absorbent material

Abstract

DEPCT64 Form an indentation groove that is pressed against the back plate at least as much as possible on the surface of the absorbent. Facing the top plate in a way that reduces the thickness of the absorbent in the thickness direction, forming grooves. Compress the left and right sides along the length of the sanitary pad, at least on the sides of the area. It conforms to the body's fluid drainage mechanisms of the wearer and molds into highly absorbent areas. The absorption capacity per unit area should be greater than other areas, at least in the area between the compression grooves. The left and right sides of the adsorbent. -----------------------------------------------------------

Description

absorbent articles

[0001] The present invention relates to absorbent articles that are primarily used for sanitary napkins, panty liners, incontinence pads, toiletries, and the like.

[0002] Conventionally, as the absorbent article, there has been known an absorbent article in which an absorbent body made of cotton-like pulp or the like is sandwiched between a liquid-impermeable back sheet such as a polyethylene sheet or a polyethylene sheet-laminated nonwoven fabric and a liquid-permeable top sheet such as a nonwoven fabric or a liquid-permeable plastic sheet.

[0003] Slim absorbent articles in which the thickness of the absorbent body is reduced have advantages such as reducing discomfort when worn and making the unevenness of the absorbent article less visible from the outside of clothing when worn (so that it does not show through outerwear), and are therefore widely available on the market.

[0004] However, due to their thin thickness, absorbent capacity per unit area is small, and their ability to retain fluid in the thickness direction is low, meaning that bodily fluids tend to spread in the planar direction. This has the disadvantage of making leakage more likely, particularly from the widthwise edges of the absorbent body (side leakage). Furthermore, wearers are concerned about leakage, which can lead to inconveniences in daily life, such as the need to frequently change absorbent articles.

[0005] A conventional technique for preventing such side leakage involves forming compressed grooves recessed from the skin side to the non-skin side of the topsheet along the longitudinal direction on both sides of the region corresponding to the wearer's body fluid excretion area, and there are many documents related to this technique. For example, Patent Document 1 listed below discloses an absorbent article in which a reference mark, which is a continuous or discontinuous outline surrounding a predetermined area of ​​the liquid receiving section, is provided in a position visible from the front side.

[0006] Furthermore, in the following Patent Document 2, an absorbent article is disclosed in which a plurality of compressed sections are formed in the absorbent body by compressing the top sheet and absorber in the thickness direction of the absorbent article, the compressed sections are provided in a central region including the center of the excretory outlet abutment region arranged opposite the excretory outlet of the wearer, and the absorbent article has a plurality of intermittently formed dot-like central compressed sections, and longitudinal compressed sections which are provided on the outside of the central region in the width direction of the absorbent article and extend in the longitudinal direction of the absorbent article, the longitudinal compressed sections being recessed from the top sheet side towards the back sheet side, and the central compressed sections being recessed from the back sheet side towards the top sheet side.

[0007] JP 2003-126140 A JP 2013-34525 A

[0008] However, the absorbent article described in Patent Document 1 does not have a thinner absorbent body, and therefore has drawbacks such as being uncomfortable to wear and easily showing through outerwear. Furthermore, the absorbent article described in Patent Document 2 has multiple central compressed dots, but these central compressed dots are designed to prevent heat damage to the topsheet while allowing the topsheet to absorb bodily fluids excreted by the wearer, and therefore are not expected to have much of an effect in terms of thinning the absorbent body. Therefore, it has the same drawbacks as Patent Document 1.

[0009] As such, the above Patent Documents 1 and 2 are not directed to absorbent articles in which the thickness of the absorbent body is reduced, and therefore do not have the problem that when a thin absorbent body is used, the absorption capacity per unit area of ​​the absorbent body becomes small, making it more likely to diffuse in the planar direction and causing side leakage.

[0010] Therefore, a main object of the present invention is to provide a slim type absorbent article in which the thickness of the absorbent body is reduced, and which suppresses the diffusion of bodily fluids in the planar direction.

[0011] In order to solve the above problems, one aspect of the present invention provides an absorbent article having an absorbent body sandwiched between a liquid-permeable top sheet and a liquid-impermeable back sheet, characterized in that a core press is formed on at least the surface of the absorbent body facing the top sheet, which is recessed toward the back sheet and compresses the thickness of the absorbent body in the thickness direction, and a pair of left and right compression grooves are formed along the longitudinal direction of the absorbent article on at least both sides of the area corresponding to the wearer's body fluid excretion area, and a high-absorbency portion having a higher absorption capacity per unit area than other areas is formed at least between the left and right compression grooves of the absorbent body.

[0012] As explained above in detail, according to the present invention, in a slim absorbent article in which the thickness of the absorbent body is reduced, the diffusion of bodily fluids in the planar direction can be suppressed, and side leakage in particular can be prevented.

[0013] FIG. 1 is a partially cutaway development view of a sanitary napkin 1 according to the present invention. FIG. 2 is a view taken along the line II-II in FIG. 1. FIG. 3 is a plan view of an absorbent body 4. FIG. 4 is a view taken along the line IV-IV in FIG. 3. FIG. 5 is a plan view of an absorbent body 4 according to a modified example. FIG. 6 is a plan view of an absorbent body 4 according to a modified example. FIG. 7 is a cross-sectional view of a sanitary napkin 1 according to another embodiment. FIG. 8 is a cross-sectional view of a sanitary napkin 1 according to another embodiment.

