Absorbent article and method for manufacturing composite sheet for use in said absorbent article

Abstract

To provide an absorbent article capable of quickly absorbing feces or the like to an absorber, and using a top sheet having preferable touch feeling and suppressing residual feces.SOLUTION: An absorbent article comprises: a top sheet 2 having a plurality of recesses 220 and salients 210 on a skin side; a second sheet 3 which is formed into a bulky state relative to the top sheet 2; and an absorber layer 4 for absorbing moisture. In the absorbent article, the absorber layer 4, the second sheet 3, and the top sheet 2 are stacked in this order, and on the recesses 220, there are formed aperture parts 230 penetrating the top sheet 2 and the second sheet 3, and the salients 210 are formed of two stage parts being upper stage and lower stage parts, and rigidity on a tip end part and a root part of the salient 210 is greater than that on an intermediate part of the salient.SELECTED DRAWING: Figure 5A

Description

[Technical field]

[0001] The present invention relates to an absorbent article that is quickly absorbed into the absorbent core, does not easily leave residue on the surface, and has a pleasant feel to the touch, and to a method for producing a composite sheet used in the absorbent article. [Background technology]

[0002] Absorbent articles such as soft stool pads are designed in consideration of preventing leakage of urine and stool, comfort after defecation and urination, motor function, ease of handling, etc. In general, absorbent articles include a hydrophilic top sheet, a second sheet formed to be bulkier than the top sheet, and an absorbent layer that absorbs moisture, and are formed by stacking the absorbent layer, the second sheet, and the top sheet in this order. In consideration of comfort after defecation and urination, the top sheet may be provided with convex portions and apertures.

[0003] For example, there is known an absorbent article having a liquid-permeable surface sheet (top sheet) with a large number of convex portions designed on the skin side thereof, and in which the embossed portions and apertures around the convex portions are each independently and planarly arranged (see, for example, Patent Document 1).

[0004] Patent Document 1 discloses that an absorbent article has a large number of convex portions on the skin side of the liquid-permeable top sheet of the absorbent article, thereby reducing the contact area with the skin surface and improving cushioning properties, and further discloses that by appropriately designing the embossed portions and openings around the convex portions, liquid can be more easily diffused and transferred to the lower layer. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 6158992 Summary of the Invention [Problem to be solved by the invention]

[0006] However, since the absorbent article described in Patent Document 1 is intended for use in sanitary napkins and the like for absorbing bodily fluids such as menstrual blood, vaginal discharge, and urine, the size of the openings is small and the article cannot be used in soft stool pads and other such items with larger openings.

[0007] In addition, conventional soft stool pads have a rough second sheet and a third sheet under the top sheet with holes, and because the size of the holes is large, the fibers of the second sheet and the like may be exposed from the holes, and when hard parts are formed by heat fusion of the pin holes, the hard parts come into contact with the skin, making it feel hard and uncomfortable to the touch. In addition, by using a top sheet with flat holes, feces are transferred to the absorbent without clogging, but backflow is also likely to occur.

[0008] The present invention has been made in consideration of the above circumstances, and has an object to provide an absorbent article that uses a top sheet that quickly absorbs feces and the like into the absorbent body, is less likely to leave behind on the surface, and is pleasant to the touch. [Means for solving the problem]

[0009] The present invention provides a viscoelastic material comprising a top sheet having a plurality of concave and convex portions on the skin side, a second sheet formed to be bulkier than the top sheet, and an absorbent layer that absorbs moisture, the absorbent layer, the second sheet, and the top sheet being stacked in this order, the concave portions being formed with openings penetrating the top sheet and the second sheet, and the convex portions being formed with an upper step portion and The upper portion is a protruding portion having a larger diameter than the upper portion. The protrusion is constructed of a two-stage structure with a lower stage and a tip stage, and the rigidity of the tip and base stages of the protrusion is higher than the rigidity of the middle stage. The boundary between the tip portion and the middle portion is set in the lower portion, The present invention provides an absorbent article characterized in that a hole edge portion is formed around the periphery of the opening portion, which protrudes toward the skin and is covered by the middle portion of the convex portion that is deformed when subjected to body pressure. Effect of the Invention

[0010] According to the present invention, it is possible to provide an absorbent article using a top sheet that quickly absorbs feces and the like into the absorbent core, is less likely to leave residue on the surface, and is pleasant to the touch. [Brief description of the drawings]

