gradient in the plane direction. Similarly, using a microscope, the area St1 of the high-density portion in the thickness direction is set, and the area St2 of the entire (high-density portion + low-density portion) in the thickness direction is measured. Then, St1 / St2 is calculated and used as the density gradient in the thickness direction. Then, by comparing the calculated Sh1 / Sh2 and St1 / St2, it can be determined that the larger the value, the smaller the ratio of the low density area, that is, the smaller the gradient of the density.

Then, among the plurality of fiber masses 100 contained in the absorber 10 (absorbent core), the thickness direction (Z direction) of the fiber mass 100 is aligned with the thickness direction of the absorber 10 (absorbent core). The ratio (quantity of fiber mass 100) arranged in is arranged so that the thickness direction (Z direction) of the fiber mass 100 is aligned with the direction perpendicular to the thickness direction of the absorber 10 (absorbent core). It is larger than the ratio (quantity of 100 fiber lumps). That is, the fiber lump 100 is easily arranged so that the plane direction (longitudinal direction, width direction) of the absorber 10 and the plane direction (X direction, Y direction) of the fiber lump 100 are aligned. As a result, the absorber 10 is more likely to absorb water in the thickness direction, is less likely to diffuse the absorbed water in the longitudinal direction and the width direction, and the absorbability of the napkin 1 is improved. The state in which the thickness direction of the fiber mass 100 is aligned with the thickness direction of the absorber means that the angle between the thickness direction of the absorber and the thickness direction of the fiber mass 100 is 45 degrees. Refers to a state that is less than. Further, the ratio of the fiber mass 100 contained in the absorber 10 in which the plane direction of the absorber 10 and the plane direction of the fiber mass 100 are aligned makes the absorber 10 have a predetermined size (for example, 1 cm square). It can be obtained by cutting out and confirming the relationship between the thickness direction of each of the fiber lumps 100 contained therein and the thickness direction of the absorber 10.

Further, in the plane direction (XY direction) of FIG. 6A, the diameter Rc of the circumscribed circle of the central portion 101 is larger than the difference between the diameter Ro of the circumscribed circle of the raised portion 102 and the diameter Rc of the circumscribed circle of the central portion 101. It is better to make it larger ((Ro-Rc) <Rc). That is, in the plane direction of the fiber mass 100, the width of the region where the central portion 101 is formed may be larger than the width of the region where the raised portion 102 is formed. In such a case, since the ratio of the raised portion 102 to the fiber mass 100 becomes small, the number of places where the fibers constituting the raised portion 102 and the fibers of the low density portion (absorber 10) around the raised portion 102 are entangled is reduced. .. Therefore, the bond between the fiber mass 100 and the low-density portion is weakened, and the absorber 10 becomes flexible as a whole. Thereby, the flexibility of the napkin 1 can be further increased.

On the other hand, in the plane direction (XY direction) of FIG. 6A, the diameter Rc of the circumscribed circle of the central portion 101 is equal to or less than the difference between the diameter Ro of the circumscribed circle of the raised portion 102 and the diameter Rc of the circumscribed circle of the central portion 101. ((Ro-Rc) ≥ Rc). That is, in the plane direction of the fiber mass 100, the width of the region where the central portion 101 is formed may be equal to or less than the width of the region where the raised portion 102 is formed. In this case, the ratio of the raised portion 102 to the fiber mass 100 is large, and the fibers constituting the raised portion 102 and the fibers of the low density portion (absorber 10) around the raised portion 102 are entangled in many places. Therefore, the position of the fiber mass 100 is easily fixed inside the absorber 10, and the absorber 10 is less likely to be twisted or deformed. For example, even if the wearer moves his / her body significantly while wearing the napkin 1, it is possible to prevent the absorber 10 from losing its shape. In this way, the composition of the fiber mass 100 contained in the absorber 10 may be adjusted according to the mode in which the napkin 1 is used.

Further, by arranging at least one of the plurality of fiber lumps 100 contained in the absorber 10 in the thickness direction as follows, the absorption performance of the absorber 10 can be improved. 7A to 7C are views for explaining the arrangement of the fiber mass 100 in the thickness direction of the absorber 10.

FIG. 7A is a schematic cross-sectional view showing a case where the fiber mass 100 is arranged so as to be in contact with a sheet member adjacent to the skin side in the thickness direction of the absorber 10. In the case of FIG. 7A, the water such as menstrual blood excreted in the sheet member (for example, the second sheet 4 and the top sheet 3) adjacent to the skin side of the absorber 10 is adjacent to the non-skin side in the thickness direction. Moisture remains on the surface of the skin-side sheet (second sheet 4 or top sheet 3) because the fiber mass 100 (high-density portion) attracts the inside of the absorber 10 and holds it in the central portion 101 of the fiber mass 100. It becomes difficult. Further, since the water retained in the central portion 101 in which the liquid-retaining fibers are concentrated at a high density does not easily move to the outside of the central portion 101, the moisture returns from the inside of the absorber 10 to the sheet on the skin side. So-called rewetting is unlikely to occur. Therefore, since the fiber mass 100 is provided in contact with the sheet member adjacent to the skin side in the thickness direction of the absorber 10, it becomes difficult for moisture to come into contact with the wearer's skin when the napkin 1 is worn. Skin troubles such as rashes are unlikely to occur, and it is possible to suppress causing discomfort to the wearer.

FIG. 7B is a schematic cross-sectional view showing a case where the fiber mass 100 is arranged so as to be in contact with a sheet member adjacent to the non-skin side of the absorber 10 in the thickness direction. In FIG. 7B, the excreted water such as menstrual blood permeates from the skin side to the non-skin side of the absorber 10 and is adjacent to the non-skin side in the thickness direction of the absorber 10 (for example, a cover sheet). It is held by a fiber mass 100 (high density portion) provided in contact with 6). That is, water tends to collect on the non-skin side of the absorber 10 in the thickness direction. Therefore, when the napkin 1 is worn, moisture is less likely to remain on the skin side surface of the absorber 10 that comes into contact with the wearer's skin. Further, since moisture is retained in the vicinity of the cover sheet 6 on the non-skin side surface farthest from the skin side, rewetting and the like are unlikely to occur. Therefore, even when the fiber mass 100 is provided in contact with the sheet member adjacent to the non-skin side of the absorber 10 in the thickness direction, it becomes difficult for moisture to come into contact with the wearer's skin when the napkin 1 is worn. Skin troubles such as rashes are unlikely to occur, and it is possible to suppress causing discomfort to the wearer.

