Absorbent article

Abstract

An absorbent article of the present application has, in a front panel (2), a plurality of first embossed rows (11) formed of a plurality of linear embossed portions arranged in series at intervals, and a plurality of second embossed rows (12) formed of a plurality of linear embossed portions arranged in series at intervals. The first embossed rows (11) and the second embossed rows (12) cross each other, and a convex portion region (14) defined by the first embossed rows (11) and the second embossed rows (12) is formed. A first high-density region (13) is located at the intersection of the first embossed rows (11) and the second embossed rows (12). A plurality of fusion portions (70) are formed in a middle panel (7). The first high-density region (13) and the fusion portions (70) at least partially overlap when viewed from above.

Description

Technical Field

[0001] This invention relates to absorbent articles. Background Technology

[0002] Absorbent articles such as menstrual pads have a front sheet that contacts the wearer's skin when worn. As such a front sheet, it is known to have a structure with linear embossed portions. For example, the applicant previously disclosed a front sheet having multiple linear embossed recesses on the skin-contacting side, and multiple demarcation regions (defined regions) divided (defined) by the multiple embossed recesses, each demarcation region having a protrusion rising towards the skin-contacting side, and the multiple embossed recesses surrounding the demarcation regions being composed of line segments, and adjacent embossed recesses not intersecting each other (Patent Document 1).

[0003] In addition, the applicant previously disclosed a front panel having a plurality of intersecting first and second recesses, forming a first region sandwiched by adjacent first recesses and a second region sandwiched by first recesses at a different interval from the first region, the first and second regions being arranged across a central region and a compression portion (Patent Document 2).

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2012-239531

[0007] Patent Document 2: Japanese Patent Application Publication No. 2016-077581 Summary of the Invention

[0008] The present invention provides an absorbent article comprising: an absorbent body; a front sheet disposed on a side of the absorbent body that is closer to the skin than the skin side; and an intermediate sheet disposed between the absorbent body and the front sheet.

[0009] Preferably, the front panel has: a plurality of first embossed rows, which are formed by a plurality of linear embossed portions arranged in a series at intervals with their length directions aligned in the same direction; and a plurality of second embossed rows, which are formed by a plurality of linear embossed portions arranged in a series at intervals with their length directions aligned in the same direction.

[0010] Preferably, the first embossing row and the second embossing row intersect each other.

[0011] Preferably, a raised area is formed by the first embossing row and the second embossing row.

[0012] The preferred high-density region, which has a higher density than the protrusion region, is located at the intersection of the first embossing row and the second embossing row.

[0013] Preferably, multiple welded portions are formed in the aforementioned intermediate sheet.

[0014] Preferably, when viewed from above, the first high-density region at least partially overlaps with the aforementioned welded portion. Attached Figure Description

[0015] Figure 1 This is a plan view showing the skin-facing side (front sheet side) of a menstrual sanitary napkin, which is an embodiment of the absorbent article of the present invention.

[0016] Figure 2 yes Figure 1 Section II-II view.

[0017] Figure 3 yes Figure 1 A plan view of the front panel.

[0018] Figure 4 (a) is Figure 3 Section III-III Figure 4 (b) is Figure 3 VV cross-sectional diagram.

[0019] Figure 5 yes Figure 2 The diagram shown is a plan view of the intermediate piece.

[0020] Figure 6 It means Figure 5 A plan view showing the arrangement of the second high-density region with the embossed pattern of the front panel and the first high-density region.

[0021] Figure 7 This is a plan view showing another embodiment of the front panel. Detailed Implementation

[0022] From the perspective of improving the wearing experience, absorbent articles are required to have a high degree of mobility for bodily fluids to migrate to the absorbent side. On the other hand, in absorbent articles that have repeatedly absorbed bodily fluids, there is a tendency for the fluids to spread and diffuse on the skin-facing side of the front panel. There is a concern that such absorbent articles may give the wearer the impression of being prone to leakage, and the diffusion of bodily fluids could be a cause for this concern. Patent documents 1 and 2 do not specifically address how to suppress the diffusion of bodily fluids on the skin-facing side of the front panel and how to improve the mobility of bodily fluids to the absorbent side.

[0023] Therefore, the present invention provides an absorbent article that inhibits the diffusion of bodily fluids on the skin-facing side of the front sheet and has excellent mobility of bodily fluids towards the absorbent side.

[0024] Hereinafter, a preferred embodiment of the absorbent article of the present invention will be described with reference to the accompanying drawings. Figure 1 and Figure 2 The image shows a menstrual sanitary napkin 1 (hereinafter also simply referred to as "sanitary napkin 1") as one embodiment of the absorbent article of the present invention. The sanitary napkin 1 has: an absorbent body 4 for absorbing and retaining bodily fluids; a front sheet 2 disposed on the skin-facing side of the absorbent body 4 and capable of contacting the wearer's skin; and a back sheet 3 disposed on the non-skin-facing side of the absorbent body 4. Furthermore, the sanitary napkin 1 has an intermediate sheet 7 disposed between the absorbent body 4 and the front sheet 2. Both the front sheet 2 and the intermediate sheet 7 are fiber sheets.

[0025] Sanitary napkin 1 Figure 1 The sanitary napkin 1 has: a longitudinal direction X, which corresponds to the wearer's front-back direction and extends from the wearer's abdomen, through the crotch, and towards the back; and a transverse direction Y, which is orthogonal to the longitudinal direction X. The sanitary napkin 1 has, along the longitudinal direction X: an excretory portion relative area B, which includes an area positioned opposite the wearer's vulva or other excretory portions when worn; a front area A, positioned further forward along the longitudinal direction X (on the wearer's abdomen) than the excretory portion relative area B; and a rear area C, positioned further backward along the longitudinal direction X (on the wearer's back) than the excretory portion relative area B, thus being divided into the above three areas.

[0026] In this specification, "skin-facing side" refers to the side of the absorbent article or its constituent parts (e.g., absorbent body 4) that faces the wearer's skin when the absorbent article is worn, and "non-skin-facing side" refers to the side of the absorbent article or its constituent parts that faces the opposite side when the absorbent article is worn. That is, the skin-facing side is the side that is relatively closer to the wearer's skin, and the non-skin-facing side is the side that is relatively farther from the wearer's skin. "Wearing" and "wearing state" refer to the state of wearing the absorbent article while maintaining the usual proper wearing position, that is, the proper wearing position of the absorbent article.

[0027] Sanitary napkin 1 Figure 1 The device shown includes: an absorbent body 5, which is elongated in the longitudinal direction X; and a pair of wings 5W, 5W, which extend outward from the opposite side portions of the excretion portion B of the absorbent body 5 along the longitudinal direction X towards the outer side in the transverse direction Y. The absorbent body 5 is the main part constituting the sanitary napkin 1, and has the aforementioned front sheet 2, back sheet 3, and absorbent body 4.

[0028] As shown in this embodiment, when the absorbent article has wings 5W, the excretion area B is the area where the wings 5W are located in the longitudinal direction X. Specifically, the area enclosed by an imaginary straight line extending in the transverse direction Y through the root of the front side of each pair of wings 5W, 5W in the longitudinal direction X, and an imaginary straight line extending in the transverse direction Y through the root of the rear side of each pair of wings 5W, 5W, is called the excretion area B.

[0029] In the sanitary napkin 1 of this embodiment, a pair of wings 5W, 5W are formed symmetrically on the left and right with reference to the longitudinal center line CL that divides the sanitary napkin 1 into two equal parts in the horizontal Y direction and extends in the vertical X direction. The root of the front side of one wing 5W and the root of the front side of the other wing 5W are located at the same position in the vertical X direction.

[0030] In the case of absorbent articles without wings (such as disposable diapers), the excretory portion relative area B only needs to be the area opposite to the excretory portion, typically located in the center of the absorbent article when it is divided into three equal parts in the longitudinal direction X.

