JP7786017B2 - absorbent articles - Google Patents

Description

The present invention relates to an absorbent article.

Conventionally, absorbent articles such as sanitary napkins are known to have a longer rear region of the main body to accommodate use during nighttime sleep or long-term use. Various designs have been considered for preventing leakage of bodily fluids in the rear region of such absorbent articles. These designs include the shape of compressed grooves (embossments) formed in the top sheet and absorbent body (see, for example, Patent Documents 1 and 2).

JP 2009-100846 A JP 2014-223215 A

However, with conventional configurations, when using absorbent articles while sleeping at night or for long periods of time, there remains a concern that bodily fluids may leak along the gluteal cleft behind or to the rear or sides of the gluteal cleft, depending on how the article is worn and the wearer's movements while wearing it. Therefore, there is a need to improve the fit around the buttocks, particularly the fit around the end of the gluteal cleft or in areas further back, to prevent leakage.

In light of the above, one aspect of the present invention aims to provide an absorbent article that provides a good fit around the buttocks and prevents leakage.

A first aspect of the present invention comprises an elongated main body comprising a skin-facing top sheet, a non-skin-facing back sheet opposite the skin-facing side, and an absorbent body disposed between the top sheet and the back sheet, wherein at least the top sheet and the absorbent body have compressed grooves formed therein that are recessed from the top sheet side to the back sheet side, and the compressed grooves include a first rear compressed groove formed in an area that faces the wearer's buttocks when worn, and a second rear compressed groove formed rearward and spaced apart from the first rear compressed groove, wherein the first rear compressed groove has a first arc-shaped portion that convex rearward, a second arc-shaped portion located left forward of the first arc-shaped portion and convex left rearward, and a third arc-shaped portion located right forward of the first arc-shaped portion and convex right rearward, and the second rear compressed groove has a rearward convex shape.

Due to the above-described shapes of the first rear compressed groove and the second rear compressed groove in the first embodiment, the apex of the first, second, and third arc-shaped portions of the first rear compressed groove, as well as the apex of the second rear compressed groove, are positions (bending base points) that can be easily bent in the longitudinal direction. Therefore, when viewed longitudinally, from front to rear, the apex of the second and third arc-shaped portions, the apex of the first arc-shaped portion, and the apex of the second rear compressed groove are easily bent in at least three stages. This allows the main body to be bent longitudinally toward the skin, easily conforming to the shape of the rear portion of the buttocks. Furthermore, when viewed laterally, the apex of the second, first, and second rear compressed grooves is easily bent in at least three stages. This allows the main body to be bent laterally toward the skin, easily conforming to the shape of the rear portion of the buttocks. Thus, according to this aspect, the region facing the buttocks can be easily bent both longitudinally and laterally, making it easy to form a three-dimensional curve. This allows the rear region of the absorbent article to fit snugly against the curve of the buttocks, particularly the rear portion. This prevents bodily fluids from leaking behind or to the rear sides of the buttocks.

In addition, in this embodiment, the first rear compressed groove and the second rear compressed groove are spaced apart, allowing for a flexibly deformable area with no compressed portion between the two compressed grooves. Therefore, when the main body is bent toward the skin along the first rear compressed groove and the second rear compressed groove, the area between the two compressed grooves may bulge toward the skin due to the compressive force. This bulge improves adhesion to the rear region of the wearer's buttocks, i.e., the area where the gluteal cleft is shallow near the end of the gluteal cleft, or the area further posterior from the end of the gluteal cleft, preventing leakage.

In a second aspect of the present invention, the front end of the second rear compression groove is located rearward of the apex of the first arc-shaped portion of the first rear compression groove.

In the second aspect, the first rear compressed groove and the second rear compressed groove do not overlap in the longitudinal direction, reducing the possibility of a decrease in flexibility between the two compressed grooves. This allows the area between the two compressed grooves to be raised toward the skin when compressive force is applied to the area between the two compressed grooves when the main body is bent, further enhancing the aforementioned effect of increasing adhesion to the rear region of the buttocks.

In a third aspect of the present invention, the connecting portion between the first arc-shaped portion and the second arc-shaped portion, and the connecting portion between the first arc-shaped portion and the third arc-shaped portion each include a portion where the slope of the tangent changes discontinuously.

According to the third aspect, the first rear compression groove has at least two relatively sharp forward depressions formed on both sides of the first arc-shaped portion. Therefore, the positions of these depressions can also serve as starting points for bending, making the main body even easier to bend and achieving a more natural curve that conforms to the shape of the buttocks.

In a fourth aspect of the present invention, the first arc-shaped portion has a pair of extensions that extend the arc of the first arc-shaped portion forward.

