Physiological absorbent products

Abstract

To provide a sanitary absorbent article that can stably maintain a good wearing comfort over a long period of time. [Solution] The physiological absorbent article 1 includes a flap portion 9 extending outward from the periphery of the absorbent body 4. The outer edge of the flap portion has an intermediate bulge portion 91 that bulges laterally outward, a forward bulge portion 92 and a rear bulge portion 93 that bulge away from the absorbent body, and a forward boundary portion 94 and a rear boundary portion 95 that are close to the absorbent body. The absorbent core 7 has a fiber mass presence region 70 containing a plurality of intertwined fiber masses, a core front region, and a core rear region. The core front region and the core rear region each have a plurality of vertical low basis weight portions that are lower in basis weight than the surrounding area and extend linearly in the longitudinal direction, and do not have low basis weight portions that extend linearly in a direction intersecting the vertical low basis weight portions. The fiber mass presence region does not have low basis weight portions.

Description

[Technical Field]

[0001] This invention relates to sanitary absorbent articles such as sanitary napkins. [Background technology]

[0002] Menstrual absorbent articles such as sanitary napkins generally comprise an absorbent core, a surface sheet placed on the skin side of the absorbent core, and a back sheet placed on the non-skin side of the absorbent core. The absorbent core, which is the main component for absorbing menstrual blood, includes, for example, absorbent fibers 41 such as pulp fibers or absorbent materials such as superabsorbent polymers.

[0003] Since sanitary absorbent articles are used in close contact with the wearer's skin, comfort, such as fit, is important. Therefore, Patent Documents 1 and 2 disclose absorbent articles equipped with an absorbent core containing a fiber mass including synthetic fibers and water-absorbing fibers, from the viewpoint of improving comfort by enhancing the compression recovery of the absorbent core. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2020-163005 [Patent Document 2] Japanese Patent Publication No. 2020-188919 [Overview of the project] [Problems that the invention aims to solve]

[0005] On the other hand, during prolonged wear, changes in the wearer's posture and movements such as walking can repeatedly and frequently apply external forces to the sanitary absorbent material, potentially causing undesirable deformations such as wrinkles, creases, and twists. Therefore, there is a need for sanitary absorbent material that can more stably maintain a good wearing experience over extended periods.

[0006] The object of this invention is a physiological absorbent article that can stably maintain a good wearing comfort over a long period of time. [Means for solving the problem]

[0007] A physiologically absorbent article according to one embodiment of the present invention comprises an absorbent body having an absorbent core containing water-absorbent fibers, a surface sheet disposed on the skin side of the absorbent body, and a back sheet disposed on the non-skin side of the absorbent body, and has a longitudinal direction corresponding to the front-to-back direction of the wearer, a transverse direction perpendicular to the longitudinal direction and corresponding to the left-to-right direction of the wearer, and a thickness direction perpendicular to the longitudinal and transverse directions. The aforementioned physiologically absorbent article is With respect to the aforementioned longitudinal direction, the material is divided into an intermediate region including the area facing the wearer's vaginal opening, an anterior region located longitudinally forward of the intermediate region, and a posterior region located longitudinally backward of the intermediate region. In a plan view from the thickness direction, the absorber further comprises a flap portion extending outward from its periphery. The outer edge of the flap portion is Located in the aforementioned intermediate region, the intermediate bulge portion that bulges outward in the lateral direction, A forward bulge is located in front of the intermediate bulge in the longitudinal direction and bulges away from the absorbent, A rearward protrusion located behind the intermediate bulge in the longitudinal direction and bulging away from the absorbent, A forward boundary portion located at the boundary between the intermediate bulge and the forward outward protrusion, and adjacent to the absorbent, It has a rear boundary portion located at the boundary between the intermediate bulge portion and the rear outward protrusion portion, and adjacent to the absorber. The absorbent core is, It includes multiple intertwined fiber masses, and the fiber mass-existing region located in the intermediate region, The core front region located longitudinally forward of the fiber mass region, It has a core rear region located longitudinally behind the fiber mass region. The aforementioned core front region and the aforementioned core rear region, within each region, The basis weight of the water-absorbent fiber is lower than that of the surroundings, and it has a plurality of longitudinally low-basis-weight portions linearly extending in the longitudinal direction, and the basis weight of the water-absorbent fiber is not lower than that of the surroundings and does not have a low-basis-weight portion linearly extending in a direction intersecting the longitudinally low-basis-weight portion. In the fiber mass presence region, the basis weight of the water-absorbent fiber is not lower than that of the surroundings and does not have a low-basis-weight portion linearly extending. [Advantages of the Invention]

[0008] According to the sanitary absorbent article of the present invention, it is possible to stably maintain a good feeling of wearing over a long period of time. [Brief Description of the Drawings]

[0009] [Figure 1] It is a plan view showing a sanitary absorbent article according to a first embodiment of the present invention. [Figure 2] It is a cross-sectional view showing the above sanitary absorbent article, and is a view showing a cross-section cut along line II-II in FIG. 1. [Figure 3] It is a cross-sectional view showing the above sanitary absorbent article, and is a view showing a cross-section cut along line III-III in FIG. 1. [Figure 4] It is a plan view showing the absorbent core of the above sanitary absorbent article. [Figure 5] It is an enlarged plan view of a main part of the above sanitary absorbent article. [Figure 6] It is an enlarged plan view of a main part of the above absorbent core. [Figure 7] It is a plan view showing a sanitary absorbent article according to a second embodiment of the present invention. [Figure 8] It is a plan view showing a sanitary absorbent article according to a third embodiment of the present invention.

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0011] [First Embodiment] [Overall Configuration of Napkin (Sanitary Absorbent Article)] The sanitary absorbent article 1 according to the first embodiment of the present invention is configured as a sanitary napkin and will be hereinafter referred to as napkin 1. As shown in Figure 1, napkin 1 has a vertical direction X corresponding to the wearer's front-to-back direction and a horizontal direction Y corresponding to the wearer's left-to-right direction and perpendicular to the vertical direction X. Furthermore, napkin 1 has a thickness direction Z perpendicular to both the vertical direction X and the horizontal direction Y. Napkin 1 can be configured, for example, to be symmetrical (left-right symmetrical) with respect to a vertical center line CL that divides napkin 1 into two equal parts in the horizontal direction Y.

[0012] In this specification, "lateral direction Y inner" means the side approaching the vertical center line CL. "lateral direction Y outer" means the side away from the vertical center line CL. In this specification, "vertical direction X forward" means the forward direction in the vertical direction X, that is, the direction toward the wearer's abdominal side. "vertical direction X backward" means the backward direction in the vertical direction X, that is, the direction toward the wearer's back side. In this specification, "skin side" in the thickness direction Z means the side of the napkin 1 that is positioned toward the wearer when worn. "Non-skin side" in the thickness direction Z means the side of the napkin 1 that is positioned toward the clothing when worn. In this specification, "plan view" means a plan view seen from the thickness direction Z.

[0013] As shown in Figure 1, the napkin 1 is divided in the longitudinal direction X into an intermediate region C, which includes the area facing the wearer's vaginal opening; an anterior region F, which is located longitudinally X forward of the intermediate region C; and a posterior region R, which is located longitudinally X backward of the intermediate region C. In this embodiment, the range of the intermediate region C in the longitudinal direction X coincides with the range of the intermediate bulge 91 in the longitudinal direction X, which will be described later.

[0014] As shown in Figure 2, the napkin 1 comprises an absorbent 4, a surface sheet 2, and a back sheet 3. In the example shown in Figure 2, the napkin 1 has a structure in which the back sheet 3, the absorbent 4, and the surface sheet 2 are laminated in this order in the thickness direction Z. These components are joined together as appropriate, for example, by adhesive or heat sealing.

[0015] The absorbent body 4 absorbs and retains bodily fluids such as menstrual blood from the skin side. In this embodiment, the absorbent body 4 has an absorbent core 7 and a core wrap sheet 8. The absorbent core 7 is the main part that absorbs menstrual blood, etc. The core wrap sheet 8 covers the absorbent core 7 and has a function such as maintaining the shape of the absorbent core 7. Furthermore, it is more preferable from the viewpoint of maintaining the shape of the absorbent core 7 to cover at least one of the non-skin side and the skin side of the absorbent core 7 with two or more core wrap sheets 8. In particular, it is preferable that two core wrap sheets 8 are arranged on the non-skin side of the fiber mass layer 44, which will be described later, as this contributes to the shape stability of the fiber mass layer 44 when worn. The core wrap sheet 8 is made of, for example, thin and soft absorbent paper or liquid-permeable nonwoven fabric, and may have functional agents such as fragrances, deodorizers, and antibacterial agents added. The composition of the absorbent core 7 will be described later.