[0014] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0015] 1 and 2, the sanitary napkin 1 according to the present invention comprises a liquid-impermeable backsheet 2 made of a polyethylene sheet or the like, a liquid-permeable topsheet 3 that allows menstrual blood, vaginal discharge, and the like (hereinafter collectively referred to as body fluids) to quickly pass through, an absorbent body 4 made of cotton-like pulp or synthetic pulp sandwiched between the two sheets 2, 3, and side nonwoven fabrics 7, 7 provided on both sides of the skin-contacting surface over substantially the entire length in the longitudinal direction. Around the periphery of the absorbent body 4, the outer edges of the backsheet 2 and the topsheet 3 are joined together at the top and bottom edges by a joining means such as a hot-melt adhesive, heat sealing, or ultrasonic sealing. Furthermore, at both side edge portions of the absorbent body 4, the backsheet 2 and the side nonwoven fabric 7, which extend laterally beyond the absorbent body 4, are joined by a joining means such as an adhesive such as hot melt, heat sealing, or ultrasonic sealing, and a pair of left and right wing-like flaps W, W are formed on the sides of the absorbent body at a position corresponding to the region H corresponding to the body fluid discharge area when viewed in the longitudinal direction. In the illustrated example, the absorbent body 4 is surrounded by an envelope sheet 5 made of crepe paper or nonwoven fabric to maintain the shape and improve diffusion, but this envelope sheet 5 is not necessary. Furthermore, although not shown, a second sheet made of hydrophilic nonwoven fabric or the like and having approximately the same shape as the topsheet 3 may be disposed adjacent to the non-skin side of the topsheet 3.

[0016] The structure of the sanitary napkin 1 will be described in further detail below. The backsheet 2 is preferably made of a water-impermeable sheet material such as polyethylene, but preferably has moisture permeability to prevent stuffiness. A suitable water-impermeable and moisture-permeable sheet material is a microporous sheet obtained by melt-kneading an inorganic filler into an olefin resin such as polyethylene or polypropylene to form a sheet, followed by uniaxial or biaxial stretching. One or more adhesive layers (not shown) are formed along the length of the napkin on the non-skin side (outer surface) of the backsheet 2, securing the sanitary napkin 1 to underwear when worn. The backsheet 2 may also be made of a polylaminated nonwoven fabric (a nonwoven fabric laminated with a polyethylene film), which is a laminate of a plastic film and a nonwoven fabric.

[0017] Next, the topsheet 3 is preferably made of a perforated or non-perforated nonwoven fabric or a porous plastic sheet. The material fibers constituting the nonwoven fabric can be synthetic fibers such as olefins (e.g., polyethylene or polypropylene), polyesters, or polyamides, as well as recycled fibers (e.g., rayon or cupra), and natural fibers (e.g., cotton). Nonwoven fabrics obtained by appropriate processing methods, such as spunlace, spunbond, thermal bond, meltblown, or needlepunch, can be used. Of these processing methods, the spunlace method excels in terms of flexibility and drapeability, while the thermal bond method excels in terms of bulk and high compression recovery. Forming numerous perforations in the topsheet 3 allows for rapid absorption of body fluids and provides an excellent dry touch. The fibers of the nonwoven fabric can be either long or short fibers, but short fibers are preferred to achieve a towel-like texture. Furthermore, olefin fibers with relatively low melting points, such as polyethylene or polypropylene, are preferred to facilitate embossing. In addition, core-sheath type fibers, in which fibers with a high melting point are used as the core and fibers with a low melting point are used as the sheath, side-by-side type fibers, and composite fibers, such as split type fibers, can also be suitably used.

[0018] As shown in the cross-sectional view of Figure 2, the width of the topsheet 3 is slightly longer than the width of the absorbent body 4, and only covers the absorbent body 4 within a predetermined section in the longitudinal direction of the napkin, including an area H corresponding to the body fluid discharge area. A side nonwoven fabric 7, separate from the topsheet 3, is disposed outward of the absorbent body 4. Specifically, the side nonwoven fabric 7 is made of a nonwoven fabric material that has been subjected to an appropriate water-repellent or hydrophilic treatment depending on the purpose, such as preventing penetration of menstrual blood or vaginal discharge, or improving the feel against the skin.

[0019] The side nonwoven fabric 7 can be made of natural fibers, synthetic fibers, recycled fibers, or the like, and processed by an appropriate method. Preferably, a nonwoven fabric with a low basis weight and breathability is used to eliminate stiffness and prevent stuffiness. Specifically, a basis weight of 13 to 23 g / m2 is used. ２ In order to reliably prevent the penetration of body fluids, it is preferable to use a water-repellent treated nonwoven fabric coated with a silicone-based, paraffin-based, or alkylchromic chloride-based water-repellent agent.

[0020] As shown in Figure 2, the portions of the side nonwoven fabric 7 outside the widthwise intermediate portion are bonded with an adhesive such as hot melt from a predetermined inner position to the outer edge of the backsheet 2, thereby forming predetermined flap portions at predetermined positions. This flap portion has a pair of wing-shaped flaps W, W on both sides at a position corresponding to region H, which corresponds to the bodily fluid discharge area, as viewed in the longitudinal direction. Each of the wing-shaped flaps W, W is provided with an adhesive layer (not shown) on the outer surface of the backsheet 2. When worn on shorts, the wing-shaped flaps W, W are folded back to the opposite side at the fold line RL (Figure 1) at their base ends and wrapped around the crotch area of ​​the shorts to fasten them. Meanwhile, the inner portions of the side nonwoven fabric 7 are laminated on the skin-facing side of the topsheet 3 and bonded to the absorbent core 4 (the skin-facing side of the topsheet 3).

[0021] [Absorbent Body] The absorbent body 4 interposed between the backsheet 2 and the topsheet 3 is composed of, for example, pulp and a superabsorbent polymer. The superabsorbent polymer is mixed in the pulp constituting the absorbent body, for example, as a granular powder. Examples of the pulp include chemical pulp obtained from wood, cellulose fibers such as dissolving pulp, and artificial cellulose fibers such as rayon and acetate. Coniferous pulp, which has longer fibers, is more suitable than hardwood pulp in terms of functionality and cost.