[0031] The front sheet 2 covers the entire area of ​​the skin-facing side of the absorber 4. The back sheet 3 covers the entire area of ​​the non-skin-facing side of the absorber 4, and extends outward from both sides of the absorber 4 along the longitudinal direction X to the outer side in the transverse direction Y, forming a wing 5W together with the side sheet 6 described below. The sheet components constituting the wing 5W are joined together by known joining methods such as adhesives, heat sealing, and ultrasonic sealing at their extensions extending outward from both sides of the absorber 4 to the outer side in the transverse direction Y. The wing 5W of this embodiment includes the back sheet 3 and the side sheet 6 extending outward from both sides of the absorber 4 to the outer side in the transverse direction Y.

[0032] In the corresponding region B of the excretion section in this embodiment, such as Figure 1 As shown, the side panel 6 and the back panel 3 extend outward in the transverse Y direction, thereby providing a pair of wings 5W, 5W extending along the longitudinal X direction on the left and right sides of the absorbent body 5. The wings 5W are as follows... Figure 1 As shown, when viewed from above, the absorbent body 5 has a roughly trapezoidal shape with its lower base (the side longer than the upper base) located on the side of the absorbent body 5. A wing adhesive portion (not shown) is formed on the non-skin-facing side of the wing 5W, which secures the wing 5W to clothing such as shorts. The wing 5W is used by folding it back to the non-skin-facing side (outer surface) of the crotch area of ​​the shorts or other clothing. Alternatively, the wing 5W is used by folding it to the non-skin-facing side (outer surface) of the crotch area of ​​the clothing, thus the surface where the wing adhesive portion is formed, i.e., the non-skin-facing side of the wing 5W, faces the wearer's skin during use, becoming the skin-facing side. Before use, the wing adhesive portion is covered by a release liner (not shown) made of a film, non-woven fabric, paper, etc.

[0033] Side pieces 6 are arranged on both sides of the skin-facing side of the absorbent body 5 (i.e., the skin-facing side of the front piece 2) along the longitudinal direction X, overlapping with the left and right sides of the absorbent body 4 along the longitudinal direction X when viewed from above. The side pieces 6 are attached to the front piece 2, back piece 3, and other components using known bonding methods such as adhesives or heat embossing. The side pieces 6 are as follows... Figure 2 As shown, the inner end of the fixed end (not shown) of the free end 6a that is not engaged with the front panel 2 and the joint portion (not shown) that is engaged with the front panel 2 is separated from the front panel 2 during use, forming a leak-proof bag that prevents side leakage.

[0034] The sanitary napkin 1 in this embodiment is as follows: Figure 2 As shown, an intermediate sheet 7 is disposed between the front sheet 2 and the absorbent body 4. The intermediate sheet 7 preferably has a width (length in the transverse Y direction) smaller than the width (length in the transverse Y direction) of the absorbent body 4, and preferably a length in the longitudinal X direction greater than the length in the longitudinal X direction of the absorbent body 4, and is disposed continuously along the entire length in the longitudinal X direction of the sanitary napkin. The intermediate sheet 7 is separate from the front sheet 2 and the absorbent body 4, and is also referred to in this art as a secondary sheet.

[0035] In this embodiment, the intermediate sheet 7 is partially bonded to both the front sheet 2 and the absorber 4 by an adhesive and a compression groove 8 described later.

[0036] In this embodiment, the sanitary napkin 1 has a compression groove 8 extending from the front sheet 2 to the absorbent body 4 (see reference). Figure 1 The compression groove 8 is a groove integrally recessed into the back panel 3 by the front panel 2, the middle panel 7, and the absorber 4. The bottom of the groove reaches the absorber 4. Figure 2 (Not shown in the figure). In the compression groove 8, the front sheet 2 and the middle sheet 7 are integrally compressed.

[0037] In this embodiment, the compression groove 8 is an annular linear groove extending longitudinally from the front region A, through the excretion-relative region B, to the rear region C. The compression groove 8 has a shape symmetrical with respect to the longitudinal center line CL. In the compression groove 8, the density of each fiber constituting the front sheet 2, the middle sheet 7, and the absorbent body 4 is greater than the density of the surrounding area of ​​the compression groove 8. This compression groove 8 can suppress the diffusion of bodily fluids in the planar direction of the absorbent body 4, thereby effectively preventing liquid leakage from around the sanitary napkin 1.

[0038] Absorber 4 Figure 1 As shown, the absorbent body 4 extends along the longitudinal direction X of the sanitary napkin 1 (absorbent body 5). In other words, the absorbent body 4 extends from the front region A through the excretory region B to the rear region C.

[0039] The absorbent body 4 of this embodiment has an absorbent sheet 40 comprising a fibrous material and a water-absorbing polymer 41 as a constituent component. Specifically, it includes two absorbent sheets 40, namely a first absorbent sheet 40a and a second absorbent sheet 40b, and has a laminated structure formed by multiple layers of the absorbent sheets 40a and 40b (see reference). Figure 2 The absorber 4 has a central absorbent portion 4a, a front absorbent portion 4b covering the skin-facing side of the central absorbent portion 4a, and a back absorbent portion 4c covering the non-skin-facing side of the central absorbent portion 4a. Each absorbent portion 4a, 4b, and 4c is formed by folding a first absorbent sheet 40a and a second absorbent sheet 40b. The first absorbent sheet 40a is formed by folding its two sides along the longitudinal direction X towards the non-skin-facing side, thus creating a central absorbent portion 4a with a two-layer structure. Furthermore, the second absorbent sheet 40b is formed by folding its two sides along the longitudinal direction X towards the non-skin-facing side and covering the outer surface of the central absorbent portion 4a, thus creating a front absorbent portion 4b and a back absorbent portion 4c. In the second absorbent sheet 40b, the portion (layer) covering the skin-facing side of the central absorbent portion 4a constitutes the front absorbent portion 4b, and the portion (layer) covering the non-skin-facing side of the central absorbent portion 4a constitutes the back absorbent portion 4c.

[0040] Absorbent sheets 40a and 40b refer to absorbent bodies that have been formed into sheet-like shapes, as opposed to general absorbent bodies constructed by piling up absorbent materials. Representative absorbent sheets include those described in Japanese Patent No. 2963647 and Japanese Patent No. 2955223. As absorbent sheets, it is preferable to use adhesives such as superabsorbent polymers in a wet state, or separately added adhesives or adhesive fibers, to bond the constituent fibers together or the superabsorbent polymer with the constituent fibers to form a sheet-like structure. Furthermore, the absorbent sheets can be used in the following ways: absorbent sheets containing pulp manufactured by the method described in Japanese Patent Application Publication No. 8-246395; dry sheets formed by stacking pulverized pulp and superabsorbent polymer supplied with an airflow and then curing them with an adhesive (such as vinyl acetate adhesive, PVA, etc.); absorbent sheets obtained by applying a hot melt adhesive or the like between paper or nonwoven fabrics containing pulp and then dispersing the superabsorbent polymer; and absorbent sheets obtained by mixing the superabsorbent polymer in the manufacturing process of spunbond or meltblown nonwoven fabrics. These absorbent sheets can be cut into a specified shape and used as sheet-like absorbents.

[0041] like Figure 3 As shown, multiple first embossed rows 11 and multiple second embossed rows 12 are formed on the skin-facing side of the front panel 2.

[0042] The first embossing row 11 is composed of a plurality of linear embossed portions 15 arranged in a series at intervals such that the length direction of each linear embossed portion 15 is in the same direction. That is, the first embossing row 11 is a discontinuous line in which adjacent linear embossed portions 15 are spaced apart from each other.

[0043] Similar to the first embossing row 11, the second embossing row 12 is also composed of a plurality of linear embossed portions 16 arranged in a series at intervals with each linear embossed portion 16 facing the same direction along its length. The second embossing row 12 consists of discontinuous lines in which adjacent linear embossed portions 16 are spaced apart from each other.

[0044] Multiple first embossed rows 11 are formed parallel to each other. In the front panel 2 of this embodiment, the interval between the parallel and adjacent first embossed rows 11 is a fixed value.

[0045] Multiple second embossed rows 12 are formed parallel to each other. In the front panel 2 of this embodiment, the spacing between the parallel and adjacent second embossed rows 12 is a fixed value.

[0046] In the front panel 2 of this embodiment, the interval between the parallel and adjacent first embossing rows 11, 11 is the same length as the interval between the parallel and adjacent second embossing rows 12, 12.