[0016] The surface sheet 2 is placed on the skin side of the absorbent material 4 and is made of a liquid-permeable sheet material such as a nonwoven fabric. The liquid-permeable sheet material is not particularly limited as long as it is a sheet material that can be used as a surface sheet for a physiological absorbent article. For example, the surface sheet 2 may contain polyolefin resins such as polyethylene or polypropylene, polyester resins such as polyethylene terephthalate, etc. The surface sheet 2 may also contain natural fibers such as cotton fibers.

[0017] The backing sheet 3 is positioned on the non-skin side of the absorbent material 4. From the viewpoint of suppressing menstrual blood leakage, the backing sheet 3 is preferably made of a sheet material having functions such as low liquid permeability and / or water repellency. Examples of such sheet materials include a thermoplastic resin film and a laminated sheet of the film and a nonwoven fabric. Furthermore, from the viewpoint of improving wearing comfort, the backing sheet 3 is preferably breathable and / or moisture permeable.

[0018] The non-skin-facing surface 3a of the back sheet 3 is provided with, for example, a main body fixing portion 6a for securing the napkin 1 to underwear. The main body fixing portion 6a is positioned so as to overlap with at least a part of the absorbent body 4 in a plan view. In the napkin 1, multiple main body fixing portions 6a extending in the lateral direction Y are intermittently arranged in the vertical direction X, and the length of the main body fixing portion 6a in the lateral direction Y is shorter than the core intermediate region 7C near the front and rear ends of the absorbent body 4. The main body fixing portion 6a may be made of, for example, an adhesive, a pressure-sensitive adhesive, a hook material, etc. As will be described later, the napkin 1 has a wing portion W, and fixing portions may also be provided on the non-skin-facing surface 3a of the wing portion W.

[0019] In the example shown in Figure 2, the napkin 1 is preferably further provided with a pair of side sheets 5, from the viewpoint of improving leak prevention on the lateral Y side. The pair of side sheets 5 are arranged on the lateral Y outer side of the surface sheet 2. The material of the side sheets 5 is preferably a sheet material with lower hydrophilicity than the surface sheet 2. Specifically, examples include nonwoven fabrics, films, and laminated sheets of nonwoven fabric and film, all of which have lower hydrophilicity than the surface sheet 2.

[0020] [Flap section configuration] In this embodiment, the napkin 1 further comprises a flap portion 9. The flap portion 9 is a portion that extends around the absorbent body 4 in a plan view. The flap portion 9 is composed of one or more of the back sheet 3, the front sheet 2, and the side sheet 5, for example, a laminate of the back sheet 3 and the front sheet 2, or a laminate of the back sheet 3 and the side sheet 5. The multiple sheet materials constituting the flap portion 9 are joined to each other by adhesive, heat, or sound wave fusion, etc.

[0021] The outer edge 9e of the flap portion 9 has a pair of intermediate bulges 91, a pair of front bulges 92, a pair of rear bulges 93, a pair of front boundary portions 94, and a pair of rear boundary portions 95, from the viewpoint of suppressing undesirable deformations such as twisting, sagging, and wrinkles when worn.

[0022] The intermediate bulge 91 is located in the intermediate region C and bulges outward in the lateral direction Y. In this embodiment, the formation range of the intermediate bulge 91 in the vertical direction X can be the intermediate region C. The front end of the intermediate bulge 91 in the vertical direction X is connected to the front boundary 94, and the rear end is connected to the rear boundary 95. "The intermediate bulge 91 bulges outward in the lateral direction Y" means that when a hypothetical straight line is drawn connecting the starting front boundary 94 and the rear boundary 95, the intermediate bulge bulges outward in the lateral direction Y beyond that line. In this embodiment, the intermediate bulge 91 can become the outer edge of the wing portion W, which will be described later. In the napkin 1 shown in Figure 1, the intermediate bulge 91 in the intermediate region C has an intermediate outward convex portion 91C located in the center in the vertical direction X and formed by a curve that is convex outward in the lateral direction Y, and first and second intermediate inward convex portions 91A and 91B located before and after it, respectively and formed by curves that are convex inward in the lateral direction Y. The intermediate bulge 91 only needs to have an intermediate outward projection 91C, and may have an intermediate straight section formed by a straight line instead of one or both of the first intermediate inward projection 91A and the second intermediate inward projection 91B. In this case, the connecting portions of the intermediate straight section and the front bulge 92 and rear bulge 93 become the front boundary section 94 and the rear boundary section 95.

[0023] The front bulge 92 is located longitudinally X forward of the intermediate bulge 91 and bulges away from the absorbent 4. In this specification, "away from the absorbent 4" means that if the outer edge 9e is located on the outside of the absorbent 4 in the lateral direction Y, it is at a position on the same imaginary line drawn parallel to the lateral direction Y, and if the outer edge 9e is on the end in the longitudinal direction X closer to the absorbent 4, it is at a position on the same imaginary line drawn parallel to the longitudinal direction X. In this case, the outer edge 9e of the flap portion 9 has a shape that bulges outward in a convex shape with respect to the direction in which the edge of the absorbent 4 extends (tangential direction). It is preferable that the distance between the outer edge 9e of the flap portion 9 and the outer edge of the absorbent 4 increases from the intermediate region C side of the napkin 1 towards the end in the longitudinal direction X. For example, the outer edge 9e longitudinally X forward of the front bulge 92 is composed of a curve that is convex outward in the longitudinal direction X, its end is the front end of the flap 9a, and the rear end of the front bulge 92 is connected to the front boundary portion 94.

[0024] The rear bulge 93 is located behind the intermediate bulge 91 in the longitudinal direction X and bulges away from the absorbent 4. For example, in napkin 1, the outer edge 9e of the rear bulge 93 in the longitudinal direction X is a rear connecting portion 93A formed by a curve that is convex inward in the longitudinal direction X, and its end is connected to the rear boundary portion 95. The rear end of the rear connecting portion 93A is connected to a rear outward convex portion 93B formed by a curve that is convex outward in the lateral direction Y. In the illustrated example, the rear end of the rear bulge 93 in the longitudinal direction X is connected to, for example, the front end of the flap inward convex portion 97, which will be described later.

[0025] The front boundary portion 94 is located at the boundary between the intermediate bulge portion 91 and the front bulge portion 92, and is close to the absorbent material 4. In other words, in the napkin 1, the front boundary portion 94 is the part at the boundary between the intermediate bulge portion 91 and the front bulge portion 92 where the distance to the absorbent material 4 in the lateral direction Y is narrowest. Specifically, the front boundary portion 94 may be a bent portion between the first intermediate inward convex portion 91A of the intermediate bulge portion 91 and the curve that constitutes the front bulge portion 92, or part of a curved portion or a short straight portion connecting these curves. In the example shown in Figure 1, the front boundary portion 94 is the part of the curved portion that curves inward in the lateral direction Y and backward in the vertical direction X, where the distance to the absorbent material 4 in the lateral direction Y is narrowest.

[0026] The rear boundary portion 95 is located at the boundary between the intermediate bulge portion 91 and the rear bulge portion 93, and is close to the absorbent material 4. In other words, in the napkin 1, the rear boundary portion 95 is the part at the boundary between the intermediate bulge portion 91 and the rear bulge portion 93 where the distance in the lateral direction Y from the absorbent material 4 is narrowest. Specifically, the rear boundary portion 95 may be a bent portion between the second intermediate inward convex portion 91B of the intermediate bulge portion 91 and the rear connecting portion 93A of the rear bulge portion 93, or a curved portion or a short straight portion connecting these curves. In the example shown in Figure 1, the rear boundary portion 95 is the part of the curved portion that curves convexly inward in the lateral direction Y where the distance in the lateral direction Y from the absorbent material 4 is narrowest.

[0027] In the above configuration, the flap portion 9 is locally close to the absorbent 4 at the front boundary portion 94 and the rear boundary portion 95. Therefore, if, for example, an external force such as a twisting force or compressive force is applied to the front region F and / or the rear region R, the front boundary portion 94 and / or the rear boundary portion 95 can become the starting point of deformation. As a result, the effect of deformation is localized to the front region F and the rear region R, and the effect extending to the intermediate region C can be suppressed. Furthermore, in order to maintain high fit in the intermediate region C, the napkin 1 of this embodiment has an absorbent core 7 with the following configuration.

