Absorbent articles

Abstract

To provide an absorbent article that offers an improved fit to the buttocks and prevents any leakage along the same.SOLUTION: An absorbent article has an elongated body comprising a skin-side top sheet, a non-skin-side back sheet on a side opposite from the skin side, and an absorber that is disposed between the top sheet and the back sheet. The absorbent article has, on a centerline extending along a longitudinal direction of the body in an intergluteal cleft-facing region that faces the gluteal cleft of a wearer when worn, a low weight portion which is elongated in the longitudinal direction and at which pulp weight of the absorber is lower than the pulp weight of at least the sides and rear side of the low weight portion. A width of the low weight portion is 5-25% of a width of the absorber. Compressed grooves that are recessed from the top sheet side to the back sheet side are formed at least in the top sheet and the absorber. The compressed grooves include a protrusion-shaped rear compressed groove that protrudes rearward and surrounds a rear end of the low weight portion.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to absorbent articles.

Background Art

[0002] As absorbent articles such as sanitary napkins, products that are for long hours or for nighttime use and have a long rear part so that the main body faces up to the buttocks are known. In such absorbent articles, various configurations have been studied to prevent leakage of body fluids by enhancing the fit to the buttocks in the rear region. For example, Patent Document 1 describes an absorbent article in which a front-rear slit extending in the front-rear direction and penetrating in the thickness direction of the absorbent core, and an auxiliary slit extending outward in the width direction from the front-rear slit are formed in the absorbent core in the rear side region.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the conventional configuration, depending on the way the wearer wears it, movements during wearing, etc., the main body may not be able to fit sufficiently to the body part along the natal cleft. Therefore, there is still a concern that body fluids may leak along the natal cleft to the rear or the rear side of the natal cleft. Thus, it is required to improve the fit to the buttocks, particularly over the area where the depth of the natal cleft changes, and prevent so-called run-off leakage.

[0005] Therefore, an aspect of the present invention is to provide an absorbent article having high fit to the buttocks and capable of preventing the occurrence of run-off leakage.

Means for Solving the Problems

[0006] A first aspect of the present invention provides a slender body comprising a skin-facing top sheet, a non-skin-facing back sheet opposite to the skin-facing side, and an absorbent disposed between the top sheet and the back sheet, wherein in the gluteal cleft-facing region that faces the gluteal cleft of the wearer when worn, the body has a longitudinally slender low-weight portion on a center line extending along the longitudinal direction of the body, the pulp basis weight of the absorbent is lower than at least the lateral and rear pulp basis weight, the width of the low-weight portion is 5 to 25% of the width of the absorbent, and at least the top sheet and the absorbent have compression grooves formed in them that are recessed from the top sheet side to the back sheet side, and the compression grooves include a rearward convex rearward compression groove that surrounds the rear end of the low-weight portion.

[0007] According to the first embodiment described above, the low-profile portion formed in the gluteal cleft-facing region is more easily bent than its laterally outer portion. Therefore, when force is applied from the laterally outer side, the laterally central part of the gluteal cleft-facing region easily bulges towards the top sheet, forming a peak. Furthermore, since the low-profile portion has a relatively narrow and elongated shape, the resulting peak is sized to easily fit into the gluteal cleft. The low-profile portion is also flexible against bending in the longitudinal direction, making it easy to conform to the shape of the gluteal cleft and preventing bodily fluids from leaking down the cleft, so-called run-through leakage. Moreover, since the low-profile portion is where the absorbent material is located, any bodily fluids received in the low-profile portion can be immediately absorbed. Therefore, this configuration is more effective in preventing leakage than configurations that promote deformation of the main body by providing slits or through grooves.

[0008] Furthermore, the low-weight portion is the part with a lower pulp basis than the rear portion; in other words, the low-weight portion is the part of the absorbent that has its rear end in the middle. Therefore, the longitudinal ridge formed by the protrusion of the low-weight portion, as described above, is prevented from extending further to the rear. As a result, the portion behind the low-weight portion can be more easily fitted to the posterior part of the gluteal cleft where the gluteal cleft is shallower, or to the part behind the end of the gluteal cleft.

[0009] Furthermore, in this embodiment, a rear compression groove is formed so as to surround the rear end of the low-profile section. This rear compression groove enhances the effect of suppressing the continuity of the aforementioned peak formed by the low-profile section to the rear of the low-profile section. In addition, since the compression groove has the effect of drawing in and retaining bodily fluids, the rear compression groove can prevent leakage to the rear, further rearward, or diagonally rearward.

[0010] In a second aspect of the present invention, the rear end of the low-profile portion is in contact with or overlaps with the rear compression groove in a plan view.