[0022] The sanitary napkin 1 is a thin, slim napkin with a low basis weight of the absorbent body 4. The basis weight of the pulp is 50 to 300 g / m ２ , preferably 80 to 220 g / m ２ The basis weight of the highly absorbent polymer is preferably 30 to 180 g / m ２ , preferably 50 to 160 g / m ２ The basis weight of the pulp and the superabsorbent polymer does not need to be constant and may be varied depending on the part of the absorbent body. For example, as will be described in detail later, a highly absorbent part 15 can be formed in which the basis weight of the pulp and the superabsorbent polymer is increased in an area corresponding to an area H corresponding to the area where the wearer's body fluids are discharged.

[0023] Synthetic fibers may be mixed into the absorbent body 4. Examples of the 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, or mixtures of two of these. Also, 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. In the case of hydrophobic synthetic fibers, it is desirable to use fibers whose surface has been treated with a hydrophilizing agent so that they have affinity for body fluids.

[0024] 3 and 4, a core press 10 is formed on at least the surface of the absorbent body 4 facing the topsheet 3 (the surface facing the skin), recessed toward the backsheet 2 (the side opposite the skin). This core press 10 is used to compress the thickness of the absorbent body 4 in the thickness direction, and does not compress the entire surface of the absorbent body 4, but rather compresses it in a predetermined pattern at predetermined intervals. As the portion subjected to the core press 10 is compressed in the thickness direction, fibers in the portion not subjected to the core press 10 are pulled in, and the portion not subjected to the core press 10 is affected and compressed to some extent, so that the thickness of the entire absorbent body 4 decreases in the thickness direction. The "thickness of the absorbent body 4" refers to the overall thickness of the absorbent body 4, and specifically refers to the maximum thickness measured at the thickest portion.

[0025] The ratio of thickness reduction by the core press 10 is calculated by dividing the thickness of the absorbent body 4 before the core press 10 by t ０ , where t is the thickness of the absorbent body 4 after the core press 10 is applied, t / t ０ = approximately 1 / 10 to 7 / 10 is preferable. If this ratio is less than 1 / 10, the absorbent body becomes hard and the wearing comfort deteriorates. Conversely, if it is more than 7 / 10, the effect of compression by the core press 10 is small and the thickness of the absorbent body 4 increases. This ratio can be changed by adjusting the compression depth of the core press 10, the spacing between adjacent core presses, the planar pattern of the core press 10, etc.

[0026] In the illustrated example, the core press 10 compresses only the skin-side surface (the surface facing the topsheet 3) of the absorbent body 4, forming concave depressions on the skin-side surface of the absorbent body 4 and leaving the non-skin-side surface (the surface facing the backsheet 2) substantially flat. This type of processing can be achieved by passing the absorbent body between a convex roll having numerous convex portions formed on its surface and an anvil roll having a flat surface. Alternatively, although not shown, concave depressions may be formed on both the skin-side surface and the non-skin-side surface of the absorbent body 4 by compressing them separately. This type of processing can be achieved by passing the absorbent body 4 between a first convex roll having numerous convex portions formed on its surface and a second convex roll having convex portions similarly formed in positions corresponding to the convex portions of the first convex roll. By compressing at least the skin-side surface, bodily fluids that have penetrated from the topsheet 3 flow into the concave portions of the core press 10 and are more likely to diffuse along the core press 10, and are absorbed into the absorbent body 4 as they diffuse.

[0027] As shown in Fig. 3, the core press 10 is preferably formed in the same pattern over almost the entire absorbent body 4. That is, the core press 10 is applied in the same pattern in the region H corresponding to the wearer's body fluid excretion area as in the other regions. This allows the entire absorbent body 4 to be made thinner, reliably reducing discomfort when worn and reliably preventing it from showing through the outer layer.

[0028] The core press 10 can be applied in any pattern as long as it can compress the thickness of the absorbent body 4 in the thickness direction, but as shown in Figure 3, it is preferable that it includes a plurality of linear press portions 11, 11... that are continuous or discontinuous at predetermined locations and formed across the edges of the absorbent body 4. The linear press portions 11 are not formed in the middle part that does not reach the outer edges of the absorbent body 4, but are formed across one edge of the front and rear edges or left and right edges of the absorbent body 4 and any other edge. By forming the linear press portions across the edges of the absorbent body 4, the entire absorbent body 4 can be compressed, ensuring a thinner body.

[0029] The core press 10 preferably includes a grid pattern formed by a plurality of first linear pressed portions 11 a, 11 a... slanting toward one side in the width direction and arranged at a predetermined interval in the longitudinal direction, and a plurality of second linear pressed portions 11 b, 11 b... intersecting the first linear pressed portions 11 a, slanting toward the other side in the width direction and arranged at a predetermined interval in the longitudinal direction. Forming the core press 10 in a grid pattern can more reliably reduce the thickness of the absorbent body 4, significantly reducing discomfort when worn and reducing interference with outerwear. The first linear pressed portions 11 a... and the second linear pressed portions 11 b... are preferably arranged at approximately the same intervals, resulting in a large number of approximately rectangular grids consisting of squares or diamonds whose peripheries are defined by the linear pressed portions 11 a, 11 b. The approximately rectangular lattice portion surrounded by the linear press portions 11a and 11b is not directly compressed, but is affected by the linear press portions 11a and 11b and becomes thinner than the original thickness.

[0030] The intersection angle between the first linear pressed portions 11a and the second linear pressed portions 11b is approximately a right angle in the illustrated example, but may be approximately 30° to 150°. The first linear pressed portions 11a and the second linear pressed portions 11b are preferably inclined with respect to the width direction of the sanitary napkin 1. This allows the absorbent body 4 to easily deform diagonally along the linear pressed portions 11a and 11b, making it easier to follow the body's movements when a torsional force is applied to the sanitary napkin 1 due to pressure from the inside of the groin when moving the left and right legs back and forth during walking, etc. Furthermore, because bodily fluids flow along these linear pressed portions 11a and 11b in the width direction of the sanitary napkin 1, side leakage can be prevented compared to when linear pressed portions extending parallel to the width direction are formed. From the viewpoint of facilitating such oblique deformation and preventing side leakage, the linear pressed portions 11a, 11b are preferably inclined at an angle of 30° or more with respect to the width direction of the sanitary napkin 1.