[0011] [Figure 1] 1 is an exploded perspective view showing an inner pad which is one embodiment of an absorbent article according to the present invention, and a disposable diaper to which the inner pad is overlapped and combined. [Diagram 2] 2 is a perspective view showing a state in which the inner pad and the disposable diaper shown in FIG. 1 are virtually worn by a wearer. [Diagram 3] 2 is a plan view of the inner pad shown in FIG. 1 as viewed from the inner surface side. [Figure 4] FIG. 4 is a cross-sectional view showing a cross section taken along line AA in FIG. [Figure 5A] FIG. 5 is an enlarged view corresponding to part M in FIG. 4 when the top sheet according to Example 1 is used. [Figure 5B] 5B is a cross-sectional view similar to FIG. 5A, illustrating a state in which a compressive load is applied to the top sheet and the second sheet shown in FIG. 5A at predetermined intervals in the thickness direction from the top sheet side. [Figure 6] FIG. 5B is an enlarged plan view of a portion of the top sheet according to Example 1 corresponding to FIG. 5A. [Figure 7A] FIG. 5 is an enlarged view corresponding to part M in FIG. 4 when a top sheet according to Example 2 is used. [Figure 7B] 7B is a cross-sectional view similar to FIG. 7A, illustrating a state in which a compressive load is applied to the top sheet and the second sheet shown in FIG. 7A at predetermined intervals in the thickness direction from the top sheet side. [Figure 8] FIG. 1 is a conceptual diagram of a five-roll method, which is an example of a method for producing a top sheet according to the present invention. [Figure 9] FIG. 2 is a perspective view of a convex portion forming pin for producing convex portions of the top sheet according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an inner pad 1, which is one embodiment of an absorbent article using a top sheet 2 according to the present invention, will be described with reference to the drawings.

[0013] FIG. 1 is an exploded perspective view showing an inner pad 1 according to the present invention and a disposable diaper 8 in which the inner pad 1 is stacked and combined, and FIG. 2 is a perspective view showing the inner pad 1 and disposable diaper 8 shown in FIG. 1 virtually worn by a wearer L.

[0014] <Configuration> The inner pad 1 to which the top sheet 2 according to the present invention is applied is used in a state in which it is disposed over the inner surface 8A side of a disposable diaper 8, as shown in Fig. 1. Note that, as will be described later, the inner pad 1 is used over a so-called tape-type disposable diaper, but the absorbent article according to the present invention is not limited to being used over a tape-type disposable diaper, and may be used over a so-called pants-type disposable diaper, a non-disposable cloth diaper, etc.

[0015] Therefore, the inner pad 1 of this embodiment may also be used by being layered on a pants-type disposable diaper, a cloth diaper, or the like.

[0016] The inner surface A of the disposable diaper 8 is the surface that faces the wearer L and is hidden inward when worn by the wearer L as shown in Figure 2, and the outer surface 8B of the disposable diaper 8 is the surface that is exposed to the outside when worn by the wearer L.

[0017] The disposable diaper 8 is formed by integrally connecting a back portion 810, a ventral portion 830, and a crotch portion 820 between the back portion 810 and the ventral portion 830. Note that the disposable diaper 8 does not have any boundary or structural difference between the back portion 810 and the crotch portion 820 or between the ventral portion 830 and the crotch portion 820.

[0018] In other words, when the disposable diaper 8 is worn by a wearer L, the portion roughly corresponding to the back side of the wearer L is defined as the back portion 810, the portion roughly corresponding to the abdominal side of the wearer L is defined as the abdominal portion 830, and the portion between the back portion 810 and the abdominal portion 830 is defined as the crotch portion 820. The direction in which the back portion 810, the crotch portion 820, and the abdominal portion 830 are connected is defined as the longitudinal direction (front-rear direction) D of the disposable diaper 8, and the direction perpendicular to the longitudinal direction D is defined as the width direction E of the disposable diaper 8.

[0019] 1, fastening tapes 860 are fixed to a back portion 810 of the disposable diaper 8, protruding outward from both ends of the back portion 810 in the width direction E. Each fastening tape 860 is provided with multiple hook-shaped engaging portions 861 on a surface corresponding to the inner surface 8A.

[0020] Meanwhile, a target tape 870 having a loop shape that engages with the hook shape of the fastening portion 861 is provided on the outer surface 8B of the abdominal portion 830. Then, when the disposable diaper 8 is worn by a wearer L as shown in Fig. 2, the fastening tape 860 fixed to the dorsal portion 810 is wrapped around the waist of the wearer L and the abdominal portion 830, and the hook shape of the fastening portion 861 engages with the loop shape of the target tape 870, thereby joining the fastening portion 861 to the target tape 870, and the disposable diaper 8 is maintained in a state where it is worn by the wearer L. The fastening portion 861 and the target tape 870 can be repeatedly joined and peeled off, and constitute a so-called hook-and-loop fastener.

[0021] 1, the inner pad 1 is also formed by integrally connecting a back side portion 110, a ventral side portion 130, and a crotch portion 120 between the back side portion 110 and the ventral side portion 130. The inner pad 1 also does not have a clear boundary or structural difference between the back side portion 110 and the crotch portion 120 or between the ventral side portion 130 and the crotch portion 120, and is merely divided into a back side portion 110, a ventral side portion 130, and a crotch portion 120 when the inner pad 1 is worn by a wearer L together with a disposable diaper 8.

[0022] The direction in which the back side portion 110 , the crotch portion 120 , and the abdominal side portion 130 are connected is called the longitudinal direction D of the inner pad 1 , and the direction perpendicular to the longitudinal direction D is called the width direction E of the inner pad 1 .

[0023] 1, the disposable diaper 8 has a gathered sheet 850 provided only around the periphery of the inner surface 8A so as to cover a top sheet 840 disposed on the outermost surface side of the inner surface 8A. The periphery of the inner pad 1 is sandwiched between the top sheet 840 and the gathered sheet 850, and the inner pad 1 is held in a superimposed state on the disposable diaper 8.

