absorbent articles

Abstract

To provide an absorbent article capable of sufficiently preventing leak of body fluid even when receiving strong force from both sides in a width direction.SOLUTION: An absorbent article comprises a liquid permeable top sheet disposed at a front side, a liquid impermeable back sheet disposed at a rear side, and an absorber disposed between the top sheet and the back sheet, and has a longitudinal direction and a width direction orthogonal to the longitudinal direction. There is provided a central compression groove recessed from the front side to the rear side, and extending along the longitudinal direction so as to include a longitudinal direction centerline extending along the longitudinal direction. The absorber is formed with a rear groove recessed from the rear side to the front side, and extending along the longitudinal direction separately from the central compression groove in the width direction on each side of the central compression groove in a plane view.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an absorbent article. [Background technology]

[0002] When worn, pad-like absorbent articles such as incontinence pads, sanitary napkins, and pad-type diapers are deformed three-dimensionally to fit the wearer's body. Since it is desirable for the deformed shape to be one that can prevent leakage of bodily fluids, various devices have been devised to promote appropriate deformation, such as structures with compressed grooves.

[0003] For example, Patent Document 1 describes an absorbent article 1 in which a plurality of compressed sections E are formed by compressing both a topsheet 21 and an absorbent core 11 together from the skin side, the compressed sections E having first compressed sections E1 provided along the longitudinal direction in the center in the longitudinal and width directions and second compressed sections E2 provided on the longitudinal end sides, and the absorbent core 11 has annular protrusions 11P surrounding the center that protrude toward the skin. According to the configuration described in Patent Document 1, bodily fluids can be temporarily stored in spaces SP11 surrounded by protrusions 11P. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-226458 Summary of the Invention [Problem to be solved by the invention]

[0005] Generally, when an absorbent article is subjected to a strong force in the width direction from the wearer's legs while being worn, for example, when the wearer tightly closes or crosses their legs, the absorbent article may be deformed so that it sharply protrudes toward the non-skin side (underwear side) at the center in the width direction. In the configuration of the absorbent article described in Patent Document 1, the absorbent article 1 may be folded strongly at the first compressed portion E1 so that it protrudes toward the non-skin side. In this case, a gap may be formed between the protruding portion 11P and the wearer's skin, and bodily fluids may leak through the gap. Therefore, there is a need for a configuration that can prevent bodily fluid leakage even when a strong force is applied from both sides in the width direction by the wearer's legs.

[0006] In view of the above, an object of one aspect of the present invention is to provide an absorbent article that can sufficiently prevent leakage of bodily fluids even when a strong force is applied from both sides in the width direction. [Means for solving the problem]

[0007] A first aspect of the present invention is an absorbent article comprising a liquid-permeable top sheet on the front side, a liquid-impermeable back sheet on the back side, and an absorbent body provided between the top sheet and the back sheet, and having a longitudinal direction and a width direction perpendicular to the longitudinal direction, and comprising a central compressed groove recessed from the front side to the back side, extending along the longitudinal direction so as to include a longitudinal center line extending along the longitudinal direction, and the absorbent body has a back groove recessed from the back side to the front side, formed on each side of the central compressed groove in a planar view, extending along the longitudinal direction and spaced apart from the central compressed groove in the width direction.

[0008] According to the first aspect, the absorbent article has a central compressed groove recessed from the front side, and a back groove recessed from the back side, which extends longitudinally and is spaced apart from the central compressed groove in a plan view. When the absorbent article is subjected to force from both sides in the width direction, the absorbent article bends so that the central compressed groove protrudes toward the back side (non-skin side), and the back grooves located on both sides of the central compressed groove protrude toward the front side (skin side), easily achieving a deformation such that the overall cross section becomes approximately M-shaped. In this deformed state, a depression is formed along the longitudinal direction in the area including the central compressed groove, and both widthwise edges of this depression are formed by convex edges protruding toward the front side at the position of the back groove formed in the absorbent body. This allows both edges of the depression to have a certain degree of rigidity, and the shape of the depression is stably maintained even when the absorbent article is subjected to external force. Furthermore, by forming such a convex edge portion protruding on the front side along the longitudinal direction, the surface of the absorbent article can be more securely adhered to the wearer's skin along the longitudinal direction, preventing leakage to the outside in the width direction.

[0009] In a second aspect of the present invention, the back groove is formed by compressing the absorbent body from the back side.

[0010] According to the second aspect, the compressed back grooves increase the density and rigidity of the absorbent body at the positions where the back grooves are formed, allowing the absorbent body to bend easily. Furthermore, capillary action makes it easier for body fluids to collect and be retained in the back grooves, further preventing leakage of body fluids outward in the width direction.

[0011] In a third aspect of the present invention, the distance in the width direction between the central compressed groove and the back groove is equal to 8 to 23% of the width of the absorbent body.

[0012] According to the third aspect, the back groove is located at an appropriate position from the central compressed groove, so that the absorbent article can be easily deformed into the above-mentioned substantially M-shape and can easily maintain that shape.

[0013] In a fourth aspect of the present invention, auxiliary back grooves shallower than the back groove are formed at least on each outer side of the back groove in the longitudinal direction.

[0014] According to the fourth aspect, the auxiliary back groove allows the absorbent body to deform more flexibly, improving the wearing comfort. Furthermore, if the density around the auxiliary back groove is high, bodily fluids are more likely to collect and be retained in the auxiliary back groove, improving the effect of preventing bodily fluids from leaking outward in the width direction.