[0031] To ensure a thin absorbent body 4, the length a of one side of each grid defined by the first linear pressed portion 11a and the second linear pressed portion 11b is preferably 4 to 10 mm, as shown in Figure 3. If it is less than 4 mm, the linear pressed portions 11a, 11b are too close to each other, making the absorbent body 4 stiff and uncomfortable to wear. On the other hand, if it is more than 10 mm, the center of each grid bulges toward the skin, making it difficult to sufficiently thin the entire absorbent body 4. The width of the linear pressed portions 11a, 11b is preferably 0.5 to 3 mm.

[0032] To ensure a thin absorbent body 4, a circular, polygonal, or other dot-like central press portion 16 may be applied to the center of each grid, spaced from the linear press portions 11a and 11b, as shown in Figures 3 and 4. This prevents the center of each grid from bulging toward the skin, ensuring a thin absorbent body 4 overall without significantly increasing its stiffness. Furthermore, bodily fluids that penetrate each grid portion are more likely to diffuse toward the dense central press portion 16 due to capillary action, improving diffusion and enabling rapid absorption of bodily fluids. The length a of one side of each grid portion when the central press portion 16 is provided can be longer than the length when the central press portion 16 is not provided; even a maximum of approximately 15 mm is not a problem from the perspective of achieving a thin absorbent body 4.

[0033] The planar shape of each lattice portion partitioned by the core press 10 may be a quadrilateral such as a square or a diamond as described above, or a polygonal pattern having pentagons or more sides. In the above embodiment, the linear press portions 11a and 11b are formed in a continuous line, but they may also be formed in a discontinuous line with a plurality of dots arranged at intervals.

[0034] 3 and 4, in addition to the core press 10, a pair of left and right compressed grooves 12, 12 are formed on the surface of the absorbent body 4 facing the topsheet 3, at least on both sides of an area H corresponding to the wearer's body fluid discharge area, along the longitudinal direction of the sanitary napkin 1. By forming the compressed grooves 12, it is possible to block bodily fluids that diffuse from the area H corresponding to the wearer's body fluid discharge area along the core press 10 in the width direction of the sanitary napkin 1 and to change the flow to follow the longitudinal direction of the sanitary napkin 1 along which the compressed grooves 12 extend, thereby preventing bodily fluids from diffusing to the widthwise edges of the absorbent body 4 and reliably preventing side leakage.

[0035] The compression grooves 12 may be formed by concave depressions formed only on the skin side of the absorbent body 4, as with the core press 10, by compressing only the skin side of the absorbent body 4, or by concave depressions formed on both the skin side and non-skin side of the absorbent body 4, by compressing both the skin side and non-skin side of the absorbent body 4.

[0036] In the embodiment shown in Fig. 3, the compressed grooves 12 are formed to extend along the longitudinal direction on both sides of region H corresponding to the wearer's bodily fluid discharge areas. That is, the compressed grooves 12, 12 are formed by arc-shaped lines that are independently arranged on the left and right sides and spaced apart at the widthwise center of the sanitary napkin 1. The compressed grooves 12 extend in the front-to-rear direction on both sides of region H corresponding to the wearer's bodily fluid discharge areas, with lengths roughly equal to those of region H corresponding to the bodily fluid discharge areas, and are preferably formed in a curved shape that bulges most outward in the widthwise direction at the longitudinal center.

[0037] As a modification of the compressed grooves 12, as shown in Fig. 5, they may be formed by annular lines formed so as to surround the periphery of region H corresponding to the wearer's bodily fluid excretion area. This makes it possible to suppress diffusion in the front-to-rear direction as well as in the width direction, thereby reliably preventing leakage from the edges in the width direction and front-to-rear direction of the absorbent body 4. In this case, the planar shape of the compressed grooves 12 is preferably circular, elliptical or oblong.

[0038] As shown in Fig. 6, the compressed grooves 12 preferably comprise a plurality of longitudinal compressed grooves 12a extending longitudinally and spaced apart in the widthwise direction on at least both sides of the region H corresponding to the wearer's bodily fluid discharge area. In the example shown in Fig. 6, two longitudinal compressed grooves 12a, 12a are formed on each side of the region H corresponding to the wearer's bodily fluid discharge area, spaced apart in the widthwise direction. Of these, the outer longitudinal compressed grooves 12a are formed by portions extending longitudinally along a circular line surrounding the region H corresponding to the wearer's bodily fluid discharge area, while the inner longitudinal compressed grooves 12a are formed by arc-shaped lines spaced apart in the widthwise center and independently arranged on the left and right. This more reliably prevents bodily fluids from spreading in the widthwise direction. The plurality of longitudinal compressed grooves 12a are preferably arranged concentrically about the approximate center of region H corresponding to the wearer's body fluid excretion area, and are preferably formed in curved shapes that bulge outward in approximately parallel directions. The compressed grooves 12a arranged furthest inward in the width direction are preferably arranged on both sides of the region that corresponds approximately to the wearer's vaginal opening, from the viewpoint of preventing the diffusion of body fluids in the width direction.

[0039] In this case, it is preferable that the longitudinal compressed grooves 12 arranged on the outer side in the width direction extend relatively farther toward the front and rear in the longitudinal direction than the longitudinal compressed grooves 12a arranged on the inner side in the width direction. This allows bodily fluid that has spread outward in the width direction by wrapping around the ends of the longitudinal compressed grooves 12a arranged on the inner side in the width direction to be blocked by the longitudinal compressed grooves 12a arranged on the outer side in the width direction, thereby more reliably preventing diffusion outward in the width direction.