[0011] According to a second aspect of the present invention, bodily fluids that have diffused backward within the low-profile section are more easily drawn into the rear compression groove. Bodily fluids drawn into the rear compression groove are more easily guided in the direction of extension of the rear compression groove, that is, they are more easily guided in the direction from the side and further forward. Therefore, this aspect improves the effect of preventing the migration of bodily fluids backward.

[0012] In a third aspect of the present invention, the compression groove further includes a pair of laterally spaced central compression grooves formed longitudinally in front of the rear compression groove, wherein the low-profile portion extends at least from a position between the rear ends of the pair of central compression grooves to a position between the front ends of the rear compression groove.

[0013] According to the third embodiment described above, the pair of central compression grooves promote deformation of the region anterior to the gluteal cleft opposing region, that is, the region opposite the perineum or an even more anterior fluid drainage opening, and also guide fluid in the longitudinal direction. Furthermore, since the low-density section is formed in a region where the compression grooves are discontinuous due to the separation between the pair of posterior compression grooves, flexibility of the low-density section and its surrounding region is ensured. As a result, the above-mentioned effect of the low-density section deforming to form a raised mound towards the top sheet and being able to be flexibly curved in the longitudinal direction is enhanced. In addition, since the ends (rear ends) of the pair of central compression grooves are located near the front end of the low-density section, and the ends (front ends) of the posterior compression grooves are located near the rear end of the low-density section, the bulging of the low-density section starting from the ends of the four compression grooves is facilitated.

[0014] In the fourth aspect of the present invention, the rear squeezing groove includes a horseshoe-shaped squeezing groove surrounding the rear end portion of the low basis weight portion, and a pair of side squeezing grooves branching from the horseshoe-shaped squeezing groove to the lateral outside and extending along the longitudinal direction, and the front ends of the pair of side squeezing grooves are located in front of the center in the longitudinal direction of the low basis weight portion.

[0015] According to the above fourth aspect, a region spreading to the side of at least the latter half of the low basis weight portion is surrounded by the side squeezing grooves. Therefore, body fluid diffusing obliquely rearward from the low basis weight portion is blocked by the side squeezing grooves, and the effect of preventing leakage can be enhanced.

Advantages of the Invention

[0016] According to one aspect of the present invention, it is possible to provide an absorbent article having high fit to the buttocks and capable of preventing the occurrence of side leakage.

Brief Description of the Drawings

[0017] [Figure 1] It is a plan view of an absorbent article according to one embodiment of the present invention as viewed from the topsheet side. [Figure 2] It is a cross-sectional view taken along line I-I of FIG. 1. [Figure 3] It is a cross-sectional view taken along line II-II of FIG. 1. [Figure 4] It is a plan view of the absorbent article of FIG. 1 with the absorbent body exposed. [Figure 5] It is a diagram for explaining the function of the rear low basis weight portion. [Figure 6] It is a partially enlarged view of FIG. 1.

Embodiments for Carrying Out the Invention

[0018] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each drawing, unless otherwise specified, the same or corresponding components may be denoted by the same reference numerals and the description thereof may be omitted.

[0019] <Basic Structure of Absorbent Article> First, regarding the basic structure of the absorbent article, a night-time or long-term use sanitary napkin will be used as an example for explanation. In FIG. 1, a plan view of the absorbent article 1 is shown. Also, in FIG. 2, a cross-sectional view taken along line I-I of FIG. 1 is shown, and in FIG. 3, a cross-sectional view taken along line II-II of FIG. 1 is shown.

[0020] As shown in FIGS. 1 to 3, the absorbent article 1 includes a liquid-permeable topsheet 3 disposed on the side facing the wearer's skin during wearing, that is, the skin side, and an impermeable backsheet 2 disposed on the non-skin side (underside) opposite to the skin side. Further, an absorber (absorbent core) 4 is disposed between the backsheet 2 and the topsheet 3. These backsheet 2, absorber 4, and topsheet 3 are laminated to form a main body (absorbent article main body) 8. The absorber 4 is disposed so as not to protrude from the backsheet 2 and the topsheet 3 in plan view. And at both end edges in the longitudinal direction D1, the edge of the backsheet 2 and the edge of the topsheet 3 may be joined by an adhesive, heat seal, or the like.

[0021] The absorbent article 1 is, as shown in the drawing, in the form of an elongated pad (a shape with a small thickness compared to the width and length). In this specification, the longitudinal direction (front-back direction) of the absorbent article 1 is D1, and the lateral direction (left-right direction or width direction) orthogonal to the longitudinal direction D1 is D2. The longitudinal direction D1 is the direction corresponding to the front-back direction of the wearer's body when the absorbent article 1 is worn, and the lateral direction D2 is the direction corresponding to the left-right direction of the body.

