Unwoven fabric for absorbent article

Abstract

To provide an unwoven fabric for an absorbent article, the unwoven fabric containing cellulose fiber and being capable of suppressing surface liquid flow.SOLUTION: An unwoven fabric for an absorbent fabric of the present invention contains cellulose fiber and includes: a first surface and a second surface; a plurality of band-shaped parts arranged so as to be separated from each other in a second plane direction and formed in a band shape extending in a first plane direction; and a plurality of interval parts arranged alternately in the band-shaped part and in the second plane direction and formed in a recessed shape with respect to the band-shaped part on the first surface. The band-shaped part includes: a plurality of first regions arranged so as to be separated in the first plane direction; and a plurality of second regions arranged alternately in the first regions and in the first plane direction and formed in a recessed shape with respect to the first region on the first surface. The interval parts are arranged adjacently to the second region in the second plane direction and have a plurality of apertures formed in a thickness direction. The aperture rate of the non-woven fabric for an absorbent fabric is equal to or greater than 1.0%.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a nonwoven fabric for absorbent articles containing cellulose fibers and an absorbent article comprising the same. [Background technology]

[0002] Absorbent articles generally comprise a topsheet forming a skin-facing surface, a backsheet, and an absorbent body disposed between the topsheet and the backsheet. Nonwoven fabrics are often used in absorbent articles, for example, for the topsheet, which is required to be liquid permeable. Due to growing environmental awareness and the sense of security associated with materials derived from natural materials, nonwoven fabrics containing cellulose fibers, such as cotton fibers, have been attracting attention as nonwoven fabrics for such absorbent articles.

[0003] On the other hand, nonwoven fabrics containing a large amount of cellulose fibers on the skin-facing surface are generally highly hydrophilic and tend to retain liquid, which can cause discomfort to the wearer. To alleviate this discomfort, cellulose fibers are sometimes treated with hydrophobic agents, but this treatment can cause excreted liquid to flow off the surface (a phenomenon known as runoff). In response to this, nonwoven fabrics for absorbent articles containing cellulose fibers and having open pores are known (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2019 / 004369 Summary of the Invention [Problem to be solved by the invention]

[0005] Patent Document 1 discloses that water absorption is affected by the arrangement of low-density regions such as open holes, but does not fully consider how to suppress runoff.

[0006] The present invention relates to a nonwoven fabric for absorbent articles containing cellulose fibers, which is capable of suppressing liquid flow on the surface, and an absorbent article including the same. [Means for solving the problem]

[0007] A nonwoven fabric for absorbent articles according to one embodiment of the present invention contains cellulose fibers and has a first planar direction, a second planar direction intersecting the first planar direction, and a thickness direction perpendicular to the first planar direction and the second planar direction. The nonwoven fabric for absorbent articles is a first surface and a second surface configured as surfaces extending in the first planar direction and the second planar direction, respectively; a plurality of strip-shaped portions that are spaced apart from each other in the second planar direction and that are each formed into a strip shape extending in the first planar direction when viewed in the thickness direction; The first surface includes a plurality of spacing portions that are arranged alternately with the band-shaped portions in the second plane direction and are formed in a concave shape in the thickness direction relative to the band-shaped portions. The band-shaped portion is a plurality of first regions arranged spaced apart from each other in the first planar direction; a plurality of second regions that are arranged alternately with the first regions in the first planar direction and are formed on the first surface in a recessed shape relative to the first regions in the thickness direction; It has. The spacing portion is The substrate has a plurality of openings arranged adjacent to the second region in the second planar direction and formed in the thickness direction. The nonwoven fabric for absorbent articles has an open pore ratio of 1.0% or more. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a nonwoven fabric for absorbent articles containing cellulose fibers, which can simultaneously suppress the discomfort caused by wet skin (liquid backflow) and the flow of liquid on the surface, and an absorbent article comprising the same. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a perspective view of a nonwoven fabric for absorbent articles according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a plan view showing a first surface of the nonwoven fabric for absorbent articles. [Figure 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. [Figure 5] FIG. 3 is a cross-sectional view taken along line VV in FIG. [Figure 6] FIG. 4 is a plan view of an absorbent article including a nonwoven fabric for absorbent articles according to a second embodiment of the present invention. [Figure 7] FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0011] First Embodiment [Configuration of nonwoven fabric for absorbent articles (nonwoven fabric)] The nonwoven fabric 10 for absorbent articles according to the first embodiment of the present invention is a liquid-permeable nonwoven fabric used in absorbent articles, and will be referred to hereinafter as "nonwoven fabric 10." In this embodiment, the absorbent article using the nonwoven fabric 10 is an article that absorbs liquid excrement (hereinafter also referred to as "liquid") such as menstrual blood, vaginal discharge, urine, and loose stool, and examples thereof include sanitary napkins, diapers, panty liners, and incontinence pads. As will be described later, the nonwoven fabric 10 according to this embodiment can be used as a liquid-permeable sheet material included in an absorbent article. For example, the nonwoven fabric 10 can be used as a topsheet, an intermediate sheet between the topsheet and the absorbent body, a core wrap sheet that covers the surface of the absorbent body, and the like, and is particularly suitable for use as a topsheet.

[0012] As illustrated in FIGS. 1 and 2, the nonwoven fabric 10 has a first planar direction X, a second planar direction Y, and a thickness direction Z. The first planar direction X and the second planar direction Y are directions extending along the surface of the nonwoven fabric 10. In this embodiment, the first planar direction X corresponds to the conveying direction (MD; Machine Direction) of the manufacturing device for the nonwoven fabric 10 and is the fiber orientation direction in which the majority of the fibers are oriented. The second planar direction Y is a direction perpendicular to the first planar direction X and corresponds to the CD (Cross Machine Direction) perpendicular to the MD. A method for determining the fiber orientation direction will be described later. The thickness direction Z is a direction perpendicular to the first planar direction X and the second planar direction Y and is a direction along the thickness of the nonwoven fabric 10.

[0013] In this specification, "plan view" means a plan view seen from the thickness direction Z. "Area" means the area in a planar shape.

[0014] The nonwoven fabric 10 includes cellulose fibers. In this embodiment, cellulose fibers are fibers primarily composed of cellulose and are classified into, for example, natural fibers, regenerated fibers, and semi-synthetic fibers. Examples of cellulose fibers classified as natural fibers include cotton fibers and fibers other than cotton fibers (flax, hemp such as Manila hemp, palm, kraft pulp, straw, etc.). Examples of cellulose fibers classified as regenerated fibers include rayon, polynosic, cupra, and lyocell. Examples of cellulose fibers classified as semi-synthetic fibers include acetate and triacetate. Of these, the cellulose fibers preferably include at least one selected from cotton fibers, rayon, and lyocell. Cotton fibers are more preferred because they are natural fibers that feel good against the skin. The cellulose fibers used in the nonwoven fabric 10 may include multiple types of fibers.

[0015] In this embodiment, nonwoven fabric 10 preferably contains cellulose fibers, and specifically, the cellulose fiber content is preferably 20% by mass or more. Furthermore, the cellulose fiber content in nonwoven fabric 10 is preferably 30% by mass or more, more preferably 40% by mass or more, more preferably 50% by mass or more, more preferably 60% by mass or more, more preferably 70% by mass or more, more preferably 80% by mass or more, more preferably 90% by mass or more, more preferably 95% by mass or more, and may even be 100% by mass.

[0016] The nonwoven fabric 10 may contain fibers other than cellulose fibers. An example of such fibers is a thermoplastic fiber primarily composed of a thermoplastic resin. Thermoplastic fibers refer to fibers containing 50% or more by mass of thermoplastic resin. Incorporating thermoplastic fibers into a nonwoven fabric can be expected to improve strength. Examples of thermoplastic resins include polyolefins such as polyethylene and polypropylene; polyesters such as polyethylene terephthalate; polyamides such as nylon 6 and nylon 66; polyacrylic acid, polymethacrylic acid alkyl esters, polyvinyl chloride, and polyvinylidene chloride. The thermoplastic fibers may be single fibers made of one type of thermoplastic resin or a blend polymer of two or more types of thermoplastic resins, or may be composite fibers. The composite fiber may have any of various configurations, including sheath-core and side-by-side types. The thermoplastic resin content of the thermoplastic fibers is preferably 75% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more.

[0017] In order to obtain the effects of the thermoplastic fibers, such as improved strength, without reducing the effects of the cellulose fibers, the content of thermoplastic fibers in the nonwoven fabric 10 of this embodiment is preferably 80% by mass or less, more preferably 70% by mass or less, more preferably 60% by mass or less, more preferably 50% by mass or less, more preferably 40% by mass or less, more preferably 30% by mass or less, more preferably 20% by mass or less, more preferably 10% by mass or less, more preferably 5% by mass or less, and may even be 0% by mass, relative to the total mass of the nonwoven fabric 10.

[0018] The nonwoven fabric 10 may be any nonwoven fabric manufactured by a method capable of forming a nonwoven fabric from cellulose fibers, such as a spunlace nonwoven fabric, a needle-punched nonwoven fabric, or a resin-bonded nonwoven fabric. It is more preferable that the nonwoven fabric 10 be a spunlace nonwoven fabric in which the fibers are entangled by a water flow, as this has good strength and appearance.

[0019] As illustrated in FIGS. 1 to 5, the nonwoven fabric 10 has a first surface 10a, a second surface 10b, a plurality of strip-shaped portions 11, and a plurality of spacing portions 12.