[0040] Furthermore, the longitudinal compressed grooves 12a arranged on the inner side in the width direction may be formed by portions extending in the front-to-rear direction on both sides of a circular annular line arranged to surround the periphery of the area corresponding to the wearer's vaginal opening, as shown in Figure 7. In other words, the compressed grooves may be formed in a pattern of double annular lines, in which compressed grooves 12 consisting of a circular annular line surrounding the periphery of the area corresponding to the vaginal opening are arranged inside compressed grooves 12 consisting of a longitudinally long elliptical annular line surrounding the periphery of area H corresponding to the bodily fluid discharge site.

[0041] As shown in Figure 7, one or more pairs of front and rear widthwise compressed grooves 12b extending along the width direction of the sanitary napkin 1 and spaced apart in the longitudinal direction may be formed at the front and rear of the region H corresponding to the wearer's bodily fluid excretion area. Providing a pair of front and rear widthwise compressed grooves 12b along the width direction can suppress the diffusion of bodily fluids in the front and rear direction, preventing leakage from the front and rear ends of the absorbent body 4. Furthermore, when the sanitary napkin 1 is worn, the pair of front and rear widthwise compressed grooves 12b function as folding guide lines when the absorbent body 4 deforms to conform to the front and rear curvatures of the body. The pair of front and rear widthwise compressed grooves 12b may be formed by widthwise extending portions of the annular lines described above, or may be formed by independent arc-shaped lines extending widthwise and spaced apart in the longitudinal direction of the sanitary napkin 1. Alternatively, as shown in the illustrated example, a combination of annular lines and arc-shaped lines may form a plurality of widthwise compressed grooves 12b (four in the illustrated example). In the illustrated example, when four widthwise compressed grooves 12b are formed on the front and rear sides, it is preferable that the outermost widthwise compressed groove 12b be formed by an elliptical annular line extending in the width direction, the innermost widthwise compressed groove 12b be formed by a circular annular line extending in the width direction, and the two intermediate widthwise compressed grooves 12b, 12b be formed by independent arc-shaped lines. In this way, the innermost annular compressed groove can suppress the diffusion of body fluids near the vaginal opening, and after the body fluid has sufficiently diffused and reached a saturated state within this region and diffuses outward, the intermediate arc-shaped widthwise compressed grooves 12b, 12b suppress outward diffusion in the longitudinal direction, thereby reliably retaining the body fluid within the region surrounded by the outermost annular compressed grooves.

[0042] 3 and 5 to 7, the core press 10 is preferably intermittently positioned in the area overlapping with the compression grooves 12 and in the vicinity thereof, thereby forming a non-pressed portion 14 of a predetermined width around the compression grooves 12. That is, the core press 10 is not formed in the area of ​​the compression grooves 12 and a predetermined width around it, forming a non-compressed region (non-pressed portion 14) between the compression grooves 12 and the core press 10. By forming the non-pressed portion 14 around the compression grooves 12, body fluids that have diffused along the core press 10 are temporarily held in the non-pressed portion 14 before reaching the compression grooves 12, so that the diffusion rate of body fluids diffusing along the core press 10 drops sharply, and the body fluids are then more likely to change to flow along the compression grooves 12. Furthermore, since the core press 10 is not connected to the outside of the compression groove 12, the body fluids diffusing along the compression groove 12 can be prevented from diffusing outward along the core press 10, and the body fluids can be reliably confined within the area surrounded by the compression groove 12.

[0043] The non-pressed portions 14 are formed all around the compressed grooves 12 to prevent direct connection between the compressed grooves 12 and the core press 10. The width of the non-pressed portions 14 is preferably 0.5 to 5 mm from the viewpoints of ensuring the function as a buffer zone for bodily fluids and preventing the absorbent body 4 from becoming thick.

[0044] It is desirable to form the non-pressed portions 14 also around the longitudinal compressed grooves 12 a and the widthwise compressed grooves 12 b. Hereinafter, the term "compressed grooves 12" is intended to include the longitudinal compressed grooves 12 a and the widthwise compressed grooves 12 b.

[0045] 3, the groove width A of the compression grooves 12 is preferably larger than the groove width B of the linear press portion 11 of the core press 10 (A>B). This makes it difficult for bodily fluids diffusing along the compression grooves 12 to migrate into the core press 10, thereby suppressing the diffusion of bodily fluids outside the compression grooves 12. The ratio of the groove widths A and B is preferably A / B=1.5 to 3.

[0046] To form the core press 10 and the compression grooves 12 in the absorbent body 4, the core press 10 and the compression grooves 12 may be applied simultaneously using a convex roll having convex portions formed thereon corresponding to the core press 10 and the compression grooves 12, or the core press 10 may be formed and then the compression grooves 12 may be formed in the next step.

[0047] In the present sanitary napkin 1, as shown in Figures 3 and 4, a high-absorbency section 15 having a higher absorption capacity per unit area than other sections is formed at least between the left and right compressed grooves 12, 12 of the absorbent body 4. The area between the left and right compressed grooves 12, 12 is a region including region H corresponding to the wearer's bodily fluid discharge area. When compressed grooves 12, 12 consisting of independent arc-shaped lines are arranged on the left and right sides as shown in Figure 3, the high-absorbency section 15 is formed in a region including the area sandwiched between these compressed grooves 12, 12. Furthermore, when compressed grooves 12 consisting of circular lines formed to surround the periphery of region H corresponding to the bodily fluid discharge area are arranged as shown in Figure 5, the high-absorbency section 15 is formed within the area surrounded by these compressed grooves 12. Furthermore, when compressed grooves consisting of circular lines formed to surround the periphery of region H corresponding to the wearer's bodily fluid discharge area are formed inside compressed grooves consisting of circular lines formed to surround the periphery of region H corresponding to the wearer's bodily fluid discharge area as shown in Figures 6 and 7, the high-absorbency section 15 is formed within the area surrounded by the outermost compressed grooves 12. The above-mentioned "the high-absorbency portion 15 is formed at least between the compressed grooves 12, 12" means that when independent arc-shaped compressed grooves 12, 12 are formed on both sides as shown in Figure 3, the high-absorbency portion 15 may be formed to extend to either or both of the front and rear sides of the area sandwiched between the compressed grooves 12, 12, and in the illustrated example, to both sides. The high-absorbency portion 15 is preferably formed over almost the entire area between the left and right compressed grooves 12, 12, but it is sufficient that it is formed over at least a portion. As shown in Figures 5 to 7, when the compressed grooves 12 are formed in a circular line surrounding the periphery of area H corresponding to the wearer's body fluid excretion area, the high-absorbency portion 15 is preferably formed over almost the entire area surrounded by the compressed grooves 12.