[0028] [Composition of the absorbent core] As shown in Figures 2 and 3, the absorbent core 7 includes absorbent fibers 41. The absorbent fibers 41 can be any absorbent fiber usable in physiological absorbent articles, such as natural fibers like wood pulp or hydrophilic synthetic fibers. The absorbent core 7 may also contain an absorbent polymer 42 to further enhance absorbency. The absorbent polymer 42 can be any absorbent polymer usable in physiological absorbent articles, such as a polymer or copolymer of acrylic acid or an alkali metal acrylate salt.

[0029] The absorbent core 7 may be mainly composed of a stacked fiber containing water-absorbing fibers 41, or it may be mainly composed of a laminate of sheets (absorbent sheets) made of water-absorbing fibers 41. The stacked fiber, for example, is mainly composed of aggregates of water-absorbing fibers 41, with water-absorbing polymer 42 supported on the aggregate as needed. On the other hand, the absorbent sheet typically has a configuration in which water-absorbing polymer 42 is fixed inside or on the surface of a sheet made of water-absorbing fibers 41. From the viewpoint of increasing flexibility and assisting the action of the fiber mass 43 described later, it is preferable that the absorbent core 7 be mainly composed of a stacked fiber.

[0030] As shown in Figure 4, the absorbent core 7 has a core front region 7F, a core middle region 7C, and a core rear region 7R. The core front region 7F, the core middle region 7C, and the core rear region 7R are aligned along the longitudinal direction X. The core middle region 7C is located in the middle region C and coincides with the extent of the middle region C in the longitudinal direction X. The core front region 7F is located in front of the core middle region 7C in the longitudinal direction X. The core rear region 7R is located behind the core middle region 7C in the longitudinal direction X.

[0031] As illustrated in Figure 2, the core intermediate region 7C has a fiber mass presence region 70 that includes multiple intertwined fiber masses 43. In this specification, a fiber mass 43 is a fiber aggregate formed by the accumulation and integration of multiple fibers in a mass-like structure. "Intertwined fiber masses 43" means that the fibers constituting adjacent fiber masses 43 are not fused to each other, and that when an external force equivalent to that applied during wear is applied, the constituent fibers of the fiber masses 43 become intertwined and bonded to each other. Note that the fiber masses 43 do not need to be intertwined when no external force is applied, but it is preferable that they are intertwined. As will be described later, the fiber masses 43 contribute to improving the fit of the absorbent 4, for example.

[0032] From the viewpoint of suppressing the deterioration of properties due to the absorption of menstrual blood, the fiber mass 43 preferably mainly contains non-absorbent fibers. In this specification, "a certain component mainly contains a certain material" means that the content of that material in the component is 50% by mass or more. The content of non-absorbent fibers in all the fibers constituting the fiber mass 43 is preferably 90% by mass or more, more preferably 95% by mass or more, and even more preferably 100% by mass. As the non-absorbent fibers constituting the fiber mass 43, fibers with lower hydrophilicity (hydrophobic fibers) compared to the absorbent fibers 41 described above are preferred, and specific examples include synthetic fibers mainly composed of thermoplastic resin.

[0033] The shape of the fiber mass 43 is not particularly limited and may be irregular in shape, but a fixed shape can also be used, for example, a sheet piece obtained by cutting a nonwoven fabric sheet to a certain size. Examples of such fixed-shaped fiber masses include the fiber masses described in Japanese Patent Publication No. 2019-063469, Japanese Patent Publication No. 2019-098157, and Japanese Patent Publication No. 2020-188918. Specifically, it is preferable that the fiber mass 43 comprises, for example, two opposing basic surfaces and a skeletal surface connecting the two basic surfaces.

[0034] The fiber mass region 70 is located in at least the region facing the excretion area, and may be located in a part of the core intermediate region 7C or in the entire core intermediate region 7C. In a plan view, the fiber mass region 70 is the region where most of the fiber masses 43 included in the entire absorbent core 7 are located, and is, for example, the region where the fiber mass layer 44 described later is located. The fiber mass region 70 contains 80% by mass or more, more preferably 90% by mass or more, of the total mass of fiber masses 43 included in the entire absorbent core 7. When the basis weight distribution of the fiber masses 43 is measured in the core intermediate region 7C, the fiber mass region 70 has the maximum basis weight value of the fiber masses 43, and it is preferable that the basis weight of the fiber masses 43 outside the fiber mass region 70 is 5% or less of the above maximum basis weight value. The planar shape of the fiber mass region 70 in a plan view may be substantially rectangular or other shapes. In the examples shown in Figures 1 and 4, the planar shape of the fiber mass region 70 is such that the front and rear boundary lines in the longitudinal direction X are formed by curves that are convex in the longitudinal direction X and rear, respectively. Furthermore, it is preferable that the location of the fiber mass 43 having the maximum basis weight is at least the central part in the longitudinal direction X and / or the central part in the transverse direction Y of the fiber mass region 70.

[0035] The fiber mass region 70 may contain not only fiber masses 43 but also absorbent fibers 41. In this case, the fiber masses 43 may be entangled with other fiber masses 43 as well as with absorbent fibers 41. Furthermore, as shown in Figure 2, the fiber mass region 70 may have a layered structure in which the fiber masses 43 are located on the non-skin side and the absorbent material, mainly composed of absorbent fibers 41, is located on the skin side. This layered structure will be described later.

[0036] The fiber mass region 70 of the core intermediate region 7C contains multiple intertwined fiber masses 43, resulting in a configuration where multiple intertwined fiber masses 43 with high fiber density coexist with surrounding regions of relatively low fiber density (e.g., substantially fiber-free spaces). Therefore, the fiber mass region 70 can be easily compressed by pressing force in the thickness direction Z, allowing the low-density regions around the fiber masses 43 to return to their original shape upon release of the pressing force. Furthermore, the fiber mass region 70 maintains high shape retention due to the multiple intertwined fiber masses 43, thus maintaining a close fit with the vaginal opening and its surroundings. In this way, the fiber mass region 70 has high compression recovery properties, which can enhance the fit to the vaginal opening and its surroundings.

[0037] On the other hand, as shown in Figures 3 and 4, the core front region 7F and the core rear region 7R each have multiple vertical low basis weight sections 71F and 71R. In this embodiment, the vertical low basis weight section of the core rear region 7R is referred to as the rear vertical low basis weight section 71R, and the vertical low basis weight section of the core front region 7F is referred to as the front vertical low basis weight section 71F. When these are not distinguished, they are simply referred to as vertical low basis weight sections 71F and 71R.

[0038] The vertical low-basis-weight sections 71F and 71R have a lower basis weight of water-absorbing fibers 41 than the surrounding area and extend linearly in the vertical direction X. The vertical low-basis-weight sections 71F and 71R may be regions containing water-absorbing fibers 41 with a lower basis weight than the surrounding area, or they may be regions that substantially do not contain water-absorbing fibers 41. From the viewpoint of preventing damage to the absorbent core 7, it is preferable that the vertical low-basis-weight sections 71F and 71R contain water-absorbing fibers 41 with a lower basis weight than the surrounding area and are configured as grooves that open from either the skin-facing surface or the non-skin-facing surface, as shown in Figure 3. Since the vertical low-basis-weight sections 71F and 71R have lower rigidity than the surrounding area and are regions where stress from the surrounding area is less likely to be transmitted, deformation without wrinkles or twists in the core front region 7F and core rear region 7R can be promoted.

[0039] In this specification, the expression "the low-basis-weight portion extends linearly" includes both linear and curved extensions, as well as a mixture of linear and curved portions. "The low-basis-weight portion extends in the vertical direction X" means that the low-basis-weight portion as a whole extends in the vertical direction X, and includes a portion in which it is curved or meandering. In this embodiment, it is preferable that the vertical low-basis-weight portions 71F and 71R extend linearly along the vertical direction X, as shown in Figure 4.

[0040] Furthermore, the core front region 7F and the core rear region 7R each have a lower basis weight of the absorbent fibers 41 than the surrounding area and do not have low basis weight sections extending in a direction that intersects with the vertical low basis weight sections 71F and 71R. As a result, the core front region 7F and the core rear region 7R have strip-shaped absorbent sections 72F and 72R that extend in the vertical direction X without being divided by the low basis weight sections between adjacent vertical low basis weight sections 71F and 71R.