[0020] The first surface 10a and the second surface 10b are configured as surfaces extending in a first planar direction X and a second planar direction Y, respectively. When the nonwoven fabric 10 is used as an absorbent article, the first surface 10a is, for example, the surface that faces the skin. In this embodiment, the first surface 10a is an uneven surface, and the second surface 10b is a substantially flat surface. The first surface 10a has a characteristic uneven shape due to the band-like portions 11 and the spacing portions 12, from the viewpoint of suppressing liquid flow.

[0021] The multiple strip-shaped portions 11 are arranged spaced apart from one another in the second planar direction Y, and are each formed in a strip shape extending in the first planar direction X in a plan view seen from the thickness direction Z. In this embodiment, "strip-shaped" refers to a shape extending in one direction and having a width in a direction perpendicular to that direction. That is, the longitudinal direction of the strip-shaped portions 11 is the first planar direction X, and the width direction is the second planar direction Y. The strip-shaped portions 11 "extending in the first planar direction X" only need to extend entirely in the first planar direction X, and specifically include a configuration extending linearly parallel to the first planar direction X, a configuration extending in a curved manner in the first planar direction X, a configuration extending in a meandering manner in the first planar direction X, and the like.

[0022] For example, the strip portion 11 may extend over a portion of the nonwoven fabric 10 in the first planar direction X, but from the viewpoint of ensuring the effects described below, it is preferable that the strip portion 11 extend over the entire nonwoven fabric 10 in the first planar direction X.

[0023] The width dimension of the strip portion 11 in the second planar direction Y may vary locally, but is preferably constant as shown in the figure. The width dimension of the strip portion 11 in the second planar direction Y is the average value of width dimension measurements taken at six or more locations along the first planar direction X at predetermined intervals (for example, about 0.4 mm). Furthermore, "the width dimension of the strip portion 11 in the second planar direction Y is constant" means that the difference between the width dimension measurements at these six or more locations is within 20% of the smallest measurement value.

[0024] The width dimensions of the multiple strip portions 11 arranged at different positions in the second planar direction Y may differ in part, but are preferably substantially the same. "The width dimensions of the strip portions 11 arranged at different positions in the second planar direction Y are substantially the same" means that the difference in the width dimensions of these strip portions 11 is within a range of 20% or less of the value of the smallest width dimension.

[0025] The multiple spacing portions 12 are arranged alternately with the band-shaped portions 11 in the second planar direction Y, and are formed on the first surface 10a in a concave shape relative to the band-shaped portions 11 in the thickness direction Z. The multiple spacing portions 12 form gaps between the multiple band-shaped portions 11 and extend in the first planar direction X along the band-shaped portions 11. That is, the first planar direction X is the longitudinal direction of the spacing portions 12, and the second planar direction Y is the width direction.

[0026] The width dimension of the spacing portion 12 in the second planar direction Y is preferably constant along the first planar direction X. The width dimension of the spacing portion 12 in the second planar direction Y refers to the average value of measurements taken at six or more intervals spaced at predetermined intervals (e.g., approximately 0.4 mm) along the first planar direction X. Furthermore, "the width dimension of the spacing portion 12 in the second planar direction Y is constant" means that the difference between the measured values ​​at these six or more intervals is within a range of 20% or less of the smallest measured value.

[0027] The width dimensions of the multiple spacing portions 12 arranged at different positions in the second planar direction Y may differ in part, but are preferably substantially the same. "The width dimensions of the spacing portions 12 arranged at different positions in the second planar direction Y are substantially the same" means that the difference in the width dimensions of these spacing portions 12 is within a range of 20% or less of the value of the smallest width dimension.

[0028] The phrase "the spacing portion 12 is formed on the first surface 10a in a concave shape relative to the strip portion 11 in the thickness direction Z" means that the height dimension of the spacing portion 12 is smaller than the height dimension of the strip portion 11. As will be described later, the strip portion 11 and the spacing portion 12 each have regions with different height dimensions along the first planar direction X. Therefore, the spacing portion 12 is configured so that the height dimension of all regions is smaller than the height dimension of the region of the strip portion 11 adjacent to it in the second planar direction Y.

[0029] The "height dimension in the thickness direction Z" of each portion of nonwoven fabric 10 refers to the dimension in the thickness direction Z from the flat surface to first surface 10a of each portion when second surface 10b is placed on the flat surface in an unloaded state, and is the average value of measurements taken at six or more points spaced at predetermined intervals (e.g., about 0.4 mm) along first planar direction X. The height dimension of each portion can be measured by profile measurement using a laser microscope or the like, as described below.

[0030] In this embodiment, the boundary between the strip portion 11 and the spacing portion 12 is a portion that extends in the first planar direction X and passes through the midpoint of the step between the strip portion 11 and the spacing portion 12. More specifically, the boundary is a portion that passes through a height that is the average value of the maximum measured values ​​of the height dimensions of the area of ​​the strip portion 11 and the area of ​​the spacing portion 12 that are adjacent in the second planar direction Y when the second surface 10b is placed on a flat surface.

[0031] 1 to 3, the strip portion 11 has a plurality of first regions 13 and a plurality of second regions 14, each having a different height. The first regions 13 are arranged spaced apart from one another in the first planar direction X. The second regions 14 are arranged alternately with the first regions 13 in the first planar direction X. In this embodiment, both the first regions 13 and the second regions 14 are regions formed across the entire width of the strip portion 11 in the second planar direction Y.

[0032] 1 and 3, the second region 14 is formed on the first surface 10a in a concave shape relative to the first region 13 in the thickness direction Z from the viewpoint of guiding liquid from the first region 13 to the second region 14. "The second region 14 is formed on the first surface 10a in a concave shape relative to the first region 13 in the thickness direction Z" means that the height dimension H2 of the second region 14 is smaller than the height dimension H1 of the first region 13. The boundary between the first region 13 and the second region 14 is a portion passing through a height that is the average of the maximum measured value of the height dimension of the first region 13 and the maximum measured value of the height dimension of the second region 14.

[0033] The first region 13 preferably has a substantially flat surface on the first surface 10a, as illustrated in Fig. 3. Similarly, the second region 14 preferably has a substantially flat surface on the first surface 10a. The "substantially flat surface" on the first surface 10a refers to a surface in which the difference in measured height values ​​at six or more points arranged at predetermined intervals (e.g., approximately 0.4 mm) along the first planar direction X and / or the second planar direction Y is within a range of 20% or less of the smallest measured value.

[0034] The gap 12 has a plurality of apertures 15. To allow liquid to flow in from the second region 14, the apertures 15 are arranged adjacent to the second region 14 in the second planar direction Y and are formed in the thickness direction Z. In this embodiment, the apertures 15 are defined as dark regions when an image is captured under predetermined conditions (hereinafter referred to as "predetermined imaging conditions") at 50x magnification using a digital microscope (VHX-6000, manufactured by Keyence Corporation) with the second surface 10b of the nonwoven fabric 10 placed on a flat surface and then binarized. The predetermined imaging conditions are brightness: auto 70, gain preset: 0 dB, white balance: 255, epi-illumination: ON, and ring illumination: ON. The threshold for the binarization process is -58. As illustrated in FIGS. 1, 2, and 4, the apertures 15 may be configured as through-holes formed in the thickness direction Z in a planar view, or may be regions containing only a small amount of fibers that are not detectable under the predetermined imaging and binarization conditions. The planar shape of the opening 15 is not particularly limited.

[0035] The phrase "the aperture 15 is disposed adjacent to the second region 14 in the second planar direction Y" means that when an imaginary line is drawn parallel to the second planar direction Y and passes through a point at which the aperture 15 in question has the maximum dimension in the first planar direction X, the region between the imaginary lines overlaps with at least a part of the second region 14 belonging to at least one of the strip portions 11 adjacent to the spacing portion 12 to which the aperture 15 belongs. In this embodiment, the ratio of the length dimension in the first planar direction X of the overlapping portion with the second region 14 to the maximum dimension of the aperture 15 in the first planar direction X is preferably 50% or more, more preferably 75%.

[0036] The porosity of nonwoven fabric 10 is 1.0% or more from the viewpoint of ensuring that liquid is transferred to second surface 10b through pores 15. The porosity of nonwoven fabric 10 is a value calculated as the ratio of the area of ​​dark regions to the total area when second surface 10b of nonwoven fabric 10 is placed on a flat surface, an image is captured under the above-mentioned predetermined imaging conditions using a digital microscope (VHX-6000, manufactured by Keyence Corporation) at a magnification of 50 times, and the image is binarized (threshold: -58).

[0037] In the above configuration, the band-shaped portion 11, which can serve as a liquid flow path, has a second region 14 formed on the first surface 10a in a recessed shape relative to the first region 13, and the openings 15 are arranged adjacent to the recessed second region 14. This allows the liquid to be guided from the first region 13 to the second region 14 on the first surface 10a, and further facilitates flow into the recessed openings 15. Furthermore, by arranging the second region 14 so that it is sandwiched between two first regions 13, the liquid is blocked near the second region 14, facilitating the flow of the liquid into the openings 15. Therefore, the nonwoven fabric 10 can suppress the flow of liquid on the first surface 10a and allow the liquid to permeate quickly.

[0038] Furthermore, in this embodiment, the strip portion 11 extends in the first planar direction X, which coincides with the fiber orientation direction, so that the liquid is easily guided along the fibers arranged along the first planar direction X in the strip portion 11. This allows the liquid to be guided from the first region 13 to the second region 14 in a stable manner.