[0024] Example 1 First, the basic structure of the inner pad 1 will be described. Fig. 3 is a plan view of the inner pad 1 shown in Fig. 1, seen from the inner surface 1A side. Fig. 4 is a cross-sectional view showing a cross section taken along line AA in Fig. 3.

[0025] 3 and 4, the inner pad 1 includes a top sheet 2, a second sheet 3, an absorbent layer 4, a liquid-impermeable sheet 5, and a back sheet 6. The inner pad 1 is constructed by stacking the top sheet 2, the second sheet 3, the absorbent layer 4, and the liquid-impermeable sheet 5 in this order from the skin side.

[0026] The top sheet 2 is preferably a water-repellent nonwoven fabric. Materials constituting the nonwoven fabric include, for example, synthetic fibers such as olefins such as polyethylene or polypropylene, polyesters, and polyamides, as well as regenerated fibers such as rayon or cupra, and natural fibers such as cotton. The top sheet 2 may be made of anything other than a nonwoven fabric as long as it has water repellency.

[0027] Fig. 5A is an enlarged view corresponding to part M in Fig. 4, showing the shape of the top sheet 2 according to Example 1. Fig. 6 is an enlarged plan view of a part of the top sheet according to Example 1 corresponding to Fig. 5A.

[0028] As shown in FIG. 5A, the top sheet 2 is provided with a plurality of convex portions 210 protruding toward the skin side and a plurality of concave portions 220 formed to correspond to the plurality of convex portions 210. Each concave portion 220 of the top sheet 2 is provided with an aperture portion 230 having a hole edge portion 231 penetrating the top sheet 2. That is, the top sheet 2 has a plurality of aperture portions 230 corresponding to the number of the plurality of concave portions 220. The aperture portion 230 penetrates the second sheet 3 corresponding to the top sheet 2 at that location. The hole edge portion 231 may be an altered portion such as a burr formed in the hole manufacturing process. In this Example 1, the hole edge portion 231 is a burr.

[0029] 5A, there is a space 250 between the protrusions 210 of the top sheet 2 and the second sheet 3. As will be described later, the second sheet 3 is joined to the non-skin side of the top sheet 2 by heat fusion (embossed portions 240 described below), but in areas (spaces 250) corresponding to the protrusions 210 of the top sheet 2, the second sheet 3 is not joined to the non-skin side of the top sheet 2.

[0030] The protrusions 210 are composed of a tip portion 201, an intermediate portion 202, and a root portion 203. The protrusions 210 are disposed on the skin side of the top sheet 2. The protrusions 210 are configured with the tip portion 201, the intermediate portion 202, and the root portion 203 in that order. The tip portion 201 is disposed within the region of an upper portion 211 of the protrusions 210, and is positioned at the outermost side of the skin side of the top sheet 2. In the lateral direction W, the protrusions 210 are formed such that the width 201W of the tip portion 201 is small, the width 202W of the intermediate portion 202 is larger than the width 201W of the tip portion 201, and the width 203W of the root portion 203 is larger than the width 202W of the intermediate portion 202. That is, in the horizontal cross section of the protrusion 210, the width of the protrusion 210 increases in the order of the width 201W of the tip 201, the width 202W of the intermediate portion 202, and the width 203W of the base portion 203. The height of the vertical width 201H of the tip 201 is formed short, the height of the vertical width 202H of the intermediate portion 202 is formed larger than the height of the vertical width 201H of the tip 201, and the height of the vertical width 203H of the base portion 203 is formed shorter than the height of the vertical width 202H of the intermediate portion 202. That is, in the protrusion 210, the height of the vertical width 202H of the intermediate portion 202 is formed larger than the height of the vertical width 201H of the tip portion 201 and the height of the vertical width 203H of the base portion 203. The above-mentioned sizes of the width and the vertical width of each element of the protrusion 210 are merely an example of the present invention. Therefore, the width and length of each element of the protrusion 210 according to the present invention are not limited to those described above, and can be modified in design depending on the intended use.

[0031] The rigidity strength of the tip portion 201, the intermediate portion 202, and the base portion 203 of the protrusion 210 according to the present invention is different. The rigidity strength of the tip portion 201 is formed to be higher than the rigidity strength of the intermediate portion 202. The rigidity strength of the base portion 203 is formed to be higher than the rigidity strength of the intermediate portion 202. In other words, the rigidity strength of the tip portion 201 and the base portion 203 is formed to be higher than the rigidity strength of the intermediate portion 202.

[0032] The convex portion 210 has a two-stage structure consisting of an upper stage portion 211 and a lower stage portion 212. In this Example 1, for example, as shown in Fig. 5A, the lower stage portion 212 is a lower stage convex portion 212a having a relatively large diameter convex shape that protrudes from the skin side surface of the top sheet 2, and the upper stage portion 211 is an upper stage convex portion 211a having a relatively small convex shape that protrudes upward from the tip end of the lower stage convex portion 212a.

[0033] 6, a plurality of embossed sections 240 are formed around each opening 230 by squeezing the skin side of the top sheet 2. That is, in the top sheet 2, the openings 230 and the embossed sections 240 are formed independently in separate regions so as not to overlap.

