Pants-type disposable diapers

Abstract

To provide an underpants type disposable diaper which allows a user to easily recognize a site of a starting point in tearing up a side seal part.SOLUTION: In an underpants type disposable diaper 1, a side seal part S, a waist opening part WH, and a leg opening part LH are formed by joining both side parts of an abdominal side part A and both side parts of a back side part B. An exterior body 3 includes a coloring sheet. In the side seal part S, a plurality of first fusion parts 41 where the abdominal side part A and the back side part B are fused are arranged at intervals in a longitudinal direction X, and a sheet forming the first fusion part 41 includes the coloring sheet. A longest circumference of (1) the first fusion part 41 or (2) an adjacent fusion part 44 where the first fusion part 41 and the sheet in the abdominal side part A or the back side part B are fused and which is constituted of a second fusion part 43 closest to the first fusion part 41 is positioned outside an end edge 23a of an absorber 23 in the longitudinal direction X.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a pants-type disposable diaper. [Background technology]

[0002] Conventionally, there have been known pants-type disposable diapers in which both sides of the abdominal section, which is positioned on the abdominal side of the wearer when worn, are joined to both sides of the dorsal section, which is positioned on the dorsal side, to form a pair of side seals, a waist opening, and a pair of leg openings (see Patent Documents 1 to 3). Such pants-type disposable diapers can generally be easily removed from the wearer after use by tearing the side seals. As pants-type disposable diapers, those in which the joining mode of the side seals has been studied from the viewpoint of ease of tearing the side seals when removing the diaper have been proposed (see Patent Document 1).

[0003] Patent Document 1 describes a pants-type disposable diaper having a side seal portion that joins the ventral portion and the dorsal portion, as well as a fused portion that fuses the outer and inner sheets that make up the outer cover. In Patent Document 1, the length of the fused portion in the width direction of the side seal portion is made shorter than the length of the side seal portion in the width direction, thereby achieving both bonding strength and ease of tearing of the side seal portion.

[0004] Furthermore, in order to improve the design of the diaper or to make it easier to determine whether the diaper is being worn properly, a part of the outer casing of the diaper is colored (see Patent Documents 2 and 3).

[0005] In the pants-type disposable diaper of Patent Document 2, a colored portion is formed by printing or the like on an outer layer sheet that forms the outer surface of the diaper in the elastic waist portion of the diaper. Patent Document 1 describes that it is possible to determine whether the diaper is being worn properly based on the visibility of the colored portion when the diaper is viewed from the outer layer sheet side.

[0006] In the pants-type disposable diaper of Patent Document 3, the outer casing of the diaper has a stretchable region and a non-stretchable region, and both regions are provided with a nonwoven fabric having a colored portion. In the non-stretchable region, the outer casing is formed with a high-density, dark-colored portion that is darker in color than the colored portion. Patent Document 2 describes that in the stretchable region, the outer casing stretches, making the color appear darker, and in the non-stretchable region, the high-density, dark-colored portion makes the color appear darker, thereby achieving a uniform color tone in the stretchable and non-stretchable regions and easily enhancing the design. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] International Publication No. 2019 / 123549 [Patent Document 2] Japanese Patent Application Publication No. 2020-89438 [Patent Document 3] Japanese Patent Application Publication No. 2017-217063 Summary of the Invention [Problem to be solved by the invention]

[0008] When the visibility of the side seals is poor, it is difficult to identify the starting point for tearing the side seals, and it can be difficult to know which part of the side seals to start tearing from, which can make tearing the side seals time-consuming.The pants-type disposable diapers in Patent Documents 1 to 3 do not consider improving the visibility of the side seals, and there is room for improvement. SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a disposable diaper in which the location that serves as the starting point for tearing the side seal portion can be easily identified. [Means for solving the problem]

[0009] The present invention provides a diaper absorbing device comprising an absorbent body and an exterior body disposed on a non-skin-facing side of the absorbent body, The present invention relates to a pants-type disposable diaper having a ventral side portion arranged on the ventral side of a wearer, a dorsal side portion arranged on the dorsal side of the wearer, and a crotch portion located between the ventral side portion and the dorsal side portion, and having a vertical direction corresponding to the front-to-back direction of the wearer through the crotch portion and a horizontal direction perpendicular to the vertical direction, and both sides of the ventral side portion and both sides of the dorsal side portion joined to form a pair of side seal portions, a waist opening, and a pair of leg openings. The exterior body includes a colored sheet. A plurality of first fused portions, in which the ventral portion and the dorsal portion are fused together, are arranged at intervals in the vertical direction in the side seal portion. In the area where the colored sheet is arranged, (1) a first fused portion, or (2) An adjacent fused portion consisting of a first fused portion and a second fused portion that fused the sheets together in the ventral portion or the dorsal portion and is closest to the first fused portion. It has. The first fused portion or the adjacent fused portion having the greatest circumferential length is located outward from the edge of the absorbent body in the longitudinal direction. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a pants-type disposable diaper in which the region that serves as the starting point for tearing the side seal portion can be easily identified. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a perspective view schematically showing one embodiment of a pants-type disposable diaper of the present invention. [Figure 2] FIG. 2 is a plan view of a part of the abdominal portion of the pants-type disposable diaper shown in FIG. 1, viewed from the non-skin-facing side. [Figure 3] FIG. 3 is a plan view of a part of the abdominal portion of the pants-type disposable diaper shown in FIG. 1, viewed from the skin-facing side. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. [Figure 5]5(a) to 5(c) are plan views schematically showing modifications of adjacent fused portions in the pants-type disposable diaper shown in FIG. [Figure 6] 6(a) to 6(c) are plan views schematically showing modified examples of the arrangement pattern of the first fused parts and the second fused parts of the pants-type disposable diaper shown in FIG. [Figure 7] FIG. 7 is a plan view, equivalent to FIG. 2, showing a typical example of another embodiment of the pants-type disposable diaper of the present invention. [Figure 8] FIG. 8 is a plan view schematically showing a modified example of the first fused portion of the pants-type disposable diaper of the present invention. [Figure 9] FIG. 9 is a cross-sectional view taken along line IX-IX in FIGS. [Figure 10] FIG. 10 is a cross-sectional view, equivalent to FIG. 9, showing a modified example of the side seal portion of the pants-type disposable diaper of the present invention. [Figure 11] 11(a) and 11(b) are plan views schematically showing other modified examples of the first fused portion of the pants-type disposable diaper of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0012] The present invention will be described below based on preferred embodiments thereof. Fig. 1 shows a pants-type disposable diaper (hereinafter referred to as "diaper") 1, which is a first embodiment of the pants-type disposable diaper of the present invention. As shown in Figs. 1 to 3, the diaper 1 has a ventral portion A that is placed on the ventral side of a wearer when worn, a dorsal portion B that is placed on the dorsal side of the wearer, and a crotch portion C that is located between the ventral portion A and the dorsal portion B. The diaper 1 also has a longitudinal direction X and a lateral direction Y that is perpendicular to the longitudinal direction X. The longitudinal direction X is a direction that passes through the crotch portion C and corresponds to the front-to-back direction of the wearer.