[0022] In the form shown in FIGS. 1 to 3, the main body 8 has a plan view shape that is substantially line-symmetric with respect to the 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-symmetric. Also, the configurations other than the shapes of the absorbent article 1 and the main body 8 (including the thickness and density of the absorber 4, the size and position of the squeezing grooves, the shape and size of the flaps extending outward in the lateral direction D2 from the main body 8, etc.) may be substantially symmetric or asymmetric with the center line CL as the axis of symmetry.

[0023] The backsheet 2 may be a sheet that is at least water-impermeable, for example, a sheet made of an olefin resin such as polyethylene or polypropylene. Alternatively, a laminated nonwoven fabric obtained by laminating a nonwoven fabric onto a polyethylene sheet, or even a laminated nonwoven fabric sheet with a waterproof film interposed to ensure substantially liquid impermeability can be used. Furthermore, it is even more desirable to use a material that is breathable from the viewpoint of preventing stuffiness. As such a water-impermeable and breathable sheet material, a microporous sheet obtained by melt-kneading an inorganic filler into an olefin resin such as polyethylene or polypropylene, forming a sheet, and then stretching it in a uniaxial or biaxial direction can be used. The backsheet 2 may be a sheet having the same external shape as the absorbent article 1.

[0024] The top sheet 3 can be a permeable sheet that allows bodily fluids such as menstrual blood, vaginal discharge, and urine to pass through quickly. Suitable materials for the top sheet 3 include perforated or non-perforated nonwoven fabrics and porous plastic sheets. As material fibers constituting the nonwoven fabric, for example, olefins such as polyethylene and polypropylene, synthetic fibers such as polyester and polyamide, regenerated fibers such as rayon and cupro, and blends thereof, as well as natural fibers such as cotton, can be used individually or in combination of two or more. Processing methods for the nonwoven fabric include the spunlace method, spunbond method, thermal bond method, meltblown method, and needle punch method. Of these processing methods, the spunlace method is preferred for producing flexible nonwoven fabrics, the spunbond method for producing nonwoven fabrics with good drape, and the thermal bond method for producing bulky and soft nonwoven fabrics. Furthermore, composite fibers such as core-sheath type fibers, side-by-side type fibers, and split type fibers, with a high melting point fiber as the core and a low melting point fiber as the sheath, can also be used.

[0025] The absorbent material 4 is not limited to any material that can absorb and retain bodily fluids, but it is preferable to include cotton-like pulp and a superabsorbent polymer. As the superabsorbent polymer, superabsorbent polymer granules (SAP), superabsorbent polymer fibers (SAF), and combinations thereof can be used. As the pulp, examples include cellulose fibers such as chemical pulp and dissolved pulp obtained from wood, and artificial cellulose fibers such as rayon and acetate. As the raw material for chemical pulp, hardwoods and softwoods can be used, but softwoods are preferably used due to their long fiber length.

[0026] The absorbent material 4 may be mixed with synthetic fibers. Suitable synthetic fibers include polyolefins such as polyethylene and polypropylene, polyesters such as polyethylene terephthalate and polybutylene terephthalate, polyamides such as nylon, and copolymers thereof. Two of these can also be mixed and used. Furthermore, 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 split fibers can also be used. Additionally, hydrophobic fibers can be surface-treated with a hydrophilizing agent to impart affinity to bodily fluids. The absorbent material 4 is preferably manufactured by a fiber stacking or airlaid method.

[0027] The absorbent material 4 may have multiple absorbent compression sections that are partially recessed from the top sheet 3 side to the back sheet 2 side, spaced apart from each other in a plan view (details will be described later). In addition, the absorbent material 4 may be wrapped in a covering sheet made of colored or uncolored (white) crepe paper, nonwoven fabric, etc., to prevent twisting, cracking, or spillage of polymer particles.

[0028] On both sides of the absorbent article 1, i.e., the sides in the transverse direction D2, side sheets 7, 7 are arranged on the skin side, along the longitudinal direction D1. The side sheets 7 may be made of a material that has been treated with an appropriate water-repellent or hydrophilic treatment, either entirely or partially, for purposes such as preventing the penetration of bodily fluids or improving the feel against the skin. The side sheets 7 are preferably nonwoven fabrics containing natural fibers, synthetic fibers, regenerated fibers, etc., or made of these fibers. If 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 from the viewpoint of improving the feel against the skin because they are less prone to creasing and wrinkles and are soft. The side sheets 7 may also be treated with water-repellent agents such as silicone-based or paraffin-based water-repellent agents.

[0029] The side sheet 7 may be folded inward in the lateral direction D2, forming multiple layers of strip-like material that extend along the side of the main body 8. Gathers may be formed between the multiple layers by arranging elastic stretchable members in an extended state along the longitudinal direction D1. In this specification, the folding and gathering configuration of the side sheet 7 will not be described or shown in the drawings.