[0034] In the plan view shown in Figure 6, the arrangement of the convex portions 210, concave portions 220, apertures 230 and embossed portions 240 on the top sheet 2 is such that the multiple convex portions 210 and multiple concave portions 220 are arranged in a staggered pattern, and one aperture portion 230 is disposed in the center of the area of ​​the concave portions 220 surrounding the convex portions 210 from all four directions, so that the apertures 230, 230... are arranged in a staggered pattern as a whole, and a plurality of the embossed portions 240 are arranged intermittently between adjacent apertures 230, 230 along the direction connecting these apertures 230, 230.

[0035] In the top sheet 2, a recess 220 is formed between the protrusions 210 and the protrusions 210, a protrusion 210 is formed between the recesses 220 and the recesses 220, and the protrusions 210 and the recesses 220 are formed to intersect with each other. As a result, in the top sheet 2, several protrusions 210 are arranged around one recess 220, and several recesses 220 are arranged around one protrusion 210. In this embodiment 1, an example in which about four protrusions 210 are arranged around one recess 220, and about four recesses 220 are arranged around one protrusion 210 will be described. Note that in the present invention, the relative arrangement number of the recesses 220 and the protrusions 210 can be appropriately designed depending on the application, etc., and is not limited to four.

[0036] The second sheet 3 is formed of a nonwoven fabric having a sparsely distributed fiber (having coarse gaps) and liquid permeability, which is a property that allows liquid to pass through. The sparsely distributed fiber is relative to the distribution state of the fibers of the third sheet 402 described later. The second sheet 3 may be any material that is hydrophilic to body fluids. Specifically, the material constituting the second sheet 3 may be a material that is hydrophilic in itself by using regenerated fibers such as rayon or cupra, or natural fibers such as cotton, or a fiber that is hydrophilic by surface-treating synthetic fibers such as olefins such as polyethylene or polypropylene, polyesters, or polyamides with a hydrophilizing agent. In addition, composite fibers such as core-sheath fibers, side-by-side fibers, and split fibers, in which fibers with a high melting point are used as the core and fibers with a low melting point are used as the sheath, may be used. The second sheet 3 is formed to be bulkier (thicker in the natural state (when no compressive load is applied)) than the top sheet 2.

[0037] As shown in Fig. 5A, the absorbent layer 4 includes an absorbent body 401, a third sheet 402, and crepe paper 403. The absorbent body 401 is composed of pulp fibers and highly absorbent polymer particles distributed among the pulp fibers. The highly absorbent polymer particles absorb water and expand, and the pulp fibers capture fine solids.

[0038] The inner pad 1 also includes a gathered sheet 7 on each side in the width direction E. The gathered sheet 7 is disposed closer to the inner surface 1A than the top sheet 2 in the thickness direction.

[0039] The absorbent body 401 has a two-layer structure including a first absorbent body made of only pulp fibers containing no superabsorbent polymer particles, which is disposed on the third sheet 402 side, and a second absorbent body made of superabsorbent polymer particles and pulp fibers, which is disposed on the crepe paper 403 side. Note that although the absorbent body 401 in this embodiment has a two-layer structure, this is merely an example, and it may have a one-layer structure made of only a single absorbent body, or a structure of three or more layers.

[0040] The third sheet 402 and the crepe paper 403 sandwich the absorbent body 401 from above and below in the thickness direction to wrap the absorbent body 401. The third sheet 402 is provided in place of crepe paper (same as the crepe paper 403) or core wrap that is generally used to wrap the absorbent body 401 and maintain the shape of the absorbent layer 4, etc.

[0041] The third sheet 402 is disposed closer to the second sheet 3 than the absorbent body 401. The third sheet 402 is preferably formed of nonwoven fabric, with fibers more densely distributed than those of the second sheet 3.

[0042] The third sheet 402 has liquid permeability similar to that of crepe paper, but unlike crepe paper, it has the function of retaining solids between the fibers.

[0043] The crepe paper 403 , together with the third sheet 402 , wraps the absorbent body 401 and maintains the shape of the absorbent layer 4 .

[0044] The liquid-impermeable sheet 5 is liquid-impermeable and is formed of, for example, a resin film. Therefore, even if there is moisture that cannot be solidified by the absorbent layer 4, the liquid-impermeable sheet 5 prevents the moisture from leaking to the back sheet 6 disposed on the outer surface 1B side.

[0045] The back sheet 6 is formed of, for example, a nonwoven fabric. The inner pad 1 of the present embodiment includes the back sheet 6 from the viewpoints of breathability and texture, but the absorbent article according to the present invention may not include a back sheet.

[0046] Next, the function of the protrusions 210 of the top sheet 2 according to the present invention will be described. FIG. 5B is a cross-sectional view similar to FIG. 5A, showing the top sheet 2 and second sheet 3 shown in FIG. 5A in a state in which body pressure P is applied in the thickness direction from the skin side of the top sheet 2.