[0013] As shown in Figs. 1 to 3, the diaper 1 comprises an absorbent main body 2 and an exterior body arranged on the non-skin-facing side of the absorbent main body 2. The exterior body includes a ventral-side exterior body 3A arranged in the ventral-side portion A and a rear-side exterior body 3B arranged in the rear-side portion B. The diaper 1 is configured such that both side portions 3e, 3e of the ventral-side exterior body 3A extending in the longitudinal direction X are joined to both side portions 3f, 3f of the rear-side exterior body 3B extending in the longitudinal direction X, thereby forming a pair of side seal portions S, S, a waist opening WH, and a pair of leg openings LH, LH. As shown in Fig. 2, the side seal portion S has a fused portion 41 (hereinafter referred to as a "first fused portion") where the ventral-side exterior body 3A and the rear-side exterior body 3B are fused together.

[0014] As shown in FIG. 2, the absorbent body 2 has an absorbent body 23, a top sheet 21 arranged on the skin-facing side of the absorbent body 23, and a back sheet 22 arranged on the non-skin-facing side of the absorbent body 23. The absorbent body 23 has a shape that is long in the longitudinal direction X of the diaper 1, similar to the absorbent main body 2, and is disposed between the topsheet 21 and the backsheet 22. In the first embodiment, as shown in Figures 2 and 3, the fixing sheet 34 is arranged so as to cover both end portions of the absorbent main body 2 in the longitudinal direction X. The fixing sheet 34 is fitted so as to straddle the end edges of the absorbent main body 2 in the longitudinal direction X. Both end portions of the fixing sheet 34 in the transverse direction Y are located in the side seal portions S.

[0015] The "skin-facing side" refers to the side of the diaper 1 or its constituent members that faces the wearer's skin when the diaper 1 is worn, and the "non-skin-facing side" refers to the side of the diaper 1 or its constituent members that faces away from the wearer's skin when the diaper 1 is worn. Furthermore, "when worn" and "worn state" refer to the state in which the diaper 1 is worn while maintaining the proper wearing position.

[0016] As described above, the exterior body includes a ventral exterior body 3A and a dorsal exterior body 3B. In the first embodiment, the ventral exterior body 3A and the dorsal exterior body 3B each have an outer layer sheet 32 ​​that forms the outer surface of the diaper 1 and an inner layer sheet 31 disposed on the skin-facing side of the outer layer sheet 32. In the first embodiment, the inner layer sheet 31 is a colored sheet. In this specification, a colored sheet is a sheet that is colored other than white.

[0017] In the ventral exterior body 3A, a plurality of elastic members 33 are arranged in a stretched state along the lateral direction Y between the outer layer sheet 32 ​​and the inner layer sheet 31. In the region overlapping with the absorbent main body 2, the elastic members 33 may be arranged so as not to exhibit elastic stretchability by being divided into small pieces or the like. In the first embodiment, the dorsal exterior body 3B has the same configuration as the ventral exterior body 3A. The description of the ventral exterior body 3A also applies to the dorsal exterior body 3B.

[0018] The ventral-side outer body 3A has a plurality of fused portions 42 that fuse the sheets within the ventral-side outer body 2A, i.e., the outer sheet 32 ​​and the inner sheet 31. The fused portions 42 that fuse the outer sheet 32 ​​and the inner sheet 31 are arranged intermittently in both the longitudinal direction X and the transverse direction Y. In the first embodiment, when the elastic member 33 arranged in a stretched state between the outer sheet 32 ​​and the inner sheet 31 contracts, the outer sheet 32 ​​and the inner sheet 31 between adjacent fused portions 42 deform so as to bulge toward the non-skin-facing side and the skin-facing side, respectively, forming pleats of the outer sheet 32 ​​or the inner sheet 31 between the adjacent fused portions 42, and forming a hollow space surrounded by the pleats between the sheets 31, 32. This provides the diaper 1 of the first embodiment with an excellent feel against the skin. In this specification, of the fused portions 42 that fuse the outer layer sheet 32 ​​and the inner layer sheet 31, the fused portion closest to the first fused portion 41 is referred to as the second fused portion 43. Note that the elastic member 33, the first fused portion 41, and the fused portion 42 are not shown in Figure 3.

[0019] The diaper 1 of the first embodiment has a first fused portion 41 and a second fused portion 43 in the region where the inner layer sheet 31, which is a colored sheet, is disposed. Specifically, as shown in Fig. 2, a plurality of first fused portions 41 are arranged at intervals in the vertical direction X in the side seal portion S. The side seal portion S has a plurality of first fused portions 41 with different circumferential lengths. Specifically, the side seal portion S has a first fused portion 41a with a relatively long circumferential length (hereinafter referred to as a "long first fused portion") and a first fused portion 41b with a relatively short circumferential length (hereinafter referred to as a "short first fused portion").