[0047] Each linear embossed portion 15, 16 constituting the first embossed row 11 or the second embossed row 12 is formed by compacting the fibers constituting the front panel 2 through an embossing process with or without heat. That is, the thickness of the linear embossed portions 15, 16 is smaller than the thickness of the portions other than the embossed portions in the front panel 2 [see reference]. Figure 4 (b)

[0048] The first embossed row 11 and the second embossed row 12 are not parallel to the longitudinal direction X, but extend in a direction intersecting the longitudinal direction X. Furthermore, the first embossed row 11 and the second embossed row 12 intersect each other. In other words, in the front panel 2, a first embossed row 11 extending in a first direction intersecting the longitudinal direction X and the transverse direction Y, and a second embossed row 12 extending in a second direction intersecting the first direction are formed.

[0049] Figure 3 The first embossed row 11 extends in a straight line from the upper right to the lower left, and the second embossed row 12 extends in a straight line from the upper left to the lower right. That is, the first direction is a diagonal direction from the upper right to the lower left, and the second direction is a diagonal direction from the upper left to the lower right.

[0050] In this embodiment, the front panel 2 has a plurality of raised regions 14 defined by a plurality of first embossing rows 11 and a plurality of second embossing rows 12. As described above, the first embossing rows 11 and the second embossing rows 12 extend in an intersecting manner, thus the front panel 2 has a plurality of polygonal (specifically rhomboid) raised regions 14 formed by the intersection of the plurality of first embossing rows 11 and the plurality of second embossing rows 12. These raised regions 14 form a column of raised regions arranged in a series along the longitudinal direction X, and multiple columns of raised regions are arranged without intervals in the transverse direction Y. Adjacent raised regions 14 in the longitudinal direction X or the transverse direction Y share the linear embossed portions 15, 16 of the adjacent raised regions 14, 14.

[0051] The front panel 2 has a convex portion on the skin-facing side. More specifically, the thickness of each linear embossed portion 15, 16 is less than the thickness of the portion of the front panel 2 other than these linear embossed portions 15, 16. Therefore, the aforementioned convex region 14 is relatively convex with respect to each linear embossed portion 15, 16 [see reference]. Figure 4 (b)]. The protrusion is formed on the skin-facing side of the front panel 2.

[0052] Furthermore, on the skin-facing side of the front panel 2, each linear embossed portion 15, 16 becomes a concave portion relative to each convex region 14 [see reference]. Figure 4 (b)

[0053] The first high-density region 13 is located at the intersection of the first embossing row 11 and the second embossing row 12. The first high-density region 13 is the region where there are no linear embossed portions 15 and 16, i.e., the non-embossed portions that have not undergone embossing processing. The first high-density region 13 is the region whose maximum thickness is less than the maximum thickness of each raised region 14, but greater than the maximum thickness of the linear embossed portions 15 and 16 (see reference). Figure 4 [a] Since the first high-density region 13 has a smaller maximum thickness than the convex region 14, its density is higher than that of the convex region 14.

[0054] From the viewpoint of further improving the mobility of the following bodily fluids, the density of the first high-density region 13 is preferably 1.5 times or more and 4.0 times or less, more preferably 2.0 times or more and 3.0 times or less, relative to the density of the convex region 14.

[0055] The densities (g / cm³) of the first high-density region 13 and the convex region 14 in the frontal sheet 2 are respectively. 3 It is possible to divide the weight B1 (g / m²) of the front sheet 2 by the thickness Tx (mm) at a specified location. 2 The result is obtained by equation (1) below. In equation (1), x represents the difference in thickness and density between the first high-density region 13 and the convex region 14.

[0056] Density Dx (g / cm³)3 = (B1×0.0001) / (Tx×0.1)……(1)

[0057] Furthermore, the method for determining the thickness Tx is explained. First, using an optical microscope (e.g., a VHX-6000 manufactured by Keyence Corporation), the cross-sections of the first high-density region 13 and the convex region 14 of the front panel 2 are observed at 100x magnification, and the maximum thickness within each region is measured. This measurement is performed at five different locations, and the arithmetic mean of the maximum thicknesses obtained at these five locations is taken as the thickness Tx.

[0058] The density of the second high-density region 71 described below was also measured using the same method as described above.

[0059] The first high-density region 13 is formed between the linear embossed portions 15 constituting the first embossed row 11 and between the linear embossed portions 16 constituting the second embossed row 12. The spacing between these linear embossed portions may be the same or different.

[0060] In this embodiment, the spacing between the linear embossed portions 15 constituting the first embossed row 11 and the spacing between the linear embossed portions 16 constituting the second embossed row 12 are of the same length.

[0061] From the viewpoint that it is easier to form linear embossed portions 15 and 16, it is preferable that the front sheet 2 includes heat-fused fibers. Heat-fused fibers are fibers that are fused together by heat, and are made from thermoplastic resins. Examples of thermoplastic resins include: polyolefins such as polyethylene (PE) and polypropylene (PP); polyesters such as polyethylene terephthalate (PET); polyamides such as nylon 6 and nylon 66; polyacrylic acid, polyalkyl methacrylate, polyvinyl chloride, polyvinylidene chloride, etc., and one of these resins can be used alone or in combination of two or more.

[0062] In this embodiment, the non-skin-facing side of the front panel 2 is flat. For ease of explanation, Figure 4 The illustration in (a) shows that on the non-skin-facing side of the front panel 2, the first high-density region 13 is formed as a concave part and the convex region 14 is formed as a convex part, but in fact the non-skin-facing side of the front panel 2 is flat.

[0063] Figure 3 and the following Figure 6 and Figure 7 In the figure, a circle is drawn in part of the first high-density region indicated by reference numeral 13, but the circle is drawn for the purpose of visualizing the area where the first high-density region exists, and is not an actual circle on the front panel 2.

[0064] like Figure 5As shown, multiple welded portions 70 are formed in the intermediate sheet 7. The welded portions 70 are portions where the constituent fibers of the intermediate sheet 7 are thermally fused together to form a film. That is, in the welded portions 70, the constituent fibers of the intermediate sheet 7 do not maintain their fiber shape. These welded portions 70 are formed by performing an embossing process.

[0065] The welded portion 70 in this embodiment has a rhomboid shape when viewed from above. The shape of the welded portion 70 is not particularly limited and can be any shape such as a triangle, quadrilateral, hexagon, or other polygonal shape, or a circle, ellipse, star, etc.

[0066] In this embodiment, the welded portions 70 are arranged with intervals in both the longitudinal (X) and transverse (Y) directions (see reference). Figure 5 More specifically, multiple weld joints 70 are arranged in series at intervals along the longitudinal direction X to form a weld joint column, which is also arranged in multiple columns at intervals along the transverse direction Y. In each weld joint column, the pitch of the weld joints 70 is a constant value, and the phase of the weld joints 70 in adjacent weld joints 70 is staggered by half a pitch. That is, the weld joints 70 are arranged in an alternating pattern.

[0067] From the viewpoint that it is easier to form the welded portion 70, it is preferable that the intermediate sheet 7 contains the aforementioned heat-welding fibers.

[0068] Figure 6 The diagram illustrates the configuration of the first high-density region 13 and the welded portion 70. In the top view, the first high-density region 13 and the welded portion 70 at least partially overlap. In this case, the welded portion 70 may completely overlap the first high-density region 13, or only a portion of the welded portion 70 may overlap the first high-density region 13.

[0069] Furthermore, in the sanitary napkin 1, there may be both a welded portion 70 that at least partially overlaps with the first high-density region 13 and a welded portion 70 that does not overlap with the first high-density region 13. Figure 6 In the figure, reference numeral 10 indicates the position where the first high-density region 13 at least partially overlaps with the welded portion 70.