According to the fourth aspect, the main body can be easily bent along the direction in which the pair of extensions extend. Furthermore, the area surrounded by the left extension and the second arc-shaped portion, and the area surrounded by the right extension and the third arc-shaped portion, have slightly higher rigidity, making these areas less susceptible to unwanted creases and wrinkles. These areas correspond to the rear portion of the wearer's intergluteal cleft or both sides near the end of the intergluteal cleft when worn. Because these areas are less susceptible to creases and wrinkles, these areas can be fitted closely to the gentle surfaces of the buttocks on both sides of the intergluteal cleft. This prevents leakage of bodily fluids that have trickled down the intergluteal cleft.

In a fifth aspect of the present invention, each of the pair of extensions is inclined so as to approach the lateral center as it extends forward, and imaginary lines drawn along the pair of extensions each pass through the front end of the second rear compression groove.

The fifth aspect of the invention makes it easier for the device to bend around a line that extends along the extension of the first rear compressed groove and to the front end of the second rear compressed groove. This further promotes the formation of a natural curve that conforms to the shape of the buttocks, further improving the fit to the buttocks.

One aspect of the present invention provides an absorbent article that provides a good fit around the buttocks and prevents leakage.

1 is a plan view of an absorbent article according to a first embodiment of the present invention, viewed from the skin side. 2 is a cross-sectional view taken along line II in FIG. 1. FIG. 2 is a partially enlarged view of FIG. 1. FIG. 10 is a plan view of an absorbent article according to a second embodiment of the present invention, as viewed from the skin side. 2 is a cross-sectional view taken along line II-II of FIG. 4. FIG. 5 is a partially enlarged view of FIG. 4 .

Embodiments of the present invention will be described below with reference to the drawings. Note that in each drawing, unless otherwise specified, identical or corresponding components will be designated by the same reference numerals and their description may be omitted.

[First embodiment]
<Basic structure of absorbent article>
First, the basic structure of an absorbent article will be described using an overnight or long-lasting sanitary napkin as an example. Fig. 1 shows a plan view of an absorbent article 1 according to a first embodiment. Fig. 2 shows a cross-sectional view taken along line II in Fig. 1.

As shown in Figures 1 and 2, the absorbent article 1 comprises a liquid-permeable top sheet 3 arranged on the side facing the wearer's skin when worn, i.e., the skin side, and a liquid-impermeable back sheet 2 arranged on the non-skin side (underwear side) opposite the skin side. Furthermore, an absorbent body 4 is arranged between the back sheet 2 and the top sheet 3. The back sheet 2, absorbent body 4, and top sheet 3 are layered to form a main body (absorbent article main body) 8. The absorbent body 4 is arranged so as not to protrude from the back sheet 2 and top sheet 3 in a plan view. At both ends in the longitudinal direction D1, the edges of the back sheet 2 and the top sheet 3 may be joined by adhesive, heat sealing, or the like.

As shown in the figure, the absorbent article 1 is in the shape of an elongated pad (a shape in which the thickness is smaller than the width and length). In this specification, the longitudinal direction (front-to-back direction) of the absorbent article 1 is designated D1, and the lateral direction (left-to-right or width direction) perpendicular to the longitudinal direction D1 is designated D2. The longitudinal direction D1 corresponds to the front-to-back direction of the wearer's body when the absorbent article 1 is worn, and the lateral direction D2 corresponds to the left-to-right direction of the body.

In the embodiment shown in Figures 1 and 2, the main body 8 has a shape in plan view that is approximately line-symmetrical with respect to a center line (longitudinal center line) CL extending in the longitudinal direction D1, but the shape of the main body 8 does not necessarily have to be line-symmetrical. Furthermore, configurations other than the shapes of the absorbent article 1 and the main body 8 (including the thickness and density of the absorbent core 4, the size and position of the compressed grooves, the shape and size of the flaps extending outward from the main body 8 in the lateral direction D2, etc.) may be approximately symmetrical or asymmetrical with respect to the center line CL as the axis of symmetry.

The backsheet 2 may be a sheet that is at least water-proof, and may be a sheet made of an olefin resin such as polyethylene or polypropylene. It may also be a laminated nonwoven fabric in which a nonwoven fabric is laminated onto a polyethylene sheet or the like, or a laminated sheet of nonwoven fabric that is substantially liquid-impermeable by inserting a waterproof film between them. It is even more desirable to use a material that is moisture-permeable to prevent stuffiness. Such a water-proof and moisture-permeable sheet material may be a microporous sheet obtained by melt-kneading an inorganic filler into an olefin resin such as polyethylene or polypropylene to form a sheet, and then stretching the sheet uniaxially or biaxially. The backsheet 2 may be a sheet that has the same outer shape as the absorbent article 1.