[0047] (Function of the protrusion 210 in the first embodiment) When the top sheet 2 receives body pressure P (compressive load) from the skin side (downward arrow ↓ in Fig. 5B), the middle portion 202 of the protrusions 210 deforms as shown in Fig. 5B. The deformation of the protrusions 210 is such that, when body pressure P is applied to the top sheet 2 from the skin side of the top sheet 2, the tip portion 201 closest to the skin side first receives the body pressure P, and then the tip portion 201 transmits the received body pressure P to the middle portion 202, and thereafter the body pressure P is applied to the root portion 203 via the middle portion 202. At this time, since the rigidity strength of the tip portion 201 and the base portion 203 is formed to be greater than the rigidity strength of the middle portion 202, when the load of the body pressure P is greater than the rigidity strength of the middle portion 202, the middle portion 202 deforms, and the shape of the convex portion 210 spreads outward along the width direction, deforming so as to cover the hole edge portion 231 of the hole portion 230 formed in the adjacent concave portion 220. As a result, the deformed portion of the middle portion 202 of the convex portion 210 covers the second sheet 3 or the altered portion (the altered portion such as a burr formed during the hole opening process, etc.) at the hole edge portion 231 of the hole portion 230, thereby preventing the second sheet 3 or the altered portion from coming into direct contact with the skin, and improving the feel on the skin.

[0048] Specifically, the deformation of the protrusion 210 is achieved by the following configuration. When a user wears the absorbent article according to the present invention, the tip portions 201 are disposed at a position closest to the skin at the site where the user wears the absorbent article. As a result, the tip portions 201 of the projections 210 disposed on the outermost side of the skin side of the top sheet 2 come into contact with the skin first, compared to other elements of the top sheet 2. Therefore, when body pressure P is applied to the top sheet 2 and second sheet 3 shown in Fig. 5A in the thickness direction from the skin side of the top sheet 2, the tip portions 201 of the projections 210 receive the body pressure P. The tip portion 201 then transmits the received body pressure P to the middle portion 202, which then transmits the body pressure P to the base portion 203. The body pressure P then reaches the second seat 3 via the base portion 203, and is received by the entire inner pad 1. At this time, the inner pad 1 receives the body pressure P, generating a receiving force BP. Here, the acting force of the body pressure P and the acting force BP oppose each other. Generally, the absolute value of the strength of these forces is P=BP. In this case, the protrusion 210 is simultaneously subjected to the body pressure P from the upper direction and the force BP from the lower direction. When the protrusion 210 receives the body pressure P from the upper direction and the force BP from the lower direction simultaneously, the middle part 202 is deformed to the width 202W. Specifically, since the rigidity strength of the middle part 202 is weaker (smaller) than the rigidity strength of the tip part 201 and the base part 203, when the load of the body pressure P is stronger (larger) than the rigidity strength of the middle part 202, the shape of the middle part 202 is deformed in a direction in which the width 202W increases and the vertical width 202H decreases. That is, as shown in FIG. 5B, the shape of the protrusion 210 is deformed so that the width 202W of the middle part 202 becomes larger than the width 203W of the base part 203. As described above, the width 202W of the intermediate portion 202 expands in the lateral direction of the top sheet 2, thereby covering the second sheet 3 or the altered portion at the hole edge 231 of the hole 230, thereby preventing the second sheet 3 or the altered portion from coming into direct contact with the skin and improving the feel against the skin. In this Example 1, the shape of the convex portion 210 is deformed so that the width 202W of the intermediate portion 202 covers the hole edge 231 of the hole 230. The above-mentioned modification of the shape of the protrusion 210 is merely one example of the present invention, and the modification of the width 202W of the middle portion 202 can be designed as necessary.

[0049] Example 2 As shown in Fig. 7A, the top sheet 2 according to Example 2 differs from the top sheet 2 according to Example 1 in that the upper portion 211 of the convex portion 210 is an upper convex portion 211b having an obliquely convex shape. Both of these differences may be adopted at the same time, or only one of them may be adopted. In Example 2, an example will be described in which the obliquely convex upper convex portion 211b is inclined at a constant angle in the same direction, but the direction and inclination angle of the upper convex portion 211b can be designed to be changed as necessary.

[0050] (Function of the protrusion 210 in the second embodiment) FIG. 7B is a cross-sectional view similar to FIG. 7A, showing the top sheet and second sheet shown in FIG. 7A in a state where a compressive load is applied at predetermined intervals in the thickness direction from the top sheet side.

[0051] Since the tip 201 of the convex portion 210 is formed within the region of the obliquely convex upper-stage convex portion 211b, the rigidity strength of the upper-stage convex portion 211b is greater than the rigidity strength of the middle portion 202 of the convex portion 210. As a result, when the body pressure P and the force BP act on the inner pad 1, as shown in FIG. 7B, in the convex portion 210, the middle portion 202 having a weak rigidity strength is guided in the oblique direction of the obliquely convex upper-stage convex portion 211b, and the width 202W expands in the lateral direction, and the shape of the convex portion 210 is deformed. As a result, the deformed portion of the middle portion 202 of the convex portion 210 can cover the second sheet 3 or the altered portion at the hole edge portion 231 of the opening portion 230 along the oblique direction of the obliquely convex upper-stage convex portion 211b, and the second sheet 3 or the altered portion can be prevented from directly contacting the skin. Even if the shape of the convex portion 210 is crushed, the oblique shape of the upper convex portion 211b is maintained, so loose stool falls down the slope of the upper convex portion 211b, and is less likely to remain in the oblique shape of the upper convex portion 211b. This further improves the feel on the skin. Also, the oblique direction and angle of the oblique convex shape of the upper convex portion 211b can be designed according to a specific application and need.