[0039] [Connection configuration example] In this embodiment, from the viewpoints of promoting the inflow of liquid into the pores 15 and ensuring the strength of the nonwoven fabric 10, it is preferable that the spacing portion 12 further includes a connecting portion 16 that connects two first regions 13 adjacent to the spacing portion 12 (see FIGS. 1, 2, and 5). In this configuration, the connecting portion 16 is formed across the entire width of the spacing portion 12 in the second planar direction Y.

[0040] By providing the connecting portions 16 in the spacing portions 12, unevenness is also formed on the first surface 10a of the spacing portions 12, with the openings 15 and their peripheries as recesses and the connecting portions 16 as protrusions. As a result, the connecting portions 16 block liquid flowing through the spacing portions 12 in the first planar direction X near the openings 15, promoting the inflow of liquid into the openings 15 and effectively suppressing the liquid flow. Furthermore, by providing the connecting portions 16 in the spacing portions 12, fibers are present between the first regions 13, which increases the strength of the nonwoven fabric 10 (particularly the tensile strength in the second planar direction Y). Increasing the strength of the nonwoven fabric 10 can suppress shape changes and the resulting pilling of the nonwoven fabric 10, and is also expected to have the effect of improving wearing comfort.

[0041] From the viewpoint of suppressing liquid flow and further increasing the strength of the nonwoven fabric 10, the spacing portions 12 preferably have a plurality of connecting portions 16. In this configuration, the connecting portions 16 are preferably arranged alternately with the openings 15 in the first planar direction X. In this configuration, the openings 15 are regularly arranged in the region surrounded by the strip portions 11 and the connecting portions 16, thereby enhancing the liquid flow suppression effect.

[0042] Since the connecting portions 16 belong to the spacing portions 12, they are formed on the first surface 10a in a concave shape in the thickness direction Z with respect to the first regions 13. That is, as illustrated in FIG. 5, the height dimension H3 of the connecting portions 16 is smaller than the height dimension H1 of the first regions 13. From the viewpoint of ensuring the thickness and strength of the nonwoven fabric 10, the connecting portions 16 preferably have a substantially flat surface on the first surface 10a, as illustrated in FIG. 5. The boundary between the connecting portions 16 and the first regions 13 is the portion that passes through a height that is the average of the maximum measured value of the height dimension of the connecting portions 16 and the maximum measured value of the height dimension of the first regions 13 when the second surface 10b is placed on a flat surface.

[0043] Furthermore, the two first regions 13 connected to the connection portion 16 are preferably arranged along the second planar direction Y. "The two first regions 13 are arranged along the second planar direction Y" refers to an arrangement in which, when two imaginary lines are drawn that pass through the center points of the two target first regions 13 in the first planar direction X and are parallel to the second planar direction Y, both of these imaginary lines pass through the two first regions 13. The center point of the first region 13 in the first planar direction X refers to the midpoint of a line segment connecting the end points of the first region 13 that have the maximum dimension in the first planar direction X.

[0044] With the above configuration, the at least two strip-shaped portions 11 and the connecting portions 16 have a lattice-like shape or a planar shape similar thereto extending in the first planar direction X and the second planar direction Y in a planar view. This enhances the effect of the connecting portions 16 in improving the tensile strength in the second planar direction Y. Furthermore, by arranging the strip-shaped portions 11 and the connecting portions 16 along the second planar direction Y, the liquid can be stably guided along the connecting portions 16.

[0045] [Examples of fiber density in the first region, second region, and joint] In this embodiment, the first region 13 preferably has a higher fiber density than the second region 14. That is, in this embodiment, the first region 13 is a region having a high fiber density and a large height dimension H1, and the second region 14 is a region having a low fiber density and a small height dimension H2. This makes the first region 13 less likely to collapse in the thickness direction Z even when the nonwoven fabric 10 is used in an absorbent article and pressure is applied in the thickness direction Z by a wearer. This allows the uneven shape of the first surface 10a of the nonwoven fabric 10 to be maintained, and the above-mentioned liquid-guiding effect from the first region 13 to the second region 14 can be stably exerted. Furthermore, by having the second region 14 have a lower fiber density than the first region 13, it is possible to provide localized regions of low fiber density and improve the softness and breathability of the nonwoven fabric 10.

[0046] Similarly, in this embodiment, the first regions 13 preferably have a higher fiber density than the connection regions 16. That is, in this embodiment, the connection regions 16 also preferably have a lower fiber density and a smaller height dimension H3 than the first regions 13. This can improve the flexibility and breathability of the nonwoven fabric 10.

[0047] In this embodiment, when the fiber density of the first region 13 is taken as 100%, the ratio of the fiber density of the second region 14 is preferably 30% or more, more preferably 40% or more, from the viewpoint of suppressing deformation of the second region 14, and is preferably 95% or less, more preferably 85% or less, from the viewpoint of improving flexibility, breathability, etc. in the second region 14. When the fiber density of the first region 13 is taken as 100%, the ratio of the fiber density of the connection portion 16 is preferably 30% or more, more preferably 40% or more, and is preferably 95% or less, more preferably 85% or less, from the same viewpoint as the second region 14.

[0048] The fiber density of the first region 13 is preferably 40 fibers / mm 3 More preferably, 50 lines / mm 3 From the viewpoint of ensuring the flexibility of the nonwoven fabric 10, the density is preferably 300 threads / mm 3 Less than or equal to 200 lines / mm 3 The fiber density of the second region 14 can be appropriately set to satisfy the above fiber density ratio, and is preferably 20 fibers / mm 3 More preferably, 30 lines / mm 3 or more, preferably 200 lines / mm 3 Less than or equal to 150 lines / mm, more preferably 3 The fiber density of the connecting portion 16 can be appropriately set to satisfy the above fiber density ratio, and is preferably 20 fibers / mm 3 More preferably, 30 lines / mm 3 or more, preferably 200 lines / mm 3 Less than or equal to 150 lines / mm, more preferably 3 The following is the result.

[0049] (Method for measuring fiber density) Using a Feather Razor (product number FAS-10, manufactured by Feather Safety Razor Co., Ltd.), each measurement object (first region, second region, and joint) is cut along the thickness direction Z. The cut surface is observed under magnification using a scanning electron microscope (magnification (150-500x) that allows measurement of 30-60 fiber cross sections), and the measurement area is determined by dividing the fiber into a certain number (0.5 mm 2 ) and count the number of fiber cross sections cut by the cutting surface of 1 mm. 2 The fiber density is calculated by converting the number of fiber cross sections per unit area into the number of fiber cross sections per unit area. As the scanning electron microscope, for example, JCM-6000 (product name) manufactured by JEOL Ltd. is used.

[0050] [Examples of shapes of the first area, second area, and connecting part] The height dimension H1 of the first region 13 in the thickness direction Z is preferably 50 μm or more, and more preferably 80 μm or more, from the viewpoint of effectively exerting the liquid blocking effect of the convex first region 13. Furthermore, the height dimension H1 is preferably 800 μm or less, more preferably 700 μm or less, and even more preferably 600 μm or less, from the viewpoint of effectively exerting the effect of guiding the liquid to the openings 15. Particularly in this embodiment, as shown in the examples, by limiting the height dimension H1 to 800 μm or less, the liquid flow can be effectively suppressed.

[0051] In this embodiment, the ratio (H2 / H1) of the height dimension H2 of the second region 14 to the height dimension H1 of the first region 13, which is taken as 100%, is preferably 50% or more, more preferably 70% or more, from the viewpoint of more effectively exerting the liquid guiding effect described above, and is preferably 99.5% or less, more preferably 99% or less, from the viewpoint of more effectively exerting the liquid blocking effect described above. In this embodiment, the height dimension H2 of the second region 14 can be appropriately set in consideration of H2 / H1, and is preferably 50 μm or more, more preferably 100 μm or more, and preferably 700 μm or less, more preferably 500 μm or less.

[0052] In this embodiment, the ratio (H3 / H1) of the height dimension H3 of the connecting portion 16 to the height dimension H1 of the first region 13, which is taken as 100%, is preferably 30% or more, more preferably 50% or more, from the viewpoint of more effectively exerting the liquid guiding effect described above, and is preferably 90% or less, more preferably 80% or less, from the viewpoint of more effectively exerting the liquid blocking effect described above. Furthermore, in this embodiment, the height dimension H3 of the connecting portion 16 can be appropriately set in consideration of H3 / H1, and is preferably 30 μm or more, more preferably 50 μm or more, and preferably 500 μm or less, more preferably 300 μm or less.

[0053] Furthermore, in this embodiment, the length dimension L1 of the first region 13 in the first planar direction X is preferably 1.0 mm or more, and more preferably 1.5 mm or more, from the viewpoint of stably guiding the liquid to the opening 15 and effectively suppressing the liquid flow. Moreover, the length dimension L1 is preferably 10.0 mm or less, more preferably 7.0 mm or less, more preferably 6.0 mm or less, and more preferably 5.0 mm or less, from the viewpoint of suppressing the liquid flow on the first region 13. In this embodiment, as an example, the length dimension L1 is preferably 1.0 mm or more, from the viewpoint of suppressing the liquid flow.

[0054] Furthermore, in this embodiment, the length dimension L2 of the second region 14 in the first planar direction X is preferably 0.3 mm or more, more preferably 0.5 mm or more, and even more preferably 0.7 mm or more, from the viewpoint of blocking the liquid and enhancing the liquid's ability to guide to the openings 15. Moreover, from the viewpoint of ensuring strength, the length dimension L2 is preferably 2.0 mm or less, and even more preferably 1.5 mm or less.