[0030] The absorbent article 1 may have a fluid drainage port facing region C that faces the wearer's fluid drainage port (vaginal opening in the illustrated example) when worn, a front region F adjacent to the front of the fluid drainage port facing region C and extending to the front end of the absorbent article 1, a perineal facing region (intermediate region) M adjacent to the rear of the fluid drainage port facing region C and facing the wearer's perineum when worn, and a buttock facing region B adjacent to the rear of the perineal facing region M and extending to the rear end of the absorbent article 1, which faces the wearer's buttocks when worn. Furthermore, the buttock facing region B includes a front buttock facing region B1 adjacent to the perineal facing region M and a rear buttock facing region B2 adjacent to the rear of the front buttock facing region B1. The front buttock facing region B1 is a region that mainly faces the gluteal cleft (groove of the buttocks) and faces the area including the anus. The posterior gluteal opposition region B2 may be an area that can oppose the posterior part of the gluteal cleft or the area further posterior to the posterior end of the gluteal cleft, particularly the area posterior to (above in an upright position) the gluteal groove, which can be considered the boundary between the buttocks and the legs. The above description of the opposition relationship between the region of the main body 8 and the wearer's body can be an approximate range when the wearer applies the absorbent material in the usual way while lying down, but this is only a guideline.

[0031] The longitudinal length D1 of the region C facing the bodily fluid drainage vent may be 50 to 120 mm, and the longitudinal length D1 of the region B facing the buttocks may be 90 to 230 mm. Furthermore, this configuration is suitable for absorbent articles where the total length of the perineal region M and the region B facing the buttocks, preferably the longitudinal length D1 of the region B facing the buttocks, is greater than the longitudinal length D1 of the region where the wing flap WF is provided, and the rear is longer. Furthermore, the longitudinal length D1 of the anterior buttock region (gluteal cleft region) B1 may be 40 to 100 mm, and the longitudinal length D1 of the posterior buttock region B2 may be 40 to 120 mm. Furthermore, the total length of the absorbent article 1 in the longitudinal direction D1 may be 250 to 450 mm.

[0032] The absorbent article 1 may be provided with a pair of wing flaps WF, WF extending laterally D2 outward from both sides of the area C facing the body fluid drainage port. The non-skin side of the wing flaps WF, WF may be provided with a slip-preventing material (not shown), which allows the wing flaps WF, WF to be folded back to the non-skin side and attached to the underwear when worn, so that the underwear is sandwiched between the wing flaps WF, WF and the main body 8. This ensures that the absorbent article 1 is securely fixed to the underwear. The wing flaps WF, WF are formed by joining the laterally D2 outward extending portions of the side sheets 7, 7 and the laterally D2 outward extending portion of the back sheet 2.

[0033] Furthermore, a pair of hip-hold flaps HF, HF may be formed extending laterally D2 outward from the side of the main body 8, from the perineal opposing region M to the buttock opposing region B. The hip-hold flaps HF, HF prevent leakage of bodily fluids from the rear of the absorbent article 1 and, by increasing the contact area with the buttocks, make it less likely for the entire absorbent article 1 to shift relative to the underwear, especially 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 laterally D2 outward extending portions of the side sheets 7, 7 and the laterally D2 outward extending portion of the back sheet 2.

[0034] <Specific composition of the absorbent body> Figure 4 shows a plan view of the absorbent article 1 from Figure 1 with the top sheet 3 and side sheets 7, 7 removed, exposing the absorbent body 4. In this embodiment, as shown in Figure 4, the basis weight of the absorbent body 4, specifically the pulp basis weight, is not uniform throughout but varies depending on the location. For example, the absorbent body 4 mainly has a medium basis weight section 4M with a moderate pulp basis weight, a high basis weight section 4H with a higher pulp basis weight than the medium basis weight section 4M, and a low basis weight section 4L with a lower pulp basis weight than the medium basis weight section 4M. Furthermore, the low basis weight section 4L is located in the perineal opposing region M and has an anterior low basis weight section 4Lf with the same width as the absorbent body 4, and a narrow posterior low basis weight section 4Lb located in the center of the lateral direction D2 of the gluteal cleft opposing region B1. It is preferable that the anterior low basis weight section 4Lf and the posterior low basis weight section 4Lb are formed continuously.

[0035] Furthermore, the high-weight section 4H, the medium-weight section 4M, and the low-weight section 4L may be uniform weight regions within each section where the weight is substantially uniform. "Substantially uniform weight within a predetermined section or region" means that even if there are areas with slightly different weights, the difference from the average weight within that predetermined section or region is 20% or less, preferably 10% or less, and more preferably 5% or less. The front low-weight section 4Lf and the rear low-weight section 4Lb may have different weights, and each may have a substantially uniform weight. In that case, the weight of the rear low-weight section 4Lb may be slightly smaller than that of the front low-weight section 4Lf.