[0015] In a fifth aspect of the present invention, the inner contour of the back groove in the width direction has a convex portion that protrudes toward the central compressed groove.

[0016] Body fluid discharged into the portion facing the body fluid discharge outlet migrates along the central compressed groove. According to the fifth aspect, the tips of the convex portions of the back groove are located near the central compressed groove in a plan view, so that body fluid easily migrates from the tips of the convex portions to the back groove outward in the width direction. Therefore, even when a large amount of body fluid is discharged, the body fluid can be quickly transferred into the absorbent body, preventing leakage of the body fluid along the surface of the absorbent article.

[0017] In a sixth aspect of the present invention, the thickness of the absorbent body is gradually or stepwise reduced on the outer side of the back groove in the width direction toward the outer side in the width direction.

[0018] According to the sixth aspect, even when the absorbent article is deformed when worn, it is unlikely to cause discomfort when both ends in the width direction come into contact with the legs.

[0019] In a seventh aspect of the present invention, the device further comprises a pair of oblique compression grooves each connected to one longitudinal end of the central compression groove and extending so that the distance between them increases as they extend outward in the longitudinal direction.

[0020] According to the seventh aspect, a compressed groove having an approximately Y-shape in plan view is formed by the central compressed groove and a pair of diagonal compressed grooves of a predetermined shape, so that the area between the pair of diagonal compressed grooves can be brought into surface contact with the front and / or rear of the wearer's body.

[0021] In an eighth aspect of the present invention, a slippage prevention portion is provided on the rear side of the back sheet, and the slippage prevention portion does not overlap the rear groove in a plan view.

[0022] According to the eighth aspect, even if the slippage prevention portion is provided, the slippage prevention portion does not impair the function of the back groove, and deformation to form the above-mentioned substantially M-shaped cross section is possible. [Effects of the Invention]

[0023] According to one aspect of the present invention, it is possible to provide an absorbent article that can sufficiently prevent leakage of bodily fluids even when a strong force is applied from both sides in the width direction. [Brief explanation of the drawings]

[0024] [Figure 1] 1 is a plan view of an absorbent article according to one embodiment of the present invention, viewed from the skin side. [Figure 2] FIG. 2 is a cross-sectional view taken along line II in FIG. [Figure 3] 3 is a cross-sectional view showing a state in which the absorbent article has been deformed from the state shown in FIG. 2. FIG. [Figure 4] 10 shows a modified example of the absorber. [Figure 5] 10 shows another modified example of the absorbent body. [Figure 6] 10 shows yet another modified example of the absorbent body. [Figure 7] 10 shows yet another modified example of the absorbent body. [Figure 8] 10 shows a modified example of the back groove. [Figure 9] FIG. 9 is a partially enlarged view of FIG. 8. [Figure 10] FIG. 10 is a plan view of an absorbent article according to a modified example, as viewed from the skin side. [Figure 11] FIG. 10 is a plan view of an absorbent article according to another modified example, as viewed from the skin side. DETAILED DESCRIPTION OF THE INVENTION

[0025] 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 will be denoted by the same reference numerals and the description thereof will be omitted.

[0026] One embodiment of the present invention may be a pad-like absorbent article such as an incontinence pad, a sanitary napkin, or a pad-type diaper. The following description will be directed to an incontinence pad. Fig. 1 shows a plan view of the absorbent article 1. Fig. 2 shows a cross-sectional view of the absorbent article 1 taken along line II. As shown in Figs. 1 and 2, the absorbent article 1 is composed of a liquid-permeable top sheet 3, a liquid-impermeable back sheet 2, and an absorbent body 4 disposed between the two sheets. The absorbent article 1 has a generally flat shape overall before being worn ( Fig. 2 ). In this specification, the top sheet 3 side of the absorbent article 1 is referred to as the front side, and the back sheet 2 side is referred to as the back side. When the absorbent article 1 is worn, the front side is the side that comes into contact with the wearer's skin, i.e., the skin side, and the back side is the side where the absorbent article 1 is secured to an undergarment, i.e., the non-skin side (undergarment side). Fig. 1 shows the absorbent article 1 as viewed from the front side.

[0027] <Basic structure of absorbent articles> As shown in FIG. 1, the absorbent article 1 may have an elongated shape in a planar view, i.e., a shape having a predetermined length in a longitudinal direction D1 and a predetermined width in a width direction D2 perpendicular to the longitudinal direction D1. When worn, the longitudinal direction D1 of the absorbent article 1 corresponds to the front-to-back direction of the wearer's body, and the width direction D2 corresponds to the left-to-right direction of the wearer's body. In the embodiment shown in FIG. 1, the absorbent article 1 has a shape that is approximately line-symmetrical with respect to a center line (longitudinal center line) CL extending in the longitudinal direction D1 in a planar view, but the shape does not have to be line-symmetrical. Furthermore, configurations other than the shape of the absorbent article 1 (including the density, material, and groove size of the absorbent body 4) may also be approximately symmetrical or asymmetrical with respect to the center line CL.