The top sheet 3 can be a liquid-permeable sheet that allows bodily fluids such as menstrual blood, vaginal discharge, and urine to pass through quickly. Suitable top sheet 3 materials include perforated or non-perforated nonwoven fabrics and porous plastic sheets. Materials constituting the nonwoven fabric include, for example, olefins such as polyethylene and polypropylene, synthetic fibers such as polyester and polyamide, regenerated fibers such as rayon and cupra, and blends thereof, as well as natural fibers such as cotton, which can be used alone or in combination. Nonwoven fabric processing methods include spunlace, spunbond, thermal bond, meltblown, and needlepunch. Of these processing methods, spunlace is preferred because it provides flexibility, spunbond is preferred because it can produce nonwoven fabrics with excellent drapeability, and thermal bond is preferred because it can produce bulky and soft nonwoven fabrics. Composite fibers, such as core-sheath fibers, side-by-side fibers, and splittable fibers, can also be used, each of which has a high-melting-point fiber as the core and a low-melting-point fiber as the sheath.

The absorbent body 4 can be made of any material capable of absorbing and retaining bodily fluids, but preferably contains cotton-like pulp and a water-absorbent polymer. Examples of water-absorbent polymers that can be used include superabsorbent polymer granules (SAP), superabsorbent fiber (SAF), and combinations of these. Examples of pulp include chemical pulp obtained from wood, cellulose fibers such as dissolving pulp, and artificial cellulose fibers such as rayon and acetate. Hardwoods and softwoods are used as raw materials for chemical pulp, with softwoods being preferred due to their long fiber length.

Synthetic fibers may be blended into the absorbent body 4. Examples of synthetic fibers that can be used include polyolefins such as polyethylene and polypropylene, polyesters such as polyethylene terephthalate and polybutylene terephthalate, polyamides such as nylon, and copolymers of these. Two of these fibers can also be blended together. Composite fibers, such as core-sheath fibers with a high-melting-point fiber as the core and a low-melting-point fiber as the sheath, side-by-side fibers, and splittable fibers, can also be used. Hydrophobic fibers can also be surface-treated with a hydrophilizing agent to impart affinity to body fluids. The absorbent body 4 is preferably manufactured using the stacking or airlaid method.

The absorbent body 4 does not need to have a uniform basis weight across its entire surface. It may have a portion with an increased basis weight, i.e., a high basis weight portion 4H, in the central region of the absorbent body in the lateral direction D2, for example, in the area corresponding to the bodily fluid outlet (blood outlet) when worn. The high basis weight portion 4H may bulge toward the skin. Therefore, the absorbent body 4 does not need to have a uniform thickness across its entire surface. The thickness of the absorbent body 4 (the length in the direction perpendicular to the longitudinal direction D1 and lateral direction D2) may be 0.5 to 25 mm, preferably 1.5 to 15 mm.

The absorbent body 4 may be wrapped in an envelope sheet made of colored or uncolored (white) crepe paper, nonwoven fabric, etc. to prevent wrinkling, cracking, or spillage of polymer particles.

Side sheets 7, 7 are arranged on both sides of the absorbent article 1, i.e., on the sides in the lateral direction D2, along the longitudinal direction D1, facing the skin. The side sheets 7 may be made of a material that has been treated, entirely or partially, with an appropriate water-repellent or hydrophilic treatment, depending on the purpose, such as preventing penetration of bodily fluids or enhancing the feel against the skin. The side sheets 7 are preferably nonwoven fabrics containing natural fibers, synthetic fibers, recycled fibers, etc., or made from these fibers. When the side sheets 7 are nonwoven fabrics, they may be air-through nonwoven fabrics, spunlace nonwoven fabrics, spunbond nonwoven fabrics, meltblown nonwoven fabrics, etc., but air-through nonwoven fabrics are preferred because they are resistant to creases, wrinkles, and soft, improving the feel against the skin. The side sheets 7 may also be treated with a water-repellent agent, such as a silicone-based or paraffin-based water-repellent agent.

The side sheet 7 may be folded back on the inside in the lateral direction D2 to form a multi-layered band-like portion extending along the side of the main body 8. Gathers may be formed between the multiple layers by disposing an elastically stretchable member in a stretched state along the longitudinal direction D1. This specification omits a description of the folds and gathers of the side sheet 7, and they are not shown in the drawings.