FIG. 7C is a schematic cross-sectional view showing a case where the fiber mass 100 is arranged so as to be in contact with the sheet members adjacent to the skin side surface and the non-skin side surface of the absorber 10 in the thickness direction, respectively. FIG. 7C shows a case where one fiber mass 100 is in contact with both the skin side surface and the non-skin side surface, but a plurality of fiber mass 100s are in contact with either the skin side surface or the non-skin side surface, respectively. It may be. In this case, the proportion of the fiber mass 100 in the thickness direction of the absorber 10 becomes high, and it becomes easy to retain water over a wide range in the thickness direction of the absorber 10. That is, the water retention capacity in the thickness direction of the absorber 10 can be increased as compared with the case where the fiber mass 100 does not exist in the absorber 10. Further, since the effects as described with reference to FIGS. 6A and 6B can be obtained, the absorbency of the absorber 10 can be further enhanced, and the wearer can be less likely to feel uncomfortable.

Further, as described with reference to FIG. 1, the napkin 1 is provided with a plurality of pressing portions 40 for integrally pressing the top sheet 3 (and the second sheet 4) and the absorber 10 (absorbent core). As shown in FIG. 1, these squeezed portions 40 include a linear squeezed portion 41 (so-called hinge) extending in the longitudinal direction while having a predetermined width. The linear pressing portion 41 has a function as a bending guide portion when the absorber 10 is bent and deformed according to the body shape of the wearer when the napkin 1 is worn, and the menstrual blood absorbed by the absorber 10 It has a function of moving water such as, etc. along the linear pressing portion 41. As a result, it is possible to prevent menstrual blood and the like from being concentratedly absorbed at one location of the absorber 10 and exceeding the absorption capacity at that location. That is, by dispersing water such as menstrual blood over a wide area of the absorber 10, the water can be absorbed in a wide area of the absorber 10.

However, since the linear pressing portion 41 is embossed or the like from the skin side in the thickness direction, the density is higher than the other regions of the absorber 10 and moisture easily moves, so that the linear pressing portion 41 is linearly pressed. Moisture such as menstrual blood may be excessively diffused along the portion 41. That is, water such as menstrual blood may not be absorbed in the thickness direction of the absorber 10 and may easily diffuse in the plane direction (longitudinal direction or width direction).

On the other hand, in the present embodiment, at least a part of the fiber mass 100 (high density portion) is provided so as to come into contact with the pressing portion 40 (linear pressing portion 41) in the thickness direction of the absorber 10. By doing so, it is possible to control the diffusion of water. FIG. 8A is a schematic cross-sectional view of the absorber 10 in the region where the squeezed portion 40 (linear squeezed portion 41) is provided. In FIG. 8A, the fiber mass 100 is provided so as to be in contact with the non-skin side of the linear pressing portion 41 in the thickness direction. In this case, a part of the water moving in the plane direction along the linear pressing portion 41 moves (absorbs) from the skin side to the non-skin side in the thickness direction so as to be attracted to the fiber mass 100. Therefore, it is possible to prevent the moisture from being excessively diffused in the plane direction of the absorber 10 along the linear pressing portion 41, and to improve the absorbability of the absorber 10.

In the linear pressing portion 41 (hinge), the entire area of the absorber 10 in the thickness direction is continuously pressed by embossing or the like, so that the following problems may occur. That is, when the napkin 1 is worn, a gap is likely to occur between the wearer's skin and the back seat 5. Further, since the thickness of the absorber 10 is reduced in the linear pressing portion 41, the water retention capacity of the absorber 10 when viewed in the plane direction (longitudinal direction and width direction) is reduced. Further, since the absorber 10 is compacted in the linear pressing portion 41, the touch is liable to deteriorate. On the other hand, if the fiber mass 100 and the linear pressing portion 41 are in contact with each other, the action of the central portion 101 (high density region) of the fiber mass 100 and the raised portion 102 (low density region) surrounding the central portion 101. Therefore, the above-mentioned problems are less likely to occur.

Further, the squeezing section 40 may include a strongly squeezed high-pressure squeezing section 45 and a low-pressure squeezing section 46 in which the absorbent core is squeezed to a lower density than the high-pressure squeezing section 45. FIG. 8B is a schematic cross-sectional view of the absorber 10 in the region where the squeezing portion 40 (linear squeezing portion 41) having the high pressure squeezing portion 45 and the low pressure squeezing portion 46 is provided. In FIG. 8B, the region deeply squeezed from the skin side to the non-skin side in the thickness direction represents the high pressure squeezed portion 45, and the region squeezed shallower than the high pressure squeezed portion 45 represents the low pressure squeezed portion 46. There is. If all the squeezing portions 40 are high-pressure squeezing portions 45, the absorber 10 is excessively bent in the high-pressure squeezing portion 45, the absorber 10 is easily torn, or the wearer's body is slightly uneven. There is a risk that the absorber 10 will not fit easily. On the other hand, by providing the low-pressure squeezing portion 46, excessive deformation of the absorber 10 can be suppressed, and the absorber 10 can be made less likely to be torn.

Then, in the napkin 1 of the present embodiment, at least a part of the fiber mass 100 (high density portion) is provided so as to be in contact with the low pressure squeezing portion 46 in the thickness direction. In the example of FIG. 8B, the low pressure squeezed portion 46 and the fiber mass 100 are in contact with each other in the thickness direction, and the high pressure squeezed portion 45 and the fiber mass 100 are in contact with each other in the width direction. According to such a configuration, water such as menstrual blood moving in the plane direction along the high-pressure squeezing portion 45 and the low-pressure squeezing portion 46 can be easily drawn in the thickness direction of the absorber by the fiber mass 100, and the absorber 10 It is possible to achieve both flexible fit and absorbency.