[0028] The back sheet 2 may be a sheet that is at least water-proof, such as a sheet made of an olefin resin such as polyethylene or polypropylene. Alternatively, a laminated nonwoven fabric in which a nonwoven fabric is laminated on a polyethylene sheet or the like, or a laminated sheet of nonwoven fabric with a waterproof film interposed therebetween to ensure substantial liquid impermeability, may be used. Furthermore, it is more desirable to use a material that is moisture-permeable in order to prevent stuffiness. Examples of such water-proof and moisture-permeable sheet materials include microporous sheets obtained by melt-kneading an inorganic filler in an olefin resin such as polyethylene or polypropylene to form a sheet, and then stretching the sheet in a uniaxial or biaxial direction.

[0029] The top sheet 3 can be a sheet that is permeable to bodily fluids such as urine, menstrual blood, and vaginal discharge. Suitable top sheet 3 materials include perforated or non-perforated nonwoven fabrics and porous plastic sheets. Examples of material fibers constituting the nonwoven fabric include 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. Examples of processing methods for nonwoven fabrics include spunlace, spunbond, thermal bond, meltblown, and needlepunch. Of these processing methods, the spunlace method is preferred because it provides flexibility, the spunbond method is preferred because it can produce nonwoven fabrics with excellent drapeability, and the thermal bond method 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.

[0030] The absorbent body 4 is not limited to any material that can absorb and retain body fluids, but preferably contains cotton-like pulp and a water-absorbent polymer. Examples of water-absorbent polymers that can be used include superabsorbent polymer (SAP), superabsorbent fiber (SAF), and combinations of these. Pulp includes 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.

[0031] 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 thereof. Two of these fibers can also be blended. 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 by stacking or air-laid methods.

[0032] The absorbent body 4 may be one in which the main body of the absorbent body 4 is wrapped in an envelope sheet made of crepe paper, nonwoven fabric, or the like. Providing the envelope sheet in the absorbent body 4 prevents the absorbent body 4 from twisting or cracking and allows it to maintain its shape. The envelope sheet may be uncolored (i.e., white) crepe paper or nonwoven fabric, or it may be colored (for example, colored in a color similar to or complementary to the color of the body fluid).

[0033] The absorbent body 4 may have a long and narrow shape in plan view with a substantially constant width as shown in FIG. 1, but the width of the absorbent body 4 may vary along the longitudinal direction D1.

[0034] At both ends of the absorbent body 4 in the longitudinal direction D1, the edges of the back sheet 2 and the edges of the top sheet 3 may be joined by adhesive, heat sealing, etc. Furthermore, a pair of side sheets 7, 7 are arranged along the longitudinal direction D1 on both side portions of the absorbent article 1, i.e., on the front side (top sheet 3 side) of both edges in the width direction D2.

[0035] The side sheets 7 may be made of a nonwoven fabric material that has been treated to be water-repellent or hydrophilic, depending on the purpose, such as preventing penetration of bodily fluids or improving the feel against the skin. The material of the side sheets 7 may be natural fibers, synthetic fibers, recycled fibers, etc. Furthermore, when the side sheets 7 are treated to be water-repellent, a silicone-based, paraffin-based, or other water-repellent agent may be used for the treatment. The absorbent article may have a configuration in which the top sheet 3 extends to the end of the absorbent article 1 in the width direction D2 and is joined to the back sheet 2, without using the side sheets 7.

[0036] Gathers may also be formed using the side sheets 7. For example, the side sheets 7 may be folded inward or outward in the width direction D2, or multiple side sheets 7 may be provided, resulting in multiple layers of side sheets 7. A stretchable member such as rubber thread may be placed between the layers of the side sheets 7 in a stretched state along the longitudinal direction D1, and adhered to each layer of the side sheets 7 that comes into contact with the stretchable member, thereby securing the stretchable member to the side sheets 7. This allows gathers to be formed when the stretchable member returns to its natural length (when the stretching force is released). The gathers may be configured so that the inner side of the side sheets 7 in the width direction D2 is secured to the top sheet 3, and the outer side in the width direction D2 is raised.

[0037] The absorbent article 1 may have a middle region M that primarily corresponds to the wearer's crotch when worn, a front region F that is adjacent to the front of the middle region M and extends to the front end of the absorbent article 1, and a rear region B that is adjacent to the rear of the middle region M and extends to the rear end of the absorbent article 1. The middle region M includes a bodily fluid discharge outlet facing portion Q. The bodily fluid discharge outlet facing portion Q is a region that faces a bodily fluid discharge outlet such as the urethral opening or vaginal opening of the wearer when worn, and its center is located on the longitudinal centerline CL. In the example shown in Fig. 1, the bodily fluid discharge outlet facing portion Q is depicted as an oval as a region corresponding to the urethral opening, but the size and shape of the illustrated bodily fluid discharge outlet facing portion Q are merely an example for explaining the absorbent article according to this embodiment.

[0038] The front region F and the rear region B can be folded back toward the skin in the longitudinal direction D1 when the absorbent article is individually packaged. In the example of Fig. 1, the front region F can be folded back along a fold line that runs along the boundary line between the front region F and the middle region M, and the rear region B can be folded back along a fold line that runs along the boundary line between the rear region B and the middle region M. This allows the absorbent article 1 to be folded in three or more folds. Either the front region F or the rear region B can be folded back first.

[0039] 1 does not have wings, the absorbent article 1 may have a pair of wings extending laterally from both side edges of the middle region M. The wings can be formed by joining the extending portions of the side sheets 7 and the extending portions of the back sheet 2.