[0052] Specifically, the deformation of the protrusion 210 according to the second embodiment is realized by the following configuration. When a user wears the absorbent article according to the present invention, the upper convex portion 211b is disposed at a position closest to the skin at the site where the user wears the absorbent article. As a result, the upper convex portion 211b of the convex portion 210 disposed on the outermost side of the skin side of the top sheet 2 comes into contact with the skin first, compared to other elements of the top sheet 2. Therefore, when body pressure P is applied to the top sheet 2 and second sheet 3 shown in Fig. 7A in the thickness direction from the skin side of the top sheet 2, the upper convex portion 211b of the convex portion 210 receives the body pressure P. The upper protrusion 211b transmits the received body pressure P to the middle portion 202, which transmits the body pressure P to the base portion 203. The body pressure P reaches the second seat 3 via the base portion 203 and is received by the entire inner pad 1. At this time, the inner pad 1 receives the body pressure P, generating a receiving force BP. Here, the acting force of the body pressure P and the acting force of the receiving force BP oppose each other. Generally, the absolute value of the strength of these forces is P=BP. In this case, the protrusion 210 is simultaneously subjected to the body pressure P from the upper direction and the receiving force BP from the lower direction. When the protrusion 210 receives the body pressure P from the upper direction and the receiving force BP from the lower direction at the same time, the middle part 202 is deformed to the width 202W. Specifically, since the rigidity strength of the middle part 202 is weaker (smaller) than the rigidity strength of the tip part 201 and the base part 203, when the load of the body pressure P is stronger (larger) than the rigidity strength of the middle part 202, the shape of the middle part 202 is deformed in a direction in which the width 202W increases and the vertical width 202H decreases. That is, as shown in FIG. 7B, the shape of the protrusion 210 is deformed to a "V" shape so that the width 202W of the middle part 202 becomes larger than the width 203W of the base part 203. As described above, the width 202W of the intermediate portion 202 expands in the lateral direction of the top sheet 2, thereby covering the second sheet 3 or the altered portion at the hole edge 231 of the hole 230, thereby preventing the second sheet 3 or the altered portion from coming into direct contact with the skin and improving the feel against the skin. In this Example 2, the shape of the convex portion 210 is deformed so that the width 202W of the intermediate portion 202 covers the hole edge 231 of the hole 230. The above-mentioned modification of the shape of the protrusion 210 is merely one example of the present invention, and the modification of the width 202W of the middle portion 202 can be designed as necessary.

[0053] The height of the convex portions 210 in the top sheet 2 of this embodiment is preferably such that loose stool does not come into contact with the skin, and must be such that the unevenness can be recognized by touch at least. Specifically, the height of the convex portions 210 is preferably, for example, 3 to 10 mm, and more preferably 4 to 7 mm. Note that the height of the convex portions 210 of 3 to 10 mm is merely an example, and the height of the convex portions 210 is not limited to 3 to 10 mm. The diameter of the convex portions 210 is preferably, for example, 3 to 13 mm, and more preferably 6 to 10 mm. Note that the diameter of the convex portions 210 of 3 to 13 mm is merely an example, and the diameter of the convex portions 210 is not limited to 3 to 13 mm.

[0054] The size of the opening 230 in the inner pad 1 of this embodiment must be a size that allows loose stool to pass through. Specifically, the size of the opening 230 is preferably 3×3 mm or more.

[0055] The shape of the opening 230 may be circular or elliptical. When the opening 230 is a shape other than circular, the ratio of the relatively long side dimension to the relatively short side dimension is preferably 3:1 to 1:1. If the long side dimension of the opening 230 is more than three times the short side dimension, the shape becomes elongated and it becomes difficult for loose stool to pass through.

[0056] The inner pad 1 of this embodiment is an inner pad that is used by layering it over a disposable diaper for adults, but the absorbent article of the present invention is not limited to an inner pad that is used by layering it over a disposable diaper for adults.

[0057] That is, the absorbent article according to the present invention may be applied not only to an inner pad that is layered on a disposable diaper, but also to a disposable diaper for adults itself, regardless of whether an inner pad is layered on the diaper or not.

[0058] The absorbent article according to the present invention may also be applied to disposable diapers for children (newborns, infants, etc.) which are smaller in size than those for adults.

[0059] Furthermore, the absorbent article according to the present invention is not limited to the above-mentioned absorbent article for absorbing loose stool, but may be an absorbent article for absorbing other fluid excrement. Therefore, the absorbent article according to the present invention can be applied to, for example, feminine hygiene products and absorbents for urinary incontinence, in addition to disposable diapers and inner pads.

[0060] In addition, when the absorbent article of the present invention is applied to feminine hygiene products or urinary incontinence absorbents, the dorsal side portion of the absorbent article of the present invention corresponds to the part closer to the back of the human body, and the ventral side portion corresponds to the part closer to the abdomen of the human body.

