absorbent articles

Abstract

To provide an absorbent article suppressing reduction of a wearing feeling caused by deviation or deformation of a wearing position.SOLUTION: An absorbent core 40 of an absorbent article comprises a plurality of fiber lumps which is formed of mainly, water absorbent fibers and synthetic fibers. The absorbent core 40 comprises on an excretion part facing region B, a fiber lump high ratio region R where the fiber lump ratio is greater than that of a front region A and a rear region C. The fiber lump high ratio region R has a width between both edges of the region R equal to a whole width of the absorbent core 40. The fiber lump high ratio region R has one or both of: a salient front side salient 43 which is salient forward of a vertical direction X by connecting both side edges; and a rear side salient 44 which is salient rearward of the vertical direction X by connecting both side edges, on a lateral direction center Y of the absorbent core 40.SELECTED DRAWING: Figure 5

Description

[Technical Field]

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

[0002] In the technical field of absorbent articles such as sanitary napkins used while being worn, various studies have been conducted to improve wearing comfort. For example, the present applicant previously disclosed an absorbent article having a central portion in a middle region of an absorbent core that is thicker than the first and second regions of the absorbent core, and the maximum width of the central portion is the same as the width of the absorbent core (Patent Document 1). In a plan view, the central portion has a front-side convex portion that is narrower than the maximum width and protrudes forward, or a rear-side convex portion that is narrower than the maximum width and protrudes rearward.

[0003] The present applicant has also previously disclosed absorbent articles equipped with an absorbent body containing fiber agglomerates containing synthetic fibers and absorbent fibers (Patent Documents 2 and 3). The absorbent articles described in Patent Documents 2 and 3 have different contents of fiber agglomerates and absorbent fibers in predetermined regions. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6221020 [Patent Document 2] Patent No. 6538948 [Patent Document 3] Patent No. 6763051 Summary of the Invention [Problem to be solved by the invention]

[0005] When worn, absorbent articles generally shift in position or become deformed, such as twisted, due to the wearer's body movements. Such shifts in position or deformation can cause a decrease in fit to the body, and there is a risk of a decrease in comfort when worn. Patent Documents 1 to 3 disclose techniques for improving comfort, but there is room for improvement in suppressing the decrease in comfort caused by shifts in position or deformation when worn.

[0006] Therefore, an object of the present invention is to provide an absorbent article that can suppress deterioration in wearing comfort caused by shifting of the wearing position or deformation. [Means for solving the problem]

[0007] The present invention relates to an absorbent article having an absorbent body with an absorbent core, which has a vertical direction corresponding to the front-to-back direction of the wearer and a horizontal direction perpendicular thereto, and which has an excretory part facing region including an area positioned facing the excretory part of the wearer, a front region located closer to the ventral side of the wearer than the excretory part facing region, and a rear region located closer to the back of the wearer than the excretory part facing region. The absorbent core preferably contains a plurality of fiber agglomerates mainly composed of absorbent fibers and synthetic fibers. The absorbent core preferably has a high fiber agglomerate ratio region in the excretory-facing region, the high fiber agglomerate ratio being greater than the front and rear regions, the fiber agglomerate ratio being the ratio of the mass of the absorbent fibers and the fiber agglomerates to the total mass of the absorbent fibers and the fiber agglomerates. The high fiber mass ratio region preferably has a width between both side edges thereof equal to the overall width of the absorbent core. It is preferable that the high fiber mass ratio region has, at the horizontal center of the absorbent core, either a front convex portion connecting both side edges and convex toward the front in the vertical direction, or a rear convex portion connecting both side edges and convex toward the rear in the vertical direction. [Effects of the Invention]

[0008] According to the absorbent article of the present invention, it is possible to suppress deterioration in wearing comfort caused by shifting of the wearing position or deformation. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a plan view schematically showing a sanitary napkin, which is one embodiment of the absorbent article of the present invention. [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Figure 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. [Figure 4] FIG. 4 is a cross-sectional view taken along line VV in FIG. [Figure 5] FIG. 5 is a perspective view of the absorbent core shown in FIG. 1, viewed from the non-skin-facing side. [Figure 6] FIG. 6 is an enlarged plan view showing a high fiber mass ratio region of the absorbent core shown in FIG. [Figure 7] FIG. 7 is an explanatory diagram schematically showing deformation of the sanitary napkin shown in FIG. 1 when worn. [Figure 8] 8(a) and (b) are enlarged plan views showing another embodiment of a high fiber agglomerate ratio region according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] The absorbent article of the present invention will now be described based on its preferred embodiments with reference to the drawings. Figures 1 to 4 show a sanitary napkin (hereinafter simply referred to as "napkin 1"), which is one embodiment of the absorbent article of the present invention. 1, the napkin 1 has a longitudinal direction X that corresponds to the front-to-back direction of the wearer and extends from the wearer's abdomen through the crotch area to the back, and a transverse direction Y that is perpendicular to the longitudinal direction X. In the longitudinal direction X, the napkin 1 has an excretory-area-facing region B including an excretory-area-facing region (excretion point) that faces the wearer's excretory area such as the vulva when worn, a front region A that is located further forward in the longitudinal direction X (toward the wearer's abdomen) than the excretory-area-facing region B, and a rear region C that is located further back in the longitudinal direction X (toward the wearer's back) than the excretory-area-facing region B, and is thus divided into three regions A, B, and C.

[0011] 1 is a plan view of a napkin 1 as viewed from the skin-facing side. In this specification, the "skin-facing side" refers to the side of an absorbent article or a component thereof (e.g., absorbent core 4) that faces the wearer's skin when the absorbent article is worn, and the "non-skin-facing side" refers to the side of an absorbent article or a component thereof that faces away from the skin when the absorbent article is worn. In other words, the skin-facing side is the side that is relatively close to the wearer's skin, and the non-skin-facing side is the side that is relatively far from the wearer's skin. "When worn" and "worn state" refer to the normal, proper wearing position, i.e., the state in which the absorbent article is worn while maintaining the proper wearing position.

[0012] As shown in Fig. 1, the napkin 1 has an absorbent main body 5 that is elongated in the longitudinal direction X. The absorbent main body 5 is the main part of the napkin 1 and comprises a topsheet 2, a backsheet 3, and an absorbent body 4. More specifically, the absorbent main body 5 comprises the absorbent body 4, which is the main liquid-absorbing part of the napkin 1, the topsheet 2 that is arranged on the skin-facing side of the absorbent body 4 and can come into contact with the wearer's skin, and the backsheet 3 that is arranged on the non-skin-facing side of the absorbent body 4. The absorbent body 4 is incorporated into the napkin 1 with its longitudinal direction aligned with the longitudinal direction X, and extends over substantially the entire length of the napkin 1 in the longitudinal direction X. In other words, the absorbent body 4 extends from the front region A through the excretory part-facing region B to the rear region C.