[0040] The overall length (total length) of the absorbent article 1 in the longitudinal direction D1 may be preferably 170 to 360 mm, more preferably 230 to 270 mm. The overall length (total length) of the absorbent article 1 in the left-right direction D2 (the width of the main body excluding the wing portions if wings are provided) may be preferably 50 to 150 mm, more preferably 70 to 120 mm. The overall thickness of the absorbent article 1 may be preferably 1 to 30 mm, more preferably 5 to 20 mm.

[0041] <Deformation of absorbent articles when worn> As shown in Figures 1 and 2, compressed grooves recessed from the front side to the back side (i.e., recessed from the top sheet 3 side to the back sheet 2 side) are formed in the absorbent article 1. In the example shown in Figure 1, the compressed groove is a central compressed groove 11 formed so as to include the center in the longitudinal direction D1 and the longitudinal centerline CL. The compressed grooves can be formed by applying pressure in a predetermined shape to predetermined locations from the top sheet 3 side of a laminate formed by overlapping at least the absorbent body 4 and the top sheet 3. In this process, for example, the laminate including the absorbent body 4 and the top sheet 3 may be passed between a roll having protrusions corresponding to the shape of the predetermined compressed grooves and a roll facing the roll with no protrusions or recesses on its surface.

[0042] As shown in Fig. 1, the central compressed groove 11 is formed so as to include the longitudinal centerline CL in plan view, i.e., so as to overlap with the longitudinal centerline CL. Preferably, the centerline of the central compressed groove 11 along the longitudinal direction D1 is formed at a position that substantially coincides with the longitudinal centerline CL of the absorbent article 1. The central compressed groove 11 is also formed so as to overlap with the portion Q facing the bodily fluid outlet. The central compressed groove 11 is formed in the middle region M of the absorbent article 1, and preferably within the middle region M. The length of the central compressed groove 11 in the longitudinal direction D1 may be 50 to 130 mm.

[0043] The degree of compression within the compression grooves (groove depth) may be uniform overall or may vary depending on the location. Although not shown in Figure 1, for example, the compression grooves may include low-compression sections and high-compression sections that are recessed deeper than the low-compression sections, and the high-compression sections may be formed intermittently within the low-compression sections (described below with reference to Figures 10 and 11).

[0044] 1 and 2, the back side of the absorbent body 4 is formed with back grooves 41, 41 recessed from the back side to the front side. The back grooves 41, 41 are formed as grooves extending in the longitudinal direction D1. Each of the back grooves 41, 41 is formed spaced apart from the central compressed groove 11 in the width direction D2, approximately parallel to the central compressed groove 11, and overlapping with the central compressed groove 11 in the longitudinal direction D1 in a plan view. Similarly to the central compressed groove 11, the back grooves 41, 41 are formed in the middle region M of the absorbent article 1, and may preferably be formed within the middle region M. The length of the back groove 41 may be approximately the same as the length of the central compressed groove 11, but is preferably shorter than the length of the central compressed groove 11. For example, as shown in Figure 1, by configuring the back groove 41 so that its front end does not extend beyond the front end of the central compressed groove 11 in a planar view, and so that its rear end does not extend beyond the rear end of the central compressed groove 11, it is possible to prevent folds from protruding to the front side in the areas in front and behind the central compressed groove 11, and it becomes easier to curve the front and rear regions of the absorbent article 1 to fit the front and rear shapes of the body.

[0045] In the illustrated example, the back grooves 41, 41 are formed in the absorbent body 4, but not in the top sheet 3 or the back sheet 2, but both the absorbent body 4 and the back sheet 2 may be recessed from the back side to the front side.

[0046] In this way, in this embodiment, central compressed groove 11 is formed, recessed from the front side to the back side, and back grooves 41, 41 recessed from the back side to the front side are formed in absorbent body 4 on each side of central compressed groove 11 in the width direction D2 in plan view, making it easy to obtain an appropriate deformation state of absorbent article 1 when worn. Figure 3 shows a cross-sectional view of absorbent article 1 after deformation when force is applied from the wearer's legs from outside to inside in the width direction D2 when worn. Figure 3 is a cross-sectional view corresponding to Figure 2.

[0047] Because the central compressed groove 11 is a groove recessed from the front side (top sheet 3 side) to the back side (back sheet 2 side), when the absorbent article 1 receives force from both sides in the width direction D2, it tends to bend and protrude toward the back side along the compressed groove. Therefore, as shown in FIG. 3, the region near the center in the width direction D2 deforms so as to protrude toward the back side (away from the wearer's skin). On the other hand, because the back grooves 41, 41 are grooves recessed from the back side to the front side, the absorbent body 4, and therefore the entire absorbent article 1, tends to bend and protrude toward the front side along the back grooves 41, 41. Therefore, when worn, when the absorbent article 1 receives force from the wearer's legs from the outside to the inside in the width direction D2, the positions of the back grooves 41, 41 each deform so as to protrude toward the front side (closer to the wearer's skin), as shown in FIG. 3. Therefore, in this embodiment, a generally M-shaped cross section or a cross section having a shape including a generally M-shape can be easily obtained as a whole. By forming such a substantially M-shaped cross section, the following effects can be obtained.