[0036] Furthermore, as mentioned above, the absorbent material 4 contains pulp and a superabsorbent polymer, and it is preferable that the basis weight of the superabsorbent polymer be roughly the same throughout the entire absorbent material 4. In that case, the relative basis weights of the pulp are reflected in the relative basis weights of the polymer.

[0037] The posterior low-profile portion 4Lb formed in the gluteal cleft opposing region B1 will be further explained with reference to Figure 5. Figure 5 is a schematic diagram of the cross-section of the absorbent article 1 according to this embodiment (corresponding to the line II cross-section in Figure 1), along with the wearer's buttocks Den. In Figure 5, the specific components such as the sheet included in the absorbent article 1 are not shown.

[0038] The aforementioned posterior low-profile portion 4Lb is more flexible and has lower rigidity against bending compared to its lateral portion, i.e., the middle-profile portion 4M on the outside in the lateral direction D2. Therefore, when the gluteal cleft opposing region B1 is subjected to force from the outside in the lateral direction D2 (arrows from both sides in the lateral direction D2 in Figure 5), for example, due to the influence of force from both legs, or when the wearer deforms the main body themselves, the posterior low-profile portion 4Lb can easily bulge towards the skin, forming a mound Mt (Figure 5(a)). Furthermore, the posterior low-profile portion 4Lb has an elongated shape along the longitudinal direction D1, and its lateral length D2 (width of the posterior low-profile portion 4Lb) is 5-25% of the lateral length D2 of the absorbent body 4 (width of the absorbent body 4). Thus, such a narrow posterior low-profile portion 4Lb is sized to easily penetrate the gluteal cleft. Therefore, when the main body is deformed to fit into the gluteal cleft during application, it can be made to adhere closely to the deeper parts of the gluteal cleft (Figure 5(b)). In order to improve the fit with the buttocks, it is conceivable to increase the adhesion with the sides of the gluteal cleft without making the gluteal cleft opposing region B1 too raised, but if there is a gap between the gluteal cleft opposing region B1 and the gluteal cleft, depending on how the wearer applies the product and the wearer's movements, bodily fluids may leak backward or diagonally backward along the gluteal cleft, a phenomenon known as "runaway leakage." In contrast, in this embodiment, the posterior low-profile portion 4Lb can be made to adhere closely to the gluteal cleft. Furthermore, unlike a slit, the posterior low-profile portion 4Lb is the part where the absorbent material is located, so it can immediately absorb bodily fluids. Therefore, runaway leakage can be effectively prevented. In recent years, wearers of nighttime or long-term absorbent products often deform the absorbent product themselves so that the main body adheres deeply to the inside of the gluteal cleft when applying it. The absorbent article 1 in this form is preferably used in such a manner.

[0039] As shown in Figure 4, the rear low-profile portion 4Lb is surrounded on both sides and rear by the middle-profile portion 4M. Thus, the longitudinal extension D1 of the rear low-profile portion 4Lb extends to just in front of the rear end of the absorber 4, and preferably it may be the same longitudinal D1 range as the gluteal cleft opposing region B1. Therefore, it is possible to suppress the formation of a ridge Mt (Figure 5) by the rear low-profile portion 4Lb when worn, from extending far to the rear. Thus, it becomes possible to adapt the main body to the shape of the area where the gluteal cleft is shallow at the rear of the buttocks, or near the end of the gluteal cleft or even further rearward. In this way, the fit from the gluteal cleft to near the end of the gluteal cleft or further rearward can be improved.

[0040] The width (lateral length D2) x of the posterior low-profile portion 4Lb (Figure 4) is preferably 5 to 30 mm, more preferably 10 to 20 mm. Having this width x makes it easier to deform and form the peak Mt, and also allows the peak Mt to be adjusted to a size that fits into the gluteal cleft. The length (longitudinal length D1) y of the posterior low-profile portion 4Lb (Figure 4) is preferably 40 to 80 mm, more preferably 50 to 70 mm. Having this length y provides a length of peak Mt that allows for the absorption of bodily fluids in the gluteal cleft, and prevents the peak Mt from losing its ability to adhere to the gluteal cleft in shallow positions as it extends posteriorly.

[0041] Furthermore, the ratio (y / x) of the length y of the rear low-profile section 4Lb to its width x may be between 2 and 8. This ratio allows for the size of the rear low-profile section 4Lb to obtain a peak shape suitable for tight contact with the gluteal cleft.

[0042] The basis weight of at least the rear low basis weight portion 4Lb is preferably 200 to 500 gsm, more preferably 300 to 400 gsm. The basis weight of the intermediate basis weight portion 4M adjacent to the side and rear of the rear low basis weight portion 4Lb is preferably 300 to 600 gsm, more preferably 400 to 500 gsm. From the viewpoint of improving the above-mentioned effect of the rear low basis weight portion 4Lb, the basis weight of the rear low basis weight portion 4Lb may be 60 to 90% of the basis weight of the intermediate basis weight portion 4M.