[0055] Furthermore, in this embodiment, the ratio (L2 / L1) of the length dimension L2 in the first planar direction X of the second region 14 to the length dimension L1 in the first planar direction X of the first region 13 is preferably 0.1 to 1.0, more preferably 0.2 to 0.9, and even more preferably 0.2 to 0.8, from the viewpoint of stably guiding the liquid to the opening 15 and effectively suppressing the liquid flow.

[0056] The length dimension of each portion of nonwoven fabric 10 is the dimension in first planar direction X measured in a plan view with second surface 10b placed on a flat surface, and is the average value of measurements taken at three or more locations spaced a predetermined distance (e.g., about 0.4 mm) apart along second planar direction Y. The length dimension of each portion can be measured by profile measurement using a laser microscope or the like, as described below.

[0057] Furthermore, in this embodiment, the width dimension W1 of the first region 13 in the second planar direction Y is preferably 1 mm or more, and more preferably 2 mm or more, from the viewpoint of increasing the ability to guide the liquid to the openings 15. Moreover, from the viewpoint of suppressing the flow of liquid on the first region 13, the width dimension W1 is preferably 7 mm or less, more preferably 5 mm or less, and even more preferably 4 mm or less.

[0058] The width dimension of each portion of nonwoven fabric 10 is the dimension in second planar direction Y measured in a plan view with second surface 10b placed on a flat surface, and is the average value of measurements taken at three or more locations spaced a predetermined distance (e.g., about 0.4 mm) apart along first planar direction X. The width dimension of each portion can be measured by profile measurement using a laser microscope or the like, as described below.

[0059] Furthermore, in this embodiment, the width W2 of the connecting portion 16 in the second planar direction Y is preferably 0.3 mm or more, more preferably 0.5 mm or more, from the viewpoint of ensuring a sufficient area for blocking the liquid. Moreover, the width W2 is preferably 2.0 mm or less, more preferably 1.5 mm or less, from the viewpoint of ensuring strength, etc.

[0060] Furthermore, in this embodiment, the ratio (W1 / W2) of the width dimension W1 in the second planar direction Y of the first region 13 to the width dimension W2 in the second planar direction Y of the connection portion 16 is preferably 0.5 to 8.0, more preferably 1.0 to 6.0, and even more preferably 1.2 to 5.0, from the viewpoint of stably guiding the liquid to the opening 15 and effectively suppressing the liquid flow.

[0061] [Example of hole configuration] In this embodiment, the arrangement and shape of the openings 15 in the nonwoven fabric 10 are preferably set so as to promote the inflow of liquid into the openings 15 and ensure the strength of the nonwoven fabric 10 .

[0062] In this embodiment, the porosity of nonwoven fabric 10 is preferably 1.0% or more and 5.0% or less, from the viewpoint of simultaneously promoting the inflow of liquid into pores 15 and maintaining high strength of nonwoven fabric 10. The lower limit of the porosity of nonwoven fabric 10 is 1.0% or more, preferably 1.3% or more, and more preferably 1.6% or more, from the viewpoint of promoting the inflow of liquid. The upper limit of the porosity is preferably 5.0% or less, more preferably 4.5% or less, and even more preferably 4.0% or less, from the viewpoint of increasing the strength of nonwoven fabric 10. Increasing the strength of nonwoven fabric 10 can suppress shape changes and the resulting pilling of nonwoven fabric 10 during wear, and is also expected to have the effect of improving the wearing comfort of the absorbent article.

[0063] In this embodiment, the area of ​​the openings 15 in a plan view seen from the thickness direction Z (average opening size) is preferably 0.005 mm from the viewpoint of achieving both the promotion of the inflow of liquid into the openings 15 and the high strength of the nonwoven fabric 10. 2 More than 0.300mm 2 or less, more preferably 0.010 mm 2 More than 0.100mm 2 The lower limit of the area of ​​the opening 15 is preferably 0.005 mm 2 From the viewpoint of increasing the strength of the nonwoven fabric 10, the upper limit of the area of ​​the openings 15 is preferably 0.300 mm 2 Less than 0.100mm, preferably 0.100mm 2 The area of ​​the apertures 15 is a value that can be obtained as the area of ​​each dark region by placing the second surface 10b of the nonwoven fabric 10 on a flat surface, capturing an image using a digital microscope (for example, VHX-6000, manufactured by Keyence) at a magnification of 50 times under the above-mentioned predetermined capturing conditions, and then binarizing the image (threshold: -58).

[0064] In relation to the arrangement and size of the apertures 15, the nonwoven fabric 10 of this embodiment preferably has an airflow resistance within a predetermined range. Specifically, the airflow resistance of the nonwoven fabric 10 is preferably 0.010 kPa·s / m or more, more preferably 0.020 kPa·s / m or more, from the viewpoint of ensuring the strength of the nonwoven fabric 10, and is preferably 0.060 kPa·s / m or less, more preferably 0.050 kPa·s / m or less, from the viewpoint of appropriately arranging the apertures 15 to promote the inflow of liquid. The method for measuring the airflow resistance of the nonwoven fabric 10 will be described later in the Examples.

[0065] [Example of nonwoven fabric properties] If the first surface 10a of the nonwoven fabric 10 has high hydrophilicity, liquid backflow, a phenomenon in which liquid that has migrated to the second surface 10b returns to the more hydrophilic first surface 10a, is likely to occur. From this perspective, the contact angle between the first surface 10a and artificial blood made from defibrinated horse blood adjusted to a viscosity of 8 mPa·s at room temperature, is preferably 30° or greater. Here, room temperature refers to a temperature in the range of 15 to 30°C. Furthermore, to effectively suppress liquid backflow, the contact angle between the first surface 10a and the artificial blood is preferably 40° or greater, and even more preferably 50° or greater. The hydrophilicity of the first surface 10a can be adjusted by degreasing the fibers constituting the nonwoven fabric 10, selecting the fibers used, or using a fiber treatment agent such as a water repellent. The artificial blood can be adjusted to a viscosity of 8 mPa·s at room temperature by mixing appropriate amounts of the plasma component and blood cell component of defibrinated horse blood. The viscosity is measured at room temperature using a B-type viscometer (for example, VISCOMETER TVB-10 (product name), manufactured by Toki Sangyo Co., Ltd.), and an error of 0.1 mPa·s or less is permitted. Note that the artificial blood was used as a liquid to replace body fluids, and is not intended to limit the absorbent article to sanitary napkins.

[0066] On the other hand, it is preferable that the hydrophilicity of first surface 10a is not too low from the viewpoint of promoting the inflow of liquid into openings 15 and suppressing the flow of liquid. Specifically, the contact angle between first surface 10a and the artificial blood is preferably 150° or less, and more preferably 130° or less.

[0067] The contact angle can be measured by a liquid drop method by cutting a piece of nonwoven fabric 10 in the first planar direction X and the second planar direction Y, setting it so that the first planar direction X is perpendicular to the camera of the contact angle meter, and analyzing an image when the artificial blood is dropped on it. Detailed measurement conditions will be described later in the Examples.

[0068] In this embodiment, the cellulose fibers preferably include, for example, cotton fibers. Natural cotton (cotton fiber), the raw material for cotton fibers, contains oils and fats such as cottonseed oil. It is also called unabsorbed cotton and has low hydrophilicity. The hydrophilicity of unabsorbed cotton can be increased by a degreasing treatment, and cotton fibers that have been degreased are called absorbent cotton. Thus, cotton fibers have the advantage that their hydrophilicity can be adjusted by the presence or absence of a degreasing treatment, in addition to the use of a fiber treatment agent. The cotton fibers include at least one type selected from absorbent cotton and unabsorbed cotton, and may contain both absorbent cotton and unabsorbed cotton to adjust the hydrophilicity of the nonwoven fabric 10. Furthermore, cotton fibers have the advantage of improving the feel of the nonwoven fabric 10 and providing users with the sense of security that comes from using natural fibers.

[0069] Furthermore, in this embodiment, from the viewpoint of adjusting the hydrophilicity of the first surface 10a and improving the feel, it is preferable that the first surface 10a contains cellulose fibers. "The first surface 10a contains cellulose fibers" means that cellulose fibers are disposed on at least a portion of the first surface 10a. When the total mass of the fibers constituting the first surface 10a is taken as 100%, the proportion of the mass of the cellulose fibers is preferably 40% or more, more preferably 50% or more, more preferably 60% or more, more preferably 70% or more, more preferably 80% or more, and more preferably 90% or more. In this embodiment, it is more preferable that the first surface 10a is composed of cellulose fibers. Note that "The first surface 10a is composed of cellulose fibers" means that when the total mass of the fibers constituting the first surface 10a is taken as 100%, the proportion of the mass of the cellulose fibers is 90% or more.

[0070] Furthermore, in this embodiment, from the viewpoint of obtaining the above-mentioned advantages of cotton fiber in the first surface 10a, it is preferable that the first surface 10a contains cotton fiber as the cellulose fiber. Furthermore, when the mass of all the fibers constituting the first surface 10a is taken as 100%, the proportion of the mass of the cotton fiber is preferably 40% or more, more preferably 50% or more, more preferably 60% or more, more preferably 70% or more, more preferably 80% or more, and more preferably 90% or more. In this embodiment, it is more preferable that the first surface 10a is made of cotton fiber. Note that "the first surface 10a is made of cotton fiber" means that when the mass of all the fibers constituting the first surface 10a is taken as 100%, the proportion of the mass of the cotton fiber is 90% or more. The nonwoven fabric 10 is preferably a single-layer nonwoven fabric, but may be a multi-layer (preferably two-layer) nonwoven fabric. When the nonwoven fabric is a multi-layer nonwoven fabric, the above-mentioned "first surface 10a" can be read as "a layer having the first surface 10a."