[0070] If menstrual blood or other bodily fluids are excreted into the sanitary napkin 1 of this embodiment, the fluid will migrate in the order of the front sheet 2, the middle sheet 7, and the absorbent core 4. In the front sheet 2, the fluid migrates along the linear embossed portions 15 and 16, reaching the first high-density region 13, where it is guided towards the non-skin-facing side, thus effectively inhibiting excessive diffusion of the fluid on the skin-facing side of the front sheet 2. Furthermore, since the first high-density region 13 at least partially overlaps with the welded portion 70, the fluid can smoothly migrate from the first high-density region 13 to the absorbent core 4 via the middle sheet 7. This is believed to be because, in the welded portion 70, the constituent fibers are fused together, making it difficult for the fluid to be absorbed; therefore, the fluid reaching the welded portion 70 will quickly migrate to areas outside the welded portion 70. By intervening in the welded portion 70, the migration of the fluid from the middle sheet 7 to the absorbent core 4 can be promoted, thereby enabling efficient migration of the fluid towards the absorbent core 4. In this way, both diffusion inhibition and migration promotion effects are achieved, thus preventing excessive diffusion of bodily fluids on the skin-facing side of the sanitary napkin 1 even if bodily fluids are repeatedly excreted. This reduces concerns about leakage. Furthermore, since bodily fluids are less likely to remain on the skin-facing side of the sanitary napkin 2, a comfortable wearing experience is achieved.

[0071] Hereinafter, the area ratio of the portion overlapping the first high-density region 13 and the welded portion 70 will also be referred to as the "welded portion overlap area ratio". From the viewpoint of achieving the above-mentioned effect more reliably, the welded portion overlap area ratio is preferably 15% or more and 45% or less, more preferably 20% or more and 35% or less.

[0072] The overlap area ratio of the welded section is measured by the following method.

[0073] <Overlap area ratio of welded joint>

[0074] Take out the front sheet 2 and the middle sheet 7 from the sanitary napkin 1, with them overlapping. For the removed front sheet 2, arbitrarily select one first high-density area 13, and mark the center of this high-density area 13 and the part of the middle sheet 7 that overlaps with the center of this high-density area 13 when viewed from above, using a ballpoint pen or similar tool. Next, observe the front sheet 2 using an optical microscope (e.g., a VHX-6000 manufactured by Keyence Corporation) with the marks near the center of the field of view, and take an observation image A. The magnification is set to 40x. In the observation image, draw a perfect circle defining the marked first high-density area, indicating that the first high-density area is tangent to the ends of the two linear embossed portions 15 of the first embossed row 11 and the two linear embossed portions 16 of the second embossed row 12. Save the observation image A. Furthermore, the perfect circle is drawn using a circle drawing tool installed by default in the software "VHX-6000Software," and is performed through image processing. Next, using the same method as with the front image 2, the intermediate image 7 is observed with the marked areas near the center of the field of view, and an observation image B (magnification 40x) is captured. Then, using the software "Adobe Photoshop Elements ver 9," the observation image A, with its opacity adjusted, is overlaid on the observation image B with the marks overlapping, creating a composite image and saving it. Furthermore, the opacity value is appropriately adjusted so that the circle in observation image A is visible, and the welded portion 70 in observation image B is visually identifiable even after overlaying observation image A. Additionally, to improve the visibility of the welded portion 70 in observation image B, the default color correction tool can be used. In the created composite image, the area overlapping between the first high-density region 13 and the welded portion 70 is measured, and the percentage obtained by dividing the overlapping area by the area of ​​the first high-density region 13 in the composite image is calculated. This same operation is performed a total of 10 times at different locations, and the arithmetic mean is set as the "welded portion overlap area ratio."

[0075] When removing the front sheet 2 or middle sheet 7 from the absorbent material as the object of measurement, if these components are fixed to other components by means of adhesive, welding, etc., the bonding force should be removed by means of blowing cold air, such as cold spray, onto the fixed part within a range that does not affect the fiber contact angle, before removing the material. This step is common to all measurements in this instruction manual.

[0076] From the same point of view as described above, the area ratio of the welded portion 70 in the intermediate sheet 7 is preferably 12% or more and 40% or less, more preferably 16% or more and 35% or less.

[0077] The area ratio of the welded portion 70 was determined using the following measurement method. A 20mm × 20mm sample piece was cut from the intermediate sheet 7. A top-view image of the sample piece was taken using an optical microscope (VHX-6000 manufactured by Keyence Corporation). The magnification was set to 40x. In the captured image, a square area with a diagonal length of 2.0mm was calculated as a percentage. 2 The percentage of the welded portion 70 in the sample piece. The above measurements were performed a total of 5 times at different locations on the sample piece, and the average value was set as the area ratio (%) of the welded portion 70.

[0078] From the viewpoint of further improving the diffusion suppression effect, it is preferable that the dimensions of the embossed rows 11 and 12 and the linear embossed portions 15 and 16 are within the following range.

[0079] The length of the linear embossed portion 15 in the first embossed row 11 is preferably 3.0 mm or more and 30 mm or less, more preferably 5.0 mm or more and 20 mm or less.

[0080] The length of the linear embossed portion 16 in the second embossed row 12 is preferably 3.0 mm or more and 30 mm or less, more preferably 5.0 mm or more and 20 mm or less.

[0081] The width of the linear embossed portions 15 and 16 is preferably 0.2 mm or more and 3.0 mm or less, more preferably 0.5 mm or more and 2.0 mm or less.

[0082] From the viewpoint of reducing the amount of body fluid absorbed in the first high-density region 13 and further improving the diffusion inhibition effect, it is preferable that the area of ​​the protruding region 14 is larger than the area of ​​the welded portion 70.

[0083] From the viewpoint of achieving the above-mentioned effects more reliably, it is preferable that the areas of the first high-density region 13 and the welded portion 70 are within the following range. This area is the area of ​​each first high-density region 13 and the area of ​​each welded portion 70.

[0084] The area of ​​the protruding region 14 is preferably 100 times or more and 400 times or less, and more preferably 150 times or more and 350 times or less, relative to the area of ​​the welded portion 70.

[0085] The area of ​​the welded portion 70 is preferably 0.10 mm. 2 Above and 4.00mm 2 Hereinafter, 0.20mm is preferred. 2 Above and 2.00mm 2 the following.

[0086] The area of ​​the convex region 14 is preferably 20 mm. 2 Above and 150mm 2The following is more preferably 50mm 2 Above and 100mm 2 the following.

[0087] The intermediate sheet 7 may also have a welded portion 70 that partially overlaps with the linear embossed portions 15 and 16, and a welded portion 70 that partially or completely overlaps with the raised portion region 14, in addition to the welded portion 70 that at least partially overlaps with the first high-density region 13.

[0088] From the viewpoint of reducing the amount of body fluid absorbed in the first high-density region 13 and further improving the diffusion inhibition effect, it is preferable that the convex region 14 overlaps with the plurality of welded portions 70 when viewed from above.

[0089] From the viewpoint of making it easier for the first high-density region 13 and the welded portion 70 to overlap, thereby further improving the diffusion suppression effect and migration promotion effect, it is preferable that the spacing between adjacent welded portions 70 is less than the maximum length L3 of the first high-density region 13 (refer to...). Figure 3 This structure is also effective for points where the first high-density region 13 and the second high-density region 71 described below can easily overlap, especially when the welded portion 70 has a rhomboid shape.

[0090] The maximum length L3 of the first high-density region 13 is the spacing between the linear embossed portions 15 constituting the first embossed row 11, or the spacing between the linear embossed portions 16 constituting the second embossed row 12, and is the longer of the two spacings (see reference). Figure 3 ).

[0091] The spacing between adjacent welded portions 70 is the spacing L5 between adjacent welded portions 70 in the longitudinal direction X (see reference). Figure 5 ), and the interval L6 between adjacent welded portions 70 in the transverse Y direction (refer to Figure 5 The longer of the intervals. When the welded portion 70 is divided by the second high-density region 71, the interval is the length excluding the width of the second high-density region 71.

[0092] From the same point of view as above, it is preferable that the spacing between adjacent welded portions 70 and the maximum length L3 of the first high-density region 13 are within the following ranges.

[0093] The spacing between adjacent welded portions 70 relative to the maximum length L3 of the first high-density region 13 (see reference). Figure 3 The preferred ratio is 0.5 times to 5.0 times, and more preferably 1.0 times to 3.0 times.

[0094] The spacing between adjacent welded portions 70 is preferably 0.50 mm or more and 3.00 mm or less, more preferably 1.00 mm or more and 2.50 mm or less.