[0043] <Compression groove> As shown in Figures 1 to 3, the main body 8 of the absorbent article 1 in this embodiment may have compression grooves (also called fit embossing) formed by compressing at least the top sheet 3 and the absorbent 4 from the top sheet 3 side. Since the compression grooves have the function of drawing in and retaining bodily fluids, they can contribute to preventing the diffusion of bodily fluids or guiding them. In the illustrated example, the compression grooves may include multiple compression grooves (indicated by reference numerals 10, 11, 12, and 13). The compression grooves may be formed symmetrically with respect to the longitudinal center line CL of the absorbent article 1 in a plan view, but are not necessarily symmetrical. The compression grooves can be formed, for example, by passing a laminate, which consists of at least the top sheet 3 and the absorbent 4, between a pair of pressure rolls. In this case, the laminate can be pressurized by sandwiching it between the two rolls, with a convex roll positioned on the top sheet 3 side and a flat roll on the absorbent 4 side. The compression groove may include a low-pressure section and a high-pressure section where the material is compressed at a higher pressure within the low-pressure section. In the drawings, the high-pressure section is shown in black.

[0044] In the configuration shown in Figure 1, a pair of central compression grooves 10, 10 extend along the longitudinal direction D1, mainly from the region C facing the fluid drainage port to the region M facing the perineum. The pair of central compression grooves 10, 10 are formed on both sides of the longitudinal centerline CL, spaced apart from each other. The pair of central compression grooves 10, 10 are positioned so as not to overlap with the high-profile portion 4H. The lateral separation distance D2 between the pair of central compression grooves 10, 10 may be constant or may vary. For example, as shown in Figure 1, it may become smaller near the boundary between the region C facing the fluid drainage port and the region M facing the perineum, become larger again behind it, and become smaller towards the rear end.

[0045] Behind the pair of central compression grooves 10, 10, a first rear compression groove (rear compression groove) 11 is formed, spaced apart from the pair of central compression grooves 10, 10. The first rear compression groove 11 is formed in the gluteal region B, mainly in the gluteal cleft region B1. The first rear compression groove 11 is formed straddling the longitudinal centerline CL and has a shape that is convex to the rear overall. More specifically, the first rear compression groove 11 includes a horseshoe-shaped compression groove 11h that overlaps the longitudinal centerline CL (or a U-shape with the ends brought close together). The first rear compression groove 11 may further include lateral compression grooves 11s, 11s that branch off from the side of the horseshoe-shaped compression groove 11h and extend forward.

[0046] Behind the first rear compression groove 11, a second rear compression groove (second compression groove) 12 is formed, spaced apart from the first rear compression groove 11. The second rear compression groove 12 is a groove that extends along the lateral direction D2 and has a shape that is convex to the rear. In addition, a front compression groove 13 is formed in front of the pair of central compression grooves 10, 10. In the example shown in Figure 1, the front compression groove 13 has a closed shape formed by combining compression grooves that are curved forward and convex with different radii of curvature.

[0047] Figure 6 shows an enlarged view of the region in Figure 1 where the posterior low-profile portion 4Lb is located on the absorbent 4, and the vicinity thereof. As shown in Figure 6, the first posterior compression groove 11, more specifically the horseshoe-shaped compression groove 11h, is formed to surround the posterior end of the aforementioned posterior low-profile portion (elongated low-profile portion) 4Lb. As described above, when the posterior low-profile portion 4Lb is subjected to force from the outside in the lateral direction D2 during installation, it bulges towards the top sheet 3 and deforms to form a peak Mt (Figure 5). This peak Mt can be interrupted by the first posterior compression groove 11 extending in the lateral direction D2, so that the peak Mt does not extend excessively far posteriorly can be further suppressed. Furthermore, the region posterior to the first posterior compression groove 11 can be aligned with the shallow part of the gluteal cleft or the part without a gluteal cleft, so that leakage of body fluids posteriorly or obliquely posteriorly can be prevented.

[0048] Furthermore, bodily fluids that have migrated from the rear low-profile section 4Lb to the rear and diagonally rearward are blocked by the first rear compression groove 11, and this blocking action also improves the leakage prevention effect. In addition, as described above, bodily fluids that have diffused from the rear low-profile section 4Lb to the lateral medium-profile section 4M are also blocked by the lateral compression grooves 11s, 11s that branch off from the horseshoe-shaped compression groove 11h and extend almost along the longitudinal direction D1. Therefore, even if a large amount of bodily fluid migrates to the rear low-profile section 4Lb, leakage to the diagonally rearward can be prevented. From the viewpoint of improving such a blocking effect, it is preferable that the front ends 11st, 11st of the lateral compression grooves 11s, 11s are located forward of the center of the longitudinal direction D1 of the rear low-profile portion 4Lb, and may be located at a position of 30% or less, preferably 25% or less, of the longitudinal direction D1 length y of the rear low-profile portion 4Lb from the front end of the rear low-profile portion 4Lb.