[0048] When worn, the absorbent article 1 deforms so as to protrude rearward at the position of the central compressed groove 11, which separates the top sheet 3 from the wearer's skin near the center of the absorbent article 1 in the width direction D2, forming a depression 47 ( FIG. 3 ). This depression 47 can temporarily store bodily fluids discharged into the bodily fluid discharge port facing portion Q. When the depression 47 is formed, it is preferable that both edge portions 48, 48 of the depression 47 be in close contact with the wearer's skin. However, if the wearer tightly closes or crosses their legs, a large force is applied to the absorbent article 1, which can disrupt the close contact between the both edge portions 48, 48 and the skin, resulting in leakage of bodily fluids outward in the width direction D2. In contrast, in this embodiment, the absorbent core 4 is further formed with rear grooves 41, 41, which allows the cross section of the absorbent article 1 to be generally M-shaped overall. As a result, both edges 48, 48 of the recessed portion 47 in the width direction D2 can be configured as convex edges that bulge outward due to bending at the positions of the rear grooves 41, 41 (FIG. 3). The convex edges are formed by bending the absorbent body 4, and therefore have a higher density and / or rigidity than unbent portions of the absorbent body 4. Therefore, even if the absorbent article 1 is subjected to a large force from the outside in the width direction D2 or is twisted, it is possible to prevent the shape of the edges of the recessed portion 47 from collapsing, and to prevent bodily fluids from leaking outward in the width direction D2 from the edges 48, 48.

[0049] In this way, the absorbent article 1 of this embodiment can stably maintain the desired deformed state of the absorbent article 1 while it is being worn, even if the absorbent article 1 is significantly deformed due to the wearer's body movements, and is therefore suitable for use as an absorbent article, such as an incontinence pad, for use by a wearer who walks or runs on a daily basis.

[0050] The width W (FIG. 1) of the central compressed groove 11 may be 2 to 15 mm. By setting the width W within this range, a depression 47 with a volume sufficient to at least temporarily store bodily fluids can be easily formed near the center in the width direction D2, and the center in the width direction D2 can be prevented from becoming hard, causing discomfort when closing the legs, etc.

[0051] The width w (FIG. 1) of each of the back grooves 41 may be 2 to 10 mm. When the width w is 2 mm or more, bending at the back grooves 41 is promoted, and deformation to form an overall cross section that includes a generally M-shape is facilitated. Furthermore, when the width w is 10 mm or less, the thickness of the convex edge formed by bending when worn is kept appropriate, the shape of the edges 48 of the recessed portion 47 can be stabilized, and the contact with the skin is also good.

[0052] Furthermore, in order to obtain the deformation that results in the aforementioned approximately M-shaped cross section of an appropriate size and shape, it is preferable that the center line extending along the longitudinal direction of the back groove 41 and the central compressed groove 11 overlap with an imaginary line X that is separated from the longitudinal center line CL of the absorbent article 1 by a length e that is 15 to 25% of the width of the absorbent core 4 (FIG. 1). Furthermore, the distance d in the width direction D2 between the central compressed groove 11 and the back groove 41 in a plan view can be 8 to 23% of the width of the absorbent core 4. Furthermore, the distance d may be 5 to 10 mm. By arranging the central compressed groove 11 and the back grooves 41, 41 as described above, an overall cross section that includes an approximately M-shape can be easily obtained when worn, and this shape can be stably maintained throughout the wear. Furthermore, the wearer's comfort during wear is also improved.

[0053] The back grooves 41 may be formed by compression, or may be formed by using a mold corresponding to the back grooves 41 when stacking the absorbent 4. When the back grooves 41 are formed by compression, the rigidity of the absorbent 4 increases around the back grooves 41, making it easier for the absorbent 4 to bend along the back grooves 41, and the above-mentioned approximately M-shaped deformation can be easily obtained. In addition, the density of the absorbent 4 increases around the grooves 41, making it easier for body fluids to be collected at the positions of the back grooves 41 and retain them, which also has the effect of preventing body fluids from leaking outward in the width direction D2.

[0054] <Modifications of absorbent body> Next, a modified example of the absorbent body 4 will be described with reference to FIG. 4. Like FIG. 2, FIG. 4 is a cross-sectional view of the absorbent article 1 cut in the width direction D2, but shows only the modified absorbent body 4. In the example shown in FIG. 4, the absorbent body 4 is formed with rear grooves 41, 41 recessed from the rear side to the front side, and further has auxiliary rear grooves 42a, 42b, 42a' formed on each side, spaced apart from the rear groove 41 in the width direction D2. These auxiliary rear grooves are shallower than the rear groove 41. In other words, the absorbent body 4 is formed with a plurality of grooves recessed from the rear side to the front side, and when worn, the absorbent article 1 is bent so as to bulge toward the front side at the position of the deepest rear grooves 41, 41 of the plurality of grooves, and the cross section is deformed to have a shape including the above-mentioned approximate M shape (up-down arrows in FIG. 4).

[0055] 4, auxiliary back grooves 42a and 42b are formed on the outer side of the back groove 41 in the width direction D2, in that order from the side closest to the back groove 41, and auxiliary back groove 42a' is formed on the inner side of the back groove 41 in the width direction D2. The number of auxiliary back grooves may be 1 to 5 on each side of the longitudinal center line CL.

[0056] The formation of auxiliary back grooves in addition to the back grooves 41, 41 makes the absorbent body 4 flexible, allowing the absorbent body 4 to deform more freely around the back grooves 41, 41. This makes it easier for the absorbent body 4 to deform so that it bulges toward the front side at the positions where the back grooves 41, 41 are formed. Furthermore, even if the absorbent article 1 undergoes significant deformation, for example, twisting, the above-mentioned desirable deformed state in which the cross section is approximately M-shaped can be maintained while it is being worn.