[0095] The maximum length L3 of the first high-density region 13 (refer to) Figure 3 The thickness is preferably 1.0 mm or more and 6.0 mm or less, and more preferably 2.0 mm or more and 4.0 mm or less.

[0096] From the viewpoint of further improving the migration-promoting effect, it is preferable that the welded portion 70 does not shrink even after absorbing bodily fluid, but rather maintains its shape. From the same viewpoint, when the maximum transverse Y length of the welded portion 70 before fluid absorption is set as W1, and the maximum transverse Y length of the welded portion after fluid absorption is set as W2, the percentage of W2 relative to W1 (W2 / W1) is preferably 80% or more, more preferably 90% or more. The closer W2 / W1 is to 100%, the better the shape of the welded portion 70 is maintained before and after absorbing bodily fluid. That is, W2 / W1 is preferably close to 100%.

[0097] The above W1 and W2 are measured by the following method.

[0098] The middle piece 7, taken from the sanitary napkin 1, is cut into pieces with a longitudinal (X) dimension of 92 mm and a transverse (Y) dimension of 62 mm, and used as a measuring piece. The skin-facing side of this measuring piece is observed using a microscope (Dino-Lite R&D kit manufactured by Anmo Electronics), and images are taken. The magnification is set to 50.0 ± 1x. In the observed images, 10 arbitrarily selected welded sections 70 are used, and the maximum transverse (Y) length of each is measured. The average of this maximum length is calculated and set as W1. The measurement is performed using the two-point measurement tool installed with the software name "DinoCapture ver.2.0" by default, through image processing.

[0099] Next, two Kimwipe sheets (registered trademark) (NIPPON PAPER CRECIA S-200 manufactured by NIPPON PAPER CRECIA Co., Ltd.) were folded in half, and the measuring slide was placed on them with the skin-to-skin side facing up. An elliptical cylindrical disk (50mm major axis, 23mm minor axis) was then placed on the measuring slide with its major axis parallel to the longitudinal direction (X). Next, a coloring solution was prepared by mixing 10g of Edible Red No. 2 (Hodogaya Chemical Co., Ltd.) with 1000g of water. 6g of this coloring solution was injected into the cylindrical disk, allowing the measuring slide to absorb the coloring solution. After this absorption, specifically 3 seconds after the entire front of the measuring slide is visible within the cylindrical disk, the measuring slide was placed on a Saran Wrap (registered trademark) manufactured by Asahi Kasei Co., Ltd. The side of the measuring slide infused with the coloring solution was observed using a microscope, and an image was taken. The magnification was set to 50.0 ± 1x. In the observed image, the portion that absorbed the dye was stained red, while the portion that did not absorb the dye (welded portion 70) remained white. Ten of these white portions (welded portions 70) were randomly selected, and the maximum length of their respective transverse Y-axis was measured. The average of these maximum lengths was calculated and designated as W2. Measurements were performed using the same image processing as described above, as for W1. When a red-stained portion was present within the white portion of a welded portion 70 in the observed image, the maximum length of the transverse Y-axis was measured, including that stained portion.

[0100] In the intermediate sheet 7 of this embodiment, a second high-density region 71 (see reference) is formed, which has a higher density than the portion other than the welded portion 70. Figure 5 and Figure 6 The welded portion 70 is defined by the second high-density region 71. That is, the welded portion 70 is surrounded by the second high-density region 71.

[0101] The second high-density region 71 is a portion of the constituent fibers of the intermediate sheet 7 that, while maintaining their fiber shape, have partially melted and solidified. Therefore, the density of the second high-density region 71 is higher than that of the portion other than the welded portion 70.

[0102] From the viewpoint of further improving the migration promotion effect, the density of the second high-density region 71 is preferably 1.5 times or more and 5.0 times or less, more preferably 2.0 times or more and 3.0 times or less, relative to the density of the portion other than the welded portion 70.

[0103] From the viewpoint of further enhancing the migration-promoting effect, it is preferable that the first high-density region 13 and the second high-density region 71 at least partially overlap when viewed from above. According to this structure, the second high-density region 71 absorbs the bodily fluid absorbed by the first high-density region 13, thus enabling the bodily fluid to migrate further towards the intermediate sheet 7. Especially when the sanitary napkin 1 has repeatedly absorbed bodily fluid, the amount of bodily fluid residue in the first high-density region 13 is reduced, thereby further enhancing the diffusion-inhibiting effect.

[0104] In the above structure, the first high-density region 13 may only partially overlap with the second high-density region 71, or it may partially overlap with both the welded portion 70 and the second high-density region 71.

[0105] Hereinafter, the area ratio of the overlapping portion of the first high-density region 13 and the second high-density region 71 will also be referred to as the "high-density region overlap area ratio". From the viewpoint of achieving the above-mentioned effect more reliably, the high-density region overlap area ratio is preferably 5% or more and 40% or less, more preferably 9% or more and 30% or less.

[0106] The overlap area ratio of high-density regions is measured by the following method.

[0107] <Overlapping area ratio of high-density regions>

[0108] Using the same method as described above for the <overlap area ratio of the welded area>, an observation image A with adjusted opacity is overlaid on observation image B to create a composite image. At this time, the opacity value is appropriately adjusted so that the circle in observation image A is visible and the second high-density region 71 in observation image B is visually identifiable even after overlaying observation image A. Furthermore, to improve the visibility of the second high-density region 71 in observation image B, the tone correction tool installed by default can also be used. In the created composite image, the area of ​​overlap between the first high-density region 13 and the second high-density region 71 is measured, and the percentage obtained by dividing the overlap area by the area of ​​the first high-density region 13 in the composite image is calculated. This same operation is performed a total of 10 times at different locations, and the arithmetic mean is set as the "high-density region overlap area ratio".

[0109] From the viewpoint of guiding bodily fluids toward the absorbent 4 to further improve the diffusion inhibition effect, it is preferable that there be a region near the compression groove 8 where multiple first high-density regions 13 and second high-density regions 71 at least partially overlap. "Near the compression groove 8" refers to the area within 3.0 mm of the compression groove 8 in both the longitudinal (X) and transverse (Y) directions.

[0110] In this embodiment, the compression groove 8 is an annular groove extending longitudinally (X). More preferably, in this compression groove 8, there are regions where a plurality of first high-density regions 13 and second high-density regions 71 at least partially overlap inside and outside its annular shape.

[0111] From the same perspective as described above, the area ratio of the region in the vicinity of the compression groove 8 where the first high-density region 13 and the second high-density region 71 at least partially overlap is preferably 5% or more and 40% or less, more preferably 9% or more and 30% or less. This area ratio can also be referred to as the overlap area ratio of the high-density regions near the compression groove 8.

[0112] From the viewpoint that it is easy for the first high-density region 13 and the second high-density region 71 to overlap, the width W5 of the second high-density region 71 is preferred (refer to...). Figure 5 It falls within the following range.

[0113] The width W5 of the second high-density region 71 (refer to) Figure 5 The maximum length L3 relative to the first high-density region 13 (refer to) Figure 3 The ratio is preferably 0.02 times or more and 0.25 times or less, and more preferably 0.05 times or more and 0.15 times or less.

[0114] The width W5 of the second high-density region 71 (refer to) Figure 5 The thickness is preferably 0.05 mm or more and 0.30 mm or less, and more preferably 0.10 mm or more and 0.20 mm or less.

[0115] The width W5 of the second high-density region 71 is measured by the following method.

[0116] The width W5 of the second high-density region 71 was measured using a microscope at 200x magnification on the intermediate section 7. Measurements were performed on 10 randomly selected locations of the second high-density region 71, and the average value was set as the width W5 of the second high-density region 71. Within the field of view, the second high-density region 71 can be identified by defining the area of ​​the welded portion 70, i.e., the area where the gaps between the constituent fibers are less than those outside the second high-density region 71. Specifically, the second high-density region 71 is the area where the constituent fibers are more densely packed than other areas, and therefore can be identified as a whiter area than other areas. Furthermore, the welded portion 70 is the area formed by the melting and film formation of the constituent fibers, and therefore can be identified as a darker area (gray area) than the second high-density region 71 within the field of view. Thus, by observing the gaps between the constituent fibers (black areas) and the brightness (white or gray) within the field of view, the welded portion 70, the second high-density region 71, and other areas can be distinguished.