[0049] Furthermore, when comparing the density (pulp density) of the rear low-weight portion 4Lb with the density (pulp density) of the medium-weight portion 4M located to the side of the rear low-weight portion 4Lb and surrounded by the lateral compression groove 11s, it is preferable that the density of the rear low-weight portion 4Lb is lower. In other words, it is preferable that the rear low-weight portion 4Lb has a smaller pulp basis and lower pulp density compared to its lateral and rear portions. This further promotes the transfer of bodily fluids from the rear low-weight portion 4Lb to the medium-weight portion 4M to its side (Figure 6). The pulp density in the rear low-weight portion 4Lb is preferably, on average, 0.035 to 0.1 g / cm³. 3 , more preferably 0.05~0.08 g / cm³ 3 It may be so. Furthermore, the pulp density in the region surrounded by the lateral compression grooves 11s on the side of the rear low basis portion 4Lb (part of the medium basis portion 4M) is preferably 0.055 to 0.15 g / cm³ on average. 3 More preferably 0.07 to 0.12 g / cm³ 3 That's fine.

[0050] As described above, the distribution of pulp density in the gluteal cleft opposing region B1 makes the absorption and diffusion of body fluids even smoother. As shown in Figure 6, body fluids directly absorbed in the posterior low-density portion 4Lb, or diffused through the absorbent material 4 from the body fluid outlet opposing region C and the perineal opposing region M, move further posteriorly within the posterior low-density portion 4Lb along the longitudinal centerline CL (Figure 6). Here, diffusion from the posterior low-density portion 4Lb, which has a relatively low pulp density, to the intermediate-density portion 4M, which is located laterally and has a relatively high pulp density, can also be promoted (Figure 6). Therefore, the sides of the absorbent material 4 in the gluteal cleft opposing region B1 can be utilized, and the amount of body fluid moving posteriorly can be reduced.

[0051] Preferably, the rear low-profile portion 4Lb extends at least in the longitudinal direction D1 from the position of the rear ends 10bt, 10bt of the pair of central compression grooves 10, 10 to the position of the front ends 11ft, 11ft of the horseshoe-shaped compression groove 11h of the first rear compression groove 11. Furthermore, it is preferable that the side portion (outer edge in the lateral direction D2) of the rear low-profile portion 4Lb is in contact with or slightly overlapping the rear ends 10bt, 10bt of the pair of central compression grooves 10, 10 (Figure 6). This allows the rear ends 10bt, 10bt of the pair of central compression grooves 10, 10 to act as a base point for the bulge in front of the rear low-profile portion 4Lb when the rear low-profile portion 4Lb deforms to bulge towards the top sheet 3 during installation (Figure 5). Furthermore, it is preferable that the side portion (outer edge in the lateral direction D2) of the rear low-profile portion 4Lb is in contact with or slightly overlaps with the front ends 11ft, 11ft of the horseshoe-shaped compression groove 11h of the first rear compression groove 11 (Figures 3 and 6). This allows the front ends 11ft, 11ft of the horseshoe-shaped compression groove 11h of the first rear compression groove 11 to serve as a base point for the rise behind the rear low-profile portion 4Lb when it is installed (Figure 5). Therefore, from the viewpoint of forming the base point for the rise of the rear low-profile portion 4Lb behind the rear, it is preferable that the front ends 11ft, 11ft of the horseshoe-shaped compression groove 11h of the first rear compression groove 11 are located behind the center of the longitudinal direction D1 of the rear low-profile portion 4Lb. Furthermore, if the rear low-profile section 4Lb slightly overlaps with the central compression grooves 10, 10 or the first rear compression groove 11, it is preferable that it does not overlap with the high-pressure compression section (black) from the viewpoint of not hindering the rise of the rear low-profile section 4Lb.

[0052] To put the above positional relationship between the rear low-profile section 4Lb and the pair of central compression grooves 10, 10 in other words, the length x of the lateral D2 of the rear low-profile section 4Lb and the distance d between the rear ends 10bt, 10bt of the pair of central compression grooves 10, 10 are as follows: 10 It is preferable that these two values ​​are approximately equal. Furthermore, regarding the positional relationship between the rear low-profile section 4Lb and the horseshoe-shaped compression groove 11h of the first rear compression groove 11, the length x of the lateral D2 of the rear low-profile section 4Lb and the distance d between the front ends 11ft, 11ft of the horseshoe-shaped compression groove 11h of the first rear compression groove 11 are preferable. 11It is preferable that these two values ​​are approximately equal. Here, "approximately equal" means that if there is a difference between the two, that difference is 10% or less, preferably 5% or less, relative to the larger of the two values.