[0061] <Method of manufacturing the top sheet 2 and the second sheet 3> A preferred embodiment of a manufacturing method for a composite sheet for producing the top sheet 2 and second sheet 3 according to the present invention will be described below with reference to the drawings based on a five-roll method. However, the manufacturing method for the top sheet 2 and second sheet 3 according to the present invention is not limited to the five-roll method, and can also be applied to other manufacturing processes such as a four-roll method.

[0062] The top sheet 2 and second sheet 3 according to the present invention are laminated and the convex portions 210 and apertures 230 are formed by, for example, a five-roll method, as shown in Fig. 8. In the manufacturing process of this manufacturing method, the top sheet 2 is made from a first sheet which is a nonwoven fabric, and the second sheet 3 is made from a second sheet.

[0063] The manufacturing method of the top sheet 2 and the second sheet 3 includes a first step of simultaneously forming a two-stage convex portion 210 and a concave portion 220 in the top sheet 2 (first sheet), a lamination step of overlapping the top sheet 2 (first sheet) and the second sheet 3 (first sheet) and simultaneously forming an aperture portion 230 and an embossed portion 240 in both sheets (the top sheet 2 and the second sheet 3), and a third step of performing an aperture design step for the aperture portion 230 at least once in both the overlapped sheets.

[0064] (Production Example 1) In the five-roll method, as shown in FIG. 8, a manufacturing apparatus 500 includes a first roll 510, a second roll 520, a first anvil roll 530, a third roll 540, and a second anvil roll 550.

[0065] The first roll 510 has recesses and protrusions on its circumferential surface. The protrusions of the first roll 510 are formed by a plurality of rod-shaped protrusion forming pins 511 formed at regular intervals along the circumferential surface, and the recesses of the first roll 510 are provided with hole-shaped pin receiving portions 512. The protrusion forming pins 511 are rod-shaped pins having a two-stage structure that protrude toward the outside of the first roll 510 along the circumferential surface of the first roll 510. The pin receiving portions 512 are holes formed toward the center of the first roll 510 adjacent to the protrusion forming pins 511 along the circumferential surface of the first roll 510. That is, on the circumferential surface of the first roll 510, the pin receiving portions 512 are arranged between the protrusion forming pins 511 and the protrusion forming pins 511, and the pin receiving portions 512 are arranged between the pin receiving portions 512 and the pin receiving portions 512.

[0066] The second roll 520 includes a plurality of projection-forming pin receiving portions 521 formed at regular intervals along its circumferential surface, a hole-opening pin 522 for forming a plurality of holes, and a plurality of embossing pins 523. The projection-forming pin receiving portions 521, the hole-opening pin 522, and the embossing pin 523 are repeatedly formed in the order of the projection-forming pin receiving portion 521, the hole-opening pin 522, and the embossing pin 523 in a counterclockwise direction along the circumferential surface of the second roll 520. The projection-forming pin receiving portion 521 is a hole having a shape into which the projection-forming pin 511 is inserted along the circumferential surface of the second roll 520 toward the center of the second roll 520. The hole-opening pin 522 is a needle-shaped pin that protrudes toward the outside of the second roll 520 along the circumferential surface of the second roll 520. The embossing pins 523 are short rod-like pins that are formed so that the height thereof protruding outwardly from the second roll 520 along the circumferential surface of the second roll 520 is shorter than the height of the hole-opening pins 522 .

[0067] The first anvil roll 530 has a plurality of hole-shaped opening pin receiving portions 531 formed at regular intervals along its circumferential surface. The opening pin receiving portions 531 are holes formed at regular intervals along the circumferential surface of the first anvil roll 530 toward the center of the first anvil roll 530. The second anvil roll 550 has a plurality of hole-shaped opening pin receiving portions 551 formed at regular intervals along its circumferential surface. The opening pin receiving portions 551 are conical holes formed at regular intervals along the circumferential surface of the second anvil roll 550 toward the center of the second anvil roll 550.

[0068] The third roll 540 has a plurality of hole-opening pins 541 formed at regular intervals along its circumferential surface. The hole-opening pins 541 are needle-shaped pins that protrude toward the outside of the third roll 540 along the circumferential surface of the third roll 540.

[0069] (Manufacturing process using the 5-roll method) The first step is a shaping step in which the first sheet is held along the peripheral surface of the first roll 510, and the first sheet is shaped to have a concave-convex shape, thereby deforming the first sheet into a concave-convex shape. In this step, the first sheet is fed between the first roll 510 and the second roll 520 while rotating the first roll 510 and the second roll 520 at a predetermined speed so as to mesh with each other, and the first sheet is shaped to have a concave-convex shape and a two-stage convex portion is formed at the same time. That is, in the first step, the convex portions 210 of the top sheet 2 and the two-stage concave portions 220 are formed at the same time.

[0070] The second and third steps are a lamination step in which the first sheet on which the concave and convex shape has been formed in the first step is laminated with a second sheet which is newly fed into the manufacturing process, and a hole-opening step.