The absorbent article 1 may have a body fluid outlet-facing region C that faces the wearer's body fluid outlet (the vaginal opening in the illustrated example) when worn; a front region F that is adjacent to the front of the body fluid outlet-facing region C and extends to the front end of the absorbent article 1; a perineum-facing region (middle region) M that is adjacent to the rear of the body fluid outlet-facing region C and faces the wearer's perineum when worn; and a buttocks-facing region B that is adjacent to the rear of the perineum-facing region M and extends to the rear end of the absorbent article 1 and faces the wearer's buttocks when worn. Furthermore, the buttocks-facing region B includes a front buttocks-facing region B1 that is adjacent to the perineum-facing region and a rear buttocks-facing region B2 that is adjacent to the rear of the front buttocks-facing region B1. The front buttocks-facing region B1 is a region that primarily faces the intergluteal cleft (gluteal groove) and faces the area including the anus. The rear buttock facing region B2 may be a region that faces the rear part of the intergluteal cleft of the buttocks or a region further rearward from near the rear end of the intergluteal cleft, particularly a region rearward of the intergluteal sulcus, which can be considered the boundary between the buttocks and the legs (above, when standing). Note that the above description of the facing relationship between the region of the main body 8 and the wearer's body can be considered to be the approximate range when the wearer wears the absorbent article in the normal manner while lying down, but is merely a guide.

The longitudinal direction D1 length of the bodily fluid outlet-facing region C may be 50 to 120 mm, and the longitudinal direction D1 length of the buttocks-facing region B may be 90 to 230 mm. This configuration is suitable for absorbent articles with a long rear, for example, where the total length of the perineum-facing region M and buttocks-facing region B, and preferably the longitudinal direction D1 length of the buttocks-facing region B, is greater than the longitudinal direction D1 length where the wing flaps WF are provided. The longitudinal direction D1 length of the front buttocks-facing region (gluteal cleft-facing region) B1 may be 40 to 100 mm, and the longitudinal direction D1 length of the rear buttocks-facing region B2 may be 40 to 120 mm. The total length of the absorbent article 1 in the longitudinal direction D1 may be 250 to 450 mm.

The absorbent article 1 may include a pair of wing flaps WF, WF extending outward in the lateral direction D2 from both sides of the region C facing the bodily fluid outlet. The non-skin sides of the wing flaps WF, WF may be provided with anti-slip materials (not shown), which allow the wing flaps WF, WF to be folded back toward the non-skin sides and attached to the underwear so that the underwear is sandwiched between the wing flaps WF, WF and the main body 8 when worn. This allows the absorbent article 1 to be securely fastened to the underwear. The wing flaps WF, WF are formed by joining the outward extensions of the side sheets 7, 7 in the lateral direction D2 and the outward extensions of the back sheet 2 in the lateral direction D2.

A pair of hip hold flaps HF, HF may be formed extending outward in the lateral direction D2 from the sides of the main body 8, from the perineum-facing region M to the buttocks-facing region B. The hip hold flaps HF, HF prevent leakage of bodily fluids at the rear of the absorbent article 1, and by increasing the contact area with the buttocks, the absorbent article 1 as a whole is less likely to shift relative to the underwear, particularly in the lateral direction D2, thereby stabilizing the wearing position of the absorbent article 1. The hip hold flaps HF, HF may also be formed by joining the outward extensions in the lateral direction D2 of the side sheets 7, 7 and the outward extensions in the lateral direction D2 of the back sheet 2.

<Compression groove>
As shown in Figures 1 and 2, the main body 8 of the absorbent article 1 of this embodiment has a plurality of compressed grooves (embossments) formed therein (in the example of Figure 1, these are shown as reference numerals 10, 11, 12, and 13). The compressed grooves may be formed in a line-symmetrical manner with respect to the longitudinal centerline CL of the absorbent article 1 in a plan view, but are not necessarily line-symmetrical. The compressed grooves are formed as grooves recessed from the top sheet 3 side to the back sheet 2 side. The compressed grooves can be formed, for example, by passing a laminate formed by stacking at least the top sheet 3 and the absorbent body 4 between a pair of pressure rolls. In this case, the laminate can be pressed by sandwiching the roll with a convex shape on the top sheet 3 side and a flat roll on the absorbent body 4 side. The compressed grooves may include a low-compression section and a high-compression section compressed at a higher pressure within the low-compression section. In the drawings, the high-compression section is shown in black.