[0117] From the viewpoint of further improving the mobility of body fluid from the first high-density region 13 to the second high-density region 71 and further enhancing the diffusion inhibition effect, it is preferable that, in a top view, the front sheet 2 and the intermediate sheet 7 are joined at a position where the first high-density region 13 and the second high-density region 71 at least partially overlap. According to this structure, the adhesion between the front sheet 2 and the intermediate sheet 7 is improved, thereby enabling body fluid to migrate more easily from the first high-density region 13 to the second high-density region 71.

[0118] From the viewpoint of further improving the above effects, it is preferable that the non-skin-facing side of the front sheet is flat.

[0119] The aforementioned bonding of the front sheet 2 and the middle sheet 7 can be achieved using known bonding methods such as adhesives. When using adhesives for the bonding, it is preferable to apply the adhesive in a pattern that produces non-coated portions of the adhesive, such as stripes or spirals.

[0120] From the viewpoint of further enhancing the migration-promoting effect, it is preferable that the density of the first high-density region 13 is lower than that of the second high-density region 71. According to this structure, a fibrous capillary force gradient is generated from the first high-density region 13 to the second high-density region 71, which can further promote the migration of body fluid from the front sheet 2 to the middle sheet 7.

[0121] From the same point of view as described above, the density of the second high-density region 71 relative to the density of the first high-density region 13 is preferably 120% or more and 500% or less, more preferably 200% or more and 300% or less.

[0122] From the viewpoint of further improving the diffusion inhibition effect and migration promotion effect, the basis weights of the front sheet 2 and the middle sheet 7 are preferably within the following range.

[0123] The preferred weight of front sheet 2 is 15 g / m². 2 Above and 40g / m 2 The following is more preferably 20g / m 2 Above and 30g / m 2 the following.

[0124] The preferred weight of intermediate slice 7 is 18 g / m³. 2 Above and 45g / m 2 The following is more preferably 25g / m 2 Above and 35g / m 2 the following.

[0125] Next, the materials used to form each component of the sanitary napkin 1 will be explained.

[0126] The front sheet 2 and back sheet 3 can be made of various materials traditionally used in absorbent products such as menstrual pads without particular restriction. The front sheet 2 is preferably a liquid-permeable sheet, such as single-layer or multi-layer nonwoven fabrics manufactured using various known methods. The back sheet 3 is preferably a liquid-impermeable sheet, such as a resin film or a laminate of a resin film and nonwoven fabric, where the resin film may also be permeable. Furthermore, regarding the back sheet 3, liquid impermeability encompasses both the property of being completely impermeable to liquids and the property of allowing only a small amount of liquid to pass through (liquid-resistant). The back sheet 3 may also be water-repellent.

[0127] As the side sheet 6, a liquid-impermeable sheet is preferred, for example, a sheet that can be used as the back sheet 3 can be used.

[0128] As the intermediate sheet 7, a liquid-permeable sheet is preferred, and a sheet that can be used as the front sheet 2 can be used.

[0129] As the absorbent material included in the absorbent body 4, any material that can be used in the absorbent body of such an absorbent article can be used without particular limitation, such as hydrophilic fiber materials and absorbent polymers. As the hydrophilic fiber material, naturally hydrophilic fibers or fibers obtained by hydrophilizing hydrophobic fibers can be used, with the former being particularly preferred. Natural fibers, cellulose-based regenerated fibers, or semi-synthetic fibers are preferred examples of naturally hydrophilic fibers, and pulp and rayon are preferred examples. In addition to wood pulps such as coniferous kraft pulp and broadleaf kraft pulp, non-wood pulps such as kapok pulp and straw pulp are also included, but there are no particular limitations. Furthermore, cross-linked cellulose fibers formed by intramolecular and / or intermolecular cross-linking of cellulose fibers, and fluffy cellulose fibers obtained by mercerizing wood pulp can also be used. As the absorbent polymer, granular or fibrous forms can generally be used. The shape of granular superabsorbent polymers is not particularly limited; for example, they can be spherical, blocky, bag-shaped, or irregularly shaped. Typically, superabsorbent polymers are based on polymers or copolymers of acrylic acid or alkali metal salts of acrylate.

[0130] The front sheet 2 and the middle sheet 7 are obtained by embossing the nonwoven fabric. The middle sheet 7, which has the aforementioned welded portion 70 and the second high-density region 71, can be manufactured, for example, by the following method.

[0131] The intermediate sheet 7 is manufactured by hot-pressing a continuous sheet formed of hot-air nonwoven fabric into a hot-pressing apparatus having a pair of rollers. One of the rollers is a embossing roller with a diamond-shaped embossing protrusion formed on its circumferential surface, and the other is a smoothing roller with a smooth circumferential surface, arranged opposite to the embossing roller. The hot-pressing process is performed by pressing the continuous sheet formed of hot-air nonwoven fabric between the embossing protrusion of the embossing roller and the smooth circumferential surface of the smoothing roller to compress it. The welded portion 70 is formed by welding the portion of the continuous sheet that contacts the pressure surface of the embossing protrusion, and the second high-density region 71 is formed along the periphery of the embossing protrusion.

[0132] From the viewpoint that it is easy to form the welded portion 70 and the second high-density region 71, it is preferable to perform the above-mentioned hot embossing process under the following conditions.

[0133] The heating temperature of the embossed protrusion is preferably 125°C or higher and 160°C or lower, more preferably 125°C or higher and 145°C or lower, and even more preferably 130°C or higher and 140°C or lower.

[0134] The pressure applied to the continuous sheet between a pair of rollers is preferably 2.9 MPa or more and 8.8 MPa or less, more preferably 4.9 MPa or more and 7.8 MPa or less.

[0135] The sanitary napkin 1 is preferably manufactured by positioning the front sheet 2 and the middle sheet 7 in a manner in which the first high-density region 13 and the welded portion 70 at least partially overlap, and then joining the front sheet 2 and the middle sheet 7 together. More preferably, the positioning of the front sheet 2 and the middle sheet 7 is such that, in addition to overlapping the first high-density region 13 with the welded portion 70, the first high-density region 13 also at least partially overlaps with the second high-density region 71.

[0136] When using an adhesive to bond the front sheet 2 to the middle sheet 7, it is preferable to apply the adhesive at the location where the first high-density region 13 and the second high-density region 71 at least partially overlap.

[0137] The front panel 2 of the above embodiment has multiple convex regions 14 with the same shape and the same area, but is not limited to this embodiment. Figure 7 Another embodiment of the front panel 2 is shown. Components identical to those in the above embodiment are labeled with the same reference numerals, and detailed descriptions are omitted.

[0138] exist Figure 7 The skin-facing side of the front panel 2 shown has multiple first embossed rows 11 and multiple second embossed rows 12.

[0139] In the first embossing row 11, straight first linear embossed portions 15a and straight second linear embossed portions 15b, which are shorter than the first linear embossed portions 15a, are arranged alternately and in series. The first embossing row 11 consists of discontinuous lines spaced apart from adjacent first linear embossed portions 15a and second linear embossed portions 15b in the embossing row 11.

[0140] In the second embossing row 12, straight third linear embossed portions 16a and straight fourth linear embossed portions 16b, which are shorter than the third linear embossed portions 16a, are arranged alternately and in series. The second embossing row 12 consists of discontinuous lines spaced apart from adjacent third linear embossed portions 16a and fourth linear embossed portions 16b in the embossing row 12.

[0141] In the front panel 2 of this embodiment, parallel and adjacent first embossed rows 11, 11 are alternately arranged with narrower intervals and wider intervals. That is, in the multiple rows of first embossed rows 11, there are regions with wider intervals and narrower intervals between parallel and adjacent linear embossed portions 15a, 15b.

[0142] Furthermore, in the front panel 2 of this embodiment, parallel and adjacent second embossed rows 12 are alternately arranged with narrower intervals and wider intervals between them. That is, in the multiple rows of second embossed rows 12, there are regions with wider intervals and narrower intervals between parallel and adjacent linear embossed portions 16a and 16b.