[0013] The topsheet 2 of this embodiment covers the entire skin-facing surface of the absorbent body 4. On the other hand, the backsheet 3 covers the entire non-skin-facing surface of the absorbent body 4, and further extends outward in the lateral direction Y from both side edges of the absorbent body 4 along the longitudinal direction X, forming side flap portions SF together with side sheets 6 described below. As the topsheet 2, various types of sheets conventionally used in absorbent articles such as sanitary napkins can be used without any particular limitation. For example, liquid-permeable sheets such as single-layer or multi-layer nonwoven fabrics and perforated films can be used. As the backsheet 3, liquid-impermeable sheets such as moisture-permeable resin films can be used.

[0014] The napkin 1 has side flap portions SF, each made of a sheet, on both sides of the absorbent body 5, extending outward from the side edges of the absorbent body 4 along the longitudinal direction X. The side flap portions SF are portions made of sheet members extending outward in the lateral direction Y from both side edges of the absorbent body 4 along the longitudinal direction X. The sheet members constituting the side flap portions SF extend from the front region A through the excretory part-facing region B to the rear region C, and are joined to each other at the extensions extending outward in the lateral direction Y from each of the both side edges of the absorbent body 4 by known joining means such as adhesive, heat sealing, or ultrasonic sealing. The side flap portions SF of this embodiment are made of a backsheet 3 and a side sheet 6 extending outward in the lateral direction Y from both side edges of the absorbent body 4.

[0015] The side flap portion SF may have a pair of wing portions extending outward in the horizontal direction Y beyond the peripheral portion on both the left and right sides along the vertical direction X of the absorbent main body 5. The pair of wing portions may be formed symmetrically with respect to a vertical center line extending in the vertical direction X by dividing the napkin 1 in half in the horizontal direction Y. In this case, the base of the front side (front region A side) of one wing portion and the base of the other wing portion are located at the same position in the vertical direction X. The wing portions generally have an adhesive portion (not shown) on their non-skin-facing side that secures the wing portions to clothing such as shorts. The wing portions are folded over onto the non-skin-facing (outer) side of the crotch of the clothing such as shorts. Therefore, the non-skin-facing side of the wing portions, on which the adhesive portion is formed, faces the wearer's skin during use, becoming the skin-facing side. Before use, the adhesive portion is covered with a release sheet (not shown) made of film, nonwoven fabric, paper, or the like.

[0016] When the side flap portions SF have wings, the excretory part facing region B is a region having the wings in the longitudinal direction X. Specifically, the excretory part facing region B is a region sandwiched between an imaginary line extending in the lateral direction Y through the base of each of the pair of wings on the front side in the longitudinal direction X, and an imaginary line extending in the lateral direction Y through the base of each of the pair of wings on the rear side.

[0017] The side flap portions SF of this embodiment do not have wing portions. In such cases where the absorbent article does not have wing portions (e.g., a disposable diaper), the excretory portion-facing region B may be any region that faces the excretory portion, and is typically a region located in the center when the absorbent article is divided into three equal parts in the longitudinal direction X.

[0018] In the napkin 1 of this embodiment, a pair of side sheets 6, 6 are arranged over substantially the entire length of the absorbent main body 5 in the longitudinal direction X so as to overlap both sides of the skin-facing surface of the absorbent main body 5, i.e., the skin-facing surface of the topsheet 2, along the longitudinal direction X. The side sheets 6 extend outward in the lateral direction Y from both side edges of the absorber 4 along the longitudinal direction X to form the skin-facing surfaces of the side flap portions SF. The pair of side sheets 6, 6 are joined to the topsheet 2 or other members by known joining means such as adhesive or heat embossing. Note that the configuration in which the topsheet 2 and the side sheets 6, 6 overlap includes both a configuration in which the two sheets 2, 6 are in contact and a configuration in which they are not in contact.

[0019] 2 and 3, the absorbent body 4 in this embodiment includes a liquid-absorbent core 40 and a liquid-permeable core wrap sheet 4a that covers the outer surface of the absorbent core 40. The absorbent core 40 forms the main body of the absorbent body 4. The absorbent core 40 and the core wrap sheet 4a may be joined together with an adhesive such as a hot-melt adhesive.

[0020] In this embodiment, the core wrap sheet 4a is a single continuous sheet. As shown in Figures 2 and 3, the core wrap sheet 4a covers the entire area of ​​one side of the absorbent core 40, and the extension portions of the core wrap sheet 4a that extend outward in the horizontal direction Y from both side edges of the absorbent core 40 along the vertical direction X are folded down below the absorbent core 40, thereby covering the entire other side of the absorbent core 40. Alternatively, the core wrap sheet 4a does not have to be a single continuous sheet, and may be composed of, for example, two sheets: a first core wrap sheet that covers one side of the absorbent core 40 and a second core wrap sheet that is separate from the first core wrap sheet and covers the other side of the absorbent core 40.

[0021] The absorbent core 40 contains a water-absorbing material. The water-absorbing material includes water-absorbent fibers 12F and water-absorbent polymers 13. The absorbent core 40 of this embodiment contains water-absorbent fibers 12F and water-absorbent polymers 13 as the water-absorbent material. The absorbent fiber 12F may be any absorbent fiber conventionally used as a material for forming the absorbent body (absorbent core) in this type of absorbent article. Examples of absorbent fibers include natural fibers such as wood pulp (e.g., softwood pulp, hardwood pulp) and non-wood pulp (e.g., cotton pulp, hemp pulp), modified pulp (e.g., cationized pulp, mercerized pulp), and regenerated fibers (e.g., cupra, rayon). These fibers may be used alone or in combination of two or more. Considering that the primary role of the absorbent fiber 12F is to improve the liquid absorbency of the absorbent body 4, natural fibers and regenerated fibers (cellulosic fibers) are preferred for the absorbent fiber 12F.

[0022] In the absorbent core 40 of this embodiment, the absorbent fibers 12F are entangled with each other, but preferably exist independently and not accumulated like the constituent fibers 11F of the fiber agglomerates 11 described below. The absorbent fibers 12F mainly contribute to improving the liquid absorbency of the absorbent core 40 and also contribute to improving the shape retention of the absorbent core 40.