[0071] In the second step, the first sheet having the unevenness is conveyed while being held on the peripheral surface of the second roll 520, and the first sheet and the second sheet are overlapped between the second roll 520 and the first anvil roll 530. Specifically, the first sheet having the unevenness is inserted into the hole-opening pin 522 of the second roll 520, and is sent to between the second roll 520 and the first anvil roll 530 together with the newly fed second sheet, and the lamination step and the hole-opening step of the first sheet and the second sheet are performed. That is, in this second step, the second sheet unwound from the original roll (not shown) is overlapped on the first sheet having the unevenness being conveyed, and the hole-opening operation of the first sheet and the second sheet is performed, and the hole-opening portion 230 is formed. The hole-opening operation here is an opening operation for forming the hole-opening portion 230. At this time, the unevenly shaped first sheet comes into contact with the second sheet at a portion corresponding to the embossed portion of the second roll 520, and the two sheets are bonded together at the embossed portion. The overlapped sheets (first sheet and second sheet) are transported so as to be fed between the first anvil roll 530 and the third roll 540.

[0072] In the third step, the two overlapping sheets (the first sheet and the second sheet) are supplied between the first anvil roll 530 and the third roll 540, and the first hole design work is performed to enlarge the hole size of the hole 230. After that, the two sheets are supplied between the third roll 540 and the second anvil roll 550 while being pierced by the hole pin 541, and the second hole design work is performed to enlarge the hole size of the hole 230. Here, the hole design work according to the present invention is a hole design process for designing the hole size and shape of the hole 230 formed by the hole design work performed in the second step. In this embodiment, an example in which a total of two hole design works, a first hole design work and a second hole design work, are performed to design the hole size and shape of the hole 230, has been described. However, the hole design work according to the present invention is not limited to the manufacturing embodiment 1, and may be any work for designing the hole size and shape, and the number and form of the hole design work may be changed as necessary.

[0073] The above manufacturing process makes it possible to simultaneously form the convex portions 210, the concave portions 220, the openings 230, and the embossed portions 240 of the top sheet 2, and also makes it possible to reliably form large openings through opening design work that increases the opening dimensions of the openings 230.

[0074] In the above manufacturing example, the protrusion forming pin 511 is a long rod-like structure formed by combining two rod-like bodies, with the upper rod-like body being shorter and wider than the lower rod-like body, and having a two-tiered protrusion structure, as shown in Figure 9(a). The shape of the protrusion forming pin 511 may be any shape that forms the protrusions 210 of the top sheet 2, and the design can be modified as necessary. For example, the protrusion forming pin 511 may be one in which the tip of the upper rod-like body has an inclined surface, as shown in Figure 9(b).

[0075] The protrusion-forming pin 511 according to the present invention forms the protrusion 210 having a two-stage structure of the upper stage 211 and the lower stage 212, and generates the protrusion 210 having different rigidity strengths at each portion, such as the tip portion 201, the intermediate portion 202, and the base portion 203. For example, in the above manufacturing example, the protrusion-forming pin 511 forms the protrusion 210 in which the rigidity strengths of the tip portion 201 and the base portion 203 are higher than that of the intermediate portion 202. However, the protrusion-forming pin 511 according to the present invention may be configured so that the rigidity strengths of each portion, such as the tip portion 201, the intermediate portion 202, and the base portion 203, of the protrusion 210 are different, and the design can be modified according to the intended use. [Explanation of symbols]

[0076] 1 Inner pad 2 Top sheet 3 Second seat 4 Absorber layer 210 Convex 220 Recess 230 Opening part 201 Tip 202 Middle section 203 Base 8. Disposable diapers D Longitudinal direction E Width direction F wearer P Body pressure BP Power

Claims

1. A top sheet having a plurality of concave and convex portions on the skin side; A second sheet formed to be bulkier than the top sheet; An absorbent layer that absorbs moisture, The absorbent layer, the second sheet, and the top sheet are stacked in this order, In the recess, an opening portion penetrating the top sheet and the second sheet is formed, the protrusion has a two-stage structure including an upper stage portion and a lower stage portion that is a protrusion having a larger diameter than the upper stage portion and protrudes from the upper stage portion, the rigidity of a tip portion and a base portion of the protrusion is higher than the rigidity of an intermediate portion, and the boundary between the tip portion and the intermediate portion is set in the lower stage portion, A hole edge portion is formed at the periphery of the opening portion, which protrudes toward the skin side and is covered by the middle portion of the protrusion that is deformed by receiving body pressure. An absorbent article characterized by:

2. The absorbent article according to claim 1 , wherein the protrusion has a space on the inside corresponding to the second sheet.

3. 3. The absorbent article according to claim 1, wherein the tip of the protrusion is inclined.

4. The absorbent article according to any one of claims 1 to 3, wherein the top sheet is water repellent.

5. A method for producing a composite sheet for producing a top sheet and a second sheet used in the absorbent article according to any one of claims 1 to 4, comprising the steps of: A first step of simultaneously forming a two-stage structure convex portion and a concave portion of the top sheet and forming a hole in the top sheet with a hole-opening pin; a second step of simultaneously carrying out a lamination step of overlapping a second sheet on the top sheet with the hole-opening pin inserted therein and a hole-opening step of forming holes in the top sheet and the second sheet; a third step of performing an opening design step at least once to increase the opening size of the opening portion; A method for producing a composite sheet comprising the steps of:

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