The napkin 1 has a plurality of creases along the width direction, and the napkin 1 is individually wrapped in a state of being folded in the longitudinal direction by the creases and distributed on the market. For example, it is folded in three in the longitudinal direction by a first fold and a second fold (both not shown) provided near both ends of the wing portion 30 in the longitudinal direction. That is, the first fold and the second fold are bending guide portions for bending the absorber 10. When such a bending guide portion is provided, the fiber mass 100 (high density portion) may be arranged so as to be in contact with the bending guide portion in the thickness direction. By doing so, it becomes easy for water to be drawn into the absorber 10 even in the bending guide portion (crease), and it is possible to prevent the water from staying on the skin side surface of the fold.

In such a case, it is preferable that the average density of the fiber mass 100 is higher than the average density of the absorber 10 in the bending induction portion. With such a configuration, even if the excrement liquid flows into the bending induction portion, the excretion liquid is easily absorbed by the fiber mass 100, so that the excretion liquid diffuses in the width direction along the bending guidance portion. It is suppressed. Thereby, the leakage of the excrement liquid can be suppressed.

Further, as another form of the bending guide portion, a low basis weight region (not shown) in which the basis weight is lower than that of other regions of the absorber 10 may be provided. For example, when a low basis weight region along the longitudinal direction is provided in the center of the width direction of the absorber, the absorber 10 tends to bend in a mountain shape in the width direction, and when the napkin 1 is worn, the absorber 10 is easily bent. Makes it easier to fit the wearer's crotch area. When such a low basis weight region is provided, the fiber mass 100 (high density portion) may be arranged so as to be in contact with the low basis weight region in the thickness direction. By doing so, it becomes easy for water to be drawn into the absorber 10 even in the bending induction portion (low basis weight region), and it is possible to prevent the water from staying on the skin side surface of the low basis weight region. ..

Further, in the napkin 1 of the present embodiment, the weight of the fiber mass 100 per unit area in the central region of the absorber 10 (absorbent core) in the longitudinal direction is the weight of the fiber mass 100 per unit area in both end regions in the longitudinal direction. It is better to make it larger than the weight. For example, in the longitudinal central region of the absorber 10, the amount of the fiber mass 100 contained in the central region may be increased by increasing the thickness of the absorber 10 as compared with the both end regions, or the fibers may be increased in the longitudinal central region as compared with the both end regions. The density of the mass 100 may be increased. In this way, in the longitudinal direction of the absorber 10, water such as menstrual blood is more likely to be retained in the central region than in both end regions, so that it is easier to prevent menstrual blood and the like from leaking to the outside in the longitudinal direction. can do.

The central region of the absorber 10 in the longitudinal direction refers to the region of the central portion when the absorber 10 is divided into three equal parts in the longitudinal direction, and the both end regions in the longitudinal direction refer to the region of both ends of the absorber 10 in the longitudinal direction. Refers to the areas on both sides when divided into three equal parts.

Similarly, in the napkin 1 of the present embodiment, the weight of the fiber mass 100 per unit area in the central region of the absorber 10 (absorbent core) in the width direction is the fiber mass 100 per unit area in both end regions in the width direction. It is better to make it heavier than the weight of. By doing so, in the width direction of the absorber 10, water such as menstrual blood is more likely to be retained in the central region than in both end regions, so that it is easy to prevent menstrual blood and the like from leaking to the outside in the width direction. can do.

The central region in the width direction of the absorber 10 refers to the region of the central portion when the absorber 10 is divided into three equal parts in the width direction, and the both end regions in the width direction refer to the region at both ends of the absorber 10 in the width direction. Refers to the areas on both sides when divided into three equal parts.

Further, in the napkin 1 of the present embodiment, the average density of the fiber mass 100 (the average density of the central portion 101 and the raised portion 102) is higher than the average density of the absorber 10. As a result, as a whole of the absorber 10, water can be easily transferred from the low-density portion to the high-density portion (fiber mass 100) by the capillary phenomenon, and the absorbability of the absorber 10 can be enhanced.

Further, the maximum outer diameter of the fiber mass 100 (the maximum value of Ro in FIG. 6A) is larger than the maximum outer diameter before the highly absorbent polymer particles (SAP) contained in the absorber 10 absorb water and swell. Is desirable. A plurality of fiber masses 100 and SAP are mixed in the absorber 10, but if the outer diameter of the SAP before swelling is larger than the outer diameter of the fiber mass 100, the outer diameter of the SAP after swelling is Since the size is further increased, the swollen SAPs are likely to come into contact with each other. In this case, in the portion where the SAPs are in contact with each other, it becomes difficult for the SAPs and the water to come into contact with each other. That is, the contact area with water on the surface of SAP becomes small, so-called "gel blocking" in which water absorption is inhibited may occur, and the absorbability by SAP may decrease.

On the other hand, if the outer diameter of the fiber mass 100 is larger than the outer diameter of the SAP before swelling, there is a high possibility that the fiber mass 100 will be arranged between two adjacent SAPs when the SAP swells. Therefore, it becomes difficult for SAPs to come into contact with each other. That is, it becomes easy to suppress the occurrence of gel blocking. As a result, it is possible to suppress the decrease in the absorbability of SAP, and it is possible to increase the water absorption efficiency of the absorber 10 as a whole.

Further, the absorber 10 of the present embodiment includes hardwood liquid-retaining fibers having a short average fiber length (average fiber length of less than 2 mm) and liquid-retaining fibers other than hardwood, which are higher than hardwood fibers. Contains liquid-retaining fibers with a long average fiber length. Examples of the liquid-retaining fiber having a longer average fiber length than the hardwood fiber include a softwood liquid-retaining fiber made of softwood and a rayon fiber. As described above, the mixture of the hardwood liquid-retaining fiber having a short fiber length and the liquid-retaining fiber having a long fiber length (coniferous liquid-retaining fiber, etc.) makes it easy for both to be entangled, and the absorber 10 The shape is easily maintained. Therefore, the flexibility is higher than the case where the absorber is formed only by the liquid-retaining fibers having a long fiber length, and compared with the case where the absorber is formed only by the liquid-retaining fibers having a short fiber length. It is possible to realize the absorber 10 which is less likely to lose its shape. That is, it is possible to easily balance the absorbability and flexibility of the absorber 10.