[0023] The water-absorbent polymer 13 is present in the absorbent core 40 as a plurality of small pieces of water-absorbent polymer, and mainly contributes to improving the liquid absorbency within the absorbent core 40. The shape of the small pieces of water-absorbent polymer 13 is not particularly limited, and may be, for example, spherical, lumpy, bale-shaped, fibrous, or irregularly shaped. The average particle size of the water-absorbing polymer 13 is preferably 10 μm or more, more preferably 100 μm or more, and is preferably 1000 μm or less, more preferably 800 μm or less. Generally, a polymer or copolymer of acrylic acid or an alkali metal salt of acrylic acid can be used as the water-absorbing polymer 13. Examples thereof include polyacrylic acid and its salts, and polymethacrylic acid and its salts, and specifically, partial sodium salts of acrylic acid polymers such as AQUALIC CA and AQUALIC CAW (both manufactured by Nippon Shokubai Co., Ltd.).

[0024] The absorbent core 40 contains a plurality of fiber agglomerates 11 along with the water-absorbent material. The constituent fibers 11F of the fiber agglomerates 11 include thermoplastic fibers. In this specification, a "fiber agglomerate" refers to a fiber aggregate in which a plurality of fibers are grouped together. The method for producing the fiber agglomerates is not particularly limited, and may be, for example, a regular-shaped fiber aggregate such as a sheet piece obtained by cutting a synthetic fiber sheet (thermoplastic fiber sheet) having a certain size with a cutter or the like, or an irregular-shaped fiber aggregate produced by crushing a nonwoven fabric mainly composed of thermoplastic fibers (synthetic fibers) into small pieces or by plucking or tearing them off. The absorbent core of the present invention may be in the form of i) fiber agglomerates containing only regular fiber aggregates, ii) fiber agglomerates containing only irregular fiber aggregates, or iii) fiber agglomerates containing a mixture of regular and irregular fiber aggregates. When the fiber agglomerates 11 are regular fiber aggregates, the orientation of the constituent fibers is uniform, and the surface tends to be smooth. Such fiber aggregates are less likely to entangle with each other, allowing for a high degree of freedom of movement and contributing to the flexibility of the absorbent body 4. From this perspective, the fiber agglomerates are preferably in the form of i). In this embodiment, the fiber agglomerates 11 are regular fiber aggregates.

[0025] The fiber agglomerates 11 are fiber aggregates in which a plurality of fibers 11F are accumulated and integrated into agglomerated form, and a plurality of fiber agglomerates 11 are present in the absorbent core 40 while maintaining their shape. The fiber agglomerates 11 contribute to improving the flexibility, cushioning properties, compression recovery, and shape retention of the absorbent core 40, for example, due to the shape of the fiber aggregates.

[0026] The absorbent core 40 has a high fiber clump ratio region R in the excretory-part-facing region B, which has a higher fiber clump ratio than the front region A and the rear region C (see FIGS. 5 and 6). In this absorbent core 40, the excretory-part-facing region B has a different fiber clump ratio from the front region A and the rear region C. Hereinafter, the regions in the front region A and the rear region C that have a lower fiber clump ratio than the high fiber clump ratio region R will also be referred to as "low fiber clump ratio region R2." The absorbent core 40 is divided into a high fiber clump ratio region R and a low fiber clump ratio region R2, which have different fiber clump ratios. In other words, in the absorbent core 40 of this embodiment, the regions other than the high fiber clump ratio region R are the low fiber clump ratio regions R2. In the absorbent core 40 of this embodiment, the high fiber clump ratio region R is located between the front and rear low fiber clump ratio regions R2 in the longitudinal direction X.

[0027] The "fiber agglomerate ratio" is the ratio of the mass of the fiber agglomerates 11 to the total mass of the water-absorbent fibers 12F and the fiber agglomerates 11 in the absorbent core 40, and is expressed by the following formula (1). Fiber clump ratio (%) = [fiber clump 1 / (absorbent fiber 12F + fiber clump 1)] × 100 (1)

[0028] The high fiber clump ratio region R has a width W (see FIG. 6) between both side edges of the region R that is equal to the overall width of the absorbent core 40. The high fiber clump ratio region R has a portion that extends continuously across the entire width of the absorbent core 40 in the lateral direction Y. Hereinafter, the portion of the high fiber clump ratio region R that has a width equal to the overall width of the absorbent core 40 will also be referred to as the "full-width portion."

[0029] The high fiber clump ratio region R has, in the center of the transverse direction Y of the absorbent core 40, a front convex portion 43 that connects both side edges of the region R and convex forward in the longitudinal direction X, and a rear convex portion 44 that connects both side edges and convex rearward in the longitudinal direction X. In other words, in a plan view, the high fiber clump ratio region R has a front end edge in the longitudinal direction X that protrudes forward, and a rear end edge in the longitudinal direction X that protrudes rearward. The front portion that protrudes forward is the front convex portion 43, and the rear portion that protrudes rearward is the rear convex portion 44. The width W of the high fiber clump ratio region R between the front convex portion 43 and the rear convex portion 44 in the longitudinal direction X is equal to the overall width of the absorbent core 40.

[0030] The high fiber agglomerate ratio region R is identified by the following method. First, in the excretory region B of the absorbent core 40 and its vicinity, a region where 80% or more of the total mass of the fiber agglomerates 11 in the absorbent core 40 is concentrated is identified as a provisional region. This provisional region has a full-width portion that is the same width as the full width of the absorbent core 40. Both side edges of this full-width portion along the longitudinal direction X become both side edges of the provisional region. Next, for each of the front and rear ends of the provisional region in the longitudinal direction X, end ranges are set that are 5 mm long in the longitudinal direction X from the front and rear ends. Next, in this end range, the basis weight of the fiber agglomerates 11 is determined to be 30 g / m 2 The edges of the region where the basis weight of the fiber agglomerates 11 is 30 g / m2 or more and is continuous with the full-width portion are traced, and the edges are identified as the edges of the front-side convex portion 43 and the rear-side convex portion 44. In the end range, the basis weight of the fiber agglomerates 11 is 30 g / m2 or more. 2If the distance is equal to or greater than this and there is no region continuous with the full-width portion, a new end region is set that is adjacent to the end region and located more inward in the longitudinal direction X than the end region, and the process of identifying the edge of the front-side convex portion 43 and the edge of the rear-side convex portion 44 is repeated. The edge of the front-side convex portion 43 is the front edge of the high fiber clump ratio region R, and the edge of the rear-side convex portion 44 is the rear edge of the high fiber clump ratio region R. The region between the edge of the front-side convex portion 43 and the edge of the rear-side convex portion 44 in the longitudinal direction X is then defined as the high fiber clump ratio region R.