[0041] Furthermore, in this embodiment, it is preferable that the fiber mass region 70 does not have low-basis-weight sections where the basis weight of the water-absorbing fibers 41 is lower than the surrounding area and extends linearly. As a result, the fiber mass region 70 does not have locally low-rigidity sections, and undesirable deformations such as wrinkles and twists can be effectively suppressed. Therefore, the fiber mass region 70 can fit the vaginal opening and its surroundings in a stable shape and can continuously exhibit compression recovery properties. The ends of the vertical low-basis-weight sections 71F and 71R on the core intermediate region 7C side may be arranged to connect with the longitudinal X-front and rear boundary lines of the fiber mass region 70, or they may be spaced apart from these boundary lines. In the example shown in Figure 4, the ends of the vertical low-basis-weight sections 71F and 71R on the core intermediate region 7C side are arranged to connect with the above boundary lines of the fiber mass region 70, and more specifically, they are arranged on both boundary lines.

[0042] In the napkin 1 shown in Figures 1 and 4, the front and rear boundary lines of the fiber mass area 70 are formed by curves that are convex in the front and rear directions of the vertical X, respectively, with the center of the horizontal Y direction being the apex. For example, during wear, the pressure from the napkin can be effectively released along the vertical X direction at the vaginal opening and its surroundings, making it less likely to cause discomfort. Furthermore, in the napkin 1, when the wearer's body pressure is strongly applied from the groin to the buttocks while sitting, deformation occurs along the wearer's buttocks due to the vertically low basis weight portion 71R of the rear region R. In particular, deformation along the gluteal cleft is easily buffered at the rear end of the fiber mass area 70, and both sides of the fiber mass area 70 can bend softly and gently towards the wearer, using the front and rear boundary lines as axes.

[0043] [Main effects and benefits of the above configuration] In this embodiment, the effects of undesirable deformations (such as twisting, wrinkling, and kinking) and stresses (such as tension and compressive force) generated in the front region F and rear region R due to the wearer's movements and changes in posture can be suppressed from extending to the fiber mass region 70. Such effects can be achieved, for example, by the flap portion 9, the core front region 7F, and the core rear region 7R of the above configuration.

[0044] The function of the flap portion 9 will now be explained. The flap portion 9 extends from the absorber 4 and has lower rigidity and higher deformability compared to the region where the absorber 4 exists. In the front boundary portion 94 and rear boundary portion 95 of the above configuration, the width of the highly deformable flap portion 9 becomes narrower, so stress and deformation generated near the front bulge portion 92 and / or rear bulge portion 93 are less likely to be transmitted to the intermediate region C. For example, in the portion of the flap portion 9 that includes the front bulge portion 92 and rear bulge portion 93 as the outer edge 9e, twisting may occur due to walking or crossing legs, with one side being pulled towards the skin and the other towards the non-skin side, generating tension. In this case, the front boundary portion 94 and rear boundary portion 95, which are close to the absorber 4, become the starting point of the twist, suppressing the transmission of the tension to the intermediate region C and localizing the twisting deformation to the front region F and rear region R. Furthermore, for example, the portion of the flap 9 that includes the front bulge 92 and the rear bulge 93 as the outer edge 9e is susceptible to external forces acting laterally inward in the Y direction due to the movement of the left and right legs and buttocks. However, this portion can flexibly deform even under such external forces, starting from the front boundary 94 and the rear boundary 95, thereby suppressing the influence of this deformation on the intermediate region C.

[0045] Next, the function of the vertically low basis weight sections 71F and 71R in the core front region 7F and core rear region 7R will be explained. Because the basis weight of the water-absorbing fibers 41 is low in the vertically low basis weight sections 71F and 71R, when stress occurs in a direction intersecting these fibers, these sections can act as the starting point for deformation and suppress the transmission of such stress. For example, in the core rear region 7R, stress in a direction intersecting the longitudinal direction X may be constantly generated when the core deforms along the shape of the buttocks and gluteal cleft. Also, for example, in the core front region 7F and core rear region 7R, stress in a direction intersecting the longitudinal direction X, such as compressive force, may be frequently generated due to the movement of the legs and buttocks. The vertically low basis weight sections 71F and 71R can exert a stress buffering effect against such stresses and can suppress undesirable deformations such as wrinkles and twists.

[0046] In addition, the core front region 7F and core rear region 7R do not have low-basis-weight sections extending in a direction that intersects the vertical low-basis-weight sections 71F and 71R, but have strip-shaped absorbent sections 72F and 72R between adjacent vertical low-basis-weight sections 71F and 71R. As a result, stress is more easily transmitted within the strip-shaped absorbent sections 72F and 72R, and even locally applied external forces can easily deform a wider area of ​​the strip-shaped absorbent sections 72F and 72R. For example, when the wearer changes posture, such as sitting or lying down, or when moving, such as walking, a part of the area where the shape of the skin changes may come into contact with the napkin 1 and apply an external force (such as pressing force in the thickness direction Z or external forces along the vertical direction X and the horizontal direction Y). In the above configuration, even if the part that receives the external force from the skin is localized, the stress generated from that part can be transmitted along the strip-shaped absorbent sections 72F and 72R. As a result, a wide area of ​​the strip-shaped absorbing sections 72F and 72R can be easily deformed even by localized external forces, and the core front region 7F and core rear region 7R can be easily deformed to follow changes in body shape. Furthermore, even when the direction of external forces changes frequently due to changes in the wearer's posture or movements, the stress transmission effect of the strip-shaped absorbing sections 72F and 72R enhances the ability of the core front region 7F and core rear region 7R to follow changes in body shape.

[0047] In this way, the flap portion 9, the core front region 7F, and the core rear region 7R of the above configuration can exhibit a buffering effect against stresses that induce undesirable deformations, while also being able to flexibly deform in accordance with changes in posture and movement. As a result, in addition to maintaining a good wearing comfort in the front region F and the rear region R, it is possible to suppress the transmission of stresses and deformations generated in the front region F and the rear region R to the intermediate region C.

[0048] By suppressing the transmission of stress and undesirable deformation to the fiber mass region 70, the shape of the fiber mass region 70 can be maintained. This allows for the maintenance of close contact between the vaginal opening and its surroundings and the intermediate region C, and enables the continuous exercise of compression recovery by the fiber mass 43. Therefore, with the above configuration, even when wearing the garment for extended periods and frequently changing postures or movements occur, the fiber mass region 70 can maintain a good fit to the vaginal opening and its vicinity, thus maintaining a good wearing comfort and high leak-proof performance.

[0049] [Example configuration of the wing section and core intermediate region] The flap portion 9 preferably further has a pair of wing portions W extending outward in the lateral direction Y, with the outer edge of the flap portion 9 being formed by an intermediate bulge portion 91, as shown in Figures 1 and 2. In the example shown in Figure 2, the wing portions W are made of a laminate of a back sheet 3 and a side sheet 5. When worn, the wing portions W are artificially folded back to the non-skin-facing side of the crotch portion of the underwear and fixed to that non-skin-facing side.

[0050] Therefore, as shown in Figure 2, the wing portion W is positioned on a non-skin-facing surface (for example, the non-skin-facing surface 3a of the back sheet 3) and has a wing fixing portion (fixing portion) 6b for fixing to underwear. The wing fixing portion 6b, like the main body fixing portion 6a, can be made of, for example, an adhesive, a pressure-sensitive adhesive, a hook material, etc. By fixing the pair of wing portions W to the underwear by the wing fixing portion 6b, the wing portion W and the intermediate region C can be integrated with the underwear in between. This increases the rigidity of the intermediate region C, making it less susceptible to the effects of deformation that occurs in the front region F and the rear region R.

[0051] Furthermore, as shown in Figure 1, it is preferable that the front end portion 70a, located furthest forward in the longitudinal direction X of the fiber mass region 70, is located behind the front boundary portion 94 in the longitudinal direction X, and the rear end portion 70b, located furthest backward in the longitudinal direction X of the fiber mass region 70, is located furthest forward in the longitudinal direction X of the rear boundary portion 95. In Figure 1, the fiber mass region 70 is indicated by a dot pattern enclosed by dashed lines.

[0052] In the above configuration, the entire fiber mass region 70 is located inside the intermediate region C, making the fiber mass region 70 less susceptible to the effects of deformation that occurs in the front region F and the rear region R. Therefore, the shape of the fiber mass region 70 is maintained more stably, and the high fit and leak-proof performance provided by the fiber mass region 70 can be continuously achieved.