In the embodiment shown in Figure 1, a pair of central compressed grooves 10, 10 extend along the longitudinal direction D1, mainly from the bodily fluid outlet facing region C to the perineum facing region M. The pair of central compressed grooves 10, 10 are formed spaced apart from each other on both sides of the longitudinal centerline CL. The pair of central compressed grooves 10, 10 are positioned so as not to overlap with the high basis weight portion 4H. The distance between the pair of central compressed grooves 10, 10 in the lateral direction D2 may be constant or may vary. For example, as shown in Figure 1, the distance may be smaller near the boundary between the bodily fluid outlet facing region C and the perineum facing region M, then larger again behind that, and gradually smaller toward the rear end.

A first rear compressed groove 11 is formed behind the pair of central compressed grooves 10, 10 and spaced apart from the pair of central compressed grooves 10, 10. The first rear compressed groove 11 is preferably formed in the buttocks-facing region B, primarily in the intergluteal cleft-facing region B1. The first rear compressed groove 11 has an overall rearwardly convex shape, and more specifically, includes at least three rearwardly convex portions (a first arc-shaped portion 11C, a second arc-shaped portion 11L, and a third arc-shaped portion 11R). Furthermore, a second rear compressed groove 12 is formed behind the first rear compressed groove 11 and spaced apart from the first rear compressed groove 11. The second rear compressed groove 12 is a groove that extends along the lateral direction D2 and has a rearwardly convex shape.

Furthermore, a front compressed groove 13 is formed in front of the pair of central compressed grooves 10, 10. In the example shown in Figure 1, the front compressed groove 13 has a closed shape formed by combining compressed grooves with different radii of curvature and a forward convex curve.

Figure 3 shows an enlarged view of the portion extending from the rear of the pair of central compression grooves 10, 10 to the second rear compression groove 12. As shown in Figure 3, the first rear compression groove 11 includes a rearwardly convex first arc-shaped portion 11C positioned so as to overlap the longitudinal centerline CL, a rearwardly convex second arc-shaped portion 11L adjacent to the left of the first arc-shaped portion 11C (convex left rearward), and a rearwardly convex third arc-shaped portion 11R adjacent to the right of the first arc-shaped portion 11C (convex right rearward). Both the second arc-shaped portion 11L and the third arc-shaped portion 11R are located forward of the first arc-shaped portion 11C and outboard in the lateral direction D2. More specifically, as shown in Figure 3, the second arc-shaped portion 11L is located left forward of the first arc-shaped portion 11C, and the third arc-shaped portion 11R is located right forward of the first arc-shaped portion 11C. It is preferable that the first arc-shaped portion 11C and the second arc-shaped portion 11L are connected, and that the first arc-shaped portion 11C and the third arc-shaped portion 11R are connected. Note that a shape that convex to the left rear refers to a shape in which a normal line drawn at the apex of the arc-shaped portion forms an angle of less than 60° with respect to the longitudinal centerline CL and moves further left from the longitudinal centerline CL as it moves rearward. Note that a shape that convex to the right rear refers to a shape in which a normal line drawn at the apex of the arc-shaped portion forms an angle of less than 60° with respect to the longitudinal centerline CL and moves further right from the longitudinal centerline CL as it moves rearward.

The configuration of the first rear compressed groove 11 and the second rear compressed groove 12 as described above allows for the formation of multiple bending base points from front to rear. That is, from front to rear, the second arc-shaped portion 11L, the third arc-shaped portion 11R, the first arc-shaped portion 11C, and the second rear compressed groove 12 facilitate bending in three stages in the longitudinal direction D1. Therefore, the entire rear of the buttocks-facing region B can be curved toward the skin (convex toward the non-skin side) when viewed in a cross section along the longitudinal direction D1. Furthermore, from left to right, the second arc-shaped portion 11L, the first arc-shaped portion 11C, the second rear compressed groove 12, and the third arc-shaped portion 11R facilitate bending in three stages in the lateral direction D2. Therefore, the rear of the buttocks-facing region B can be curved toward the skin (convex toward the non-skin side) when viewed in a cross section along the lateral direction D2. Thus, according to this embodiment, the buttocks-facing region B can be easily bent in both the longitudinal direction D1 and the lateral direction D2, easily forming a three-dimensional curve that follows the curvature of the buttocks. As a result, the main body 8 can be well fitted to the area where the curve of the buttocks becomes sharper, from near the posterior end of the intergluteal cleft to further posterior to the intergluteal cleft.