Further, as a liquid-retaining fiber having an average fiber length longer than that of hardwood fiber, a hydrophobic thermoplastic fiber may be contained. With such a configuration, the fibers having a short average fiber length and the fibers having a long average fiber length are entangled and entangled, so that the shape of the absorber 10 is less likely to be lost, and the hydrophobic fibers are formed. By being contained, the diffusibility of water in the absorber 10 can be improved. As a result, the moisture is easily diffused over a wide range of the absorber 10, and the moisture is easily absorbed and retained throughout the absorber 10. Therefore, the absorbability of the absorber 10 can be further improved.

Further, in the napkin 1 of the present embodiment, at least in the pressing portion 40 in which the top sheet 3 and the absorber 10 (absorbent core) are integrally pressed in the thickness direction, a plurality of thermoplastic fibers are fused to each other. ing. When the squeezed portion 40 is formed, the thermoplastic fibers are fused to each other, so that the top sheet 3 and the absorber 10 become more integrally and the shape of the absorber 10 becomes more stable. This makes it easier to prevent the absorber 10 from losing its shape or deteriorating water absorption even when the wearer moves his / her body significantly while wearing the napkin 1, for example.

If the thermoplastic fibers are heat-sealed to each other in a portion of the absorber 10 other than the squeezed portion 40, the absorber 10 becomes hard or becomes a film at the location where the heat fusion occurs. Problems such as reduced liquid diffusivity may occur. On the other hand, since the squeezed portion 40 of the absorber 10 is a portion that conforms to the deformation of the absorber 10 by being squeezed and hardened, the thermoplastic fibers may be heat-sealed and hardened at the portion. The effect of reduced liquid diffusivity is small. Therefore, even if the thermoplastic fibers are fused to each other in the squeezed portion 40 of the napkin 1, a problem is unlikely to occur.

Further, it is desirable that the average fiber length of the hardwood liquid-retaining fiber is smaller than the width of the squeezed portion 40. For example, the length (width) of the above-mentioned linear pressing portion 41 (see FIG. 1) in the width direction is about 1.0 mm to 2.0 mm, and the average fiber length of the hardwood liquid-retaining fiber (in the present embodiment). It is larger than 0.79 mm). With such a configuration, the probability that the liquid-retaining fibers are overlapped with both ends in the width direction of the squeezed portion 40 is low. That is, it is easy to prevent the water-retaining fibers from being arranged straddling both ends of the pressed portion 40 in the width direction (that is, the interface between the pressed portion and the non-pressed portion). If the water-retaining fibers are straddled at the interface between the pressed portion and the non-compressed portion, the interface becomes harder than when the straddling does not occur. On the other hand, by reducing the water-retaining fibers that straddle the interface between the pressed portion 40 and the non-compressed portion, the hardness felt by the body when the pressed portion is deformed is reduced, and a comfortable wearing feeling is realized. Sexual goods can be provided.

Further, the abundance density of the fiber mass 100 may have a gradient in the thickness direction of the absorber 10. If the density of the fiber mass 100 near the skin-side surface in the thickness direction of the absorber 10 is higher than the density in other regions in the thickness direction, it is possible to facilitate absorption of liquids such as menstrual blood from the skin-side surface. it can. Further, if the density of the fiber mass 100 near the non-skin side surface of the absorber 10 in the thickness direction is higher than the density in other regions in the thickness direction, it is easy to repel the liquid to a position farther from the wearer's skin. can do.

<Modification example>
In the above-described embodiment, the case where the shape of the absorber 10 is a rectangular parallelepiped shape (rectangular cross section) as shown in FIG. 2 has been described, but the absorber 10 protrudes toward the skin in the thickness direction. It may be deformed so as to have a portion that has been removed. FIG. 9 is a schematic cross-sectional view showing a modified example of the absorber 10. The absorber 10 of the modified example has a middle-high portion 10H of the absorber that rises toward the skin in the thickness direction from the base portion 10L of the absorber in the central portion in the left-right direction (the region between the linear squeezed

portions

41 and 41 in FIG. 1). have. An inclined portion 10S inclined in the thickness direction is formed between the middle and high portion 10H of the absorber and the base portion 10L of the absorber. By providing such an absorber middle / high portion 10H in the central portion of the absorber 10, it is possible to enhance the cushioning property of the crotch portion of the wearer and the absorbency of excrement liquid when the napkin 1 is worn.

Further, when the absorber 10 is provided with such an inclined portion 10S, a part of the fiber mass 100 (high density portion) is crushed or the raised portion 102 is unevenly arranged in the inclined portion 10S. You may do it. Further, the plane direction of the fiber mass 100 (XY direction in FIG. 6A) may be arranged along the inclined surface of the inclined portion 10S. In FIG. 9, for a part of the fiber mass 100, the central portion 101 is arranged so as to be in contact with the skin-side surface of the inclined portion 10S, and one end of the raised portion 102 extends toward the apex of the absorber middle / high portion 10H and is raised. An example is shown in which the other end of the portion 102 is arranged so as to extend in the direction of the base portion 10L in the collection. By providing the raised portion 102 in this way, even when the absorber 10 has the absorber middle / high portion 10H and the inclined portion 10S, the flexibility and absorption are the same as in the above-described embodiment. It is possible to achieve both sex.

=== Other embodiments ===
Although the embodiments of the present invention have been described above, the above-described embodiments are for facilitating the understanding of the present invention, and are not for limiting the interpretation of the present invention. Further, the present invention can be changed or improved without departing from the spirit thereof, and it goes without saying that the present invention includes an equivalent thereof.

In the above-described embodiment, the sanitary napkin 1 as an example of the absorbent article has a pair of wing portions 30, but the present invention is not limited to this. That is, the wing portion 30 may be omitted.

Further, in the above-described embodiment, the absorber 10 is covered with two sheets, a second sheet 4 and a cover sheet 6, but the present invention is not limited to this. For example, the skin side surface and the non-skin side surface of the absorber 10 may be covered with a single sheet.

In the above-described embodiment, a sanitary napkin, a vaginal discharge sheet (panty liner), and a light incontinence pad have been described as an example of an absorbent article, but other absorbent articles may be used. For example, the present invention can be applied to breast milk pads, fecal incontinence pads, shorts type napkins, and various disposable diapers such as tape type and pants type. That is, by providing an absorbent core including a high-density portion (fiber mass, knots) and a low-density portion described in the above-described embodiment, a breast milk pad, a fecal incontinence pad, etc. that have both flexibility and absorbability can be provided. It can be realized.