[0053] [Example of flap configuration in the rear region] As described above, the rear bulge 93 preferably has a rear outward curved portion 93B that curves outward in the lateral direction Y, as shown in Figure 5. In this case, the outer edge 9e of the flap portion 9 preferably further has a pair of flap tapered portions 96 that extend from the apex 93a located on the outermost side in the lateral direction Y of the rear outward curved portion 93B to the rear end portion 9b of the flap. The pair of flap tapered portions 96 is a region in which the distance in the lateral direction Y gradually decreases from the apex 93a toward the rear end portion 9b of the flap. In napkin 1, the flap tapered portion 96 includes the flap inward curve 97 and the rear end portion 9b of the flap.

[0054] With the above configuration, the flap portion 9 in the posterior region R has a shape that fits the shape of the gluteal cleft, which gradually becomes shallower towards the posterior (dorsal) side from near the boundary between the buttocks and the thigh (gluteal groove). For example, the posterior lateral convex portion 93B is located near the gluteal grooves on either side of the anus, and the flap tapered portion 96 extends from near the gluteal groove along the gluteal cleft to near the coccyx or sacrum at the posterior end of the gluteal cleft. In this way, the posterior region R can fit the shape of the gluteal cleft and its surroundings without discomfort. Furthermore, the flap portion 9 in the posterior region R is less likely to extend significantly to the posterior side of the buttocks. For example, during movements such as walking, the muscles on the posterior side of the buttocks contract and expand significantly. Also, in sitting or supine positions, the surface of the buttocks comes into contact with the seat or floor surface through clothing, and friction may occur between the buttocks and these surfaces due to changes in the wearer's posture. The rear region R of the above configuration does not extend easily to the back of the buttocks, making it less susceptible to external forces such as changes in the shape of the buttocks or friction. Therefore, the flap portion 9 of the above configuration can achieve a high level of comfort in the rear region R while suppressing undesirable deformations such as wrinkles and creases.

[0055] Furthermore, the flap tapered portion 96 has a flap convex portion 97 that curves inward in the lateral direction Y. The shape of the flap convex portion 97 that "curves inward in the lateral direction Y" means that when a straight line L1 is drawn that is tangent to two points on the outer edge of the flap tapered portion 96, the convex portion 97 curves inward in the lateral direction Y more than the straight line L1. The point on the flap convex portion 97 where the distance from the straight line L1 is maximum is defined as the apex 97a.

[0056] The inward convex portion 97 of the flap, which is part of the flap tapered portion 96, has a curved shape that follows the curves of the left and right buttocks facing toward the gluteal cleft (midline). This allows the flap tapered portion 96 to fit comfortably to the shape of the gluteal cleft and its surroundings. Therefore, the wearing comfort in the posterior region R can be further improved.

[0057] The flap tapered portion 96 preferably has the following shape from the viewpoint of more reliably improving the wearing comfort. For example, the angle θ1 formed by two imaginary straight lines L2 connecting the rear end portion 9b of the flap and the tops 93a of the pair of rear outward protrusions 93B is preferably 40° or more, more preferably 45° or more, even more preferably 50° or more, and preferably 100° or less, more preferably 95° or less, and even more preferably 90° or less.

[0058] Furthermore, the ratio (D2 / D1) of the distance D2 between the top 93a of the rear outward projection 93B and the rear end 9b of the flap in the lateral direction Y to the dimension D1 in the longitudinal direction X between the top 93a of the rear outward projection 93B and the rear end 9b of the flap is preferably 0.8 or more, more preferably 0.9 or more, and preferably 1.4 or less, and more preferably 1.3 or less.

[0059] Furthermore, it is preferable that the core rear region 7R is positioned on the lateral Y-inward side of the inward protrusion 97 of the flap. This allows the core rear region 7R, which has higher rigidity than the flap portion 9, to conform to the shape of the buttocks, thereby improving the wearing comfort and adaptability to changes in body shape in the rear region R.

[0060] Furthermore, it is preferable to have a core rear region 7R of sufficient length between the pair of flap tapered portions 96. Specifically, referring to Figure 5, when the dimension D1 in the longitudinal direction X between the top 93a of the rear outward protrusion 93B and the rear end portion 9b of the flap is taken as 100%, the ratio of the distance D5 in the longitudinal direction X between the core rear end portion 7b and the rear end portion 9b of the flap is preferably 50% or less, more preferably 30% or less. This allows the rigid core rear region 7R to restrict deformation in the area between the flap tapered portions 96, suppressing undesirable deformations such as wrinkles and twists. It also improves leak resistance in the rear region R.

[0061] Furthermore, as shown in Figure 5, it is preferable that the pair of flap tapered portions 96 are connected to each other at the rear end portion 9b of the flap to form a flap tip protrusion 98. The flap tip protrusion 98 is located behind the flap inner protrusion 97 in the longitudinal direction X and curves convexly in the longitudinal direction X rearward. From the viewpoint of fitting the shape of a narrow gluteal cleft, it is preferable that the radius of curvature of the flap tip protrusion 98 be smaller than the radius of curvature of the flap inner protrusion 97. Specifically, the ratio of the radius of curvature of the flap tip protrusion 98 to the radius of curvature of the flap inner protrusion 97 is preferably 0.05 or more, more preferably 0.1 or more, preferably 0.9 or less, and more preferably 0.85 or less. The radius of curvature of the flap tip protrusion 98 is preferably 5 mm or more, more preferably 7 mm or more, preferably 90 mm or less, and more preferably 80 mm or less. The radius of curvature of the inward protrusion 97 of the flap is preferably 10 mm or more, more preferably 15 mm or more, preferably 120 mm or less, and more preferably 100 mm or less.

[0062] [Example configuration of the core rear region] As shown in Figures 5 and 6, the core rear region 7R preferably has a core tapered portion 73 including the core rear end 7b. The core tapered portion 73 gradually decreases in dimension in the lateral direction Y from the front in the longitudinal direction X toward the core rear end 7b. The core rear end 7b is the part of the absorbent core 7 that is located furthest rear in the longitudinal direction X.

[0063] Furthermore, it is preferable that the core tapered portion 73 has a core inward curved outer edge which is a core inward curved convexly in the lateral direction Y. The shape of the core inward curved convexly in the lateral direction Y refers to a shape in which, when a straight line L3 is drawn tangent to two points on the outer edge of the core tapered portion 73 (for example, the end and another point in the longitudinal direction X forward of the core tapered portion 73), the core inward curves convexly in the lateral direction Y more than the straight line L3. The point on the core inward curved convex 74 where the distance from the straight line L3 is maximum is defined as the apex 74a.

[0064] In the above configuration, the core tapered portion 73, together with the flap tapered portion 96, has a shape that fits the shape of the gluteal cleft, which gradually becomes shallower from the vicinity of the gluteal groove towards the posterior (dorsal) side. The core inward convex portion 74, which is the outer edge of the core tapered portion 73, has a curved shape that follows the bulge of the buttocks facing toward the gluteal cleft (midline side). As a result, the core posterior region 7R itself, which is more rigid than the flap portion 9, has a shape that fits the shape of the gluteal cleft and its surroundings without discomfort, further improving the wearing comfort in the posterior region R. In addition, because the core posterior region 7R fits along the skin of the gluteal cleft and its surroundings, leakage of menstrual blood from the gluteal cleft and its surroundings can be effectively suppressed.

[0065] Furthermore, it is preferable that the core tapered portion 73 has a core tip projection 75 located behind the core inward projection 74 in the longitudinal direction X, and that this projection is an outer edge that curves convexly in the longitudinal direction X rearward. The end of the core tip projection 75 in the longitudinal direction X forward may be, for example, an inflection point between it and the core inward projection 74. Also, the apex of the core tip projection 75 in the longitudinal direction X rearward may be the core rear end portion 7b.

[0066] Behind the wearer's gluteal cleft, there is a protrusion caused by the coccyx and sacrum in the lower part of the spine. Because the core tapered portion 73 has a curved core tip protrusion 75, when the posterior end portion 7b of the core is located near the coccyx or sacrum, the core tip protrusion 75 can surround the protrusion. This allows the core tapered portion 73 to fit the shape of the posterior part of the buttocks more closely.