[0020] In the first embodiment, as described above, the side seal portion S has a first fused portion 41. The sheet forming the first fused portion 41 includes a colored sheet. Specifically, as shown in FIG. 4 , the first fused portion 41 is formed by fusing the inner layer sheet 31 and the outer layer sheet 32 ​​of the ventral exterior body 3A and the inner layer sheet 31 and the outer layer sheet 32 ​​of the dorsal exterior body 3B. In the first embodiment, as described above, the inner layer sheets 31 of the ventral exterior body 3A and the dorsal exterior body 3B are colored sheets. Because the fiber density of the sheet is higher at the peripheral edge portion 51 of the first fused portion 41 than on the inside of the peripheral edge portion 51, the fiber density of the inner layer sheet 31, which is a colored sheet, is naturally also high. Therefore, the peripheral edge 51 of the first fused portion 41 appears darker in color than the inside of the peripheral edge 51 of the first fused portion 41 and the other portions of the side seal portion S other than the first fused portion 41, thereby improving the visibility of the side seal portion S. In this way, in the diaper 1 of the first embodiment, the visibility of the side seal portion is naturally improved by forming the first fused portion 41, so there is no need to, for example, print on the side seal portion S in order to improve the visibility of the side seal portion.

[0021] In the first embodiment, as shown in Fig. 2, a plurality of second fused portions 43 are arranged at intervals in the vertical direction X. The plurality of second fused portions 43 have the same circumferential length. As with the first fused portion 41, the peripheral edge 53 of the second fused portion 43 has a higher fiber density than the inside of the peripheral edge 53, and the fiber density of the inner layer sheet 31, which is a colored sheet, is also high, so the peripheral edge 53 of the second fused portion 43 appears darker in color than the inside of the peripheral edge 53 of the second fused portion 43 and the parts of the outer casing other than the second fused portion 43.

[0022] In the first embodiment, as shown in Fig. 2, a plurality of adjacent fused portions 44, each consisting of a first fused portion 41 and a second fused portion 43, are arranged in the longitudinal direction X. The adjacent fused portion 44 is a pair of fused portions consisting of the first fused portion 41 and the second fused portion 43. The diaper 1 has a plurality of adjacent fused portions 44 with different circumferential lengths. Specifically, the diaper 1 has an adjacent fused portion 44a (hereinafter referred to as "long adjacent fused portion") 44a, which is made up of a long first fused portion 41a and a second fused portion 43 and has a relatively long circumferential length, and an adjacent fused portion 44b (hereinafter referred to as "short adjacent fused portion") 44b, which is made up of a short first fused portion 41b and a second fused portion 43 and has a relatively short circumferential length. The circumferential length of the adjacent fused portion 44 means the total length of the circumferential length of the first fused portion 41 that constitutes the adjacent fused portion 44 and the circumferential length of the second fused portion 43 that constitutes the adjacent fused portion 44.

[0023] In the diaper 1, the adjacent fused portion 44 having the longest perimeter (hereinafter referred to as the "longest adjacent fused portion") 44A is located outward from the edge 23a of the absorbent body 23 in the longitudinal direction X. In the first embodiment, the longest adjacent fused portion 44a is the longest adjacent fused portion 44A. By arranging the longest adjacent fused portion 44A in the above-mentioned positional relationship, the diaper 1 allows the location that serves as the starting point for tearing the side seal portion S to be easily identified. This point will be described in detail below. As described above, the first fused portion 41 and the second fused portion 43 have relatively darker peripheral colors. The longest adjacent fused portion 44A has a longer peripheral length than the other adjacent fused portions 44, and therefore has a longer peripheral darker color. Therefore, the longest adjacent fused portion 44A has good visibility. Therefore, in the diaper 1 of the first embodiment, the longest adjacent fused portion 44A can be used as a marker to easily identify the location that serves as the starting point for tearing the side seal portion S.

[0024] The adjacent fused portions 44 will be described in detail with reference to Figures 5(a) to 5(c). Figure 5(a) shows five first fused portions 41 and three fused portions 42. In Figure 5(a), the five first fused portions 41 are indicated by reference numerals 41e, 41f, 41g, 41h, and 41i, respectively, and the three fused portions 42 are indicated by reference numerals 42e, 42f, and 42g, respectively. Focusing on the first fused portion 41e, the fused portion 42e is the fused portion 42e closest to the first fused portion 41e, so the fused portion 42e is the second fused portion 43e, and the first fused portion 41e and the second fused portion 43e are adjacent fused portions 44e. Focusing on first fused portion 41f, first fused portion 41f does not have a nearest second fused portion 43. Fused portions 42e, 42f are closer to first fused portions 41e, 41g than first fused portion 41f. In this way, if fused portions 42e, 42f closest to first fused portion 41f have first fused portions 41e, 41g closer than first fused portion 41f, then fused portions 42e, 42f are not second fused portions 43, and first fused portion 41f does not form adjacent fused portion 44. Focusing on the first fused portions 41h, 41i, fused portion 42g is located equidistant from each of the first fused portions 41h, 41i. In this case, fused portion 42g is the second fused portion 43g of each of the first fused portions 41h, 41i. Therefore, first fused portion 41h and second fused portion 43g form adjacent fused portion 44h, and first fused portion 41i and second fused portion 43g form adjacent fused portion 44i.