<About functional materials>
In the above-described embodiment, the functional material may be provided in at least a part of the absorbent core. As the functional material, for example, a warming agent, a cooling sensation agent, a fragrance, an antibacterial agent and the like can be used.

The warming agent has a function of relieving the wearer's menstrual pain and cold symptoms, and includes a warming stimulant that the stimulated wearer feels warm by stimulating the wearer's temperature sensation. The warmth stimulant is mixed with a volatile solvent (or the warmth stimulant is volatile).

The warming stimulant stimulates and activates TRPV1 which is one of the temperature-sensitive TRP channels, such as capsaicin and vanillyl butyl ether. That is, it activates TRPV1 of the wearer and causes heat production (the wearer produces heat in the body) in the wearer through the sympathetic nervous system. The warming stimulant is preferably a plant-derived compound from the viewpoint of the wearer's sense of security. For example, capsicoside, capsaicin (LD50: 47 mg / kg, molecular weight: 305), capsaicinoids (dihydrocapsaicin, nordihydro). Capsaicin, homodihydrocapsaicin, homocapsaicin, nonibamide, etc.), capsantin, benzyl nicotinate (LD50: 2,188 mg / kg, molecular weight: 213), β-butoxyethyl nicotinate, N-acylwanylamide, vanillylamide nonanoate, Polyhydric alcohol, chili powder, chili tincture, chili extract, vanillyl ether nonanoate, vanillyl alcohol alkyl ether derivative (eg, vanillyl ethyl ether, vanillyl butyl ether (LD50: 4,900 mg / kg, molecular weight: 210), Vanillyl pentyl ether, vanillyl hexyl ether), isovanillyl alcohol alkyl ether, ethyl vanillyl alcohol alkyl ether, veratrial alcohol derivative, substituted benzyl alcohol derivative, substituted benzyl alcohol alkyl ether, vanillin propylene glycol acetal, ethyl vanillin propylene glycol Included are ethers, ginger extracts, ginger oils, gingerol (LD50: 250 mg / kg, molecular weight: 294), gingereon, hesperidin, and pyrrolidone carboxylic acids, and any combination thereof.

The solvent is not particularly limited as long as it can contain a warming stimulant, and examples thereof include lipophilic solvents and hydrophilic solvents. The solvent can dissolve, disperse, or the like, for example, a warming stimulant. When the warmth stimulant is a volatile substance, a solvent is not always required, and only the warmth stimulant may be used. Examples of the lipophilic solvent include fats and oils, for example, natural oils (for example, fatty acid esters such as triglycerides, coconut oil, linseed oil, tri (capril / capric acid) glyceryl, etc.), hydrocarbons (for example, paraffin, for example, liquid paraffin). And so on. Examples of the hydrophilic solvent include water and alcohol. Examples of the alcohol include lower alcohols such as methanol, ethanol, ethylene glycol and glycerin, higher alcohols such as capryl alcohol, lauryl alcohol and myristyl alcohol.

The cooling sensation agent has a function of reducing discomfort due to the wearer's stuffiness and stickiness, and is preferably one that stimulates the temperature-sensitive TRP channel like the warming sensitizer. As the cooling sensation agent, for example, menthol (for example, l-menthol) and its derivatives (for example, menthyl lactate), methyl salicylate, camphor, essential oils derived from plants (for example, mint, eucalyptus) and the like can be used.

The fragrance has a function of volatilizing the aroma component into the atmosphere under atmospheric pressure to make it difficult for the wearer to perceive the unpleasant odor of excrement. As the fragrance, the same fragrances that have been conventionally used in the technical field can be used, but when a green herbal-like fragrance (green herbal-like fragrance) is used, mental discomfort is caused. It can be safely and easily relieved without giving physical irritation to the body and without oral administration. In addition to this, a feeling of comfort can be obtained.

The green herbal-like scent is a scent containing a green-like scent (green note) or a herbal-like scent (herbal note). Green-like aroma refers to the refreshing aroma of grass and young leaves. Herbal note is a natural, herbal-like scent that uses herbs. Fragrance compositions containing fragrances with a green herbal-like aroma include cis-3-hexenol, cis-3-hexenyl formate, cis-3-hexenyl acetate, cis-3-hexenyl propionate, cis-3-hexenyl butyrate, Trans-2-hexenal, trans-2-hexenyl acetate, hexyl acetate, styralyl acetate, 2-methyl-3- (3,4-methylenedioxyphenyl) -propanal (IFF company name, helional), 3 (4)- (5-Ethylbicyclo [2,2,1] heptyl-2) -cyclohexanol-allyl 2-pentyroxyglycolate (IFF company name, allylamylglycolate), 4-methyl-3-decene-5-ol (Givaudan) It preferably contains one or more fragrances selected from (company name, undecavertor), hexyl aldehyde, 2,4-dimethyl-3-cyclohexenylcarboxyaldehyde (IFF company name, triplar) and phenylacetaldehyde. .. Commercially available products can also be used as these fragrances. Fragrances containing these mainly produce green-like fragrances. Fragrance compositions containing fragrances with a green herbal-like aroma further include l-menthol, 1,8-cineole, methyl salicylate, citronellal, camphor, borneol, isobornyl acetate, terpinyl acetate, eugenol, anethole, 4-methoxybenzyl. It preferably contains one or more fragrances selected from alcohol and estragole. The fragrances containing these mainly produce herbal-like fragrances.

The antibacterial agent has a function of suppressing the growth of bacteria in the body fluid or the like absorbed by the absorbent article and making it difficult to generate an odor due to putrefaction or the like. As the antibacterial agent, the same antibacterial agent as those conventionally used in the art can be used. For example, examples of cationic antibacterial agents include quaternary ammonium salts, guanidine-based antibacterial agents (eg, chlorhexidine gluconate, chlorhexidine hydrochloride), biguanide-based antibacterial agents, metal ion carriers, hexetidine, metalonidazole, and the like. Salt is preferred.