[0067] Furthermore, the ratio (D4 / D3) of the dimension parallel to the lateral Y direction D4 between the outermost lateral Y end of the core tapered portion 73 and the core rear end 7b of the core tip protrusion 75 to the length dimension D3 of the core tapered portion 73 in the longitudinal direction X of the core tapered portion 73 is preferably 0.6 or more, more preferably 0.7 or more, particularly preferably 0.75 or more, and preferably 1.3 or less, more preferably 1.2 or less, and particularly preferably 1.15 or less. Within this range, the fit to the curve of the buttocks is good, and even when the wearer moves vigorously, the core tapered portion 73 fits around the buttock cleft, making it easier to suppress leakage of menstrual blood from the rear. Specifically, the length dimension D3 is the dimension in the longitudinal direction X between the front end 73a, which is located furthest forward in the longitudinal direction X of the core tapered portion 73, and the core rear end 7b.

[0068] The radii of curvature of the core tip projection 75 and the core inner projection 74 can be set to fit the shape of the buttocks and gluteal cleft, respectively. For example, the ratio of the radius of curvature of the core tip projection 75 to the radius of curvature of the core inner projection 74 is preferably 0.6 or more, more preferably 0.7 or more, preferably 1.4 or less, and more preferably 1.3 or less.

[0069] [Example of configuration for the vertically low-basic-weight section] From the viewpoint of more effectively exhibiting the above-mentioned effects, the vertical low-basis-weight sections 71F and 71R preferably have the following configuration. For example, the total number of multiple rear vertical low-basis-weight sections 71R is preferably 2 or more, more preferably 3 or more, preferably 10 or less, and more preferably 8 or less. The total number of front vertical low-basis-weight sections 71F is preferably 2 or more, more preferably 3 or more, preferably 10 or less, and more preferably 8 or less. The total number of front vertical low-basis-weight sections 71F may be the same as or different from the total number of rear vertical low-basis-weight sections 71R, but from the viewpoint of achieving a more comfortable wearing experience, it is preferable that the total number of these sections be the same. Furthermore, in this case, it is even more preferable that the front vertical low-basis-weight sections 71F are arranged on a virtual extension line that extends the rear vertical low-basis-weight section 71R in the vertical direction X forward.

[0070] For example, the width dimension of each vertical low-basis-weight section 71F, 71R perpendicular to the extending direction is preferably 0.5 mm or more, more preferably 1 mm or more, from the viewpoint of exhibiting sufficient deformability. Furthermore, the width dimension is preferably 5 mm or less, more preferably 4 mm or less, from the viewpoint of suppressing damage to the absorbent core 7. The width dimensions of each vertical low-basis-weight section 71F, 71R may be the same or different.

[0071] For example, the distance (spacing) in the lateral direction Y between adjacent vertical low-basis-weight sections 71F and 71R in the lateral direction Y is preferably 4 mm or more, more preferably 5 mm or more, preferably 20 mm or less, and more preferably 15 mm or less.

[0072] [Example of the structure of the fiber mass region] As described above, in the fiber mass region 70, from the viewpoint of enhancing the absorbency of the water-absorbing fibers 41, it is preferable that the fiber mass 43 is predominantly located on the non-skin side. From this viewpoint, referring to Figure 2, when the fiber mass region 70 is divided into two equal parts in the thickness direction Z to form a skin-side region 7P and a non-skin-side region 7Q, it is preferable that the ratio of the mass of the fiber mass 43 to the total mass of the water-absorbing fibers 41 and the fiber mass 43 in the non-skin-side region 7Q is higher than the ratio in the skin-side region 7P. This allows the water-absorbing fibers 41 to be predominantly located in the skin-side region 7P, thereby enhancing the absorbency of menstrual blood. Furthermore, the fiber mass 43 can be predominantly located in the non-skin-side region 7Q, allowing it to exhibit the above-mentioned compression recovery without hindering absorbency.

[0073] The method for calculating the above ratio will now be explained. First, a portion of the skin-side region 7P of the fiber mass region 70 is cut to obtain a cut piece. The mass of the fiber mass 43 and the water-absorbing fibers 41 present in this cut piece is measured. By dividing the mass of the fiber mass 43 by the total mass of the fiber mass 43 and the water-absorbing fibers 41, the above ratio for the skin-side region 7P can be calculated. The above ratio for the non-skin-side region 7Q can be calculated in the same manner.

[0074] From the viewpoint of realizing the above configuration, it is preferable that the fiber mass region 70, as shown in Figure 2, has a fiber mass layer 44 mainly containing fiber masses 43 and an absorbent layer 45 mainly consisting of water-absorbing fibers 41, which is located on the skin side of the fiber mass layer 44.

[0075] The fiber agglomeration layer 44 may contain only fiber agglomerations 43, or it may contain absorbent fibers 41 in addition to fiber agglomerations 43. The fiber agglomeration layer 44 contains 50% by mass or more, preferably 90% by mass or more, more preferably 95% by mass or more, and even more preferably 100% by mass. In this embodiment, it is preferable that the fiber agglomeration layer 44 is arranged along the entire length of the lateral Y direction of the fiber agglomeration region 70.

[0076] The absorbent layer 45 may be a stacked fiber mainly composed of absorbent fibers 41, or a laminate of absorbent sheets mainly composed of absorbent fibers 41. The content of absorbent fibers 41 in the absorbent layer 45 is 50% by mass or more, preferably 80% by mass or more, and more preferably 90% by mass or more. From the viewpoint of enhancing absorbency, the absorbent layer 45 may also contain an absorbent polymer 42 in addition to the absorbent fibers 41.

[0077] The absorbent layer 45 is preferably in contact with the fiber mass layer 44. In this case, the absorbent fibers 41 contained in the absorbent layer 45 are preferably entangled with the fibers of the fiber mass 43 at the boundary with the fiber mass layer 44. This facilitates stress transmission between the absorbent layer 45 and the fiber mass layer 44, making the fiber mass layer 44 more susceptible to compressive deformation by external forces from the skin side. The boundary between the absorbent layer 45 and the fiber mass layer 44 may be indistinct.

[0078] Furthermore, the absorbent layer 45 may be formed continuously with the core front region 7F and the core rear region 7R. This allows the absorbent core 7 to maintain its shape even during prolonged wear. In this case, the fiber mass region 70 becomes thicker than the core front region 7F and the core rear region 7R by the amount of the fiber mass layer 44, making it easier to fit the wearer's excretory area.

[0079] The aforementioned "compression recovery" can be evaluated using the compression work (hereinafter also referred to as "WC") and recovery work (hereinafter also referred to as "WC'") as indicators. WC is an indicator of the cushioning properties of the object being measured; the larger the WC value, the better the cushioning properties of the object, and therefore the better the compression recovery properties. WC' is an indicator of the recovery properties (compression recovery) of the object being measured after an external force is applied to compress it and then the external force is removed; the larger the WC' value, the better the compression recovery properties of the object being measured.

[0080] This section describes the measurement method for compression work (WC) and recovery work (WC'). It is generally known that the WC and WC' to be measured can be expressed by measurements taken using the KES (Kawabata Evaluation System) manufactured by Kato Tech Co., Ltd. (Reference: Standardization and Analysis of Texture Evaluation (2nd Edition), author: Sueo Kawabata, published July 10, 1980). Specifically, WC and WC' can be measured using the KES-G5 compression test apparatus manufactured by Kato Tech Co., Ltd. The measurement procedure is as follows: First, the sample is mounted on the test stand of the compression test apparatus. The sample is, for example, a physiologically absorbent item such as napkin 1. The sample is dry and has a rectangular shape in plan view with dimensions of 5 mm in length and 5 mm in width. Next, the sample is measured over an area of ​​2 cm². 2 The sample is compressed between steel plates with circular planes. The portion to be compressed is the uncompressed part of the sample, i.e., the part that has not undergone any compression processing and retains its original form. The compression speed is 0.2 cm / sec, and the maximum compression load is 2450 mN / cm². 2 SENS is set to 10 and DEF to 20. The recovery process is also measured at the same rate. WC is expressed by the following formula (1), and WC' is expressed by the following formula (2), with the unit being "mN·cm / cm". 2 ". In the following formula, T m This is at maximum load (2450 mN / cm²). 2 (4.9kPa)) indicates the thickness, and T0 is the minimum load (4.902mN / cm²). 2 This indicates the thickness of (49 Pa). Also, P in equation (1) below a and P in equation (2) below brespectively represent the measured load (mN / cm 2 ) during the compression process and the measured load (mN / cm 2 ) during the thickness recovery process.

[0081] [Number]

[0082] [Number]

[0083] Note that WC' is not displayed on the measurement result screen of KES - G5. What is displayed on the measurement result screen is WC and the compression recovery rate or compression resilience (hereinafter also referred to as "RC") calculated from WC'. In such a case, WC' is calculated by the following formula using the parameters (WC, RC) displayed on the measuring device.