[0053] The rear end of the rear low-profile section 4Lb may be separated from the first rear compression groove 11 in a plan view, but it is preferable that it is in contact with the first rear compression groove 11 or overlaps with it as shown in Figure 6. Furthermore, it is preferable that it extends to the rear end of the first rear compression groove 11, i.e., to the apex of the horseshoe-shaped compression groove 11h, and is in contact with or overlaps with the horseshoe-shaped compression groove 11h at the position of the apex of the horseshoe-shaped compression groove 11h. This makes it easier for bodily fluids that have diffused rearward within the rear low-profile section 4Lb to be drawn into the first rear compression groove 11. The bodily fluids drawn into the first rear compression groove 11 can then be guided first in the direction of extension of the horseshoe-shaped compression groove 11h, i.e., outward in the lateral direction D2, and further forward. In addition, a portion of the bodily fluids can also be guided forward along the lateral compression grooves 11s, 11s. Thus, the effect of preventing leakage to the rear is enhanced.

[0054] Furthermore, when the buttock-facing region B is curved along the buttocks during attachment, the main body 8 can be bent along the first rear compression groove 11, enabling a three-dimensional curve that conforms to the curvature of the buttocks. In addition, the branching positions of the lateral compression grooves 11s, 11s (Figure 6) become recessed portions 11r, 11r that are indented forward when viewed from the rear. Therefore, when the buttock-facing region B is curved, these recessed portions 11r, 11r also serve as bending points, allowing for the formation of a smoother curve.

[0055] Although the present invention has been described above based on embodiments, the present invention is not limited to these embodiments. Furthermore, the above embodiments can be modified, altered, replaced, added, deleted, and combined in various ways within the scope of the claims, and these also fall within the technical scope of the present invention. [Explanation of symbols]

[0056] 1. Absorbent items (sanitary napkins) 2 back seats 3 Top Sheet 4 Absorbent 4H absorbent material with high basis weight 4L absorbent material low basis part 4Lf Front low-profile section 4Lb Rear low-profile section (slender low-profile section) 4M absorbent core, medium weight portion 7 Side Seats 8. Main body (absorbent material body) 10 Central compression groove 10bt Rear end of central compression groove 11. First rear compression groove 11ft Front end of the first rear compression groove 11s Lateral compression groove 11th lateral compression groove front end 11r recessed area 11h Horseshoe-shaped compression groove 12. Second rear compression groove 13 Front compression groove B Area opposite the buttocks B1 Anterior buttock opposing area (gluteal cleft opposing area) B2 Posterior buttock opposing area C Area facing body fluid outlet CL Longitudinal Centerline D1 Longitudinal direction D2 Horizontal F Anterior area HF Hip Hold Flap M Middle area (opposite perineum area) WF Wing Flap

Claims

1. It has an elongated body comprising a top sheet on the skin side, a back sheet on the non-skin side opposite to the skin side, and an absorbent material positioned between the top sheet and the back sheet. In the gluteal cleft-facing region that faces the wearer's gluteal cleft when worn, the main body has a longitudinally elongated rear low-weight portion on the center line extending along its longitudinal direction, where the pulp basis weight of the absorbent material is lower than at least the lateral and rear pulp basis weights. The width of the aforementioned lower rear portion is 5 to 25% of the width of the absorbent body. At least the top sheet and the absorbent body have compression grooves formed therein that are recessed from the top sheet side to the back sheet side, and the compression grooves include a rearward convex rear compression groove that surrounds the rear end of the rear low base portion. The rear compression groove includes a horseshoe-shaped compression groove surrounding the rear end of the low rear portion, and a pair of lateral compression grooves branching laterally outward from the horseshoe-shaped compression groove and extending along the longitudinal direction. An absorbent article wherein the front ends of the pair of lateral compression grooves are located forward of the longitudinal center of the rear low-profile portion, and the distance between the front ends of the pair of lateral compression grooves is wider than the lateral width of the horseshoe-shaped compression groove.

2. A front low-weight portion is provided in front of the rear low-weight portion, and the pulp basis of the absorbent is lower than at least the pulp basis of the lateral and rear pulp basis of the rear low-weight portion, and has the same width as the absorbent, The absorbent article according to claim 1, wherein the lateral compression groove is located to the side of the rear low basis portion and is provided in a medium basis portion where the pulp basis is higher than that of the rear low basis portion.

3. The absorbent article according to claim 1 or 2, wherein the rear end of the rear low-profile portion is in contact with or overlaps with the rear compression groove in a plan view.

4. The compression groove further includes a pair of central compression grooves that are separated laterally from each other and formed longitudinally in front of the rear compression groove, The absorbent article according to claim 1 or 2, wherein the rear low-profile portion extends at least from a position between the rear ends of the pair of central compression grooves to a position between the front ends of the rear compression grooves.

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