[0143] The front panel 2 of this embodiment has multiple convex regions 14a, 14b, 14c, and 14d divided by multiple first embossing rows 11 and multiple second embossing rows 12. As described above, the first embossing rows 11 and the second embossing rows 12 extend in an intersecting manner, thus the front panel 2 has multiple polygonal convex regions 14a, 14b, 14c, and 14d formed by the intersection of multiple first embossing rows 11 and multiple second embossing rows. Specifically, the front panel 2 has three types of convex regions 14a, 14b, 14c, and 14d with different areas. The convex region with the largest area among these convex regions is also called "large convex region 14a", the convex region with the second largest area is also called "medium convex region 14b, 14c", and the convex region with the smallest area is also called "small convex region 14d".

[0144] In the front panel 2 of this embodiment, in the top view, the large convex region 14a and the small convex region 14d are rhombuses, and the medium convex regions 14b and 14c are parallelograms.

[0145] The three types of regions, namely large convex region 14a, medium convex regions 14b and 14c and small convex region 14d, are adjacent in the longitudinal X or transverse Y direction, separated by the first high-density region 13.

[0146] In this embodiment, the front panel 2 has multiple rows of mixed convex regions R1 arranged alternately in the horizontal Y direction, consisting of large convex regions 14a and small convex regions 14d arranged in the vertical X direction. Furthermore, between the mixed convex region rows R1, the front panel 2 has multiple rows of medium convex regions R2 arranged in the horizontal Y direction, consisting of medium convex regions 14b and 14c arranged in the vertical X direction. The medium convex region rows R2 are formed by alternating medium convex regions 14b (divided by the first linear embossing portion 15a and the fourth linear embossing portion 16b) and medium convex regions 14c (divided by the third linear embossing portion 16a and the second linear embossing portion 15b) arranged in the vertical X direction. The medium convex regions 14b and 14c adjacent in the vertical X direction within the medium convex region rows R2 have a shape that is linearly symmetrical with respect to an imaginary line extending in the horizontal Y direction through these regions 14b and 14c. Therefore, the central convex region R2 is formed in a periodic meandering manner with amplitude in the transverse Y direction.

[0147] Figure 7 Because the first high-density region 13 of the front panel 2 is non-embossed, it has higher softness. Therefore, when the wearer performs actions such as walking, the protrusions formed in the protrusion regions 14a, 14b, 14c, and 14d maintain a high degree of conformity to the skin. Furthermore, bodily fluids flowing along the mixed protrusion region row R1 and the intermediate protrusion region row R2 are absorbed in the first high-density region 13, thus further reducing fluid residue on the skin-facing surface of the front panel 2 and improving the tactile feel.

[0148] As described above, the area of ​​the welded portion 70 in the intermediate sheet 7 is preferably smaller than the convex region of the front sheet 2. In this case, for the front sheet 2 having convex regions 14a, 14b, 14c, and 14d with different areas, the area of ​​the welded portion 70 only needs to be smaller than the area of ​​the smallest convex region (small convex region 14d) among these convex regions.

[0149] The present invention has been described above based on a preferred embodiment, but the present invention is not limited to the above embodiment and can be appropriately modified without departing from the spirit of the present invention.

[0150] For example, the front panel can have a two-layer structure consisting of an upper layer and a lower layer, or it can have a single-layer structure.

[0151] Furthermore, the pattern of the linear embossed area in front panel 2 is not limited to... Figure 3 The structure shown can also be formed into linear embossed areas, for example, by forming a pattern of convex areas that form triangles or hexagons.

[0152] Furthermore, the absorbent 4 in the above embodiment includes absorbent sheets 40a and 40b, but it can also have an absorbent core comprising fibrous material and a water-absorbing polymer, and a coating layer covering the surface of the absorbent core. The absorbent core is formed from a composite of fibrous material and water-absorbing polymer.

[0153] Example

[0154] The present invention will now be described in more detail with reference to embodiments. However, the scope of the present invention is not limited to these embodiments. Unless otherwise specified, "%" means "mass %".

[0155] [Example 1]

[0156] In Example 1, the following fibers S1 to S3 were used to manufacture... Figure 7 The front sheet 2 shown is a two-layer structure consisting of an upper layer and a lower layer. The upper layer is made by mixing fibers S1 and S2 in a 1:1 mass ratio, and the lower layer is made using fiber S3. The laminate formed by overlapping the upper and lower layers is embossed from the upper layer side. Thus, a front sheet 2 is manufactured having embossed rows 11 and 12, a large convex region 14a, medium convex regions 14b and 14c, a small convex region 14d, and a first high-density region 13. The parameters of the resulting front sheet 2 are shown in Table 1.

[0157] Fiber S1: Thermally elongated core-sheath composite fiber (fineness 2.4 dtex, core is polypropylene / sheath is polyethylene)

[0158] Fiber S2: Thermo-melt fiber (fineness 2.4 dtex, core of polyethylene terephthalate / sheath of polyethylene)

[0159] Fiber S3: Thermo-melt fiber (fineness 1.8 dtex, core of polyethylene terephthalate / sheath of polyethylene)

[0160] In Example 1, an intermediate sheet 7 having multiple welded portions 70 was manufactured using a hot-air nonwoven fabric formed from the following fibers S4. Specifically, the nonwoven fabric was fed into a hot embossing apparatus with a pair of rollers to manufacture the intermediate sheet. During the hot embossing process, the heating temperature of the embossing protrusions was set to 125°C, and the pressure applied to the nonwoven fabric was set to 4.9 MPa. Thus, an intermediate sheet 7 having multiple welded portions 70 divided by a second high-density region 71 was manufactured. The parameters of the resulting intermediate sheet 7 are shown in Table 1. The welded portions 70 in Example 1 have a longitudinally elongated rhomboid shape extending in the longitudinal direction X.

[0161] Fiber S4: Thermo-melt fiber (fineness 2.2 dtex, core of polyethylene terephthalate / sheath of polyethylene)

[0162] [Example 2]

[0163] The front sheet 2 and the middle sheet 7 were manufactured using the same method as in Example 1, except for the following: in the manufacturing conditions of the middle sheet, the heating temperature of the embossing protrusions in the hot embossing device with a pair of rollers was set to 130°C, and the pressure applied to the nonwoven fabric was set to 4.9 MPa. The parameters of the front sheet 2 and the middle sheet 7 of Example 2 are shown in Table 1.

[0164] [Example 3]

[0165] The front sheet 2 and the middle sheet 7 were manufactured using the same method as in Example 1, except for the following: forming a welded portion 70 with a transversely elongated rhomboid shape extending in the transverse Y direction; furthermore, in the manufacturing conditions of the middle sheet, the heating temperature of the embossing protrusion in the hot embossing device with a pair of rollers was set to 136°C, and the pressure applied to the nonwoven fabric was set to 7.6 MPa. The parameters of the front sheet 2 and the middle sheet 7 of Example 3 are shown in Table 1.

[0166] [Example 4]

[0167] The front sheet 2 and the middle sheet 7 were manufactured using the same method as in Example 2, except for the following: the spacing between adjacent welded portions 70 and the size of one welded portion 70 differed from that in Example 2, and the welded portion 70 had a transversely elongated rhomboid shape extending in the transverse Y direction; furthermore, in the manufacturing conditions of the middle sheet, the heating temperature of the embossing protrusion in the hot embossing device with a pair of rollers was set to 158°C, and the pressure applied to the nonwoven fabric was set to 3.2 MPa. The parameters of the front sheet 2 and the middle sheet 7 of Example 4 are shown in Table 1.

[0168] [Comparative Example 1]

[0169] The front sheet 2 was manufactured using the same method as in Example 1, except that the first high-density region 13 was not formed, but rather multiple embossed rows were formed in a grid pattern of two intersecting embossed rows. Furthermore, the intermediate sheet was manufactured using the same method as in Example 1, except that the heating temperature of the embossing protrusions in the hot embossing apparatus with a pair of rollers was set to 120°C, the pressure applied to the nonwoven fabric was set to 4.9 MPa, and the area ratio of the welded portion 70 was changed. The parameters of the front sheet 2 and intermediate sheet 7 of Comparative Example 1 are shown in Table 1.