[0031] In this embodiment, the width of the front-side convex portion 43 gradually narrows toward the front in the longitudinal direction X, and the width of the rear-side convex portion 44 also gradually narrows toward the rear in the longitudinal direction X. Each of the front-side convex portion 43 and the rear-side convex portion 44 has a protruding edge that is curved outward in the longitudinal direction X. Such a protruding edge is curved with an apex located at the center in the lateral direction Y. As shown in FIG. 6, the width of each of the front-side convex portion 43 and the rear-side convex portion 44 is narrower than the width W of the entire width portion (see FIG. 6), so that the high fiber agglomerate ratio region R has a convex shape that protrudes forward or backward in the longitudinal direction X.

[0032] In this embodiment, the high fiber clump ratio region R is located in the excretory part-facing region B, and therefore, when the napkin 1 is worn, the high fiber clump ratio region R is located at the position of the wearer's excretory part. The high fiber clump ratio region R has a fiber clump ratio greater than that of the front and rear low fiber clump ratio regions R2, R2 and has an overall width portion the same width as the absorbent core 40, so that it can exhibit deformation suppression and deformation recovery properties against external forces applied to the napkin 1 when worn. For example, when the wearer moves, such as walking, torsional stress is likely to be applied about the diagonal lines E1, E2 of the napkin 1 (see FIG. 7), but since the high fiber clump ratio region R, which has a large fiber clump ratio, is located in the excretory part-facing region B, deformation (twisting) in the excretory part-facing region B is effectively suppressed. Furthermore, since the high fiber clump ratio region R contains a higher proportion of fiber clumps 11 than the low fiber clump ratio regions R2, R2, the napkin has high recovery from deformation caused by pressure from the wearer's legs and movement, and a good fit is achieved. As a result, wrinkles and gaps between the napkin 1 and the body are less likely to form, especially in the full-width portion, thereby preventing leakage. Furthermore, in the high fiber clump ratio region R, the front convex portions 43 and the rear convex portions 44 protrude outward in the longitudinal direction X, making these convex portions 43, 44 softer and more easily deformed than in the full-width portion. As a result, even if the napkin is misaligned, the front convex portions 43 and the rear convex portions 44 will conform well to the wearer's excretory area (vaginal opening) or intergluteal cleft. Due to the above effects, the napkin 1 of this embodiment provides an excellent fit even if the wearing position shifts, and therefore, deterioration in wearing comfort due to shifting of the wearing position or deformation can be effectively suppressed.

[0033] The high fiber agglomerate ratio region R of this embodiment has both the front side convex portion 43 and the rear side convex portion 44, but may have only one of the front side convex portion 43 and the rear side convex portion 44. From the viewpoint of further improving the fit, the high fiber clump ratio region R preferably has a front convex portion 43, and more preferably has both a front convex portion 43 and a rear convex portion 44.

[0034] From the viewpoint of improving the fit to the wearer's excretory area (vaginal opening) or intergluteal cleft and the ability to follow the body during movements such as walking, it is preferable that the front-side convex portion 43 extends to the front region A in the longitudinal direction X, or the rear-side convex portion 44 extends to the rear region C. In other words, it is preferable that the high fiber clump ratio region R continues beyond the front edge of the excretory area-facing region B to the rear end of the front region A in the longitudinal direction X, or continues beyond the rear edge of the excretory area-facing region B to the front end of the rear region C.

[0035] In the high fiber clump ratio region R, the protruding length L1 of the front convex portion 43 and the protruding length L3 of the rear convex portion 44 may be the same or different. From the viewpoint of further reducing the likelihood of gaps occurring between the body and the sanitary napkin and further improving the fit to the body, it is preferable that the protruding length L3 of the rear convex portion 44 be longer than the protruding length L1 of the front convex portion 43.

[0036] To further improve the fit to the wearer's excretory area (vaginal opening), the protruding length L1 (see FIG. 6) of the front convex portion 43 is preferably 5 mm or more and 25 mm or less, more preferably 10 mm or more and 20 mm or less. To further improve the fit to the wearer's intergluteal cleft, the protruding length L3 (see FIG. 6) of the rear convex portion 44 is preferably 5 mm or more and 40 mm or less, and more preferably 10 mm or more and 20 mm or less. The protruding length L1 of the front-side protrusion 43 (see FIG. 6) is the length in the longitudinal direction X between the front end of the front-side protrusion 43 and the entire width portion. The protruding length L3 (see FIG. 6) of the rear-side protrusion 44 is the length in the longitudinal direction X between the rear end of the rear-side protrusion 44 and the entire width portion.

[0037] To further improve fit, the length L (see FIG. 6) of the high fiber clump ratio region R in the longitudinal direction X is preferably 60 mm or more and 140 mm or less, and more preferably 80 mm or more and 120 mm or less. The length L of the high fiber clump ratio region R in the longitudinal direction X is the length from the front end of the front-side convex portion 43 to the rear end of the rear-side convex portion 44 in the longitudinal direction X (see FIG. 6).

[0038] To further reduce the deterioration of wearing comfort due to shifting of the wearing position or deformation, the fiber clump ratio (%) of the high fiber clump ratio region R is preferably 20% or more, more preferably 30% or more, and also preferably 60% or less, more preferably 50% or less, and also preferably 20% to 60%, more preferably 30% to 50%. The fiber clump ratio of such high fiber clump ratio region R is the fiber clump ratio in the entire width portion. From the same viewpoint as above, the fiber agglomerate ratio (%) of the low fiber agglomerate ratio regions R2, R2 is preferably 0% or more, and preferably 20% or less, more preferably 10% or less, and also preferably 0% or more and 20% or less, more preferably 0% or more and 10% or less.

[0039] Increasing the rigidity of the absorbent core 40 in the excretory region B relative to the front region A and the rear region C is effective in deforming the absorbent core 40 to curve along the body, and can contribute to better fit. From this perspective, it is preferable that the absorbent core 40 has a higher basis weight of the water-absorbent fiber 12F in the excretory region B relative to the front region A and the rear region C. From the same viewpoint as above, it is preferable that the basis weight of the water-absorbent fiber 12F of the absorbent core 40 in each of the regions A, B, and C is within the following range. In the absorbent core 40, the basis weight of the absorbent fibers 12F in the excretory region B is preferably 100% to 500%, more preferably 120% to 300%, of the basis weight of the absorbent fibers 12F in the front region A or the rear region C. The absorbent core 40 has a basis weight of the absorbent fiber 12F in the excretory region B of preferably 100 g / m 2 More than 640g / m 2 or less, more preferably 150 g / m 2 More than 490g / m 2 The following is the result. The absorbent core 40 has a basis weight of the water-absorbent fiber 12F in the front region A or the rear region C of preferably 100 g / m 2 More than 400g / m 2 or less, more preferably 150 g / m2 More than 350g / m 2 The following is the result. The basis weight of the absorbent fibers 12F in each of the front region A, excretory region B, and rear region C of the absorbent core 40 is the average basis weight of the absorbent fibers 12F in each region A, B, and C.