[0025] Whether a fused portion 42 is a second fused portion 43 or not can be determined by the shortest distance between the fused portion 42 and the first fused portion 41. This point will be described in detail with reference to Figures 5(b) and 5(c). Figures 5(b) and 5(c) show two first fused portions 41 and one fused portion 42. In Figure 5(b), the two first fused portions 41 are indicated by reference numerals 41j and 41k, respectively, and in Figure 5(c), the three first fused portions 41 are indicated by reference numerals 41m and 41n, respectively. 5(b), the distance D1 between the first fused portion 41j and the fused portion 42 is the same as the distance D2 between the first fused portion 41k and the fused portion 42. Therefore, the fused portion 42 is the second fused portion 43 of each of the first fused portions 41j and 41k. Therefore, the first fused portion 41j and the second fused portion 43 form an adjacent fused portion 44j, and the first fused portion 41k and the second fused portion 43 form an adjacent fused portion 44k. 5(c), the distance D3 between the first fused portion 41m and the fused portion 42 is greater than the distance D4 between the first fused portion 41n and the fused portion 42. Therefore, the fused portion 42 is the second fused portion 43 of the first fused portion 41m, but not the second fused portion 43 of the first fused portion 41n. Therefore, the first fused portion 41m and the second fused portion 43 form the adjacent fused portion 44m, and the first fused portion 41n does not form the adjacent fused portion 44k.

[0026] In the first embodiment, by having the second fused portion 43, the circumferential length of the adjacent fused portion 44 can be made longer compared to when only the first fused portion 41 is provided, thereby further improving the visibility of the side seal portion S and making it easier to identify the area that will serve as the starting point when tearing the side seal portion S.

[0027] In the first embodiment, as shown in Fig. 6(a), it is also preferable that the circumferential length of the second fused portion 43 increases from the inside to the outside in the longitudinal direction X. This further increases the circumferential length of the adjacent fused portion 44 located on the outside in the longitudinal direction X, further improving the visibility of the side seal portion S and making it easier to identify the location that will serve as the starting point for tearing the side seal portion S. The circumferential length of the second fused portion 43 may increase in stages or gradually from the inside to the outside in the longitudinal direction X.

[0028] In the first embodiment, it is also preferable that a portion of the second fused portion 43 overlaps the first fused portion 41, as shown in FIG. 6(b). This makes the color of the portion where the second fused portion 43 overlaps the first fused portion 41 darker, further improving the visibility of the side seal portion S and making it easier to identify the location that will serve as the starting point for tearing the side seal portion S. When the exterior body has multiple second fused portions 43, the second fused portion 43 that partially overlaps the first fused portion 41 may be only one, a portion of the multiple second fused portions 43, or all of the second fused portions 43. From the perspective of making it easier to identify the location that will serve as the starting point for tearing the side seal portion S, it is preferable that the second fused portion 43 that partially overlaps the first fused portion 41 is the second fused portion 43 that forms the longest adjacent fused portion 44A.

[0029] In the first embodiment, the area S1 of the first fused portion 41 constituting the adjacent fused portion 44 is preferably larger than the area S2 of the second fused portion 43 constituting the adjacent fused portion 44. This further improves the visibility of the side seal portion S, making it easier to identify the location that will serve as the starting point for tearing the side seal portion S. To make this effect more pronounced, the ratio S1 / S2 of the area S1 to the area S2 is preferably 1.1 or more, more preferably 1.2 or more, and is also preferably 2.0 or less, more preferably 1.8 or less, and is preferably 1.1 or more and 2.0 or less, and more preferably 1.2 or more and 1.8 or less.

[0030] In the first embodiment, as shown in FIG. 6(c), adjacent fused portions 44 and first fused portions 41 without adjacent fused portions 44 may be mixed.

[0031] Fig. 7 shows a diaper 1 according to a second embodiment of the present invention. Unlike the diaper 1 of the first embodiment, the diaper 1 of the second embodiment does not have a fused portion 42, as the outer layer sheet 32 ​​and the inner layer sheet 31 of the ventral outer body 3A and the dorsal outer body 3B are not fused together. Therefore, the diaper 1 of the second embodiment does not have an adjacent fused portion 44. The diaper 1 of the second embodiment has a first fused portion 41 in the region where the inner layer sheet 31, which is a colored sheet, is arranged.

[0032] In the diaper 1 of the second embodiment, the first fused portion 41 having the longest perimeter (hereinafter referred to as the "longest first fused portion") 41A is located outward from the edge 23a of the absorbent body 23 in the longitudinal direction X. In the second embodiment, the longest first fused portion 41a is the longest first fused portion 41A. By arranging the longest first fused portion 41A in the above-mentioned position, the diaper 1 allows the location that serves as the starting point for tearing the side seal portion S to be easily identified. This point will be described in detail below. As described above, the first fused portion 41 has a relatively dark color around its periphery. The longest first fused portion 41A has a longer periphery than the other first fused portions 41, and therefore has a longer dark-colored periphery. Therefore, the longest first fused portion 41A has particularly good visibility. Therefore, in the diaper 1 of the second embodiment, the longest first fused portion 41A can be used as a marker to easily identify the location that serves as the starting point for tearing the side seal portion S.

[0033] Next, matters common to the above-described embodiments will be described. 8, the first fused portion 41 may be made up of small fused portions 41c arranged at intervals in the horizontal direction Y. When the first fused portion 41 is made up of a plurality of small fused portions 41c, the circumferential length of the first fused portion 41 is the sum of the circumferential lengths of the small fused portions 41c.

[0034] In the first and second embodiments, the ventral exterior body 3A and the dorsal exterior body 3B each have an inner layer sheet 31 as a colored sheet, as described above, and the two exterior bodies 3A, 3B are joined at the side seal portion S. In the first and second embodiments, as shown in Fig. 9, in the region R where the longest first fused portion 41A or the longest adjacent fused portion 44A exists, the inner layer sheets 31, which are colored sheets, are adjacent to each other in the thickness direction. The inner layer sheets 31 being adjacent to each other in the thickness direction means that no other sheet is interposed between the inner layer sheet 31 of the ventral exterior body 3A and the inner layer sheet 31 of the dorsal exterior body 3B. The colored sheets directly overlap each other in the region R where the longest first fused portion 41A or the longest adjacent fused portion 44A is present, which allows the fiber density of the colored sheets to be further increased in the first fused portion 41, thereby making it possible to make the color of the peripheral edge 51 of the first fused portion 41 darker and making it easier to identify the area that will serve as the starting point for tearing the side seal portion S. To make this effect more pronounced, the number of colored sheets directly overlapping each other in the region R where the longest first fused portion 41A or the longest adjacent fused portion 44A is present is preferably two or more and preferably four or less, and more preferably two or more and four or less.