Explaining the above configuration more specifically, as shown in Figure 3, the apex 11Lt of the second arc-shaped portion 11L is located forward and outward in the lateral direction D2 from the apex 11Ct of the first arc-shaped portion 11C, and the apex 11Rt of the third arc-shaped portion 11R is located forward and outward in the lateral direction D2 from the apex 11Ct of the first arc-shaped portion 11C. Furthermore, the apex 12t of the second rear compressed groove 12 is located rearward from the apex 11Ct of the first arc-shaped portion 11C of the first rear compressed groove 11. Note that, in this specification, the apex 11Ct of the first arc-shaped portion 11C can be located at either of the two edges or at the rearmost position on the centerline of the first arc-shaped portion 11C. The apex 12t of the second rear compressed groove 12 can also be located at either of the two edges or at the rearmost position on the centerline of the second rear compressed groove 12. The apex 11Lt of the second arc-shaped portion 11L and the apex 11Rt of the third arc-shaped portion 11R may each be located at a position where the radius of curvature is smallest on any edge or center line of the arc-shaped portion. In the example shown in FIG. 3 , the apex 11Ct of the first arc-shaped portion 11C is located at the rearmost position of the rear edge of the first arc-shaped portion 11C, and the apex 12t of the second rear compressed groove 12 is located at the rearmost position of the rear edge of the second rear compressed groove. Furthermore, the apex 11Lt of the second arc-shaped portion 11L is located at a position where the radius of curvature is smallest on the rear edge of the second arc-shaped portion 11L, and the apex 11Rt of the third arc-shaped portion 11R is located at a position where the radius of curvature is smallest on the rear edge of the third arc-shaped portion 11R.

As described above, when the main body 8 is curved three-dimensionally to follow the curve of the buttocks during wear, the fit to the entire buttocks is improved. However, in the center of the buttock-facing region B, i.e., near the center of the buttock-facing region B in the longitudinal direction D1 and near the lateral direction D2, the degree of curvature convex toward the non-skin side may become too great, potentially impairing the fit to the buttocks. In contrast, in this embodiment, as shown in Figure 3, the first rear compressed groove 11 and the second rear compressed groove 12 are spaced apart in the longitudinal direction D1. This allows for the formation of a flexibly deformable region without a compressed groove between the first rear compressed groove 11 and the second rear compressed groove 12. If the region between the first rear compressed groove 11 and the second rear compressed groove 12 is flexible, that region will receive a compressive force when worn, particularly in the longitudinal direction D1 from the first rear compressed groove 11 and the second rear compressed groove 12, and will be able to deform so as to bulge toward the skin. This bulge can then be made to face the rear region of the wearer's buttocks, particularly the region where the intergluteal cleft is shallow near the end of the intergluteal cleft, or the region further posterior from the end of the intergluteal cleft, thereby preventing leakage of bodily fluids even if they migrate rearward along the intergluteal cleft.

It is also preferable that the apex 11Ct of the first arc-shaped portion 11C of the first rear compressed groove 11 and the front ends 12ft, 12ft of the second rear compressed groove 12 are spaced apart in the longitudinal direction D1. This prevents the flexible region between the first rear compressed groove 11 and the second rear compressed groove 12 from being completely surrounded by the compressed grooves, thereby reducing flexibility.

It is preferable that the distance between the first rear compressed groove 11 and the second rear compressed groove 12 in the longitudinal direction D1, i.e., the distance _d1 between the apex 11Ct of the first arc-shaped portion 11C of the first rear compressed groove 11 and the front ends 12ft, 12ft of the second rear compressed groove 12, be 5 to 20 mm. By setting the distance _d1 within this range, it is possible to prevent the first rear compressed groove 11 and the second rear compressed groove 12 from being too close to each other, thereby preventing the rigidity of the area between the two compressed grooves from becoming unnecessarily high, and to allow the area between the two compressed grooves to receive an appropriate amount of compressive force and rise more appropriately toward the skin.

Furthermore, the separation distance _d2 between the first rear compressed groove 11 and the second rear compressed groove 12 on the longitudinal centerline CL is preferably 15 to 40 mm. By setting the separation distance _d2 within this range, when the buttocks-facing region B is bent while wearing the garment, the region between the first rear compressed groove 11 and the second rear compressed groove 12 is subjected to a compressive force and rises appropriately toward the skin, preventing the region from becoming hard and reducing its ability to absorb bodily fluids and the fit.

In the first rear compression groove 11, the outer portions of the second arc-shaped portion 11L and the third arc-shaped portion 11R in the lateral direction D2 each extend significantly forward along the longitudinal direction D1. This allows the second arc-shaped portion 11L and the third arc-shaped portion 11R to also function to prevent lateral leakage (outward in the lateral direction D2). Because the second arc-shaped portion 11L and the third arc-shaped portion 11R extend relatively far in the longitudinal direction D1, the first rear compression groove 11 as a whole has a shape that extends relatively widely in both the longitudinal direction D1 and the lateral direction D2. The ratio (a/b) of the extension length a in the lateral direction D2 to the extension length b in the longitudinal direction D1 may be approximately 0.8 to 1.2.