[0040] As described above, the absorbent core 40 of this embodiment contains the water-absorbent polymer 13 (see FIGS. 2 to 4). The distribution of the water-absorbent polymer 13 in the absorbent core 40 is not particularly limited, and it may be distributed uniformly throughout the absorbent core 40, or may be unevenly distributed in a portion of the absorbent core 40. From the viewpoint of further improving absorption performance, it is preferable that the water-absorbent polymer 13 is present in the high fiber agglomerate ratio region R. Alternatively, the water-absorbent polymer 13 may be present in the low fiber agglomerate ratio region R2. In order to increase the rigidity of the absorbent core 40 in the excretory region B compared to the front region A and the rear region C, thereby making it easier for the absorbent core 40 to deform along the body, it is preferable that the absorbent core 40 have a higher basis weight of the absorbent polymer 13 in the excretory region B than in the front region A and the rear region C, respectively.

[0041] From the same viewpoint as above, it is preferable that the basis weight of the water-absorbent polymer 13 of the absorbent core 40 in each of the regions A, B, and C is within the following range. In the absorbent core 40, the basis weight of the absorbent polymer 13 in the excretory region B is preferably 100% or more, more preferably 500% or more, and preferably 130% or less, more preferably 200% or less, of the basis weight of the absorbent polymer 13 in the front region A or the rear region C. The absorbent core 40 has a basis weight of the water-absorbent polymer 13 in the excretory region B of preferably 15 g / m 2 More than 100g / m 2 Less than 20 g / m, more preferably 2 More than 80g / m 2 The following is the result. The absorbent core 40 has a basis weight of the water-absorbing polymer 13 in the front region A or the rear region C of preferably 10 g / m 2 More than 70g / m2 Less than 15 g / m, more preferably 2 More than 60g / m 2 The following is the result. The basis weight of the water-absorbent polymer 13 in each of the front region A, excretory region B, and rear region C of the absorbent core 40 is the average basis weight of the water-absorbent polymer 13 in each of the regions A, B, and C.

[0042] In the absorbent body 4 of this embodiment, the high fiber clump ratio region R has a higher basis weight of the absorbent fibers 12F and fiber clumps 11 that are the materials forming the absorbent core 40 than the low fiber clump ratio region R2. As a result, the thickness t1 (see FIG. 2) of the high fiber clump ratio region R is greater than the thickness t2 (see FIG. 3) of the low fiber clump ratio region R2. In order to further improve the wearing comfort of the napkin 1, it is preferable that the thicknesses of the high fiber clump ratio regions R and the low fiber clump ratio regions R2 are within the following ranges. The thickness t2 of the low fiber agglomerate ratio region R2 (see Figure 3) is preferably 10% or more, more preferably 30% or more, and preferably 90% or less, more preferably 80% or less of the thickness t1 of the high fiber agglomerate ratio region R (see Figure 2). The thickness t1 (see FIG. 2) of the high fiber clump ratio region R is preferably 3 mm or more, more preferably 4 mm or more, and preferably 20 mm or less, more preferably 15 mm or less, and even more preferably 10 mm or less. When the absorbent body 4 is composed of an absorbent core 40 and a core wrap sheet 4a, multiple core wrap sheets may partially overlap (for example, the portion where two layers of core wrap overlap in the center in the lateral direction Y of the non-skin-facing surface of the absorbent core 40 in FIG. 2), and in that case, the thickness t1 of the high fiber clump ratio region R is the thickness at the position where the core wrap sheets do not overlap. The thickness t2 (see FIG. 3) of the low fiber agglomerate ratio region R2 is preferably 2 mm or more, more preferably 3 mm or more, and is preferably 7 mm or less, more preferably 5 mm or less. The thickness of each portion of the absorbent body 4, such as the high fiber clump ratio region R, is measured by the following method.

[0043] <Thickness measurement method> The absorbent body is placed on a horizontal surface without any wrinkles or bends, and a measurement sample is cut out from the absorbent body to obtain a measurement sample. 2 The thickness is measured under a load of 5 cN / cm. For example, a thickness gauge, PEACOCK DIAL UPRIGHT GAUGES R5-C (manufactured by OZAKI MFG.CO.LTD.), is used to measure the thickness. At this time, a load of 5 cN / cm is applied between the tip of the thickness gauge and the measurement sample. 2 The thickness is measured by placing a plate (an acrylic plate with a thickness of about 5 mm) that is circular or square in plan view and has been adjusted to fit the thickness. The thickness is measured at 10 random locations on the measurement sample, and the average value of the thicknesses at those 10 locations is calculated and used as the thickness of the measurement sample.

[0044] In the high fiber clump ratio region R of this embodiment, the fiber clumps 11 are not uniformly distributed throughout the absorbent core 40 in the thickness direction Z of the absorbent body 4, but are present in greater numbers on the non-skin-facing side than on the skin-facing side (see FIGS. 2 and 4). From the perspective of further improving absorbency and fit, it is preferable that the fiber clumps 11 are unevenly distributed on the non-skin-facing side of the absorbent core 40, at least in the high fiber clump ratio region R. Specifically, when the high fiber clump ratio region R is divided into two equal parts in the thickness direction Z into a skin-facing side region and a non-skin-facing side region, it is preferable that the fiber clumps 11 are more abundant on the non-skin-facing side region than on the skin-facing side region. In this case, the non-skin-facing side region has a higher fiber clump ratio than the skin-facing side region. This configuration is effective in that it allows the skin-facing side region to absorb body fluids well and maintains the shape retention of the high fiber clump ratio region R well even when the skin-facing side region becomes wet after absorbing body fluids.

[0045] The absorbent core 40 of this embodiment comprises a fiber agglomerate layer 47 and an absorbent layer 48 in the high fiber agglomerate ratio region R (see FIGS. 2 and 4). The fiber agglomerate layer 47 is a layer mainly containing fiber agglomerates 11. "Mainly containing" means that the content of fiber agglomerates 11 in the layer is 50% by mass or more. The content of fiber agglomerates 11 in the fiber agglomerate layer 47 is preferably 70% by mass or more, more preferably 90% by mass or more, and most preferably 100% by mass. The fiber agglomerate ratio of the absorbent layer 48 is lower than that of the fiber agglomerate layer 47. In this embodiment, the fiber agglomeration layer 47 is composed only of fiber agglomerations 11, and the absorbent layer 48 is composed of absorbent fibers 12F and absorbent polymers 13. By placing the fiber agglomeration layer 47 side on the non-skin facing side, the fiber agglomerations 11 are unevenly distributed on the non-skin facing side in the thickness direction Z of the absorbent core 40, as described above.