[0170] The front sheet 2 and the intermediate sheet 7 obtained in each embodiment and comparative example are overlapped, and bonded together using an adhesive. For the front sheet 2 and the intermediate sheet 7 of Examples 1-3, the adhesive is applied at the location where the first high-density region 13 and the second high-density region 71 at least partially overlap. Using the bonded front sheet 2 and the intermediate sheet 7, a product is manufactured. Figure 1 The sanitary napkin shown. The components other than the front panel 2 and the middle panel 7 are the same as those of the menstrual sanitary napkins manufactured by Kao Corporation (trade name "Laurier slim guard Extra Heavy Flow Daytime 25cm"). The sanitary napkin 1 has... Figure 1 The compression groove 8 is shown. The resulting sanitary napkin 1 is a measurement sample of the liquid diffusion area in the front panel described below. Furthermore, the overlap area ratio of the welded section, the overlap area ratio of the high-density area, and the overlap area ratio of the high-density area near the compression groove were measured on this sanitary napkin 1. These area ratios were measured using the methods described above. The measurement results are shown in Table 1.

[0171] [Measurement of the liquid diffusion area in the front sheet]

[0172] The sanitary napkins of each embodiment and comparative example were fixed to menstrual panties and worn on a dynamic human body model. A movable female waist model capable of walking was used as the dynamic human body model. The dynamic model was made to start walking. One minute after the start of walking, 3g of defibrinated horse blood (manufactured by Nippon Biological Laboratory Co., Ltd.) was injected into the liquid excretion point for 15 seconds (first time). The defibrinated horse blood was manufactured by Nippon Biological Laboratory Co., Ltd., and the viscosity was adjusted to 24cp at a liquid temperature of 25°C. Furthermore, this viscosity was measured in a TVB-10M type viscometer manufactured by Toki Sangyo Co., Ltd., using a rotor named L / Adp (rotor code 19) rotating at a speed of 12rpm. Then, three minutes after the end of the first injection of fibrinous horse blood, another 3g of defibrinated horse blood was injected for 15 seconds (second time). After the second injection, the walking action of the dynamic model was immediately stopped, the sanitary napkin was torn off from the menstrual panties, and the sanitary napkin was left to stand still on a flat surface. Then, the area of ​​the stained portion (the diffusion area of ​​defibrinated horse blood) on the front side of the sanitary napkin (section 2) was measured and set as the liquid diffusion area in the front side. It can be seen that the smaller this area, the higher the diffusion inhibition effect and migration promotion effect. The measurement results are shown in Table 1.

[0173]

[0174] As shown in Table 1, the liquid diffusion area in the front sheet of the sanitary napkins in Examples 1-4 is smaller compared to that of Comparative Example 1. This result indicates that the absorbent articles of the present invention, having the front sheet 2 and the middle sheet 7 of Examples 1-4, can suppress the diffusion of body fluids on the skin-facing side of the front sheet, and exhibit excellent migration of body fluids towards the absorbent side.

[0175] Furthermore, the comparison of Examples 1 to 4 shows that increasing the overlap area ratio of the welded portion, the overlap area ratio of the high-density region, or the overlap area ratio of the high-density region near the compression groove helps to improve the diffusion suppression effect and the migration promotion effect.

[0176] Industrial availability

[0177] According to the present invention, an absorbent article is provided that can inhibit the diffusion of bodily fluids on the skin-facing side of the front sheet and has excellent mobility of bodily fluids towards the absorbent body side.

Claims

1. An absorbent article comprising: an absorbent body; a front sheet disposed on a side opposite to the skin closer to the absorbent body; and an intermediate sheet disposed between the absorbent body and the front sheet, wherein the absorbent article is characterized in that: The front sheet has the following formed: The system comprises multiple first embossed rows, which are formed by multiple linear embossed portions arranged in a series at intervals with their length directions aligned in the same direction; and multiple second embossed rows, which are formed by multiple linear embossed portions arranged in a series at intervals with their length directions aligned in the same direction. The first and second embossing rows intersect each other. It forms a region defined by the first and second embossing rows, which contains convex portions constituting fibers throughout its thickness direction. A first high-density region with a higher density than the protruding region is located at the intersection of the first embossing row and the second embossing row. This first high-density region is the region where none of the linear embossed portions exist. The plurality of linear embossed portions are formed only on the front panel. Multiple welded portions are formed in the intermediate sheet. When viewed from above, the first high-density region at least partially overlaps with the welded portion. A second high-density region is formed in the intermediate sheet, which has a higher density than the portion outside the welded section. The plurality of welded portions are each defined by the second high-density region. When viewed from above, the first high-density region and the second high-density region at least partially overlap. The non-skin-facing side of the front panel is flat. When viewed from above, at a location where the first high-density region and the second high-density region at least partially overlap, the front sheet and the middle sheet are joined by an adhesive. The first high-density region is a perfectly circular region that is tangent to the ends of two adjacent linear embossed portions in the first embossed row separated by the intersection point and the ends of two adjacent linear embossed portions in the second embossed row separated by the intersection point. The area ratio of the portion where the first high-density region overlaps with the welded portion is 15% or more and 45% or less.

2. The absorbent article as claimed in claim 1, characterized in that: Compared to the second high-density region, the density at the location of maximum thickness in the first high-density region is lower.

3. The absorbent article as described in claim 2, characterized in that: The density at the location of the maximum thickness of the second high-density region is more than 120% and less than 500% relative to the density at the location of the maximum thickness of the first high-density region.

4. The absorbent article as described in any one of claims 1 to 3, characterized in that: It has a compression groove formed by integrally pressing the front sheet and the middle sheet together. Near the compression groove, there are multiple regions where the first high-density region and the second high-density region at least partially overlap.

5. The absorbent article as described in any one of claims 1 to 3, characterized in that: The area of ​​the protruding region is larger than the area of ​​the welded portion. When viewed from above, the convex region overlaps with multiple welded portions.

6. The absorbent article as claimed in claim 5, characterized in that: The first high-density region is a perfectly circular region that is tangent to the ends of two adjacent linear embossed portions in the first embossed row separated by the intersection point and the ends of two adjacent linear embossed portions in the second embossed row separated by the intersection point. The area of ​​the protruding region excluding the first high-density region is more than 100 times and less than 400 times the area of ​​the welded portion.

7. The absorbent article as described in any one of claims 1 to 3, characterized in that: It has a longitudinal direction corresponding to the wearer's front-back direction and a transverse direction orthogonal to that longitudinal direction. When the maximum lateral length of the welded portion before liquid absorption is set as W1, and the maximum lateral length of the welded portion after liquid absorption is set as W2, the percentage of W2 relative to W1 (W2 / W1) is 80% or more.

8. The absorbent article as described in any one of claims 1 to 3, characterized in that: The first high-density region is a perfectly circular region that is tangent to the ends of two adjacent linear embossed portions in the first embossed row separated by the intersection point and the ends of two adjacent linear embossed portions in the second embossed row separated by the intersection point. The welded portion has a rhomboid shape. The spacing between adjacent welded portions is less than the maximum length of the first high-density region.

9. The absorbent article as described in any one of claims 1 to 3, characterized in that: It has a longitudinal direction corresponding to the wearer's front-back direction and a transverse direction orthogonal to that longitudinal direction. The front panel has three different areas as the convex regions. When the largest area is designated as the large convex region, the second largest area as the medium convex region, and the smallest area as the small convex region, the large convex region and the small convex region are rhombuses, and the medium convex region is a parallelogram. The three regions are adjacent to each other in the longitudinal or transverse direction, separated by the first high-density region.

10. The absorbent article as described in any one of claims 1 to 3, characterized in that: The density at the location of the maximum thickness of the first high-density region is more than 1.5 times and less than 4.0 times the density at the location of the maximum thickness of the convex region.

11. The absorbent article as claimed in any one of claims 1 to 3, characterized in that: The area ratio of the welded portion in the intermediate sheet is 12% or more and 40% or less.

12. The absorbent article as described in any one of claims 1 to 3, characterized in that: The first high-density region is the region whose maximum thickness is less than the maximum thickness of each of the protruding regions, but greater than the maximum thickness of the linear embossed portion.

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