[0035] In the first and second embodiments, the outer layer sheet 32 ​​may extend beyond the end 31a of the inner layer sheet 31 in the longitudinal direction X and be folded back onto the skin-facing side, as shown in Fig. 10. In the embodiment shown in Fig. 10, the outer layer sheet 32 ​​is a colored sheet, and the inner layer sheet 31 is an uncolored sheet. In the embodiment shown in Fig. 10, the region R is divided into a region R1 outward from the end 31a of the inner layer sheet 31 in the longitudinal direction X, and a region R2 inward from the end 31a.

[0036] 10 , in region R where the longest first fused portion 41A or the longest adjacent fused portion 44A is present, the number of colored sheets included in the sheets forming the first fused portion 41 is equal to or greater than the number of uncolored sheets included in the sheets forming the first fused portion 41. Specifically, in region R1, the outer layer sheet 32 ​​and the folded-back portion 32b of the outer layer sheet 32 ​​of the ventral exterior body 3A, and the outer layer sheet 32 ​​and the folded-back portion 32b of the outer layer sheet 32 ​​of the dorsal exterior body 3B, overlap. That is, in region R1, four colored sheets overlap, and no uncolored sheets exist. Furthermore, in region R2, the outer layer sheet 32, the inner layer sheet 31, and the folded-back portion 32b of the outer layer sheet 32 ​​of the ventral exterior body 3A, and the outer layer sheet 32, the inner layer sheet 31, and the folded-back portion 32b of the outer layer sheet 32 ​​of the dorsal exterior body 3B, overlap. That is, in the region R2, four colored sheets are overlapped and two non-colored sheets are overlapped.

[0037] In the region R, by making the number of colored sheets included in the sheet forming the first fused portion 41 equal to or greater than the number of non-colored sheets included in the sheet forming the first fused portion 41, the difference in color between the peripheral portion 51 of the first fused portion 41 and the color of the portion of the side seal portion S other than the first fused portion 41 can be made even greater, thereby further improving the visibility of the side seal portion S and making it easier to identify the area that will serve as the starting point when tearing the side seal portion S.

[0038] 2 and 6, in the first and second embodiments, the longest first fused portion 41A or the longest adjacent fused portion 44A is preferably located outward in the longitudinal direction X from the other first fused portions 41 or adjacent fused portions 44. In other words, it is preferable that the first fused portion 41 or adjacent fused portion 44 located furthest outward in the longitudinal direction X is the longest first fused portion 41A or the longest adjacent fused portion 44A. This further improves the visibility of the outer end of the side seal portion S in the longitudinal direction X, making it easier to identify the location that will serve as the starting point for tearing the side seal portion S.

[0039] In the first and second embodiments, the circumferential length LA of the longest first fused portion 41A or the longest adjacent fused portion 44A is preferably 110% or more of the circumferential length LB of the first fused portion 41 or the adjacent fused portion 44, which has the next longest circumferential length after the longest first fused portion 41A or the longest adjacent fused portion 44A. This further improves the visibility of the longest first fused portion 41A or the longest adjacent fused portion 44A, thereby further improving the visibility of the side seal portion S and making it easier to identify the location that serves as the starting point for tearing the side seal portion S. From the viewpoint of making this effect more pronounced, the circumferential length LA is preferably 110% or more, more preferably 130% or more, and also preferably 300% or less, more preferably 200% or less of the circumferential length LB.

[0040] In the first and second embodiments, the colors of the inner layer sheet 31 and the outer layer sheet 32 ​​are not particularly limited. Examples of colors of the inner layer sheet 31 and the outer layer sheet 32 ​​include white, pale red, pale pink, pale blue, and pale green. The colors of the inner layer sheet 31 and the outer layer sheet 32 ​​may be the same or different. A preferred combination of the color of the inner layer sheet 31 and the color of the outer layer sheet 32 ​​is white and a color other than white.

[0041] In the first and second embodiments, the color of the inner sheet 31 is preferably darker than the color of the outer sheet 32. More specifically, the color of the inner sheet 31 preferably has a smaller L* value in the L*a*b* color system than the color of the outer sheet 32. This further increases the difference in color between the side seals S and the color of the portion of the outer cover between the side seals S, thereby further improving the visibility of the side seals S and making it easier to identify the tearing point of the side seals S. Specifically, when the diaper 1 is viewed from the outer sheet 32 ​​side, which is the non-skin-facing side, the difference in color between the outer sheet 32 ​​and the peripheral portions of the first fused portion 41 and the adjacent fused portion 44 is greater, thereby further improving the visibility of the first fused portion 41 and the adjacent fused portion 44 and the side seals S. To make this effect even more pronounced, the difference in the L* value between the inner layer sheet 31 and the outer layer sheet 32 ​​is preferably at least 1, more preferably at least 3, and even more preferably at least 5. The L* value is a value indicating brightness in the "L*a*b* color system" defined in JIS Z 8729.

[0042] From the viewpoint of further improving the visibility of the side seal portion S, the L* value of the inner layer sheet 31 is preferably 60 or more, more preferably 65 or more, even more preferably 70 or more, and is preferably 90 or less, more preferably 85 or less, even more preferably 80 or less, and is preferably 60 or more and 90 or less, more preferably 65 or more and 85 or less, even more preferably 70 or more and 80 or less.

[0043] From the viewpoint of further improving the visibility of the side seal portion S, the L* value of the outer layer sheet 32 ​​is preferably 70 or more, more preferably 75 or more, and even more preferably 80 or more.

[0044] To further enhance the effect of improving the visibility of the side seal portion S, the color difference between the inner layer sheet 31 and the outer layer sheet 32 ​​is preferably 5 or more, more preferably 10 or more, and even more preferably 15 or more. To prevent the color of the inner layer sheet from becoming too dark and to prevent a decrease in the visibility of the peripheral edges of the first fused portion 41 and the adjacent fused portion 44, the color difference between the inner layer sheet 31 and the outer layer sheet 32 ​​is preferably 50 or less, and more preferably 40 or less.