[0046] When worn, the excretory part-facing region B is located between the wearer's legs, and therefore, due to pressure and movement from the legs, gaps are likely to form between the napkin 1 and the body, and wrinkles are likely to form in the absorbent body 4. From the perspective of further suppressing the formation of such wrinkles and gaps and further improving the leakage suppression effect, it is preferable that the overall widths of the high fiber clump ratio region R and the absorbent core 40 in the excretory part-facing region B are equal. In this embodiment, the width of the full-width portion of the high fiber clump ratio region R is the same as the full width of the absorbent layer 48. In this case, the width W between both side edges of the high fiber clump ratio region R is equal to the full width of the absorbent core 40, and therefore the full width of the absorbent layer 48 and the full width of the fiber clump layer 47 in the excretory part-facing region B are also equal to the full width of the absorbent core 40.

[0047] In the absorbent core 40 of this embodiment, a plurality of longitudinal grooves 42 extending in the longitudinal direction X and a plurality of lateral grooves 41 extending in the lateral direction Y are arranged in each of the front region A and the rear region C (see FIG. 5). These longitudinal grooves 42 and lateral grooves 41 have openings on the non-skin-facing surface of the absorbent core 40. In the absorbent core 40 of this embodiment, the longitudinal grooves 42a in the front region A are arranged continuously from one end to the other end in the longitudinal direction X of the front region A. In addition, in the absorbent core 40 of this embodiment, the longitudinal grooves 42c in the rear region C are arranged continuously from one end to the other end in the longitudinal direction X of the rear region C. Each of these longitudinal grooves 42a, 42c is linear in plan view, and is arranged in plurality at predetermined intervals in the transverse direction Y. The absorbent core 40 of this embodiment has five longitudinal grooves 42a, 42c arranged intermittently in the transverse direction Y in each of the front region A and the rear region C (see FIG. 5). For convenience of explanation, the longitudinal grooves 42 and the lateral grooves 41 are omitted from FIG.

[0048] In the absorbent core 40 of this embodiment, the lateral grooves 41a in the front region A are arranged continuously between both side edges of the front region A. In addition, in the absorbent core 40 of this embodiment, the lateral grooves 41c in the rear region C are arranged continuously between both side edges of the rear region C. These lateral grooves 41a, 41c are linear in plan view and are arranged at predetermined intervals in the longitudinal direction X. The absorbent core 40 of this embodiment has three lateral grooves 41a, 41c arranged intermittently in the longitudinal direction X in each of the front region A and the rear region C (see FIG. 5). The lateral groove 41a located most inward in the longitudinal direction X in the front region A is disposed at the boundary between the front region A and the excretory part facing region B. The lateral groove 41c located most inward in the longitudinal direction X in the rear region C is disposed at the boundary between the rear region C and the excretory part facing region B.

[0049] In this embodiment, the longitudinal grooves 42 and the lateral grooves 41 are perpendicular to each other and form a lattice pattern in a plan view. As a result, the absorbent core 40 in each of the front region A and the rear region C is divided into a plurality of small absorbent sections s1 by the longitudinal grooves 42 and lateral grooves 41 that intersect with each other. That is, the absorbent core 40 in each of the front region A and the rear region C has a block structure having a plurality of block regions each consisting of a small absorbent section s1 with a relatively high basis weight and a longitudinal groove 42 and lateral groove 41 that surrounds the small absorbent section s1 and has a relatively low basis weight. When the absorbent core 40 has this block structure in each of the front region A and the rear region C (see FIG. 5), the absorbent core 40 in each of the front region A and the rear region C can deform more flexibly and more easily, thereby improving its ability to conform to the wearer's body.

[0050] From the viewpoint of further improving the ability to conform to the wearer's body, the width of each of the longitudinal grooves 42 and the lateral grooves 41 is preferably 0.5 mm or more and 4.0 mm or less, and more preferably 1.0 mm or more and 2.0 mm or less.

[0051] Each of the grooves 41, 42 in the absorbent core 40 has a shape in which the bottom is located on the side opposite the opening (so-called "depression" or "concave"). Alternatively, each of the grooves 41, 42 may have an opening on the skin-facing surface of the absorbent core 40 and a bottom on the side opposite the opening (non-skin-facing surface).

[0052] On the non-skin-facing surface of the absorbent core 40 of this embodiment, the front region A and the rear region C have a block structure, whereas the excretory part-facing region B has a flat surface.

[0053] In the absorbent core 40 of this embodiment, adjacent fiber agglomerates 11 are entangled with each other, and adjacent fiber agglomerates 11 are entangled with absorbent fibers 12F. The plurality of fiber agglomerates 11 in the high fiber agglomerate ratio region R may be bonded to the constituent fibers (fibers 11F, 12F) in the absorbent core 40 by entanglement to form a single continuous fiber agglomerate. In this manner, at least some of the plurality of fiber agglomerates 11 are entangled with other fiber agglomerates 11 or absorbent fibers 12F. The absorbent core 40 may contain a plurality of fiber agglomerates 11 that are all intertwined to form a single continuous fiber agglomerate, or may contain a plurality of continuous fiber agglomerates that are not bonded to each other and are mixed together.

[0054] The low fiber agglomerate ratio region R2 in the absorbent core 40 may or may not contain fiber agglomerates 11. When the low fiber agglomerate ratio region R2 contains fiber agglomerates 11, the fiber agglomerates 11 in the region R2 may be uniformly distributed in the thickness direction Z, unevenly distributed on the non-skin-facing side, or unevenly distributed on the skin-facing side.

[0055] Figure 8 shows another embodiment of the absorbent core according to the present invention. Regarding the embodiment shown in Figure 8, components that differ from the above-described embodiment will be mainly described, and similar components will be given the same reference numerals and will not be described again. For components that are not specifically described, the description of the above-described embodiment will be applied as appropriate.

[0056] In the absorbent core 40 of the above-described embodiment, the protruding edges of the front-side convex portions 43 and the rear-side convex portions 44 are curved, have an apex at the center in the horizontal direction Y, and have an arc shape that is convex outward in the vertical direction X. However, the present invention is not limited to this configuration. For example, as in the high fiber agglomerate ratio regions Ra and Rb shown in Figures 8(a) and 8(b), the protruding edges of the front-side convex portions 43a, 43b and the rear-side convex portions 44a, 44b may have a straight portion extending in the horizontal direction Y. In any configuration, the front end of the front-side convex portion in the vertical direction X and the rear end of the rear-side convex portion in the vertical direction X are located at the center of the absorbent core 40 in the horizontal direction Y.