The quaternary ammonium salt is not particularly limited as long as it has a quaternary ammonium salt structure in the molecule, but for example, an alkyltrimethylammonium salt, a polyoxyethylene alkylmethylammonium salt, and an alkylbenzyldimethyl salt. Examples thereof include ammonium salts and alkylpyridinium salts, and examples thereof include quaternary ammonium salts represented by the following formulas (1) to (4).
[R (CH3) 3N +] lX equation (1)
[R (CH3) N + (CH2CH2O) mH [(CH2CH2O) nH]] lX equation (2)
[R (CH3) 2N + CH2C6H5] lX equation (3)
[RPy +] lX formula (4)
(In the formula, R independently represents an alkyl group, X independently represents a monovalent or divalent anion, and l independently represents an integer of 1 or 2, respectively. Represented, m and n each independently represent an integer of 2 to 40, and Py represents a pyridine ring.)

Examples of the biguanide antibacterial agent include polyaminopropyl biguanide and salts thereof, such as hydrochloride, stearate, phosphate, etc., chlorhexidine gluconate, chlorhexidine hydrochloride, polyhexamethylene guanidine hydrochloride, polyhexamethylene guanidine phosphate, etc. Examples include salts, polyhexamethylene biguanide hydrochloride, polyhexamethylene biguanide stearate, poly [oxyethylene (dimethyliminio) ethylene (dimethyliminio) ethylenedichloride], and any combination thereof. Examples of the metal ion carrier include those capable of releasing metal ions, for example, metal salts. Examples of the metal ion include silver ion, zinc ion, aluminum ion, cobalt ion, zirconium ion, cerium ion, iron ion, copper ion, nickel ion, platinum ion and the like, and silver ion is preferable. The metal salts include, for example, silver nitrate, for example, silver nitrate, aluminum nitrate, cobalt nitrate, zirconium nitrate, cerium nitrate, iron nitrate, copper nitrate, nickel nitrate, acetate, for example, silver acetate, hydrochloride, for example, cerium chloride. Examples thereof include iron chloride, zinc chloride, copper chloride and sulfate, such as silver sulfate, aluminum sulfate, copper sulfate and zinc sulfate.

By providing such a functional material in the absorbent core having a high-density portion (fiber mass, knots) and a low-density portion, the functional material can be easily held in the high-density portion. The effect of the functional material can be exhibited more effectively. For example, by retaining the antibacterial agent in the high-density portion (fiber mass, knots) of the absorbent core, it is possible to facilitate the antibacterial action in the portion where absorbed urine or menstrual blood is accumulated. In addition, the fragrance, cooling sensation, and warming agent are retained and accumulated in the high-density portion (fiber mass, knots), so that the effect of these functional materials can be easily maintained for a long time.

<Relationship between high-density part content and water absorption>
The relationship between the ratio of the high-density portion contained in the absorber (content ratio of the high-density portion) and the water absorption of the absorber will be described. Specifically, we prepared four types of samples (absorbents) with different high-density parts (notts) content, conducted an experiment to measure the water absorption rate for each sample, and verified the water absorption from the results. It was.

First, four types of absorbers (absorbent cores) are produced and used as samples based on the methods described in FIGS. 4A and 4B. When producing an absorber, first, a pulp sheet (pulp roll) is pulverized using a saw mill as shown in FIG. 4A. At this time, by adjusting the rotation speed of the saw mill to change the amount of pulp crushed per unit time, the content of high-density parts (notts) contained in the crushed pulp can be increased or decreased. .. In this experiment, the pulp crushed at 120 kg / h as the processing amount of the saw mill was designated as Example 1, the pulp crushed at 240 kg / h was designated as Example 2, and the pulp crushed at 360 kg / h was designated as Example 3. Further, pulp crushed at 60 kg / h was used as a comparative example. Then, an absorber is formed from each of these four types of crushed pulp as shown in FIG. 4B. Each absorber has the same shape, has a predetermined area (for example, length 200 mm × width 70 mm), has a basis weight of 300 g / m ² , and has a thickness of 2.0 mm.

Next, for these four types of samples, the content rate of the high-density part (notts) (that is, the weight ratio of the high-density part contained in the total weight of the absorber) is measured. The content of the high-density part shall be measured as follows using a sieve shaker (for example, a sieve shaker SS-HK60 manufactured by AS ONE Corporation) according to the test method specified in JIS K0069. Can be done.

First, the total weight of each of the four types of samples (absorbents of Examples 1 to 3 and Comparative Example) is measured and recorded using an electronic balance or the like. Next, the sample of Example 1 is placed on a 14-mesh sieve provided in a sieve shaker. In addition, a cylinder with the same diameter as the sieve is installed under the mesh, and a hole is made on the side surface of the cylinder at a height of 70 mm below the mesh to prevent a gap from being created. W101: A suction minimum inner diameter of 22 mm and a pressure of 0.5 Mpa) are installed. Further, an air ejection device (for example, Air Duster Gun AG-101 manufactured by TONE Co., Ltd .: nozzle length 95 mm, nozzle inner diameter 4 mm, pressure 0.5 Mpa) is installed at a height of 50 mm above the mesh. For the mesh installed on the sieve, use the standard sieve wire mesh specified in JIS Z8801. For example, the 14 mesh is a wire mesh having a mesh size of 1.18 mm, a wire diameter of 0.63 mm, and a hole opening area of 42.3%.

Next, while shaking for 15 minutes under the condition of an amplitude of 70 mm and 60 times / minute, the air ejection device is evenly injected, and the fibers are sucked by the suction device to separate the fibers from the absorber. Then, after 15 minutes have passed, the fibers remaining on the sieve (14 mesh) are designated as "Nots" (corresponding to the above-mentioned high-density portion (fiber mass 100)), and the weight of the Nots is measured and recorded. .. Then, the fibers that have passed through the 14 mesh are collected, placed on a sieve of the 60 mesh, and the fibers are separated again under the same conditions. Then, after 15 minutes have passed, the fibers remaining on the sieve (60 mesh) are designated as "Accept", and the weight is measured and recorded. Further, the fiber that has passed through the sieve (60 mesh) is referred to as "Fine", and the value obtained by subtracting the weights of Nots and Access from the total weight of the sample (absorbent) of Example 1 is recorded as the weight of Fine. Then, by dividing each of these measured weights by the total weight of the sample (absorbent), the contents (% by weight) of Nots, Accept, and Fine in the sample can be obtained.