In the first rear compressed groove 11, connecting portions 11r, 11r are formed between the arc-shaped portions, i.e., between the first arc-shaped portion 11C and the second arc-shaped portion 11L, and between the first arc-shaped portion 11C and the third arc-shaped portion 11R. When viewing the first rear compressed groove 11 from a region rearward of the first rear compressed groove 11, these connecting portions 11r, 11r can be described as recesses formed between the first arc-shaped portion 11C and the second arc-shaped portion 11L, and between the first arc-shaped portion 11C and the third arc-shaped portion 11R, recessed forward and toward the longitudinal centerline CL. When worn, connecting portions 11r, 11r can also serve as bending base points, allowing the main body 8 to bend more smoothly and naturally to conform to the shape of the buttocks, further improving its fit to the buttocks. The connecting portions 11r, 11r may have a smoothly curved shape in which the tangent to the groove changes continuously. In this case, the second arc-shaped portion 11L, the first arc-shaped portion 11C, and the third arc-shaped portion 11R are all wavy. Alternatively, as shown in FIG. 3 , the connecting portions 11r, 11r may include portions where the tangent to the groove changes discontinuously. This results in sharply recessed portions at the boundary between the first arc-shaped portion 11C and the second arc-shaped portion 11L and the boundary between the first arc-shaped portion 11C and the third arc-shaped portion 11R, respectively. This makes bending at the connecting portions 11r, 11r easier, further enhancing the effect of improving adhesion. Note that, in this specification, the tangent to the groove may be a tangent drawn at either of the two edges or the center line of the groove.

Second Embodiment
Fig. 4 shows a plan view of an absorbent article 1A according to a second embodiment of the present invention, as seen from the skin side. Fig. 5 shows a cross-sectional view taken along line II-II in Fig. 4. Fig. 6 shows a partially enlarged view of Fig. 4. The absorbent article 1A according to the second embodiment is similar in basic configuration to the first embodiment (Figs. 1 to 3), but differs from the first embodiment in the shape of the first rear compressed groove 11. More specifically, as shown in Figs. 4 and 6, in the absorbent article 1A according to the second embodiment of the present invention, the first arc-shaped portion 11C of the first rear compressed groove 11 has a pair of extensions 11ex, 11ex at the front. The absorbent article 1A according to the second embodiment also provides the same effects as the first embodiment, but in this embodiment, additional effects are obtained by the pair of extensions 11ex, 11ex.

As shown in Figure 6, the pair of extensions 11ex, 11ex of the first arc-shaped portion 11C extend from the front of the first arc-shaped portion 11C. Because the first arc-shaped portion 11C is inclined so that it approaches the longitudinal centerline CL as it moves forward, the pair of extensions 11ex, 11ex are also inclined so that it approaches the longitudinal centerline CL as it moves forward. In other words, the distance between the portions of the first arc-shaped portion 11C separated on either side of the longitudinal centerline CL becomes smaller as it moves forward.

By forming extensions 11ex, 11ex, when worn, extensions 11ex, 11ex serve as the base point for bending, allowing both sides of the line along extensions 11ex, 11ex to deform closer to the skin. This makes bending at connecting portions 11r, 11r easier, resulting in a natural curve that conforms to the buttocks and improved fit.

Furthermore, the presence of extensions 11ex, 11ex slightly increases the rigidity of region 30, which is surrounded by extension 11ex of first arc-shaped portion 11C and second arc-shaped portion 11L on both sides of first arc-shaped portion 11C, as well as region 30', which is surrounded by extension 11ex of first arc-shaped portion 11C and third arc-shaped portion 11R (regions 30, 30' are shown with diagonal lines in Figure 6). These regions 30, 30' face the rear portion of the wearer's gluteal cleft or both sides of the posterior end of the latter when worn. Furthermore, when worn, wearers often deform the garment, particularly the center of the gluteal cleft-facing region B1 in the lateral direction D2, so that it fits into the gluteal cleft, which can apply force to regions 30, 30' and their surrounding areas, resulting in unwanted creases and wrinkles. However, because region 30 is partially surrounded by the extension 11ex of first arc-shaped portion 11C and second arc-shaped portion 11L, and region 30' is partially surrounded by the extension 11ex of first arc-shaped portion 11C and third arc-shaped portion 11R, the above-mentioned kinking and other problems can be prevented, and the main body 8 can be aligned along the surfaces of the buttocks on both sides of the intergluteal cleft, allowing for surface contact and improving fit. This prevents leakage even if bodily fluids that have traveled up the intergluteal cleft further migrate outward in the lateral direction D2.