[0057] From the viewpoint of promoting deformation of the absorbent body 4 so that it bulges outward at the position of the back groove 41, it is preferable to form the auxiliary back grooves closest to the back groove 41 (auxiliary back grooves 42a, 42a' in the example of FIG. 4) 2 to 10 mm away from the back groove 41 in the width direction D2. Furthermore, as shown in FIG. 4, when multiple auxiliary back grooves are formed on one side of the back groove 41 in the width direction D2, it is preferable that the depth of the auxiliary back grooves farther from the back groove 41 is shallower than the depth of the auxiliary back grooves closer to the back groove 41. This allows the auxiliary back grooves to promote deformation of the absorbent body 4 at the position where the back groove 41 is formed, while properly maintaining the shape of the entire absorbent body 4.

[0058] In addition, when an auxiliary back groove is formed in addition to the back grooves 41, 41, the width of each groove may be narrower than in a configuration in which one back groove 41 is formed on each side of the longitudinal center line CL.

[0059] FIG. 5 shows another modified example of the absorbent body 4. In the example shown in FIG. 5, the absorbent body 4 also has multiple auxiliary back grooves in addition to the back grooves 41, 41. Specifically, auxiliary back grooves 42a, 42b are formed on the outer side of the back groove 41 in the width direction D2, and auxiliary back grooves 42a', 42b' are formed on the inner side of the back groove 41 in the width direction D2. In the example shown in FIG. 5, the arrangement and depth of the auxiliary back grooves are symmetrical in the width direction D2, with a line passing through the center of the back groove 41 in the width direction D2 as the axis of symmetry. Furthermore, in the example shown in FIG. 5, the pitch pa, pa' between the back groove 41 and the auxiliary back grooves 42a, 42a' closest to the back groove 41 is smaller than the pitch pb, pb' between the auxiliary back grooves 42a, 42a' and the adjacent auxiliary back grooves 42b, 42b'. In other words, the auxiliary back grooves are formed so that the pitch in the width direction D2 between the grooves increases with increasing distance from the back groove 41. By making the pitches pa, pa' narrower than the pitches pb, pb', the auxiliary back grooves 42a, 42a' enhance the effect of assisting the deformation of the absorbent body 4 at the position of the back groove 41, whereby the absorbent body 4 bulges outwards.

[0060] FIG. 6 also shows another modified example of the absorbent body 4. In the example shown in FIG. 6, auxiliary back grooves 42a, 42b, 42c, and 42d are formed on the outer side of the back groove 41 in the width direction D2, and auxiliary back groove 42a' is formed on the inner side of the back groove 41 in the width direction D2. Overall, the pitch between the grooves narrows as one approaches the end of the absorbent body 4 in the width direction D2. Arranging the back groove 41 and auxiliary back grooves 42a, 42b, 42c, 42d, and 42a' as described above and forming compressed grooves by compression is preferable because it enhances the ability to collect and retain bodily fluids in the region near the end of the width direction D2. This prevents leakage of bodily fluids outward in the width direction D2, even when a large amount of bodily fluid is excreted at once.

[0061] FIG. 7 also shows another modified example of the absorbent body 4, and the configuration of the back grooves 41, 41 is similar to that of the absorbent body 4 shown in FIG. 2. However, in the example shown in FIG. 7, the absorbent body 4 has thin portions 4S, 4S at both ends in the width direction D2, where the thickness of the absorbent body 4 is reduced. More specifically, the absorbent body 4 has portions where the thickness gradually decreases outward in the width direction D2. This makes it easier for the absorbent article 1 to deform into a substantially M-shaped cross section as described above when subjected to force from the wearer's legs while wearing the absorbent article 1. This also reduces the discomfort felt when the outer ends in the width direction D2 come into contact with the legs when the absorbent article 1 is in a deformed state. Note that the thickness of the absorbent body 4 at the ends in the width direction D2 may decrease in stages rather than gradually.

[0062] <Modification of the back groove> Fig. 8 shows an absorbent article 1A having the same basic structure as the absorbent article 1, but equipped with modified back grooves 41A, 41A instead of the back grooves 41, 41. Fig. 8 is a plan view of the absorbent article 1A as seen from the front side. As shown in Fig. 8, the back groove 41A extends along the longitudinal direction D1, but the inner contour of the back groove 41A in the width direction D2 is not linear, and has multiple protrusions r, r, ... that protrude toward the longitudinal center line CL. The number of protrusions r, r, ... is not limited to three as shown, and may be one to six depending on the size of the back groove 41A (the lengths in the longitudinal direction D1 and the width direction D2).

[0063] FIG. 9 shows an enlarged view of the area in FIG. 8 where the central compressed groove 11 and the back grooves 41A, 41A are formed, and explains the function of the back grooves 41A, 41A. As shown in FIG. 9, bodily fluid discharged into or around the bodily fluid discharge port facing portion Q is easily transferred forward and backward along the central compressed groove 11. Furthermore, since each back groove 41A, 41A has convex portions r, r, ... during the transfer in the front-to-rear direction along the central compressed groove 11, bodily fluid is easily absorbed from the apexes of the convex portions r, r, .... This allows the absorbent core 4 to more quickly draw bodily fluid outward in the width direction D2. Therefore, even if a large amount of bodily fluid is discharged at once, it is possible to prevent the bodily fluid from leaking outward in the width direction D2 due to insufficient transfer in the longitudinal direction D1. Therefore, a configuration such as the back grooves 41A, 41A is particularly preferable for low-viscosity bodily fluids such as urine. The rapid transfer of bodily fluids by the convex portions r, r, . . . is particularly enhanced by the rear grooves 41A, 41A being compressed grooves formed by compression.