[0045] In this specification, color difference refers to "color difference in the L*a*b* color system" and can be measured by the following method. The larger the color difference, the more noticeable the difference in color is.

[0046] [Method for measuring color difference (ΔE* value)] An X-Rite colorimeter / densitometer can be used as the color difference meter. In the "L*a*b* color system" specified in JIS Z 8729, L* indicates brightness, a* and b* indicate color directions, with a* indicating approximately red, -a* indicating approximately green, b* indicating approximately yellow, and -b* indicating approximately blue. ΔE* is a value calculated using the following formula (1): ΔE*=[(ΔL*)2+(Δa*)2+(Δb*)2]1 / 2···(1) ΔL*, Δa*, and Δb* are the differences in the L*, a*, and b* values ​​between two colors, respectively. For example, ΔL* is calculated by ΔL*=L*2-L*1. When measuring, a sample is cut from the inner layer sheet or the outer layer sheet, and eight of the samples are placed on a horizontal surface without wrinkles or folds. If the inner layer sheet or outer layer sheet to be measured is incorporated into a product such as a commercially available disposable diaper, the disposable diaper is sprayed with a cold spray to solidify the adhesive bonding the constituent parts of the disposable diaper, and the diaper is then disassembled into each part, such as the inner layer sheet and the outer layer sheet. The tip of the sensor is then pressed against the eight stacked samples to measure. This measurement is taken at three arbitrary points on each of the inner layer sheet 31 and the outer layer sheet 32, and the average values ​​are used as the respective measured values.

[0047] In the first and second embodiments, the outer layer sheet 32 ​​is preferably white. This allows for a greater difference in color between the side seal portions S and the portions of the exterior body between the side seal portions S, further improving the visibility of the side seal portions S and making it easier to identify the areas that serve as starting points for tearing the side seal portions S.

[0048] In the first and second embodiments, the first fused portion 41 may be made up of a plurality of small fused portions 41c arranged at intervals in the lateral direction Y, as described above.

[0049] Furthermore, when the first fused portion 41 is composed of a plurality of small fused portions 41c, it is preferable that the number of small fused portions 41c included in the longest first fused portion 41A or the longest adjacent fused portion 44A is greater than the number of small fused portions included in the other first fused portions 41 or adjacent fused portions 44 (see FIG. 11(b)). This further improves the visibility of the longest first fused portion 41A or the longest adjacent fused portion 44A and further improves the visibility of the side seal portion S, making it easier to identify the location that will serve as the starting point for tearing the side seal portion S. To make this effect more pronounced, the difference between the number of small fused portions 41c included in the longest first fused portion 41A or the longest adjacent fused portion 44A and the number of small fused portions included in the other first fused portions 41 or adjacent fused portions 44 is preferably 1 or more.

[0050] In the first and second embodiments, as shown in Figs. 2 and 6, the elastic member 33 is preferably arranged so as to pass between adjacent first fused portions 41 in the longitudinal direction X. In other words, the elastic member 33 is preferably arranged so as not to overlap with the first fused portions 41. This prevents the color depth of the first fused portions 41 from decreasing, and maintains the visibility of the side seal portion S. From the same perspective, the elastic member 33 is also preferably arranged so as to pass between adjacent second fused portions 43. In other words, the elastic member 33 is also preferably arranged so as not to overlap with the second fused portions 43.

[0051] Next, the materials constituting the diaper 1 will be described. The topsheet 21 can be a liquid-permeable sheet, such as a nonwoven fabric or a perforated film. The topsheet may have an uneven surface on its skin-facing side. For example, a plurality of scattered protrusions can be formed on the skin-facing side of the topsheet. Alternatively, ridges and grooves extending in one direction can be formed alternately on the skin-facing side of the topsheet. For such purposes, the topsheet 21 can be formed using two or more sheets of nonwoven fabric.

[0052] On the other hand, the backsheet 22 may be made of, for example, a liquid-impermeable film or a spunbond, meltblown, or spunbond laminated nonwoven fabric. A liquid-impermeable film may be provided with a plurality of micropores to impart water vapor permeability to the film. To further improve the feel of the disposable diaper, a sheet with a pleasant texture, such as a nonwoven fabric, may be laminated on the outer surface of the backsheet.

[0053] The absorbent body 23 has an absorbent core. The absorbent core may be composed of, for example, a stack of hydrophilic fibers such as cellulose, a mixed stack of the hydrophilic fibers and an absorbent polymer, a pile of absorbent polymer, or a laminated structure in which an absorbent polymer is supported between two absorbent sheets. At least the skin-facing surface of the absorbent core may be covered with a liquid-permeable core wrap sheet, or the entire surface, including the skin-facing and non-skin-facing surfaces, may be covered with the core wrap sheet. Examples of the core wrap sheet that can be used include tissue paper made of hydrophilic fibers and liquid-permeable nonwoven fabric.

[0054] In addition to the top sheet 21, back sheet 22, and absorber 23, the absorbent body 2 may be provided with longitudinally extending leakage-preventing cuffs on both longitudinal sides of the skin-facing side, depending on the specific application of the pants-type disposable diaper. The leakage-preventing cuffs generally have a base end and a free end. The base end of the leakage-preventing cuff is located on the skin-facing side of the disposable diaper, and the cuffs extend upward from the skin-facing side. The leakage-preventing cuffs are made of a liquid-resistant or water-repellent, breathable material. An elastic member made of rubber thread or the like may be provided in a stretched state at or near the free end of the leakage-preventing cuff. When the pants-type disposable diaper is worn, contraction of this elastic member causes the leakage-preventing cuffs to extend upward toward the wearer's body, effectively preventing fluid excreted on the top sheet from leaking laterally outward along the top sheet of the pants-type disposable diaper.