[0084] [Number]

[0085] The ratio of the WC of the intermediate region C to the WC of the front region F or the rear region R is preferably 1.5 or more, more preferably 1.7 or more. The WC of the intermediate region C is preferably 100 mN·cm / cm 2 or more, more preferably 120 mN·cm / cm 2 or more. The upper limit of the WC of the intermediate region C is not particularly limited, but from the perspective of reducing the thickness in the individual packaging state of the sanitary absorbent article, it is preferably 300 mN·cm / cm 2 or less, more preferably 280 mN·cm / cm 2 or less.

[0086] The ratio of the WC' of the intermediate region C to the WC' of the front region F or the rear region R is preferably 1.5 or more, more preferably 1.7 or more. The WC' of the intermediate region C is preferably 100 mN·cm / cm 2 or more, more preferably 120 mN·cm / cm2 That concludes the explanation. There is no particular upper limit to WC' in intermediate region C, but from the viewpoint of reducing the thickness of the individually packaged physiological absorbent articles, it is preferably 300 mN·cm / cm. 2 More preferably, 280 mN·cm / cm 2 The following applies:

[0087] [Example of compression groove configuration] As shown in Figures 1 and 6, the absorbent body 4 preferably further comprises a pair of first compression grooves 11 extending in both the longitudinal direction X and the transverse direction Y and located in the rear region R. In this specification, "compression groove" is a groove formed by compression processing from the surface sheet 2 toward the absorbent body 4, and the surface sheet 2 and the absorbent body 4 have a configuration in which they are integrally recessed on the non-skin side. Furthermore, "the compression groove extends in a predetermined direction" is not limited to the compression groove extending linearly in that predetermined direction, and at least a part of it may be bent and / or curved. The compression groove may be configured in which recessed compression portions are continuously formed, or a plurality of compression portions may be arranged with slight intervals between them, forming a groove as a whole. When the compression groove is formed by a plurality of compression portions, the distance between adjacent compression portions is preferably 5 mm or less, more preferably 4 mm or less.

[0088] The first compression groove 11 is more rigid and less prone to deformation compared to other areas. Therefore, when the napkin 1 is subjected to a relatively large external force, the first compression groove 11 can function as a deformation initiation point that promotes deformation in the surrounding low-rigidity areas.

[0089] For example, the first compression grooves 11 are arranged spaced apart from each other on both sides of the longitudinal center line CL in the lateral direction Y. Preferably, the distance between a pair of first compression grooves 11 in the lateral direction Y gradually decreases from the front to the rear in the longitudinal direction X. With this configuration, the first compression grooves 11 can serve as the starting point for deformation along the shape of the gluteal cleft. Specifically, the gluteal cleft has a shape that gradually narrows from the area near the anus towards the rear due to the bulge of the buttocks. By gradually decreasing the distance between the first compression grooves 11 towards the rear, the first compression grooves 11 can be positioned along this gradually narrowing boundary between the gluteal cleft and the buttocks. This makes the first compression grooves 11 the starting point for deformation along the buttocks that rise steeply to the left and right from the depression of the gluteal cleft. It is preferable that the rear end portion 11a of the first compression groove 11, which is located furthest rear in the longitudinal direction X, be positioned within the core tapered portion 73 from the viewpoint of fitting it to the shape of the gluteal cleft.

[0090] In this embodiment, it is preferable that the first compression groove 11 overlaps with at least one rear longitudinal low basis weight section 71R in a plan view. As described above, the regions on both sides of the first compression groove 11 can deform significantly along the contours of the buttocks, but the overlap with the first rear longitudinal low basis weight section 71a can alleviate the stress generated around the first compression groove 11. Therefore, the occurrence of wrinkles and twists due to deformation starting from the first compression groove 11 can be suppressed, and the induction of wrinkles and twists in the core intermediate region 7C by these wrinkles and twists can be suppressed.

[0091] Furthermore, referring to Figure 6, it is preferable that the angle θ3 formed by the pair of first compression grooves 11 is smaller than the angle θ2 formed by two hypothetical straight lines L4 connecting the rear end 7b of the core and the front end 73a of the pair of core tapered portions 73, respectively. This allows the first compression grooves 11 to be positioned to better conform to the steeper body shape on the gluteal cleft side (midline side), promoting desirable deformation by the first compression grooves 11. Therefore, discomfort for the wearer can be suppressed. The angle θ3 formed by the pair of first compression grooves 11 is the angle formed by a hypothetical straight line L5 that extends the pair of first compression grooves 11 along their respective extension directions. If the first compression grooves 11 are not straight, the straight line L5 is the straight line connecting the longitudinal X-front end and the rear end 11a of the first compression groove 11.

[0092] Specifically, from the viewpoint of fitting the first compression groove 11 to the boundary between the gluteal cleft and the buttocks, the angle θ3 is preferably 20° or more, more preferably 30° or more, preferably 100° or less, and more preferably 80° or less. Also, from the viewpoint of positioning the core inward protrusion 74 along the rounded shape of the buttocks, the angle θ2 is preferably 40° or more, more preferably 50° or more, preferably 120° or less, and more preferably 100° or less. Furthermore, from the viewpoint of suppressing discomfort when wearing, the difference between angle θ3 and angle θ2 is preferably 10° or more, more preferably 20° or more, preferably 60° or less, and more preferably 45° or less.

[0093] The minimum distance between the pair of first compression grooves 11 is preferably 7 mm or more, more preferably 8 mm or more, preferably 30 mm or less, and more preferably 25 mm or less, from the viewpoint of further improving the fit to the boundary between the gluteal cleft and the gluteal region.

[0094] Furthermore, as shown in Figure 1, the absorbent material 4 may have compression grooves other than the first compression groove 11. For example, the absorbent material 4 may have a pair of second compression grooves 12 that extend in the vertical direction X and are spaced apart from the first compression groove 11 and located in the intermediate region C. In the example shown in Figure 1, the second compression grooves 12 have a shape that is curved outward in the lateral direction Y, for example. The second compression grooves 12 serve as a starting point for deformation that causes the central part of the intermediate region C in the lateral direction Y to bulge towards the skin, and the high density arrangement of absorbent fibers 41 can suppress leakage of menstrual blood outward in the lateral direction Y due to capillary action, etc.

[0095] Furthermore, in the example shown in Figure 1, the absorbent material 4 may have a third compression groove 13 extending in the lateral direction Y and positioned longitudinally X behind the fiber mass region 70. In addition, the napkin 1 may have a fourth compression groove 14 extending in the lateral direction Y and positioned longitudinally X in front of the fiber mass region 70. The third compression groove 13 and / or the fourth compression groove 14 can suppress leakage of menstrual blood longitudinally X forward and / or backward by means of capillary action, for example.

[0096] The width dimension of these compression grooves (length in the direction perpendicular to the extension direction) is not particularly limited, but from the viewpoint of effectively exerting the effects of the compression grooves, it is preferably 1 mm or more, more preferably 2 mm or more, and preferably 5 mm or less, and more preferably 4 mm or less.

[0097] [Other dimensions of absorbent cores] Referring to Figure 6, the maximum width dimension of the absorbent core 7 in the lateral direction Y (for example, twice the dimension D4 shown in Figure 6) is preferably 40 mm or more, more preferably 50 mm or more, preferably 100 mm or less, and more preferably 90 mm or less.

[0098] Furthermore, near the rear end 11a of the first compression groove 11, it is preferable that the width dimension of the absorbent core 7 be sufficiently smaller than the maximum width dimension so that the core convex portion 74 can easily conform to the contour shape of the buttocks. From this viewpoint, if the width dimension D6 is the width dimension of the absorbent core 7 at the same position in the longitudinal direction X as the rear end 11a of the first compression groove 11, then the ratio of the width dimension D6 to the maximum width dimension (for example, twice the dimension D4) is preferably 85% or less, more preferably 80% or less, and even more preferably 76% or less. Also, from the viewpoint of covering the buttocks and ensuring absorbency near the first compression groove 11, the ratio of the width dimension D6 to the maximum width dimension is preferably 20% or more, more preferably 30% or more. More specifically, the width dimension D6 is preferably 20 mm or more, more preferably 25 mm or more, preferably 80 mm or less, and more preferably 70 mm or less.