[0057] 8(a), the protruding edges of the front and rear convex portions 43a, 44a are formed by straight line segments extending in the horizontal direction Y and oblique line segments connecting the straight line segments to the side edges of the high fiber clump ratio region Ra and intersecting the vertical direction X and the horizontal direction Y. With this configuration, the high fiber clump ratio region Ra has a substantially octagonal shape in plan view. In this embodiment, the front convex portion 43a and the rear convex portion 44a have a trapezoidal shape.

[0058] 8(b), the protruding edges of the front and rear convex portions 43b, 44b include a U-shaped portion that protrudes outward in the longitudinal direction X, and the side edges of the high fiber clump ratio region Ra are connected by the U-shaped portion and linear portions located on both sides of the U-shaped portion and extending in the transverse direction Y. With this configuration, the high fiber clump ratio region Rb has a generally cross-shaped shape in plan view. In this embodiment, the front convex portion 43b and the rear convex portion 44b have a rectangular shape.

[0059] In order to further improve the fit to the wearer's excretory area (vaginal opening) and intergluteal cleft, the front side convex portion and the rear side convex portion are preferably arc-shaped, trapezoidal, or rectangular, and more preferably arc-shaped or trapezoidal. From the viewpoint of further improving the deformation recovery property against the torsional stress about the diagonal lines E1, E2 of the napkin 1 due to walking or the like, the front side convex portion and the rear side convex portion are preferably arc-shaped or trapezoidal.

[0060] Next, a method for manufacturing an absorbent core according to the present invention will be described using the absorbent core 40 of the embodiment shown in the above-mentioned FIGS. 1 to 6 as an example. The absorbent core 40 can be manufactured in a conventional manner using a known fiber stacking device equipped with a rotating drum. The fiber stacking device typically includes a rotating drum having an accumulation recess formed on its outer circumferential surface and a duct having an internal flow path for transporting the core-forming materials (fiber mass 11, absorbent fiber 12F, and absorbent polymer 13) to the accumulation recess. While the rotating drum is rotated around its rotation axis along the drum circumferential direction, the core-forming materials are transported by an airflow generated in the flow path by suction from the inside of the rotating drum and stacked in the accumulation recess. The fiber stack formed in the accumulation recess by this fiber stacking process is the absorbent core 40. The specific arrangement of the core-forming materials in the absorbent core 40 described above can be achieved by appropriately adjusting the stacking order of the core-forming materials on the rotating drum in the manufacturing method using the fiber stacking device. The basis weight of the absorbent core 40 is preferably 200 g / m 2 More preferably, 250 g / m 2 or more, and preferably 500 g / m 2 Less than 400 g / m 2 The following is the result.

[0061] The absorbent core 40 can be manufactured by the following two methods using a known fiber stacking device. 1) A method in which two stacking devices are used to stack and integrate a stack produced by one stacking device with a stack produced by the other stacking device (hereinafter also referred to as the "first manufacturing method"). 2) A method in which one fiber stacking device is used, and the timing of supplying the fiber masses to the accumulation recess is made different from that of the water-absorbent fibers (hereinafter also referred to as the "second manufacturing method").

[0062] In the first manufacturing method, first, absorbent fibers and, if necessary, absorbent polymers are used as core-forming materials, and these absorbent materials are accumulated in an accumulation recess of a first fiber-stacking device to produce an absorbent fiber stack. Separately, fiber agglomerates are accumulated in an accumulation recess of a second fiber-stacking device to produce a fiber agglomerate stack. This fiber agglomerate stack is produced so that its longitudinal length is shorter than that of the absorbent fiber stack. Next, the fiber agglomerate stack is placed on the desired position of the absorbent fiber stack (for example, the center in the longitudinal direction), and pressure is applied in the thickness direction to integrate the absorbent fiber stack and the fiber agglomerate stack, thereby obtaining a laminate. Alternatively, a known suction means such as a vacuum conveyor may be used, and the absorbent fiber stack is placed on the suction surface of the suction means, and while the suction force of the suction surface is acting, the fiber agglomerate stack is placed on top of the absorbent fiber stack and integrated with the absorbent fiber stack, thereby obtaining a laminate. Regardless of the integration method, the absorbent fibers and fiber agglomerates are entangled at the interface between the absorbent fiber stack and the fiber agglomerate stack. In this manner, the absorbent core 40 is obtained. In the absorbent core 40, the portion where the fiber agglomerate stack is arranged corresponds to the high fiber agglomerate ratio region R. The fiber agglomerate stack corresponds to the fiber agglomerate layer 47 in the high fiber agglomerate ratio region R, and the absorbent fiber stack corresponds to the absorbent layer 48 in the high fiber agglomerate ratio region R.

[0063] In the second manufacturing method, a fiber stacking device is used in which the suction force of the accumulation recesses differs in parts. For example, an accumulation recess having a low suction recess and a high suction recess with a suction force higher than that of the low suction recess is used. The low suction recess and the high suction recess are connected in the rotation direction (circumferential direction) of the rotating drum of the fiber stacking device. Then, a fiber stacking device having such a configuration is operated, and the rotating drum is rotated in the circumferential direction to transport the accumulation recesses in one direction, while suction from the inside of the rotating drum generates an airflow from the outside of the rotating drum toward the accumulation recesses, and the core-forming material is supplied to and accumulated in the accumulation recesses by the airflow (accumulation process). In the accumulation process, first, fiber agglomerates 11 are supplied to and accumulated in the accumulation recesses. At this time, the fiber agglomerates 11 are concentrated and accumulated in the high suction recesses, and a fiber agglomerate stack is formed in the high suction recesses. Next, after or during the accumulation of the fiber agglomerates, absorbent fibers 12F and, if necessary, absorbent polymers 13 are supplied to the accumulation recess and accumulated. At this time, the absorbent fibers and polymers are accumulated in the low suction recesses of the accumulation recesses, and also on the fiber agglomerates 11 accumulated in the high suction recesses. In other words, absorbent fiber stacks are formed over the entire accumulation recesses. Because the fiber agglomerates 11 are breathable, even when the fiber agglomerates are accumulated in the high suction recesses, a suction force capable of attracting the absorbent fibers acts on the accumulated fiber agglomerates 11, allowing the absorbent fibers 12F and the absorbent polymers 13 to be accumulated on top of the fiber agglomerates 11 accumulated in the high suction recesses. In this way, a laminate of the fiber agglomerate stack and the absorbent fiber stack is formed in the high suction recesses, and the fiber agglomerates and the absorbent fibers are entangled at the interface between the two stacks. In this way, an absorbent core 40 is obtained. In the absorbent core 40, the portion where the fiber agglomerates 11 are concentratedly accumulated by the high suction recessed portion corresponds to the high fiber agglomerate ratio region R.