[0055] The outer layer sheet 32 ​​and the inner layer sheet 31 can each be made of a nonwoven fabric or a resin film produced by various methods. Examples of nonwoven fabrics include spunbond nonwoven fabric, air-through nonwoven fabric, and needle-punched nonwoven fabric. Both sheets 31 and 32 may each have a single-layer structure or a laminate structure in which two or more sheets are laminated. Furthermore, both sheets 31 and 32 may each be a stretchable sheet that is stretchable in the lateral direction Y, or a non-stretchable sheet that is not stretchable.

[0056] The colored sheet preferably contains fibers with a coloring material kneaded into it. This allows the color of the peripheral edge 51, 53 of the first fused portion 41 or the second fused portion 43, where the fiber density of the sheet is high, to be made darker, further improving the visibility of the side seal portion S and making it easier to identify the area that will serve as the starting point for tearing the side seal portion S. Examples of coloring materials include pigments and dyes, with pigments being preferred.

[0057] Although the pants-type disposable diaper of the present invention has been described above based on its preferred embodiments, the pants-type disposable diaper of the present invention is not limited to the above-described embodiments. For example, the pants-type disposable diaper of the present invention is not limited to one in which the ventral outer body 3A and the dorsal outer body 3B have the same configuration. Only one of the ventral outer body 3A and the dorsal outer body 3B may have the above-described configuration.

[0058] In addition, either or both of the ventral exterior body 3A and the dorsal exterior body 3B may have a fused portion 42 that fuses the outer layer sheet 32 ​​and the inner layer sheet 31. In addition, either or both of the ventral exterior body 3A and the dorsal exterior body 3B may have a second fused portion 43.

[0059] In addition, in each of the above-described embodiments, the outer casing was divided into a ventral outer casing 3A and a dorsal outer casing 3B, but the outer casing may be continuous across the ventral portion A, the crotch portion C, and the dorsal portion B.

[0060] Furthermore, in each of the above-described embodiments, the first fused portion 41 and the second fused portion 43 have a rectangular shape, but the shapes of the first fused portion 41 and the second fused portion 43 are not limited to this and may be, for example, circular, elliptical, polygonal, star-shaped, etc.

[0061] The present invention further discloses the following additional notes. <1> The absorbent body includes an outer cover disposed on the non-skin-facing side of the absorbent body, A pants-type disposable diaper having a ventral side portion disposed on the ventral side of a wearer, a dorsal side portion disposed on the dorsal side of the wearer, and a crotch portion located between the ventral side portion and the dorsal side portion, the crotch portion having a longitudinal direction corresponding to the front-to-back direction of the wearer and a lateral direction perpendicular to the longitudinal direction, the ventral side portion and the dorsal side portion being joined together to form a pair of side seal portions, a waist opening, and a pair of leg openings, The exterior body includes a colored sheet, A plurality of first fused portions, in which the ventral portion and the dorsal portion are fused to each other, are arranged at intervals in the vertical direction in the side seal portion, In the area where the colored sheet is arranged, (1) a first fused portion, or (2) An adjacent fused portion consisting of a first fused portion and a second fused portion that fused the sheets together in the ventral portion or the dorsal portion and is closest to the first fused portion. and A pants-type disposable diaper, wherein the first fused portion or the adjacent fused portion having the greatest circumferential length is located outward from the edge of the absorbent body in the longitudinal direction.

[0062] <2> In a region where the first fused portion or the adjacent fused portion having the longest circumferential length exists, two or more, preferably two to four, of the colored sheets are adjacent to each other in the thickness direction. <1> 1. The pants-type disposable diaper according to claim 1. <3> In a region where the first fused portion or the adjacent fused portion having the largest circumferential length exists, the number of the colored sheets included in the sheet forming the first fused portion is equal to or greater than the number of non-colored sheets included in the sheet forming the first fused portion. <1> or <2> 1. The pants-type disposable diaper according to claim 1. <4> the first fused portion or the adjacent fused portion having the largest circumferential length is located outward in the longitudinal direction from other first fused portions or the adjacent fused portions; <1> ~ <3> 1. The pants-type disposable diaper according to any one of the preceding claims. <5> the circumferential length of the first fused portion or the adjacent fused portion having the largest circumferential length is 110% or more, preferably 110% or more and 300% or less, more preferably 130% or more and 200% or less, of the circumferential length of the first fused portion or the adjacent fused portion having the second largest circumferential length; <1> ~ <4> 1. The pants-type disposable diaper according to any one of the preceding claims.

[0063] <6> the exterior body includes the colored sheet and an outer layer sheet disposed on the non-skin-facing side of the colored sheet, the color of the colored sheet has a smaller L* value in the L*a*b* color system than the color of the outer layer sheet; <1> ~ <5> 1. The pants-type disposable diaper according to any one of the preceding claims. <7> the difference in L* value in the L*a*b* color system between the outer layer sheet and the colored sheet is 1 or more, preferably 3 or more; <6> The absorbent article according to claim 1. <8> The outer layer sheet is a white sheet. <7> 1. The pants-type disposable diaper according to claim 1. <9> The colored sheet includes fibers into which a coloring material is kneaded. <1> ~ <8> 1. The pants-type disposable diaper according to any one of the preceding claims. <10> The colored sheet has an L* value in the L*a*b* color system of 60 or more and 90 or less, preferably 65 or more and 85 or less, and more preferably 70 or more and 80 or less. <9> 1. The pants-type disposable diaper according to claim 1.