[0099] [Example dimensions of sanitary napkins (absorbent items for menstruation)] From the viewpoint of more effectively exhibiting the effects of the flap portion 9 described above, it is preferable to set the dimensions of each part of the napkin 1 as follows. The front boundary portion 94 is preferably located at a position 40 mm or more, more preferably 50 mm or more, and preferably within 150 mm, and more preferably within 140 mm, behind the front end portion 9a of the flap of the napkin 1 in the vertical direction X. The rear boundary portion 95 is preferably located at a position 100 mm or more, more preferably 120 mm or more, and preferably within 350 mm, and more preferably within 330 mm, in front of the rear end portion 9b of the flap of the napkin 1 in the vertical direction X. The distance between the front boundary portion 94 and the rear boundary portion 95 in the vertical direction X is preferably 40 mm or more, more preferably 60 mm or more, and preferably 250 mm or less, and more preferably 230 mm or less. The maximum width dimension of the napkin 1 in the horizontal direction Y is preferably 60 mm or more, more preferably 80 mm or more, and preferably 200 mm or less, and more preferably 180 mm or less. The portion of the napkin 1 having the maximum width dimension is typically located in the intermediate region C, which in the illustrated configuration is the portion where the top of the intermediate bulge 91 is located. The total length of the napkin 1 in the longitudinal direction X is preferably 100 mm or more, more preferably 140 mm or more, and preferably 450 mm or less, and more preferably 420 mm or less. The minimum distance between the top 97a of the flap inward protrusion 97 and the absorbent body 4 is preferably 4 mm or more, more preferably 5 mm or more, and preferably 30 mm or less, and more preferably 20 mm or less, from the viewpoint of ensuring sufficient absorption capacity while mitigating the excessive contribution of the rigidity of the absorbent body 4 and making it easier to exert the effect of the characteristic outer shape of the rear region R.

[0100] <Second Embodiment> The configuration of the forward boundary portion 94 is not limited to the example of the first embodiment described above. In the following embodiments, components similar to those in the first embodiment described above are denoted by the same reference numerals and their descriptions are omitted.

[0101] As shown in Figure 7, in the napkin (absorbent article for menstruation) 1A according to the second embodiment of the present invention, the front boundary portion 94 may be the portion of the curved part that is convex inward in the lateral direction Y and is close to the absorbent body 4. In this case as well, the front boundary portion 94 can function as the starting point of twisting, and the above-mentioned effects can be obtained.

[0102] <Third Embodiment> In the first embodiment described above, the flap portion 9 was described as having a wing portion W, but this is not limited to that. For example, the flap portion 9 does not have to have a wing portion W.

[0103] As shown in Figure 8, in the napkin (absorbent menstrual product) 1B according to the third embodiment of the present invention, the flap portion 9 has an intermediate bulge portion 99 that bulges outward in the lateral direction Y and whose outer edge is formed by an intermediate bulge portion 91. The intermediate bulge portion 99 does not have a fixing portion on the non-skin-facing side. Therefore, the intermediate bulge portion 99 is used without being artificially folded back to the non-skin side of the crotch portion of the underwear. When the napkin 1B is placed on the skin side of the crotch portion before wearing, the intermediate bulge portion 99 can extend outward in the lateral direction Y from the side edge of the crotch portion. When the wearer pulls up the shorts from this state to the crotch area, the front boundary portion 94 and the rear boundary portion 95 become the starting points for deformation, and the intermediate bulge portion 99 can deform so that it folds at the side edge of the crotch portion. As a result, the intermediate bulge portion 99 can suppress leakage of menstrual blood outward in the lateral direction Y while eliminating the need to fix it to the shorts.

[0104] <Other Embodiments> Although embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above, and various modifications can be made without departing from the spirit of the present invention.

[0105] For example, although it has been explained that the flap tapered portion 96 has an inward convex portion 97, it is not limited to this. For example, the flap tapered portion 96 may be configured in a straight line or it may be curved outward in the lateral direction Y. Also, the core tapered portion 73 may not have an inward convex portion 74 and may have a straight outer edge or a curved outer edge that is curved outward in the lateral direction Y.

[0106] In other embodiments of the present invention, the rear region R of the physiologically absorbent article does not necessarily have a flap tapered portion 96 and a core tapered portion 73. In this case, the rear region R may have a shape symmetrical to the front region F, and may be configured symmetrically with respect to a center line that bisects the physiologically absorbent article in the longitudinal direction X. [Explanation of Symbols]

[0107] 1…Menstrual absorbent products (sanitary napkins) 2…Surface sheet 3…Back sheet 4… Absorbent 7… Absorbent core 7F…Core forward region 7C…Core intermediate area 7R…Core rear region 70… Region where fiber aggregates exist 71F, 71R... Low-grain area 9...Flap section 9e...outer edge 91…Intermediate bulge 92...Anterior bulge 93...Posterior bulge 94...front boundary 95…Backward boundary F…Front area C…middle area R…Rear area

Claims

1. A physiologically absorbent article comprising an absorbent core containing water-absorbing fibers, a surface sheet disposed on the skin side of the absorbent core, and a back sheet disposed on the non-skin side of the absorbent core, having a longitudinal direction corresponding to the wearer's front-to-back direction, a transverse direction perpendicular to the longitudinal direction and corresponding to the wearer's left-to-right direction, and a thickness direction perpendicular to the longitudinal and transverse directions, With respect to the aforementioned longitudinal direction, it is divided into an intermediate region including the area facing the wearer's vaginal opening, an anterior region located longitudinally forward of the intermediate region, and a posterior region located longitudinally backward of the intermediate region. In a plan view from the thickness direction, the absorber further comprises a flap portion extending outward from its periphery. The outer edge of the flap portion is A pair of intermediate bulges located in the aforementioned intermediate region and bulging outward in the lateral direction, A pair of forward bulges are located in front of the intermediate bulge in the longitudinal direction and bulge away from the absorbent, A pair of rear bulges are located behind the intermediate bulge in the longitudinal direction and bulge away from the absorbent, A pair of forward boundary portions located at the boundary between the intermediate bulge and the forward bulge, and adjacent to the absorbent, It has a pair of rear boundary portions located at the boundary between the intermediate bulge and the rear bulge, and adjacent to the absorbent, The absorbent core is It includes multiple intertwined fiber masses, and the fiber mass-existing region located in the intermediate region, The core front region located longitudinally forward of the fiber mass region, It has a core rear region located longitudinally behind the fiber mass region, The aforementioned core front region and the aforementioned core rear region, within each region, The absorbent fiber has a lower basis weight than the surrounding area and has multiple vertically low basis weight portions that extend linearly in the vertical direction, and The basis weight of the absorbent fiber is lower than that of the surrounding area and does not have a low basis weight portion that extends linearly in a direction intersecting the vertical low basis weight portion. The region where the fiber mass exists is, The aforementioned absorbent fibers have a lower basis weight than the surrounding area and do not have low basis weight portions that extend in a linear manner. Absorbent items for menstrual use.

2. When the region containing the fiber mass is divided into two equal parts in the thickness direction, into a skin-side region and a non-skin-side region, In the non-skin-facing region, the ratio of the mass of the fiber mass to the total mass of the absorbent fibers and the fiber mass is higher than the ratio in the skin-facing region. The physiologically absorbent article according to claim 1.

3. The aforementioned flap portion is, It further has a pair of wing portions extending laterally outward, the outer edge of which is formed by the aforementioned intermediate bulge portion, The wing portion has a fixing portion positioned on the non-skin-facing side for securing to underwear. The front end of the fiber mass region, which is located furthest forward in the longitudinal direction, is located further back in the longitudinal direction than the front boundary portion. The rearmost end of the fiber mass region, located furthest to the rear in the longitudinal direction, is located further forward in the longitudinal direction than the rear boundary. A physiologically absorbent article according to claim 1 or 2.

4. The aforementioned rear bulge has a rear outward convex portion that is curved outward in a convex shape in the lateral direction, The outer edge of the flap portion further has a pair of flap tapered portions extending from the apex of the rear outward protrusion that is located most laterally outward to the rear end of the flap that is located most longitudinally rearward in the flap portion. The pair of flap tapered portions are The distance between the rear outward protrusion and the rear end of the flap gradually decreases in the lateral direction from the rear in the vertical direction toward the rear end of the flap. A physiologically absorbent article according to claim 1 or 2.

5. The aforementioned core rear region is, The absorbent core includes the rear end of the core located furthest to the rear in the longitudinal direction, and has a core tapered portion in which the dimensions in the lateral direction gradually decrease from the front in the longitudinal direction toward the rear end of the core. The core tapered portion has a core convex portion which is an outer edge that curves convexly inward in the lateral direction. A physiologically absorbent article according to claim 1 or 2.

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