In addition, to further enhance the effect of preventing twisting and the like in the rigidity of the above-mentioned regions 30, 30', it is also possible to form multiple compressed grooves at separate points in the absorbent body 4 in regions 30, 30'. There are no particular restrictions on the form (shape, size, and formation method) of the compressed portions formed in the absorbent body 4, as long as they prevent twisting and the like in regions 30, 30' and ensure flexibility to fit the surface of the buttocks.

Furthermore, as shown in FIG. 6, it is preferable that imaginary lines Y, Y' drawn along the extensions 11ex, 11ex pass through the front ends 12ft, 12ft of the second rear compression groove 12, respectively. The imaginary lines drawn along the extension 11ex may be imaginary lines drawn from the front end to the rear end of the extension 11ex without extending beyond the extension 11ex. In the illustrated example, the imaginary lines Y, Y' extend so that the distance between them increases as they extend rearward.

The above configuration makes it easier for the main body 8 to bend along a line extending in the extension direction of the extension portion 11ex and extending from the front end of the extension portion 11ex to the front end 12ft of the second rear compressed groove 12. In other words, bending occurs more easily around the imaginary lines Y and Y'. As a result, no base point for bending is formed in the area between the first rear compressed groove 11 and the second rear compressed groove 12, allowing for a relatively small curvature in that area. As described above, the area between the first rear compressed groove 11 and the second rear compressed groove 12 faces a region near the end of the wearer's gluteal cleft or a region further rearward than the end of the gluteal cleft. Therefore, the area between the first rear compressed groove 11 and the second rear compressed groove 12 can be fitted closely to an area where the gluteal cleft is shallow or where no gluteal cleft exists, preventing bodily fluids from leaking rearward.

The present invention has been described above based on embodiments, but the present invention is not limited to these embodiments. Furthermore, the above embodiments can be subject to various changes, modifications, substitutions, additions, deletions, and combinations within the scope of the claims, and these also fall within the technical scope of the present invention.

1, 1A Absorbent articles (sanitary napkins)
2 Back sheet 3 Top sheet 4 Absorbent body 4H Middle part of absorbent body 7 Side sheet 8 Main body (absorbent article main body)
10 Central compression groove 11 First rear compression groove 11C First arc-shaped portion 11Ct Apex 11ex of first arc-shaped portion Extension portion 11L Second arc-shaped portion 11Lt Apex 11R of second arc-shaped portion Third arc-shaped portion 11Rt Apex 11r of third arc-shaped portion Connecting portion 12 Second rear compression groove 12ft Front end 12t of second rear compression groove Rear apex 13 of second rear compression groove Front compression groove C Body fluid discharge outlet facing region CL Longitudinal center line D1 Longitudinal direction D2 Lateral direction F Front region HF Hip hold flap M Middle region (perineum facing region)
B Buttock opposing area B1 Front buttock opposing area (gluteal cleft opposing area)
B2 Rear buttock facing area WF Wing flap

Claims (4)

an elongated main body including a top sheet on the skin side, a back sheet on the non-skin side opposite to the skin side, and an absorbent body disposed between the top sheet and the back sheet;
At least the top sheet and the absorbent body have compressed grooves recessed from the top sheet side to the back sheet side,
the compression grooves include a central compression groove formed in an area facing the wearer's bodily fluid outlet and an area facing the perineum when the device is worn, a first rear compression groove formed in an area facing the wearer's buttocks, and a second rear compression groove formed rearward of the first rear compression groove and spaced apart from the first rear compression groove,
the first rear compression groove has a first arc-shaped portion that is convex rearward, a second arc-shaped portion that is located left forward of the first arc-shaped portion and is convex left rearward, and a third arc-shaped portion that is located right forward of the first arc-shaped portion and is convex right rearward,
The second rear compression groove has a rearward convex shape,
An absorbent article , wherein the apex of the first arc-shaped portion of the first rear compressed groove and the front end of the second rear compressed groove are spaced apart in the longitudinal direction . The absorbent article according to claim 1 , wherein the connecting portion between the first arc-shaped portion and the second arc-shaped portion and the connecting portion between the first arc-shaped portion and the third arc-shaped portion each include a point where the slope of the tangent changes discontinuously. The absorbent article according to claim 1 , wherein the first arc-shaped portion has a pair of extensions extending the arc of the first arc-shaped portion forward. The absorbent article of claim 3, wherein each of the pair of extensions is inclined so as to approach the horizontal center as it extends forward, and an imaginary line drawn along each of the pair of extensions passes through the front end of the second rear compression groove.