[0048] The high-absorbency section 15 is set to have a larger absorption capacity per unit area than other sections. By providing the high-absorbency section 15 in the region H corresponding to the wearer's body fluid excretion area, the excreted body fluid can be sufficiently absorbed and retained in the high-absorbency section 15, and it is possible to prevent the body fluid from diffusing to regions outside the high-absorbency section 15. In addition, it is possible to prevent the body fluid from overflowing outside the compressed grooves 12 when the region surrounded by the compressed grooves 12 exceeds capacity (saturates), thereby preventing the body fluid from diffusing to the outside.

[0049] The absorption capacity per unit area is measured as follows. (1) With the napkin in a taut state (with the napkin unfolded along a flat surface without wrinkles or folds), the high absorbency section 15 and the other sections are cut out and the area is measured. At this time, the back sheet 2 and top sheet 3 are removed in advance. (2) Each of the divided sections is placed in a separate mesh bag, the openings are closed, and the bag is immersed in 0.9% by weight physiological saline and left to stand for 30 minutes. (3) The bag is dehydrated in a centrifugal dehydrator (10G) for 3 minutes. (4) The absorption capacity per unit area of ​​each section is calculated using the following formula: Absorption capacity per unit area (g / cm ２ ) = ((weight after dehydration (g) - (weight before immersion (g)) / area of ​​each part (cm ２ )

[0050] The absorption capacity per unit area measured as described above is 0.3 to 2.0 g / cm in the high absorbency portion 15. ２ , preferably 0.3 to 1.0 g / cm ２ The absorption capacity per unit area of ​​the high absorbency portion 15 is preferably 1.5 to 5 times, and more preferably 1.5 to 2.5 times, the absorption capacity per unit area of ​​the other portions.

[0051] The absorption capacity per unit area can be increased by increasing the basis weight of the pulp and superabsorbent polymer or by changing the type of superabsorbent polymer to one with a higher water absorption capacity. When increasing the basis weight of the pulp and superabsorbent polymer, increasing only the basis weight of the superabsorbent polymer makes this region harder, making the granular feel of the superabsorbent polymer more noticeable when worn. Therefore, it is preferable to increase the basis weight of the pulp at a rate roughly equivalent to the increase in the superabsorbent polymer. The increase in the basis weight of the pulp and superabsorbent polymer in the high absorbency section 15 should be 1.5 to 5 times, preferably 1.5 to 2.5 times, compared to other regions. Increasing the basis weight of the pulp and superabsorbent polymer increases the thickness of the high absorbency section 15 compared to other regions. However, because the core press 10 is also applied to the high absorbency section 15, even a slight increase in thickness does not affect the wearing comfort. Specifically, the difference in thickness between the high absorbency section 15 and other regions is preferably limited to an increase of 1 mm or less, although this will vary depending on the overall thickness of the absorbent body 4.

[0052] When the absorption capacity per unit area is increased by increasing the basis weight of the pulp and superabsorbent polymer, the rigidity of the highly absorbent section 15 becomes relatively high and the rigidity of other sections becomes relatively low, which has the effect of allowing the area H corresponding to the wearer's body fluid excretion section to remain in close contact with the body while the other sections can more easily follow the movement of the body.

[0053] When increasing the absorption capacity per unit area by changing the type of superabsorbent polymer, this can be achieved by using a superabsorbent polymer with a large water absorption capacity determined in accordance with JIS K7223 for the superabsorbent portion 15.

[0054] As shown in Fig. 6, when a plurality of longitudinal compressed grooves 12a are formed on at least both sides of region H corresponding to the wearer's body fluid excretion area, the absorbent body can be designed so that the inner region, bounded by the longitudinal compressed groove 12a, has a higher absorption capacity per unit area than the outer region. By gradually decreasing the absorption capacity per unit area from the inner region to the outer region, bounded by the longitudinal compressed groove 12a, body fluid can be sufficiently absorbed in the inner region before being dispersed to the outer region, further suppressing dispersion of body fluid and reliably preventing side leakage. In the example shown in Fig. 6, two longitudinal compressed grooves 12a are formed on each side. The central portion between the inner longitudinal compressed grooves 12a, 12a is designated as a high absorbency portion 15a having the highest absorption capacity per unit area, the annular portion between the outer longitudinal compressed groove 12a and the inner longitudinal compressed groove 12a is designated as a medium absorbency portion 15b having a lower absorption capacity per unit area than the central high absorbency portion 15a, and the portion outside the outer longitudinal compressed groove 12a (compression groove 12) is designated as a low absorbency portion having the lowest absorption capacity per unit area.