[0064] The protrusions r, r, ... may or may not be in contact with the central compressed groove 11 in plan view, but since this allows body fluids to migrate more easily in the width direction D2, it is preferable that the protrusions r, r, ... are in contact with the central compressed groove 11 in plan view as shown in Figure 9. Furthermore, the protrusions r, r, ... may overlap with the compressed groove 11 in plan view.

[0065] <Modified compression groove> Figure 10 shows an absorbent article 1B with compressed grooves according to a modified example. Similar to the absorbent article 1 (Figure 1) and the absorbent article 1A (Figure 8), the absorbent article 1B has a central compressed groove 11 that extends along the longitudinal direction D1 so as to overlap with the longitudinal centerline CL. The absorbent article 1B also has a pair of back grooves 41B, 41B recessed from the back side to the front side, at a position spaced apart in the width direction D2 from the central compressed groove 11 in a plan view. Therefore, when the middle region M is subjected to leg force from the outside in the width direction D2 during wear, the central compressed groove 11 and the back grooves 41B, 41B allow the absorbent article 1B to deform so that its cross section has a shape that includes a substantially M-shape.

[0066] However, in the absorbent article 1B shown in Figure 10, in addition to the central compressed groove 11, there are formed a pair of front oblique compressed grooves 12f, 12f each connected to the front end of the central compressed groove 11, and a pair of rear oblique compressed grooves 12b, 12b each connected to the rear end of the central compressed groove 11. Here, the pair of front oblique compressed grooves 12f, 12f and the pair of rear oblique compressed grooves 12b, 12b may be collectively referred to as a pair of oblique compressed grooves 12, 12.

[0067] The pair of oblique compressed grooves 12, 12 extend so that the distance between them increases as they move outward in the longitudinal direction D1. That is, the pair of front oblique compressed grooves 12f, 12f extend so that the distance between them increases as they move forward, and the pair of rear oblique compressed grooves 12b, 12b extend so that the distance between them increases as they move rearward. In other words, the pair of front oblique compressed grooves 12f, 12f may be a pair of compressed grooves extending diagonally forward to the right and diagonally forward to the left, and the pair of rear oblique compressed grooves 12b, 12b may be a pair of compressed grooves extending diagonally rearward to the right and diagonally rearward to the left.

[0068] By providing the pair of oblique compressed grooves 12, 12 as described above, substantially V-shaped compressed grooves are formed at the front and rear of the absorbent article 1. Alternatively, if the end of the central compressed groove 11 is included, a substantially Y-shaped compressed groove is formed. These substantially V-shaped or Y-shaped compressed grooves form two folding base points in a cross section taken along the width direction D2, allowing the region where the pair of oblique compressed grooves 12 are formed to curve naturally. More specifically, by providing the pair of front oblique compressed grooves 12f, 12f, when worn, the absorbent article 1 bends weakly at each of the pair of front oblique compressed grooves 12f, 12f so that the absorbent article 1 protrudes to the back side. As a result, the front region F of the absorbent article 1 can deform so as to come into surface contact with the front of the wearer's body (the rounded area near the pubic bone). Similarly, the absorbent article 1 is bent slightly at each of the pair of rear diagonal compression grooves 12b, 12b so that it protrudes to the back side, and therefore the rear region B of the absorbent article 1 can be deformed so as to make surface contact along the rear of the wearer's body (the curve of the buttocks).

[0069] This deformation of the front region F and the rear region B, together with the above-mentioned deformation that results in an approximately M-shaped cross section, allows the absorbent article 1 to fit to the shape of the body, and this fitted state can be stably maintained, thereby preventing leakage of bodily fluids.

[0070] Each of the pair of oblique compressed grooves 12, 12 may extend linearly in a plan view or may be curved. However, as shown in Fig. 10, by curving the grooves so as to be convex toward the longitudinal center line CL, it becomes possible to deform the front and rear of the absorbent article 1 along the curves of the legs.

[0071] Furthermore, it is not necessary for both the pair of front diagonal compressed grooves 12f, 12f and the pair of rear diagonal compressed grooves 12b, 12b to be formed, and as long as either the pair of front diagonal compressed grooves 12f, 12f or the pair of rear diagonal compressed grooves 12b, 12b are formed, the above-mentioned effect can be obtained at the front or rear of the absorbent article 1.

[0072] The length in the longitudinal direction D1 of the pair of diagonal compressed grooves 12 is preferably 30 to 60% of the length in the longitudinal direction D1 of the central compressed groove 11. Furthermore, the pair of diagonal compressed grooves 12, 12 may be formed within the range in which the absorbent body 4 is arranged in a planar view, and are preferably formed within the range in which the top sheet 3 is exposed in a planar view. Furthermore, the width of the diagonal compressed groove 12 may be 1 to 4 mm.