[0071] [Detailed example of cellulose fiber composition] In this embodiment, the nonwoven fabric 10 preferably includes first cellulose fibers and second cellulose fibers that are more hydrophilic than the first cellulose fibers. In this configuration, the first cellulose fibers, which have low hydrophilicity, have a hydrophobic effect to prevent liquid backflow, while the second cellulose fibers, which have high hydrophilicity, contribute to suppressing liquid flow. The hydrophilicity of the first cellulose fibers and the second cellulose fibers can be compared based on the contact angle between the fibers and water, and it can be determined that the smaller the contact angle, the higher the hydrophilicity. In the above configuration, the first contact angle, which is the contact angle between the first cellulose fibers and water, is larger than the second contact angle, which is the contact angle between the second cellulose fibers and water. A method for measuring the contact angle of fibers will be described later.

[0072] In this embodiment, the nonwoven fabric 10 is more preferably a nonwoven fabric containing a mixture of first and second cellulose fibers. The term "a nonwoven fabric containing a mixture of first and second cellulose fibers" refers to a nonwoven fabric in which the first and second cellulose fibers are mixed and arranged in the same layer. Such a nonwoven fabric is produced by subjecting a web containing a mixture of the first and second cellulose fibers to a process for entangling and / or bonding the fibers. By applying the nonwoven fabric 10 having the above configuration to an absorbent article, it is possible to stably suppress both the return of liquid by the first cellulose fibers and the flow of liquid by the second cellulose fibers.

[0073] Furthermore, it is preferable that the nonwoven fabric 10 is a single-layer nonwoven fabric. A "single-layer nonwoven fabric" means that it does not have a laminated structure formed by stacking multiple webs or multiple nonwoven fabrics. This allows the above-mentioned effects to be exhibited more reliably.

[0074] In this embodiment, from the viewpoint of preparing cellulose fibers with different hydrophilicities, it is preferable that the first cellulose fibers are primarily composed of undefatted fibers and the second cellulose fibers are primarily composed of defatted fibers. Undefatted fibers refer to cellulose fibers that have not been subjected to a defatting treatment, and defatted fibers refer to cellulose fibers that have been subjected to a defatting treatment. The expression "the first cellulose fibers are primarily composed of undefatted fibers" means that the first cellulose fibers contain undefatted fibers as the fiber body, and includes, for example, a configuration in which the first cellulose fibers are composed of undefatted fibers and a configuration in which the first cellulose fibers contain undefatted fibers and a fiber treatment agent. Similarly, the expression "the second cellulose fibers are primarily composed of defatted fibers" means that the second cellulose fibers contain defatted fibers as the fiber body, and includes, for example, a configuration in which the second cellulose fibers are composed of defatted fibers and a configuration in which the second cellulose fibers contain defatted fibers and a fiber treatment agent. By using defatted fibers and undefatted fibers, the hydrophilicity of the first cellulose fibers and the second cellulose fibers can be reliably and easily adjusted.

[0075] Preferred examples of the hydrophilicity of cellulose fibers are described below. The first contact angle, which is the contact angle between the first cellulose fibers and water, is preferably 89° or less. The second contact angle, which is the contact angle between the second cellulose fibers and water, is preferably 70° or less and smaller than the first contact angle. By setting the first and second contact angles within the above ranges, the hydrophobicity of the first cellulose fibers can be reduced and the hydrophilicity of the second cellulose fibers can be sufficiently increased. This allows liquid flow in the nonwoven fabric 10 to be sufficiently suppressed. Furthermore, from the viewpoint of more reliably suppressing liquid flow in the nonwoven fabric 10, the upper limit of the first contact angle is more preferably 85° or less, and even more preferably 80° or less. From the same viewpoint, the upper limit of the second contact angle is more preferably 65° or less, and even more preferably 60° or less.

[0076] Regarding the lower limit of the contact angle, the first contact angle is preferably 30° or more. The second contact angle is preferably 10° or more and smaller than the first contact angle. By setting the first contact angle and the second contact angle within the above ranges, liquid return in the nonwoven fabric 10 can be effectively suppressed. Furthermore, from the viewpoint of more reliably suppressing liquid return in the nonwoven fabric 10, the lower limit of the first contact angle is more preferably 20° or more, and even more preferably 30° or more. From the same viewpoint, the lower limit of the second contact angle is more preferably 40° or more, and even more preferably 50° or more.

[0077] The contact angle of a fiber is measured as follows. First, a fiber is removed from a predetermined location on the nonwoven fabric, and the contact angle of water with that fiber is measured. An automatic contact angle meter, MCA-J (product name), manufactured by Kyowa Interface Science Co., Ltd., is used as the measuring device. Distilled water is used to measure the contact angle. The amount of liquid ejected from the inkjet water droplet ejection unit (CTC-25 pulse injector with a 25 μm nozzle diameter, manufactured by Cluster Technology Co., Ltd.) is set to 10 picoliters, and the water droplet is dropped directly onto the fiber. The dropping behavior is recorded on a high-speed video recorder connected to a horizontally placed camera. For later image analysis, a personal computer equipped with a high-speed capture device is preferred as the video recorder. In this measurement, images are recorded every 17 msec. In the recorded video, the first image of a water droplet landing on a fiber removed from the nonwoven fabric is analyzed using the accompanying software FAMAS (software version 2.6.2, analysis method: sessile drop method, analysis method: θ / 2 method, image processing algorithm: non-reflective, image processing image mode: frame, threshold level: 200, no curvature correction), and the angle between the surface of the water droplet in contact with the air and the fiber is calculated, which is taken as the contact angle. If the fiber removed from the nonwoven fabric is 2 mm long or longer, it is cut to a fiber length of 2 mm and placed on the sample stage of the contact angle meter and maintained horizontally. The contact angle is measured at 10 different points for each fiber, for a total of five fibers. The average value (rounded to two decimal places) of the contact angles at a total of 50 points is defined as the contact angle.

[0078] The first and second cellulose fibers may contain a hydrophilizing agent and / or a hydrophobizing agent to adjust their hydrophilicity. When the first and second cellulose fibers are composed of undefatted and defatted fibers, the contact angles of the first and second cellulose fibers tend to be lower than the preferred range of contact angles described above. Therefore, it is preferable that the fibers contain a hydrophobizing agent that reduces hydrophilicity. The hydrophobizing agent is not particularly limited, and examples include conventionally known hydrophobizing agents such as paraffin-based and silicone-based agents, as well as surfactants. It is also preferable that the first and second cellulose fibers contain the same hydrophobizing agent.

[0079] Furthermore, it is preferable to adjust the ratio of the content of the second cellulose fibers to the content of the first cellulose fibers in order to adjust the balance between suppressing liquid return and suppressing liquid flow in the nonwoven fabric 10. Specifically, in the nonwoven fabric 10, the mass ratio P / Q, which is the ratio of the content P of the first cellulose fibers to the content Q of the second cellulose fibers, is preferably 1 / 9 or more and 1 or less. This optimizes the balance between suppressing liquid return and suppressing liquid flow in the nonwoven fabric 10, allowing both effects to be exerted.

[0080] [Example of nonwoven fabric manufacturing method] In this embodiment, the method for producing nonwoven fabric 10 made of spunlace nonwoven fabric includes a hydroentangling step in which a water stream is sprayed onto a web (a fiber aggregate with unbonded fibers), which is a precursor of the nonwoven fabric. For example, the web is placed on a support of a predetermined shape extending along the XY plane and transported in a predetermined machine direction (MD). Water streams are sprayed from water stream nozzles toward the support, entangling the fibers of the web and forming nonwoven fabric 10. The shape of the nonwoven fabric 10 described above can be formed, for example, by adjusting at least one of the shape of the support and / or the water stream spraying conditions.

[0081] The support may be composed of a plate having a base (base plate) extending along the XY plane and an uneven structure such as protrusions, apertures, or depressions formed on the base, or may be composed of a conveyor net having a predetermined shape. As an example of how the shape of the nonwoven fabric 10 can be adjusted using the support, for example, apertures 15 can be formed by protrusions projecting from the base in the thickness direction Z or by convex structures such as lines on a conveyor net. In this case, apertures 15 are formed by the web being pressed by the water flow and the fibers in the portion in contact with the convex structures being sorted. Alternatively, for example, by providing depressions or apertures near the convex structures, the fibers pressed by the water flow can accumulate in the depressions or apertures, forming convex first regions 13.

[0082] Examples of water jetting conditions include the arrangement of the water jet nozzles that jet the water jets, the number of water jet nozzles, the nozzle hole diameter of the water jet nozzles, the size of the nozzle surface including the multiple nozzle holes, and water pressure. Multiple water jet nozzles may be arranged, and in this case, the water jet nozzles may be arranged in rows in the MD and / or CD. The water jetting conditions for each water jet nozzle may be different.

[0083] As an example of formation by adjusting the water jetting conditions, by jetting locally high water pressure at positions corresponding to second region 14 or joint 16, the fibers can accumulate on the first region 13 side, forming the uneven shape of first surface 10a described above. In this case, by combining the water jetting conditions with the uneven shape of the support, nonwoven fabric 10 with the desired uneven shape can be formed more efficiently. As another example of formation, open pores 15 can also be formed on the support by jetting locally high water pressure water onto the support to the extent that the fibers are separated.