[0055] In the sanitary napkin 1 configured as described above, the absorbent body 4 is compressed in the thickness direction by the core press 10, thereby reducing its thickness, resulting in a slim napkin that is less likely to affect outerwear. However, depending on the conditions of use, body fluids may spread along the core press 10, raising concerns about side leakage, particularly from the widthwise edges. To address this issue, a pair of left and right compressed grooves 12, 12 are formed along the longitudinal direction of the sanitary napkin 1 on at least both sides of the region H corresponding to the wearer's body fluid excretion area, thereby blocking body fluids from spreading to the widthwise edges of the absorbent body 4. Furthermore, a high-absorbency section 15, which has a higher absorption capacity per unit area than other sections, is formed at least between the left and right compressed grooves 12, 12 of the absorbent body 4, allowing excreted body fluids to be absorbed and retained in the absorbent body 4 without spreading in the planar direction.

[0056] 2, the compressed grooves 12 are formed by compressing the absorbent body 4 from the skin side, either by compressing the absorbent body 4 alone or by compressing the enveloping sheet 5 and the absorbent body 4 together, so that the topsheet 3 covers the skin side of the compressed grooves 12 while forming spaces in the compressed grooves 12. However, as shown in Fig. 8, the compressed grooves 12 may also be formed by compressing the topsheet 3 from the skin side of the topsheet 3, with the topsheet 3 laminated on the skin side of the absorbent body 4, to integrally depress the topsheet 3 and the absorbent body 4, so that depressions are formed in the topsheet 3 along the sides and bottom of the compressed grooves 12. By depressing the topsheet 3 integrally with the absorbent body 4 at the compressed grooves 12, bodily fluids flowing widthwise outward on the surface of the topsheet 3 flow into the depressions of the compressed grooves 12 and are absorbed by the absorbent body 4 from the compressed grooves 12, and side leakage caused by fluid flowing laterally along the surface can also be prevented. Furthermore, by recessing the surface sheet 3 and the absorbent body 4 together, the surface sheet 3 and the absorbent body 4 become one body between the left and right compression grooves 12, 12 and come into close contact with the wearer's body fluid excretion area H, resulting in a good fit to the body, improved body fluid absorption performance, and improved wearing comfort.

[0057] 9, a pair of left and right compressed grooves 12, 12 may be formed by compressing the absorbent body 4 from the skin side, or by compressing the absorbent body alone or the enveloping sheet 5 and absorbent body 4 together, and then, with the topsheet 3 laminated to the skin side of the absorbent body 4, the topsheet 3 may be compressed from the skin side to separate the compressed grooves 12, 12 outward in the width direction, thereby depressioning the topsheet 3 and absorbent body 4 together, forming compressed grooves 13 in which the topsheet 3 is arranged along the sides and bottom of the depressions. The leakage prevention effect is further improved by forming compressed grooves 13 in which the topsheet 3 and absorbent body 4 are depressions together outside the compressed grooves 12 in which only the absorbent body 4 is depressioned.

[0058] Preferred embodiments of the present invention will be described below.

[0059] (Appendix 1) An aspect according to Appendix 1 is an absorbent article having an absorbent body interposed between a liquid-permeable top sheet and a liquid-impermeable back sheet, wherein a core press is formed on at least the surface of the absorbent body facing the top sheet, recessed toward the back sheet, and compressing the thickness of the absorbent body in the thickness direction, and a pair of left and right compression grooves is formed along the longitudinal direction of the absorbent article on at least both sides of a region corresponding to the wearer's body fluid excretion area, and a high-absorbency portion having a larger absorption capacity per unit area than other portions is formed at least between the pair of left and right compression grooves of the absorbent body.

[0060] In the aspect according to Supplementary Note 1, the absorbent body is core-pressed to compress its thickness in the thickness direction and reduce its thickness. Conventionally, in absorbent bodies with such core presses, body fluids diffuse along the core-pressed portion, where the fibers are densified by compression. This can lead to leakage (side leakage), particularly from the widthwise edges, depending on the conditions of use. However, in the present invention, a pair of left and right compressed grooves are formed along the longitudinal direction of the absorbent article on at least both sides of the region corresponding to the wearer's body fluid discharge area. This blocks fluid diffusion to the widthwise edges of the absorbent body, and a high-absorbency portion with a higher absorption capacity per unit area than other regions is formed between at least the left and right compressed grooves of the absorbent body. This allows the absorbent body to absorb and retain discharged body fluid without dispersing it in the planar direction.

[0061] Therefore, it is possible to provide a slim type absorbent article in which the thickness of the absorbent body is reduced, and in which the diffusion of bodily fluids in the planar direction, particularly in the width direction, is suppressed.

[0062] (Supplementary Note 2) In an embodiment according to Supplementary Note 2, there is provided the absorbent article according to Supplementary Note 1, wherein the compressed grooves are formed so as to surround the periphery of an area corresponding to an area where bodily fluids are excreted by the wearer.

[0063] In the aspect of Supplementary Note 2 above, by forming the compressed groove so as to surround the area corresponding to the wearer's bodily fluid excretion area, it is possible to suppress diffusion not only in the width direction but also in the front-to-back direction, thereby making it possible to reliably prevent leakage from the edge of the absorbent body.

[0064] (Appendix 3) As an aspect relating to Appendix 3, there is provided an absorbent article as described in either Appendix 1 or 2, in which the compressed grooves are formed in multiple rows on at least both sides of an area corresponding to the wearer's body fluid excretion area, and the absorption capacity per unit area of ​​the absorber is set to be larger in the inner area than in the outer area of ​​the compressed groove.

[0065] In the embodiment according to Supplementary Note 3, when a plurality of compressed grooves are formed on both sides of the absorbent article, the absorbent capacity per unit area is varied in stages at each compressed groove. This makes it possible to further suppress the diffusion of bodily fluids and more reliably prevent side leakage. The absorbent capacity per unit area can be adjusted by changing the basis weight of the pulp and the superabsorbent polymer or the type of superabsorbent polymer.