[0073] In the example shown in Figure 10, the central compressed groove 11 and the pair of diagonal compressed grooves 12, 12 each include a low-compression section and a high-compression section that is formed within the area where the low-compression section is formed and is compressed deeper than the low-compression section. In Figure 10, the high-compression section is shown in black. By including both the low-compression section and the high-compression section, even with compressed grooves that are relatively wide, the function of the compressed grooves, i.e., the ability of the absorbent article 1 to deform and form depressions and the ability to allow bodily fluids to move smoothly along the compressed grooves, can be maintained, and the areas where the compressed grooves are formed and their surrounding areas can be prevented from hardening, which would hinder deformation or cause discomfort.

[0074] <Other configurations> FIG. 11 is a reprint of FIG. 10 showing the absorbent article 1B, but also shows a slip-preventing portion provided on the back side of the absorbent article 1B. More specifically, the slip-preventing portion is provided on the back side of the backsheet 2 and is a component for reliably fixing the absorbent article to the underwear when worn, thereby preventing the absorbent article from slipping off the underwear. The slip-preventing portion is preferably an adhesive slip-preventing portion. An adhesive slip-preventing portion can be formed, for example, by applying a fluid adhesive or by attaching a pre-formed adhesive layer (such as adhesive tape). The adhesive used as the slip-preventing portion can be a known adhesive, such as a hot-melt type adhesive. Its main components include a styrene-based polymer, a tackifier, a plasticizer, and combinations thereof.

[0075] In the example shown in Fig. 11, the slip-preventing portion is divided into multiple parts. The arrangement of the slip-preventing portion is not particularly limited, but it is preferable that the slip-preventing portion is formed so as not to overlap the central compressed groove 11 and the back grooves 41B, 41B in a plan view, as shown in Fig. 11. Since the slip-preventing portion does not overlap the central compressed groove 11 and the back grooves 41B, 41B, it does not prevent the middle region M of the absorbent article 1B from deforming to have the above-mentioned generally M-shaped cross section. Therefore, while the slip-preventing portion has the effect of preventing slippage of the entire absorbent article 1B, it also has the effect of stably maintaining the deformed state of the absorbent article 1B when worn, as described above.

[0076] In the example shown in Figure 11, the slippage prevention portions may include side slippage prevention portions 9S, 9S that overlap or are located close to the ends of the absorbent core 4 in the width direction D2 in plan view, and central slippage prevention portions 9C, 9C that are located on both sides of the longitudinal centerline CL and further inward in the width direction D2 than the side slippage prevention portions S, 9S. The side slippage prevention portions 9S, 9S extend continuously in the longitudinal direction D1. Meanwhile, the central slippage prevention portions 9C, 9C are each discontinuous in the longitudinal direction so as not to overlap the central compressed groove 11 and the back grooves 41B, 41B in plan view. The slippage prevention portions may be arranged in a manner other than that shown in Figure 11, as long as they do not overlap the central compressed groove 11 and the back grooves 41B, 41B in plan view. For example, one side anti-slip portion 9S, two central anti-slip portions 9C, and the other side anti-slip portion 9S may be formed continuously at the front and / or rear.

[0077] Although the present invention has been described above based on the embodiments, the present invention is not limited to these embodiments. Furthermore, the above embodiments can be variously changed, modified, substituted, added, deleted, and combined within the scope of the claims, and these also fall within the technical scope of the present invention. [Explanation of symbols]

[0078] 1, 1A, 1B Absorbent articles 2 Back Seat 3 Topsheet 4. Absorber 4S Thin part 7 Side seats 9C, 9S Anti-slip part 11 Central compression groove 12f Front diagonal compression groove 12b Rear oblique compression groove 41, 41A, 41B back groove 42a, 42b, 42a', 42b' Auxiliary back groove 47 Recess 48 Edge of recess CL longitudinal centerline D1 Longitudinal direction (first direction) D2 Width direction (second direction) F Anterior area M middle area B Posterior area Q Opposite body fluid outlet r Convex part X Longitudinal virtual line

Claims

1. A liquid-permeable top sheet on the front side and a liquid-impermeable back sheet on the back side and an absorbent body provided between the top sheet and the back sheet, and a width direction perpendicular to the longitudinal direction, A longitudinal centerline extending along the longitudinal direction. It has a central compressed groove that is recessed from the front to the back, The absorbent body has a pair of compressed grooves on each side of the central compressed groove in a plan view, the compressed grooves being spaced apart from the central compressed groove in the width direction. A back groove extending along the longitudinal direction and recessed from the back side to the front side is formed, auxiliary back grooves shallower than the back grooves are formed at least on each side of the back groove in the width direction; The inner contour of the back groove in the width direction has a convex portion that protrudes toward the central compressed groove. Absorbent articles.

2. 2. The method according to claim 1, wherein the back groove is formed by squeezing the absorbent body from the back side. The absorbent article described above.

3. The distance in the width direction between the central compressed groove and the back groove is 8 to 23% of the width of the absorbent body. The absorbent article of claim 1 or 2, wherein the absorbent article has a thickness equal to

4. The thickness of the absorbent body is increased toward the outside in the width direction at the outside of the back groove in the width direction. The absorbent article according to any one of claims 1 to 3, which is gradually or stepwise thinned by Product.

5. The central compression grooves are respectively connected to one end of the central compression groove in the longitudinal direction, and the distance between the central compression grooves is Further provided with a pair of oblique compression grooves extending so as to become larger toward the outside in the longitudinal direction. The absorbent article according to claim 1 ,

6. A slip prevention portion is provided on the back side of the back sheet, The method according to any one of claims 1 to 5, wherein the slippage prevention portion does not overlap the back groove in a plan view. The absorbent article described above.

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