[0084] Furthermore, the method for producing nonwoven fabric 10 may include other steps in addition to the hydroentangling step, as needed. For example, the method for producing nonwoven fabric 10 may include a drying step of drying the water content of the web after the hydroentangling step. Alternatively, if nonwoven fabric 10 contains thermoplastic fibers in addition to cellulose fibers, the method for producing nonwoven fabric 10 may include a heating step of heating the web after the hydroentangling step.

[0085] [Additional remarks] (Method for determining fiber orientation direction) The fiber orientation direction can be determined by the following method. First, a nonwoven fabric is placed in a JEOL JCM-6000 (trade name) scanning electron microscope, and a planar image (adjusted to a magnification capable of measuring at least 10 fibers; 70x to 300x) is acquired. The image is then printed and the fibers are traced on a transparent PET sheet. This image is imported into a computer and binarized using nexusNewQube (trade name) (standalone version) image processing software from Nexus Corporation. Next, the binarized image is Fourier transformed using Fiber Orientation Analysis 8.13 Single (trade name), a fiber orientation analysis program, to obtain a power spectrum. The orientation angle is then determined from an elliptical distribution diagram. The orientation angle indicates the angle at which the fibers are most oriented, and this angle direction is referred to as the "fiber orientation direction."

[0086] (grammage of nonwoven fabric) The basis weight of the nonwoven fabric 10 is preferably 20 g / m from the viewpoint of ensuring strength. 2 More preferably, 30 g / m 2 From the viewpoint of enhancing liquid permeability and flexibility, it is preferably 50 g / m 2 Less than 40 g / m 2 The basis weight of the nonwoven fabric 10 is the average basis weight of three rectangular test pieces, each having a side of 8 cm along the first planar direction X and a side of 7 cm along the second planar direction Y. The basis weight is calculated by measuring the mass of the test piece and dividing this mass by the area. If it is not possible to obtain a test piece of the above size because the area of ​​the nonwoven fabric to be measured is small, for example, a test piece with as large an area as possible is cut out.

[0087] Second Embodiment [Configuration of absorbent articles] As a second embodiment of the present invention, an embodiment in which the nonwoven fabric 10 is used in an absorbent article will be described. In the following embodiment, the same reference numerals will be used to designate components corresponding to those in the first embodiment, and duplicated descriptions will be omitted.

[0088] The absorbent article 1 according to this embodiment is configured as a sanitary napkin and will be referred to hereinafter as the napkin 1. As shown in FIG. 6, the napkin 1 comprises a main body M and a pair of wing portions W. The napkin 1 has a longitudinal direction X corresponding to the front-to-back direction of the wearer and a lateral direction Y corresponding to the left-to-right direction of the wearer and perpendicular to the longitudinal direction X. Furthermore, the napkin 1 has a thickness direction Z perpendicular to both the longitudinal direction X and the lateral direction Y. In this embodiment, the longitudinal direction X coincides with the first planar direction X of the first embodiment. The lateral direction Y coincides with the second planar direction Y of the first embodiment. The thickness direction Z coincides with the thickness direction Z of the first embodiment. The napkin 1 may be configured, for example, to be line-symmetric (bilaterally symmetric) with respect to a longitudinal centerline CL that divides the napkin 1 into two equal parts in the lateral direction Y.

[0089] In this embodiment, "inner side in the lateral direction Y" means the side closer to the longitudinal center line CL. "outer side in the lateral direction Y" means the side away from the longitudinal center line CL. In this embodiment, "front side in the longitudinal direction X" means the front in the longitudinal direction X, i.e., the direction toward the wearer's abdomen. "rear side in the longitudinal direction X" means the rear in the longitudinal direction X, i.e., the direction toward the wearer's back. In this embodiment, the "skin side" in the thickness direction Z means the side that is placed on the wearer's side when the napkin 1 is worn. The "non-skin side" in the thickness direction Z means the side that is placed on the clothing side when the napkin 1 is worn.

[0090] As shown in Fig. 6, the napkin 1 is divided in the longitudinal direction X into a middle region B including a region facing the excretory part of the wearer, a front region A located in front of the middle region B, and a rear region C located behind the middle region B. In this embodiment, the excretory part is the vaginal opening. In Fig. 6, the middle region B is the region between the front and rear base ends of the wing portions W. The front region A is the region located in front of the middle region B (towards the ventral side of the wearer). The rear region C is the region located behind the middle region B (towards the dorsal side of the wearer).

[0091] The wing portions W extend outward in the lateral direction Y from the main body M in the intermediate region B. The wing portions W are used by folding them over onto the non-skin-facing side of the crotch portion of underwear such as shorts. As a variation of this embodiment, the napkin 1 may not have the wing portions W. In that case, the napkin 1 is divided into three equal parts in the longitudinal direction X, with the central region being the intermediate region B, the front region being the front region A, and the rear region being the rear region C.

[0092] As shown in Fig. 7, the napkin 1 comprises a main body M, an absorbent body 4, a topsheet 2, a backsheet 3, and an intermediate sheet 5. In the example shown in Fig. 7, the napkin 1 has a configuration in which the backsheet 3, absorbent body 4, intermediate sheet 5, and topsheet 2 are layered in this order in the thickness direction Z. These components are joined together as appropriate, for example, by means of compressed grooves, adhesives, heat sealing, etc., as described below.

[0093] The absorbent body 4 is disposed between the top sheet 2 and the back sheet 3. The absorbent body 4 absorbs and retains fluids such as menstrual blood from the skin side. In this embodiment, the absorbent body 4 has an absorbent core 40 and a core wrap sheet 41 that covers the absorbent core 40. The absorbent core 40 is composed of a fibrous body of absorbent fibers or a laminate of absorbent sheets, and may contain an absorbent polymer. The core wrap sheet 41 is composed of thin absorbent paper, liquid-permeable nonwoven fabric, or the like. However, the configuration of the absorbent body 4 is not limited to the example shown in the figure, and for example, it may not have a core wrap sheet 41.

[0094] The topsheet 2 is placed on the skin side of the absorbent body 4. In this embodiment, the topsheet 2 is made of the nonwoven fabric 10 containing cellulose fibers described in the first embodiment. The skin-facing surface 2a of the topsheet 2 is made of the first surface 10a of the nonwoven fabric 10. The non-skin-facing surface 2b of the topsheet 2 is made of the second surface 10b of the nonwoven fabric 10.

[0095] The intermediate sheet 5 is disposed between the topsheet 2 and the absorbent body 4. The intermediate sheet 5 is disposed to improve the transfer of liquid from the topsheet 2 to the absorbent body 4 and to prevent liquid absorbed by the absorbent body 4 from returning to the topsheet 2. The intermediate sheet 5 preferably contains thermoplastic fibers as a main component. "The intermediate sheet 5 contains thermoplastic fibers as a main component" means that the thermoplastic fiber content is 50% by mass or more, where the mass of the intermediate sheet 5 is 100% by mass. Furthermore, the thermoplastic fiber content in the intermediate sheet 5 is preferably 75% by mass or more, more preferably 90% by mass or more, and even more preferably 100% by mass. As a variation of this embodiment, the napkin 1 does not have to have an intermediate sheet 5.

[0096] The backsheet 3 is placed on the non-skin side of the absorbent body 4. From the viewpoint of suppressing leakage of menstrual blood, the backsheet 3 is preferably made of a sheet material having properties such as low liquid permeability and / or water repellency. Examples of such sheet materials include a thermoplastic resin film and a laminate sheet of such a film and a nonwoven fabric. Furthermore, from the viewpoint of improving wearing comfort, the backsheet 3 is preferably breathable and / or moisture permeable.

[0097] The non-skin-facing surface 3a of the backsheet 3 may be provided with, for example, fastening parts 7 for fastening the napkin 1 to underwear. The fastening parts 7 may be arranged, for example, on the main body M and the wing parts W. The fastening parts 7 may be made of, for example, an adhesive, a pressure-sensitive adhesive, a hook material, or the like.

[0098] As illustrated in Figures 6 and 7, the napkin 1 preferably further comprises a pair of side sheets 6 from the viewpoint of improving the leakproofness of the side portions in the lateral direction Y. The pair of side sheets 6 are arranged on the outer sides of the topsheet 2 in the lateral direction Y. The material of the side sheets 6 is preferably a sheet material that is less hydrophilic than the topsheet 2, and specific examples include nonwoven fabrics, films, and laminated sheets of nonwoven fabrics and films that are less hydrophilic than the topsheet 2. The side sheets 6 and the backsheet 3 are joined to each other by known joining means such as adhesives, heat sealing, or ultrasonic sealing at the extending portions from both side edges of the absorbent body 4 along the longitudinal direction X. In the illustrated example, the wing portions W are formed by joining the side sheets 6 and the backsheet 3.

[0099] 6 and 7, the napkin 1 may further comprise a plurality of central compressed sections 8 located in the center of the intermediate region B in the transverse direction Y. The napkin 1 may also comprise outer compressed sections 9 located outward in the transverse direction Y of the central compressed sections 8 and extending in the longitudinal direction X. These compressed sections have a configuration in which the topsheet 2, intermediate sheet 5 and absorbent body 4 are integrally recessed toward the non-skin side, and are formed, for example, by compressing the topsheet 2 in the thickness direction Z.