[0066] (Supplementary Note 4) In an aspect related to Supplementary Note 4, there is provided an absorbent article according to any one of Supplementary Notes 1 to 3, wherein the core press includes a plurality of linear press portions formed across the edge portions of the absorbent body, which are continuous or intermittent in the compression grooves.

[0067] In the aspect according to Supplementary Note 4, the core press is provided with a linear press portion formed across the edges of the absorbent body, thereby making it possible to reliably compress the thickness of the absorbent body.

[0068] (Appendix 5) In an aspect relating to Appendix 5, there is provided an absorbent article as described in Appendix 4, wherein the core press includes a first linear press portion that is inclined to one side in the width direction and is arranged in a plurality of positions at a predetermined interval in the longitudinal direction, and a second linear press portion that intersects with the first linear press portion, is inclined to the other side in the width direction, and is arranged in a plurality of positions at a predetermined interval in the longitudinal direction.

[0069] In the aspect according to Supplementary Note 5, the core press is formed in a grid pattern including first and second linear press portions that are inclined in different directions. This allows bodily fluids to diffuse along the first and second linear press portions, thereby suppressing diffusion in the width direction and making it easier for the absorbent body to deform obliquely along the first and second linear press portions, allowing it to more easily follow the movement of the body when torsion is applied to the absorbent body.

[0070] (Supplementary Note 6) In an aspect according to Supplementary Note 6, there is provided the absorbent article according to either Supplementary Note 4 or 5, wherein the groove width of the compressed grooves is set larger than the groove width of the linear press portion.

[0071] In the aspect of Supplementary Note 6 above, the groove width of the compression groove is made larger than the groove width of the linear press portion in order to prevent the diffusion of body fluids outside the compression groove by causing the body fluids that reach the compression groove to flow along the compression groove rather than through the core press adjacent to the outside of the compression groove.

[0072] (Appendix 7) As an aspect relating to Appendix 7, there is provided an absorbent article according to any one of Appendices 1 to 6, in which a pair of front and rear compressed grooves are formed along the width direction of the absorbent article at the front and rear of an area corresponding to the wearer's bodily fluid discharge area.

[0073] In the aspect according to Supplementary Note 7 above, by forming a pair of front and rear compressed grooves along the width direction of the absorbent article at the front and rear of the area corresponding to the wearer's bodily fluid discharge area, the diffusion of bodily fluids in the front and rear directions is suppressed, the effect of preventing leakage from the front and rear ends of the absorbent body is enhanced, and the pair of front and rear compressed grooves also function as folding guide lines that make it easier for the absorbent body to deform in line with the front and rear curvatures of the body.

[0074] (Appendix 8) In an aspect related to Appendix 8, there is provided an absorbent article according to any one of Appendices 1 to 7, in which the core press is intermittently pressed in the area overlapping with the compressed groove and in the vicinity thereof, thereby forming a non-pressed portion of a predetermined width around the compressed groove.

[0075] In the aspect according to Supplementary Note 8 above, by forming a non-pressed portion around the compression groove, the body fluid that has diffused along the core press is temporarily retained in the non-pressed portion before reaching the compression groove, thereby slowing down the diffusion rate of the body fluid and making it easier for the body fluid to diffuse along the compression groove thereafter.

[0076] This application claims priority based on Japanese Patent Application No. 2018-038352, filed with the Japan Patent Office on March 5, 2018, the entire contents of which are incorporated herein by reference.

[0077] DESCRIPTION OF SYMBOLS 1... sanitary napkin, 2... back sheet, 3... top sheet, 4... absorbent body, 5... envelope sheet, 7... side nonwoven fabric, 10... core press, 11... linear press section, 11a... first linear press section, 11b... second linear press section, 12... compressed grooves, 12a... longitudinal compressed grooves, 12b... widthwise compressed grooves, 13... compressed grooves, 14... non-pressed section, 15... high absorbency section, 16... central press section

Claims

DEPCT641. Assembled absorbent material: an absorbent provided between an impermeable back sheet and a permeable top sheet, which has at least one axial indentation formed on the surface of the absorbent facing the top sheet in a manner that reduces the thickness of the absorbent in the thickness direction; at least one left and right compression grooves are formed along the longitudinal direction of the absorbent material on the sides of the area corresponding to the body fluid drainage area of ​​the wearer; and at least one high-absorption area with a greater absorption capacity per unit area than other areas is formed between the left and right compression grooves of the absorbent material.

2. Absorbent material as claimed in claim 1, which has compression grooves formed around the area corresponding to the body fluid drainage area of ​​the wearer.3.The absorbent material as claimed in claim 1 is formed by multiple longitudinal compression grooves extending in the longitudinal direction and spaced apart from one another in the width direction at least on each side of the area corresponding to the body's fluid drainage area; and the absorption capacity per unit area of ​​the absorbent in the inner area within the longitudinal compression grooves is greater than the absorption capacity per unit area of ​​the absorbent in the outer area outside the longitudinal compression grooves.

4. The absorbent material as claimed in claim 1 is formed by multiple axial and linear compression sections between the edges of the absorbent and are either continuous or extending into the compression grooves. 5.The absorbent material as claimed in claim 4, the axial compression grooves include several first linear compression sections provided in the longitudinal direction at a predetermined distance and sloped laterally to one side in the width direction; and several second linear compression sections provided in the longitudinal direction at a predetermined distance, which slope laterally to the other side in the width direction and intersect the first linear compression section.

6. The absorbent material as claimed in claim 4, where the width of the compression groove is greater than the width of the linear compression groove.

7. The absorbent material as claimed in claim 1, where compression grooves are formed front and back along the width direction of the absorbent material in front and back of the area corresponding to the fluid drainage area of ​​the wearer's body. 8.The absorbent material as claimed in claim 1, which eliminates axial indentations at various locations where the axial indentations overlap with the compression grooves and in the vicinity of the compression grooves, in a manner that forms a non-compressive portion of a predetermined width around each compression groove.