This operation is performed for four types of samples (Examples 1 to 3 and Comparative Example), and the contents of Nots, Accect, and Fine are determined for each sample. It is possible to measure the contents of Nots (high-density part), Accect, and Fine in a commercially available absorbent article by the same method. In that case, after peeling off the sheets (top sheet 3, second sheet 4, cover sheet 6, etc. described above) laminated on the upper and lower sides of the absorber in the product state, the fibers are separated and measured according to the above method. Do. Further, when the size of the absorber is large, the measurement may be performed in a plurality of times.

After measuring the content of Nots (high density part) etc. for each of the four types of samples, the water absorption of the sample is measured. First, a surface sheet (corresponding to the above-mentioned top sheet 3, for example, a surface sheet of Sophie SPORTS manufactured by Unicharm Co., Ltd.) is placed on the upper surface (one side in the thickness direction) of each sample, and a hole is placed on the surface sheet. A perforated acrylic plate (for example, a 200 mm (length) × 100 mm (width) acrylic plate having a hole of 40 mm × 10 mm in the center) is placed on top of each other. Next, using an auto burette (for example, Multidojimat E725-1 type manufactured by Shibata Kagaku Kikai Kogyo Co., Ltd.), 2 ml of artificial menstrual blood is injected at 90 ml / min into the holes of the acrylic plate. As "artificial menstrual blood", 80 g of glycerin, 8 g of sodium carboxymethyl cellulose, 10 g of sodium chloride, 4 g of sodium hydrogen carbonate, 8 g of red 102, 2 g of red, and 2 g of yellow 5 are added to 1 L of ion-exchanged water. A well-stirred product was used. Then, after the start of injection of artificial menstrual blood, the time (brush time) from the inside of the surface sheet until the artificial menstrual blood disappears is measured. Since the brushing time becomes shorter as the absorber easily absorbs water, the water absorption of the absorber can be evaluated by the measured length of the brushing time.

Table 1 shows the relationship between the content of Nots, Access, and Fine measured for each sample and the brushing time. According to Table 1, it can be confirmed that the higher the content of Nots (high density portion) in the absorber, the shorter the brushing time. Generally, when wearing a sanitary napkin, if the absorption rate of body fluid (that is, brushing time) is 10 seconds or less, the wearer tends to feel comfortable, and if the absorption rate of body fluid exceeds 20 seconds, it is worn. It is known that a person is likely to cause discomfort. In Examples 2 and 3, the brushing time was shorter than 10 seconds and the evaluation of water absorption was 〇, which is suitable as a napkin. Further, even in Example 1, since the brushing time is shorter than 20 seconds, it can be practically used as a napkin. On the other hand, in the comparative example, the brushing time is 20 seconds or more, and the evaluation of water absorption is x.

As described above, it was clarified that the evaluation of water absorption was good (〇 or Δ) in Examples 1 to 3 in which the content of Nots contained in the absorber was higher than the content of Fine. .. This is because, as compared with Fine, which is fine enough for the fibers to pass through a 60-mesh sieve, the higher the content of Nots in which the fibers are aggregated, the more easily voids are generated inside the absorber, and water such as body fluids can pass through. It is considered that this is because an absorber having excellent liquid permeability is formed. Further, as described above, the Nots (high-density portion) itself easily holds the liquid, so that the higher the content of Nots, the more excellent the water-retaining absorber can be formed.

Therefore, it is desirable that the content of Nots contained in the absorber is higher than the content of Fine. In other words, when the fibers of the absorber (absorbent core) are separated using a sieve shaker conforming to JIS K0069, the weight of the fibers (Nots) remaining on the 14-mesh sieve is used as the weight of the absorber. It is desirable that the value divided by the weight is larger than the value obtained by dividing the weight of the fiber (Fine) that has passed through the 60-mesh sieve by the weight of the absorber. By setting the content of Nots (high density portion) in the absorber in such a relationship, the water absorption of the absorber (absorbable core) can be further improved.

1 Sanitary napkin (absorbent article),
2 side seats, 3 top seats, 4 second seats,
5 back seats, 6 cover seats,
10 Absorber (absorbent core),
10H absorber middle and high part, 10L absorber base part, 10S inclined part,
20 Napkin body,
30 wing part,
40 squeezing part, 41 linear squeezing part, 45 high pressure squeezing part, 46 low pressure squeezing part,
61 transport mechanism, 62 saw mill,
70 rotating drum, 71 recess, 72 suction part,
80 material supply, 80a hood,
81 Particle supply unit,
100 fiber mass (high density part)
101 central part, 102 raised part,
PS pulp sheet