[0064] As described above, the fiber agglomerates 11 used in the absorbent core 40 are fiber aggregates in which multiple synthetic fibers are accumulated and integrated into agglomerates. That is, they are fiber aggregates in which multiple fibers are integrated together, and are configured separately from the absorbent fibers 12F. Such fiber agglomerates 11 can be obtained, for example, by cutting a synthetic fiber sheet to a specific size, resulting in a fiber aggregate of a fixed shape, such as a rectangular or disc-shaped sheet piece. Examples of suitable fiber agglomerates 11 include those described in JP 2019-063469 A, JP 2019-098157 A, and JP 2020-188918 A.

[0065] The size of the fiber agglomerates 11 is not particularly limited, and can be set appropriately taking into consideration the cushioning properties, liquid permeability, etc. of the absorbent core 40. For example, the area of ​​the largest surface among the multiple surfaces of a regular-shaped fiber agglomerate 11 can be an index of the size of the fiber agglomerates 11. The area of ​​the largest surface of the fiber agglomerates 11 is preferably 1 mm 2 More than 5mm, preferably 2 More than 100mm, preferably 2 Less than 50mm, preferably 2 The following is the result.

[0066] The constituent fibers 11F of the fiber agglomerates 11 include synthetic fibers such as thermoplastic fibers. It is preferable to use thermoplastic fibers as the fibers 11F. The content of synthetic fibers as the constituent fibers 11F in the fiber agglomerates 11 is preferably 90 mass% or more relative to the total mass of the fiber agglomerates 11, and it is most preferable that it is 100 mass%, i.e., the fiber agglomerates 11 are formed only from synthetic fibers.

[0067] Furthermore, from the viewpoint of enabling the absorbent core 40 to exhibit excellent effects in terms of shape retention, flexibility, cushioning, compression recovery, resistance to twisting, etc. in both dry and wet states, it is preferable that the fiber agglomerates 11 have a three-dimensional structure in which multiple thermoplastic fibers are heat-fused to each other. In order to obtain fiber agglomerates 11 in which a plurality of heat-fused portions are dispersed three-dimensionally, it is preferable to use a raw fiber sheet in which a plurality of heat-fused portions are dispersed three-dimensionally to manufacture the fiber agglomerates 11. Such a raw fiber sheet can be manufactured by subjecting a web or nonwoven fabric mainly made of thermoplastic fibers to a heat treatment such as hot air treatment.

[0068] The resin constituting the synthetic fiber is preferably a thermoplastic resin. Examples of thermoplastic resins include polyolefins such as polyethylene and polypropylene; polyesters such as polyethylene terephthalate; polyamides such as nylon 6 and nylon 66; polyacrylic acid, polymethacrylic acid alkyl esters, polyvinyl chloride, and polyvinylidene chloride. These can be used singly or in combination of two or more. Fiber 11F may be a single fiber made of one type of synthetic resin or a blend polymer of two or more types of synthetic resins, or a composite fiber. The composite fiber referred to here is a synthetic fiber obtained by combining two or more types of synthetic resins with different components in a spinneret and simultaneously spinning them. The multiple components are each continuous in the fiber length direction and mutually bonded within the single fiber. The form of the composite fiber may be a core-sheath type, a side-by-side type, or the like, and is not particularly limited.

[0069] Although the present invention has been described above based on the embodiments thereof, the present invention is not limited to the above embodiments and can be modified as appropriate. For example, in the high fiber clump ratio region R, the protruding end edge of the front side convex portion 43 may be arc-shaped, and the protruding end edge of the rear side convex portion 44 may be trapezoidal. The absorbent article of the present invention broadly includes articles used to absorb body fluids (urine, loose stools, menstrual blood, sweat, etc.) discharged from the human body, and includes not only the sanitary napkins mentioned above, but also sanitary shorts, so-called flat-type disposable diapers with fastening tapes, pants-type disposable diapers, incontinence pads, etc. [Explanation of symbols]

[0070] 1. Sanitary napkins (absorbent articles) 2 Surface sheet 3 Back sheet 4. Absorbent 4a Core Wrap Sheet 40 absorbent core 41 Yokomizo 42 Vertical grooves 43 Front convex part 44 Rear convex part 11 Fiber mass 12F Absorbent Fiber 13 Water-absorbent polymer A Anterior area B Excretory area facing area C Posterior area R High fiber mass ratio area R2 Low fiber mass ratio region s1 Small absorption area

Claims

1. An absorbent article comprising an absorbent body having an absorbent core, the absorbent body having an excretory part facing region including a region disposed facing the excretory part of the wearer, the region having a longitudinal direction corresponding to the front-to-back direction of the wearer and a lateral direction perpendicular thereto, a front region located closer to the ventral side of the wearer than the excretory part facing region, and a rear region located closer to the back of the wearer than the excretory part facing region, The absorbent core contains a plurality of fiber masses mainly composed of absorbent fibers and synthetic fibers, the absorbent core has a high fiber clump ratio region in the excretory region, the high fiber clump ratio region being higher than the front region and the rear region, the fiber agglomerate ratio is a ratio of the mass of the fiber agglomerates to the total mass of the absorbent fibers and the fiber agglomerates; the absorbent core, in the high fiber agglomerate ratio region, comprises a fiber agglomerate layer mainly containing the fiber agglomerates and an absorbent layer having a lower fiber agglomerate ratio than the fiber agglomerate layer, the fiber agglomerate layer being located closer to the non-skin-facing surface than the absorbent layer; In the excretory region facing region, the width between the opposite side edges of the high fiber clump ratio region is equal to the overall width of the absorbent core, and the absorbent article has, at the horizontal center of the absorbent core, either or both of a front side convex portion connecting the opposite side edges and convex toward the front in the vertical direction, and a rear side convex portion connecting the opposite side edges and convex toward the rear in the vertical direction.

2. The absorbent article according to claim 1 , wherein the absorbent core has a basis weight of the absorbent fibers in the excretory-facing region higher than that in the front region and the rear region.

3. The absorbent article according to claim 1 or 2, wherein the absorbent core contains a water-absorbing polymer, and the water-absorbing polymer has a basis weight higher in the excretory-facing region than in the front region and the rear region.

4. The absorbent article according to any one of claims 1 to 3, wherein the front side convex portion extends to the front region, or the rear side convex portion extends to the rear region.

5. An absorbent article described in any one of claims 1 to 4, wherein the front side convex portion or the rear side convex portion has a protruding end edge that is arc-shaped.

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