[0100] In the above configuration, the topsheet 2 made of nonwoven fabric 10 is arranged so that the first surface 10a faces the skin and the second surface 10b faces away from the skin. By making the topsheet 2 out of nonwoven fabric 10, it is possible to suppress the flow of excreted fluid on the first surface 10a, thereby suppressing discomfort such as a wet feeling in the topsheet 2 and liquid leakage. Furthermore, by setting the porosity to 4.5% or less, for example, it is possible to ensure the strength of the nonwoven fabric 10 and suppress deformation or tearing of the topsheet 2 during wear and the discomfort caused by pilling that results from this.

[0101] <Other embodiments> Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and it goes without saying that various modifications can be made within the scope of the gist of the present invention.

[0102] The nonwoven fabric 10 may be used as the intermediate sheet 5 or the core wrap sheet 41.

[0103] In the above embodiment, a sanitary napkin is shown as an example of an absorbent article, but the absorbent article of the present invention is not limited to this. For example, the absorbent article of the present invention may be a urine absorption pad, a panty liner, a disposable diaper, or the like. [Example]

[0104] <Test Example 1: Evaluation of Liquid Permeability> In Test Example 1, nonwoven fabric samples with different configurations were prepared and evaluated for liquid permeability, such as liquid flow. The nonwoven fabrics of Examples 1 to 4 fulfilled the configuration of nonwoven fabric 10 of the present invention, comprising a plurality of strip-shaped portions 11 each having a first region 13 and a second region 14, a plurality of openings 15 adjacent to the second region 14, and an opening rate of 1.0% or more. On the other hand, the nonwoven fabrics of Comparative Examples 1 to 5 did not fulfill at least one of the above requirements.

[0105] [Nonwoven fabric manufacturing] In a spunlace method using a web containing a mixture of two types of cotton fibers, the shape of the support and / or the water jetting conditions were adjusted to produce the nonwoven fabrics of Examples 1 to 4 and Comparative Examples 1 to 5. The webs of Examples 1 to 2 and 4 and Comparative Examples 2 to 5 contained 75% by mass of absorbent cotton and 25% by mass of unabsorbed cotton, and were mixed together. To adjust the hydrophilicity of the obtained nonwoven fabric, 0.4% by mass of an oil agent composed of an alkyl phosphate ester salt was applied by kiss roll coating. The web of Example 3 was a mixture of 75% absorbent cotton and 25% unabsorbed cotton. To adjust the hydrophilicity of the resulting nonwoven fabric, 0.7% by mass of an oil agent composed of an alkyl phosphate ester salt was applied by spray coating. The web of Comparative Example 1 was made of 100% absorbent cotton.

[0106] The nonwoven fabrics of Examples 1 to 4 had a first region, a second region, a joint, open holes adjacent to the second region, and an open area ratio of 1.0% or more, and were configured to have the respective measured values ​​shown in Table 1. The nonwoven fabrics of Comparative Examples 1 and 2 had no belt-like portions, no joints, and no open area ratio of 1.0% or more. The nonwoven fabric of Comparative Example 3 had an open area ratio of 1.0% or more, but no belt-like portions or joints. The nonwoven fabric of Comparative Example 4 had belt-like portions, joints, and an open area ratio of 1.0% or more, but did not have the uneven structure of the belt-like portions (first and second regions). The nonwoven fabric of Comparative Example 5 had a first region, a second region, and a joint, but did not have an open area ratio of 1.0% or more. Furthermore, in the nonwoven fabrics of Examples 1 to 4 and Comparative Examples 4 and 5, the belt-like portions extended along the MD.

[0107] [Measurements related to the shape of nonwoven fabric] Using each nonwoven fabric, the following shape measurements were carried out.

[0108] (Measurement of basis weight of nonwoven fabric) The nonwoven fabric to be measured was cut to obtain rectangular test pieces with sides 8 cm along the MD and 7 cm along the CD. The mass of each test piece was measured, and the measured mass was divided by the area to calculate the basis weight of each test piece. This procedure was performed on three test pieces of one type of nonwoven fabric, and the average value of the measurements of the three pieces was used as the basis weight of each nonwoven fabric. The results are shown in Table 1.

[0109] (Measurement of ventilation resistance) The airflow resistance of the 8cm x 7cm test pieces was measured using a measuring device (KES F8-AP1 Air Permeability Tester, manufactured by Kato Tech Co., Ltd.) with the measurement conditions set to "Sensor High." The above procedure was performed on three test pieces of one type of nonwoven fabric, and the average of the three measurements was taken as the airflow resistance of each nonwoven fabric. The results are shown in Table 1.

[0110] (Measurement of pore rate and average pore size) Using a digital microscope (VHX-6000, manufactured by Keyence Corporation), enlarged images of the 8 cm x 7 cm test pieces were captured under the following imaging conditions: magnification: 50x, brightness: Auto 70, gain preset: 0 dB, white balance: 255, epi-illumination: ON, and ring illumination: ON. The acquired images were binarized using a threshold value of -58, and the average area of ​​the dark regions and the ratio of the area of ​​the dark regions to the total area (area ratio) were calculated using the automatic area measurement mode. This procedure was performed on three test pieces of one type of nonwoven fabric. The average value of the average area of ​​the dark regions of the three test pieces was used as the average pore size for each nonwoven fabric, and the average area ratio was used as the pore ratio for each nonwoven fabric. The results are shown in Table 1.

[0111] (Measurement of height dimensions H1, H2, H3 of the first and second areas and the connection part) A laser microscope (VK-X3000, Keyence Corporation) was used to capture magnified images of the 8 cm x 7 cm test piece described above under the following imaging conditions: objective lens 5x (zoom 1.0x), laser confocal mode, high-resolution (2048 x 1536), high accuracy, and 8.00 μm pitch. The height dimension H1 of the first region was measured by profile measurement (shape measurement) along a line segment connecting the center of the first region and the center of the surrounding open-hole region on the image. Specifically, 50 average profiles were obtained at 8.08 μm intervals along this line segment. Based on the obtained average profile data, the height dimension between the open-hole region and the first surface of the first region was measured, and the average value of the six measurements was taken as the height dimension H1 of the first region. The height dimension H2 of the second region was determined by performing a profile measurement on a line segment connecting the center of the second region to the center of the surrounding open hole region in the same manner as above, measuring the height dimension of the second region, and taking the average of the measurements at six locations as the height dimension H2 of the second region.Furthermore, the height dimension H3 of the connection portion was determined by performing a profile measurement on a line segment connecting the center of the connection portion to the center of the surrounding open hole region in the same manner as above, measuring the height dimension of the connection portion, and taking the average of the measurements at six locations as the height dimension H3 of the connection portion.The results are shown in Table 1. Since the nonwoven fabrics of Comparative Examples 1 to 3 did not have the first and second regions and joints, their thicknesses were measured under the following conditions. The thickness measurements were also performed in the same manner on the nonwoven fabric of Example 1. A load of 50 Pa was applied to one side of the 8 cm x 7 cm test piece using a horizontal plate (a circular plate with a diameter of 2.5 cm and a mass of 2.45 g), and the thickness of the test piece was measured using a laser thickness meter (Omron Corporation, "ZSLD-80"). This procedure was performed three times for each type of nonwoven fabric, and the average of the three measurements was taken as the thickness of each nonwoven fabric. As a result, the thicknesses of the nonwoven fabrics of Example 1 and Comparative Examples 1 to 3 were all 0.39 mm.

[0112] (Measurement of the length dimension L1 of the first region and the length dimension L2 of the second region) The length dimension of the first region and the length dimension L2 of the second region were measured by profile measurement under the same conditions as the height dimension using the same measuring equipment as used to measure the height dimension. The length dimension L1 of the first region was obtained by acquiring 50 average profiles at 8.08 μm intervals along a line segment parallel to the CD (second planar direction Y) connecting the centers of the first regions 13 at both ends of the sample, and calculating the average value of the length dimension measurements of the first region at six locations based on the obtained data. The length dimension L2 of the second region was also obtained in the same manner as the length dimension L1 of the first region. The results are shown in Table 1.

[0113] (Measurement of width W1 of the first region and width W2 of the connection portion) The width dimension W1 of the first region and the width dimension W2 of the connection portion 16 were measured by profile measurement under the same conditions as the height dimension using the same measuring equipment as used to measure the height dimension. The width dimension W1 of the first region was obtained by obtaining 50 average profiles at 8.08 μm intervals along a line segment parallel to the MD (first planar direction X) connecting the centers of the first regions 13 at both ends of the sample, and calculating the average value of the measured width dimensions of the first region at six locations based on the obtained data. The width dimension W2 of the connection portion 16 was also obtained in the same manner as the width dimension W1 of the first region. The results are shown in Table 1.

[0114] [Table 1]

[0115] [Preparation of artificial blood] Sterile defibrated equine blood (Japan Biomaterials Center Co., Ltd.) (hereafter referred to as "horse blood") was prepared. The plasma and blood cell components of horse blood were separated into upper and lower halves in a reagent bottle and mixed at room temperature to prepare pseudo-blood samples with viscosities of 8 mPa·s ± 0.1 mPa·s and 24 mPa·s ± 0.1 mPa·s, respectively. Viscosity was measured using a VISCOMETER TVB-10 (Toki Sangyo Co., Ltd.).

[0116] [Contact angle measurement] The nonwoven fabric was cut into strips approximately 7 cm in the MD and 1 cm in the CD, and the contact angle of each nonwoven fabric piece with 8 mPa·s of simulated blood was measured using the liquid drop method. First, the nonwoven fabric piece was positioned so that the MD was parallel to the camera of a contact angle meter ("Automatic Contact Angle Meter MCA-J" manufactured by Kyowa Interface Science Co., Ltd.). 10 μL of the above-mentioned simulated blood was applied perpendicularly to the nonwoven fabric piece. Images of the droplet were captured with a horizontally mounted camera at 100-millisecond intervals for up to 3 seconds after droplet application, and the images were recorded. The captured images were analyzed using an ellipse fitting method ("FAMAS" image analysis software manufactured by Kyowa Interface Science Co., Ltd.), and the angle between the droplet's surface exposed to air and the nonwoven fabric surface was calculated as the contact angle. The results are shown in Table 1.