Claims

It has a longitudinal direction, a width direction, and a thickness direction that are orthogonal to each other.
An absorbent article with an absorbent core having crushed liquid-retaining fibers.
The liquid-retaining fiber has a hardwood liquid-retaining fiber made of hardwood, and has a liquid-retaining fiber.
The absorbent core has a plurality of high-density portions in which the liquid-retaining fibers are aggregated.
The absorbent core has at least one high-density portion on one side or the other side in the thickness direction of the high-density portion, which has a low density portion in which the density of the liquid-retaining fiber is lower than that of the high-density portion.
Absorbent article characterized by that.
The absorbent article according to claim 1.
In the high-density portion, the liquid-retaining fibers are concentrated, and the central portion that is not entangled with the fibers of the low-density portion and the raised portion that is entangled with the fibers of the low-density portion outside the central portion. Has a part and
The average density of the high density portion is higher than the average density of the absorbent core.
An absorbent article characterized in that the weight of the fiber contained in the central portion is larger than the weight of the fiber contained in the raised portion.
The absorbent article according to claim 1.
In the high-density portion, the liquid-retaining fibers are concentrated, and the central portion that is not entangled with the fibers of the low-density portion and the raised portion that is entangled with the fibers of the low-density portion outside the central portion. Has a part and
The average density of the high density portion is higher than the average density of the absorbent core.
An absorbent article characterized in that the weight of the fiber contained in the central portion is equal to or less than the weight of the fiber contained in the raised portion.
The absorbent article according to claim 2 or 3.
The shape of the high-density portion is flat and
The maximum width of the region occupied by the raised portion in the plane direction of the high-density portion is longer than the maximum width of the region occupied by the raised portion in the direction orthogonal to the plane direction.
Among the plurality of high-density portions included in the absorbent core, the proportion of the high-density portion arranged so as to be perpendicular to the plane direction with respect to the thickness direction of the absorbent core is The absorbent article is characterized in that it is larger than the proportion of the high-density portion arranged so that the direction perpendicular to the plane direction is along the longitudinal direction or the width direction of the absorbent core.
The absorbent article according to any one of claims 2 to 4.
In the plane direction of the high-density portion, when the diameter of the circle circumscribing the central portion is Rc and the diameter of the circle circumscribing the raised portion is Ro, (Ro-Rc) <Rc. A characteristic absorbent article.
The absorbent article according to any one of claims 2 to 4.
In the plane direction of the high-density portion, when the diameter of the circle circumscribing the central portion is Rc and the diameter of the circle circumscribing the raised portion is Ro, (Ro-Rc) ≥ Rc. A characteristic absorbent article.
The absorbent article according to any one of claims 1 to 6.
An absorbent article characterized in that, in the thickness direction, at least a part of the high-density portion is in contact with a sheet member adjacent to the skin side of the absorbent core.
The absorbent article according to any one of claims 1 to 7.
An absorbent article characterized in that, in the thickness direction, at least a part of the high-density portion is in contact with a sheet member adjacent to the non-skin side of the absorbent core.
The absorbent article according to any one of claims 1 to 8.
In the thickness direction, at least a part of the high-density portion is in contact with both the sheet member adjacent to the skin side of the absorbent core and the sheet member adjacent to the non-skin side of the absorbent core. An absorbent article characterized by.
The absorbent article according to any one of claims 1 to 9.
It has a topsheet located closer to the skin in the thickness direction than the absorbent core.
It has a pressing portion that integrally presses the top sheet and the absorbing core in the thickness direction.
An absorbent article characterized in that the pressed portion and the high-density portion are in contact with each other in the thickness direction.
The absorbent article according to claim 10.
The squeezed portion has a low-pressure squeezed portion and a high-pressure squeezed portion in which the absorbent core is squeezed at a higher density than the low-pressure squeezed portion.
An absorbent article characterized in that the low-pressure squeezed portion and the high-density portion are in contact with each other in the thickness direction.
The absorbent article according to any one of claims 1 to 11.
In the longitudinal direction, the weight of the high-density portion contained per unit area of the central region when the absorbent core is divided into three equal parts is
An absorbent article characterized in that, in the longitudinal direction, the weight of the high-density portion included per unit area of both end regions when the absorbent core is divided into three equal parts is larger than the weight of the high-density portion.
The absorbent article according to any one of claims 1 to 12.
In the width direction, the weight of the high-density portion included per unit area of the central region when the absorbent core is divided into three equal parts is
An absorbent article characterized in that, in the width direction, it is larger than the weight of the high-density portion included per unit area of both end regions when the absorbent core is divided into three equal parts.
The absorbent article according to any one of claims 1 to 13.
The absorbent core contains a highly absorbent polymer and
An absorbent article characterized in that the maximum outer diameter of the high-density portion is larger than the maximum outer diameter of the highly absorbent polymer.
The absorbent article according to any one of claims 1 to 14.
The average fiber length of the hardwood liquid-retaining fiber is less than 2 mm.
An absorbent article characterized in that the absorbent core contains a liquid-retaining fiber made of a material other than hardwood and having a longer average fiber length than the hardwood liquid-retaining fiber. ..
The absorbent article according to claim 15.
The average fiber length of the hardwood liquid-retaining fiber is less than 2 mm.
An absorbent article characterized in that the absorbent core contains hydrophobic thermoplastic fibers having a longer average fiber length than the hardwood liquid-retaining fibers.
The absorbent article according to any one of claims 1 to 16.
The average fiber width of the hardwood liquid-retaining fiber is 15 μm or less.
Number of the hardwood liquid retention fiber per unit area of the absorbent core 300 lines / mm 2 or more and less than 2,500 / mm 2,
An absorbent article characterized by having a highly absorbent polymer between the plurality of the hardwood liquid-retaining fibers.
The absorbent article according to any one of claims 1 to 17.
The standard deviation of the fiber length of the hardwood liquid-retaining fiber is 0.27 or less.
An absorbent article characterized in that the standard deviation of the fiber width of the hardwood liquid-retaining fiber is 7.55 or less.
The absorbent article according to claim 18.
The value obtained by adding the standard deviation of the fiber length of the hardwood liquid-retaining fiber to the average fiber length of the hardwood liquid-retaining fiber is smaller than twice the value of the average fiber length of the hardwood liquid-retaining fiber.
The value obtained by subtracting the standard deviation of the fiber length of the hardwood liquid-retaining fiber from the average fiber length of the hardwood liquid-retaining fiber is larger than the value of 1/2 of the average fiber length of the hardwood liquid-retaining fiber. Absorbent article characterized by being large.
The absorbent article according to any one of claims 1 to 19.
The absorbent core contains a plurality of thermoplastic fibers and has a pressing portion for integrally pressing the absorbent core in the thickness direction.
An absorbent article characterized in that the thermoplastic fibers are fused to each other in the squeezed portion.
The absorbent article according to any one of claims 1 to 20.
The absorbent article is at least one of a sanitary napkin, a vaginal discharge sheet, and a light incontinence pad.
The absorbent article according to any one of claims 1 to 21.
An absorbent article comprising a pair of wing portions extending from a central region in the longitudinal direction to both outer sides in the width direction.
The absorbent article according to any one of claims 1 to 22.
An absorbent article characterized in that an adhesive portion for attaching the absorbent article to the wearer's underwear when worn is provided on the non-skin side surface of the absorbent article.
The absorbent article according to any one of claims 1 to 23.
An absorbent article characterized in that a functional material is provided in at least a part of the absorbent core.
The absorbent article according to any one of claims 1 to 24.
When the fibers contained in the absorbent core are separated using a sieve shaker conforming to JIS K 0069,
The value obtained by dividing the weight of the fibers remaining on the 14-mesh sieve of the sieve shaker by the weight of the absorbent core before separation is calculated.
An absorbent article characterized in that the weight of the fibers that have passed through the 60-mesh sieve of the sieve shaker is greater than the value obtained by dividing the weight of the absorbent core before separation.