[0064] <11> the first fused portion is made up of a plurality of small fused portions spaced apart in the lateral direction, <1> ~ <10> 1. The pants-type disposable diaper according to any one of the preceding claims. <12> the first fused portion is made up of a plurality of small fused portions spaced apart in the lateral direction, the number of the small fused portions included in the first fused portion or the adjacent fused portion having the largest circumferential length is greater than the number of the small fused portions included in other first fused portions or the adjacent fused portions; <1> ~ <11> 1. The pants-type disposable diaper according to any one of the preceding claims. <13> The sheets in the ventral side portion or the dorsal side portion are fused together, and a second fused portion is located closest to the first fused portion. <1> ~ <12> 1. The pants-type disposable diaper according to any one of the preceding claims. <14> a plurality of second fused portions are arranged at intervals in the vertical direction, The circumferential length of the second fused portion increases from the inside to the outside in the longitudinal direction. <13> 1. The pants-type disposable diaper according to claim 1. <15> a part of the second fused portion overlaps with the first fused portion; <13> or <14> 1. The pants-type disposable diaper according to claim 1. <16> the area of ​​the first fused portion constituting the adjacent fused portion is larger than the area of ​​the second fused portion constituting the adjacent fused portion; <13> ~ <15> 1. The pants-type disposable diaper according to any one of the preceding claims. <17> the ratio of the area of ​​the first fused portion to the area of ​​the second fused portion is 1.1 or more and 2.0 or less, preferably 1.2 or more and 1.8 or less; <16> 1. The pants-type disposable diaper according to claim 1. <18> the exterior body has an elastic member arranged in a stretched state along the lateral direction, The elastic member is arranged so as to pass between adjacent second fused portions in the vertical direction. <13> ~ <17> 1. The pants-type disposable diaper according to any one of the preceding claims. [Explanation of symbols]

[0065] 1. Pants-type disposable diapers 2. Absorbent body 21 Surface sheet 22 Back sheet 23 absorber 3A Ventral exterior body 3B Dorsal exterior body 31 Inner layer sheet 32 outer layer sheet 33 Elastic member 34 Fixing sheet 41 1st fusion part 43 Second fusion part 44 Adjacent fusion A. Ventral part B Dorsal part C Inseam S Side seal part WH Waist opening LH leg opening X vertical direction Y horizontal direction

Claims

1. The present invention includes an absorbent body and an exterior body disposed on a non-skin facing side of the absorbent body, A pants-type disposable diaper having a ventral side portion disposed on the ventral side of a wearer, a dorsal side portion disposed on the dorsal side of the wearer, and a crotch portion located between the ventral side portion and the dorsal side portion, the crotch portion having a vertical direction corresponding to the front-to-rear direction of the wearer and a horizontal direction perpendicular to the vertical direction, the ventral side portion and the dorsal side portion being joined to each other to form a pair of side seal portions, a waist opening, and a pair of leg openings, The exterior body includes a colored sheet, A plurality of first fused portions in which the ventral portion and the dorsal portion are fused to each other are arranged at intervals in the vertical direction in the side seal portion, The lateral end portions of the exterior body in the dorsal side portion and the ventral side portion are located laterally outward of the first fused portion, In the area where the colored sheet is arranged, (1) a first fused portion, or (2) An adjacent fused portion consisting of a first fused portion and a second fused portion that fused the sheets in the ventral side portion or the dorsal side portion together and is closest to the first fused portion. having the first fused portion or the adjacent fused portion having the maximum circumferential length is located outward from an edge of the absorbent body in the longitudinal direction; In a region where the first fused portion or the adjacent fused portion has a maximum circumferential length, two or more of the colored sheets are adjacent to each other in a thickness direction, This pants-type disposable diaper has peripheral parts of the first fused part and the adjacent fused part that have a higher fiber density and appear darker in color than the inside of these peripheral parts and the parts other than the fused parts.

2. 2. The pants-type disposable diaper according to claim 1, wherein in a region where the first fused portion or the adjacent fused portion having the longest circumferential length is present, the number of the colored sheets included in the sheet forming the first fused portion is equal to or greater than the number of non-colored sheets included in the sheet forming the first fused portion.

3. 3. The pants-type disposable diaper according to claim 1, wherein the first fused portion or the adjacent fused portion having the greatest circumferential length is located outward in the longitudinal direction relative to other first fused portions or the adjacent fused portions.

4. The pants-type disposable diaper according to any one of claims 1 to 3, wherein the perimeter of the first fused portion or the adjacent fused portion having the largest perimeter is 110% or more of the perimeter of the first fused portion or the adjacent fused portion having the second largest perimeter.

5. The exterior body includes the colored sheet and an outer layer sheet disposed on the non-skin-facing side of the colored sheet, 5. The pants-type disposable diaper according to claim 1, wherein the color of the colored sheet has a smaller L* value in the L*a*b* color system than the color of the outer sheet.

6. 6. The pants-type disposable diaper according to claim 5, wherein the outer sheet is a white sheet.

7. The pants-type disposable diaper according to any one of claims 1 to 6, wherein the colored sheet contains fibers having a coloring material kneaded therein.

8. 8. The pants-type disposable diaper according to claim 1, wherein the first fused portion is made up of a plurality of small fused portions spaced apart in the lateral direction.

9. the first fused portion comprises a plurality of small fused portions spaced apart in the lateral direction, The pants-type disposable diaper according to any one of claims 1 to 8, wherein the number of the small fused portions included in the first fused portion or the adjacent fused portion having the largest circumferential length is greater than the number of the small fused portions included in other first fused portions or the adjacent fused portions.

10. The pants-type disposable diaper according to any one of claims 1 to 9, further comprising a second fused portion that is fused between the sheets in the abdominal portion or the dorsal portion and is closest to the first fused portion.

11. A plurality of second fused portions are arranged at intervals in the vertical direction, The pants-type disposable diaper according to claim 10, wherein a circumferential length of the second fused portion increases from the inside to the outside in the longitudinal direction.

12. The pants-type disposable diaper according to claim 10 or 11, wherein a part of the second fused portion overlaps with the first fused portion.

13. The pants-type disposable diaper according to any one of claims 10 to 12, wherein an area of ​​a first fused portion constituting the adjacent fused portion is larger than an area of ​​a second fused portion constituting the adjacent fused portion.

14. The exterior body has an elastic member arranged in a stretched state along the lateral direction, The pants-type disposable diaper according to any one of claims 1 to 13, wherein the elastic members are arranged so as to pass between adjacent second fused portions in the longitudinal direction.

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