[0117] [Making napkins] The nonwoven fabrics of Examples 1 to 4 and Comparative Examples 1 to 5 and the air-through nonwoven fabric (25 g / m) made of core-sheath thermoplastic fibers (core: polyethylene terephthalate, sheath: polyethylene) 2 A napkin was produced by laminating a nonwoven fabric (2.4 dtex, 1.8 mm thick) with an absorbent (same specifications as "Shiawase Suhada Fluffy Type 22.5 cm with Wings" manufactured by Kao Corporation) and bonding them together with a hot melt adhesive. In the napkins, the nonwoven fabrics of Examples 1 to 4 and Comparative Examples 1 to 5 were used as topsheets.

[0118] [Measurement of liquid return amount] A cylindrical acrylic plate for evaluation was placed in the center of the prepared napkin, and 3 g of the above-mentioned artificial blood adjusted to 8 mPa·s was poured into it. The time from the moment of pouring until the liquid level disappeared was measured, and the napkin was left to stand for 1 minute from the moment the liquid level disappeared. After 1 minute had passed, tissue paper (folded in three, 100 mm x 50 mm square, Kleenex (trade name) manufactured by Nippon Paper Crecia Co., Ltd.) was placed on the napkin and 5 g / cm 2 The tissue was allowed to rest for 2 minutes from the moment the tissue was removed, and then 3 g of simulated blood was injected again. The above procedure was repeated once more, and the amount of liquid returned was measured after a total of 6 g of simulated blood had been injected. The above measurement of the amount of liquid returned was performed three times for each type of sample, and the average of the three amounts of liquid returned was calculated as the amount of liquid returned for each sample. The results are shown in Table 1.

[0119] [Measurement of average and maximum liquid flow rates] The napkin was placed on an acrylic plate tilted at 45°, the tip of the tube was set 10 mm above the surface of the napkin, and the artificial blood adjusted to 24 mPa·s using a micropump was dripped onto the tube at a rate of 0.1 g / sec for 5 seconds. The distance the artificial blood flowed from the drop point to the tip was measured using a ruler and recorded as the amount of liquid flow (runoff value). The average and maximum amount of liquid flow for each napkin sample measured three times are shown in Table 1.

[0120] [Evaluation results] As shown in Table 1, the samples of Comparative Examples 1 to 3, which do not have a band-like portion, had larger average and maximum liquid flow rates and were more likely to experience liquid flow on the first surface than the samples of Examples 1 to 4. Comparative Example 5, which has a band-like portion but an open area ratio of less than 1.0%, also had larger average and maximum liquid flow rates and was more likely to experience liquid flow on the first surface than the samples of Examples 1 to 4.

[0121] It was found that the sample of Comparative Example 4, which had a band-shaped portion without a first region or a second region, had a larger maximum liquid flow rate and greater variation in the liquid flow rate than the samples of Examples 1 to 4. This instability in the liquid flow is thought to be due to the fact that, in a band-shaped portion of approximately constant height, no region that blocks the liquid is formed within the band-shaped portion, causing liquid to flow down the band-shaped portion without being guided to the openings.

[0122] These results demonstrate that the nonwoven fabrics of Examples 1 to 4, which have a strip-shaped portion having alternating first and second regions and an opening adjacent to the second region, and have an opening rate of 1.0% or more, can stably exert a liquid flow suppression effect.

[0123] Comparing the samples of Examples 1 and 4, the sample of Example 4, in which the height dimension H1 of the first region was 748 μm, had larger average and maximum liquid flow rates than the sample of Example 1, in which the height dimension was 201 μm. This shows that the liquid flow suppression effect can be further improved by setting the height dimension of the first region to 800 μm or less.

[0124] Furthermore, from the results of the liquid flow rate and liquid return rate in Comparative Examples 1 and 2, it was found that the sample of Comparative Example 1, which had a contact angle of less than 30°, had a smaller liquid flow rate but a larger liquid return rate than Comparative Example 2, which had a contact angle of 30° or more. This shows that liquid return can be improved by setting the contact angle to 30° or more.

[0125] <Test Example 2: Evaluation of Strength> In Test Example 2, the nonwoven fabric samples of Examples 1, 2 and 4 were used to evaluate the tensile strength in the MD.

[0126] [Measurement of tensile strength] Rectangular test pieces measuring 75 mm in the MD and 50 mm in the CD were cut from each nonwoven fabric. The test pieces were set in a measuring device (Autograph AG-IS, manufactured by Shimadzu Corporation) so that the chuck distance along the MD was 50 mm. The test pieces were pulled in the MD at a tensile speed of 300 mm / min, and the maximum point test force was measured. The average of the maximum point test forces for three test pieces for each type of sample was taken as the tensile strength in the MD of each sample.

[0127] [Table 2]

[0128] [Tensile strength measurement results] The nonwoven fabrics of Examples 1 and 2, which had an open area ratio of 4.5% or less, had higher tensile strength than the nonwoven fabric of Example 4, which had an open area ratio of more than 4.5%. The tensile strength also tended to increase as the open area ratio decreased. These results demonstrate that the strength of the nonwoven fabric can be improved by setting the open area ratio to 4.5% or less. [Explanation of symbols]

[0129] 10...Nonwoven fabric (nonwoven fabric for absorbent articles) 10a...Side 1 10b…Second side 11...Strip 12...Spacing section 13...First area 14…Second area 15...Open hole 16...Connection

Claims

1. A nonwoven fabric for absorbent articles, comprising cellulose fibers, and having a first planar direction, a second planar direction intersecting the first planar direction, and a thickness direction orthogonal to the first planar direction and the second planar direction, a first surface and a second surface configured as surfaces extending in the first planar direction and the second planar direction, respectively; a plurality of strip-shaped portions that are spaced apart from each other in the second planar direction and that are each formed into a strip shape extending in the first planar direction when viewed in the thickness direction; a plurality of spacing portions that are arranged alternately with the band-shaped portions in the second plane direction and are formed in the first surface in a concave shape relative to the band-shaped portions in the thickness direction, The band-shaped portion is a plurality of first regions arranged spaced apart from each other in the first planar direction; a plurality of second regions that are arranged alternately with the first regions in the first planar direction and are formed on the first surface in a recessed shape relative to the first regions in the thickness direction; and The spacing portion is a plurality of openings arranged adjacent to the second region in the second planar direction and formed in the thickness direction; The nonwoven fabric for absorbent articles has an open pore ratio of 1.0% or more. Nonwoven fabric for absorbent articles.

2. the gap further includes a connection portion connecting two of the first regions adjacent to the gap; The nonwoven fabric for absorbent articles according to claim 1.

3. The first region has a higher fiber density than the second region. The nonwoven fabric for absorbent articles according to claim 1.

4. The height dimension of the first region in the thickness direction is 50 μm or more and 800 μm or less. The nonwoven fabric for absorbent articles according to claim 1.

5. The length dimension of the first region in the first planar direction is 1.5 mm or more. The nonwoven fabric for absorbent articles according to claim 1.

6. The nonwoven fabric for absorbent articles has an open pore ratio of 1.0% or more and 5.0% or less. The nonwoven fabric for absorbent articles according to claim 1.

7. The area of ​​the opening in a plan view seen from the thickness direction is 0.01 mm ２ 0.30mm or more ２ Below is the The nonwoven fabric for absorbent articles according to claim 1.

8. The air resistance is 0.025 kPa s or more and 0.06 kPa s or less, The nonwoven fabric for absorbent articles according to claim 1.

9. a contact angle between the first surface and a blood simulant made of defibrinated horse blood adjusted to a viscosity of 8 mPa·s at room temperature is 30° or more; The nonwoven fabric for absorbent articles according to claim 1.

10. The cellulose fibers include cotton fibers. The nonwoven fabric for absorbent articles according to claim 1.

11. An absorbent article comprising an absorbent body and a topsheet disposed on the skin side of the absorbent body, the absorbent article having a vertical direction corresponding to the front-to-back direction of a wearer, a horizontal direction corresponding to the left-to-right direction of the wearer and perpendicular to the vertical direction, and a thickness direction perpendicular to the vertical direction and the horizontal direction, the top sheet is made of a nonwoven fabric containing cellulose fibers, The top sheet is a skin-facing surface and a non-skin-facing surface configured as surfaces extending in the longitudinal direction and the lateral direction, respectively; a plurality of strip-shaped portions that are spaced apart from each other in the horizontal direction and that are each formed into a strip shape extending in the vertical direction in a plan view seen from the thickness direction; a plurality of spacing portions that are arranged alternately with the band-shaped portions in the lateral direction and are formed on the skin-facing surface in a concave shape relative to the band-shaped portions in the thickness direction, The band-shaped portion is a plurality of first regions spaced apart from one another in the vertical direction; a plurality of second regions arranged alternately with the first regions in the longitudinal direction and formed on the skin facing surface in a concave shape relative to the first regions in the thickness direction; and The spacing portion is a plurality of openings disposed adjacent to the second region in the lateral direction and formed in the thickness direction; The surface sheet has an opening rate of 1.0% or more. Absorbent articles.

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