Disposable shorts-type clothing

Abstract

A shorts-type disposable wearing article is provided, which is less likely to tear transversely at a portion where the number of layers of an outer body changes. The above-mentioned problem is solved by a shorts-type disposable wearing article, which is characterized in that a slit (61) is formed, which is adjacent to the side seal portion (21) at the center side in the width direction of the side seal portion (21) and vertically penetrates the layer number change portion (62) at a portion where the number of layers of the layered sheets constituting the outer body (20) changes, wherein the side seal portion (21) is formed by respectively joining the two side portions of the front body portion and the two side portions of the back body portion, and no perforation line is formed from the waist opening to the leg opening.

Description

Technical Field

[0001] The present invention relates to a pant-type disposable wearing article. Background Art

[0002] Disposable shorts-type wearing articles such as shorts-type disposable diapers, shorts-type disposable sanitary napkins, and shorts-type disposable diaper covers have side seals formed by welding the two sides of the front body portion and the two sides of the back body portion together. By forming the side seals, a waist opening and leg openings are pre-formed.

[0003] In such shorts-type disposable diapers, when removing the diaper after defecation, the side seals are torn to remove the diaper from the body. Therefore, the side seals are required to have not only peel strength to prevent rupture during wear but also to be easily breakable after use (see, for example, Patent Documents 1 and 2). Tearing the side seals includes a tearing action that breaks one of the front and back sections along the widthwise center edge of the side seal, a peeling action that causes interfacial peeling of the fused joint between the front and back sections, and a combination of a tearing action and a peeling action.

[0004] There are various factors that hinder the rupture of the side seals. A particularly important factor is the change in the number of sheets stacked in the side seals in the rupture direction. Specifically, in the changing portion of the side seal where the number of sheets changes (particularly, the transition from a smaller number of sheets to a larger number of sheets), rupture is more likely to occur along the boundary where the number of sheets changes than in the longitudinal direction. Consequently, "transverse tearing," where the sheet tears from the changing portion toward the center in the width direction, is more likely to occur.

[0005] As a solution to this problem, there has been proposed a method of forming perforated lines for separating the waist opening from the leg opening in the front or back body portion closer to the center in the width direction than the side seals, without modifying the joining pattern of the side seals (see Patent Document 3).

[0006] However, in order to facilitate the start of the perforation line cutting, it is necessary to have a cut that reaches the edge of the waist opening or the edge of the leg opening (see Patent Document 3). Figure 4 、 Figure 10 11, etc.), and the incision at the starting end of the perforated line may make the wearing feel worse. In contrast, the rupture of the conventional side seal portion begins naturally by applying force to the edge of the joint portion, so it is extremely easy.

[0007] Furthermore, when perforations are formed from the waist opening to the leg openings, the perforations have many cuts, which may easily cause leakage and may also deteriorate the aesthetics.

[0008] Prior art literature

[0009] Patent Literature

[0010] Patent Document 1: Japanese Patent Application Laid-Open No. 2018-61545

[0011] Patent Document 2: Japanese Patent No. 4522469

[0012] Patent Document 3: Japanese Patent Application Laid-Open No. 2018-139718 Summary of the Invention

[0013] Problems to be solved by the invention

[0014] Therefore, the main subject of the present invention is to make it difficult for transverse tearing to occur at the portion where the number of sheet layers is changed, and to eliminate the need for forming perforated lines for cutting from the waist opening to the leg opening.

[0015] Means for solving problems

[0016] The shorts-type disposable wearing article that has solved the above-mentioned problems is as follows.

[0017] <First Method>

[0018] A shorts-type disposable wearing article, characterized in that the shorts-type disposable wearing article has:

[0019] a front body portion and a back body portion;

[0020] Side seals formed by welding the two side portions of the front body portion and the two side portions of the back body portion;

[0021] a waist portion which is continuous in a tubular shape with the aid of a side seal portion;

[0022] a waist opening, which is an opening on the waist side of the waist portion; and

[0023] A pair of leg openings on the left and right sides are formed closer to the legs than the waist.

[0024] The front body portion and the back body portion are formed by bonding a plurality of sheet layers.

[0025] There is at least one stacking number changing portion at the side seal portion and at a portion adjacent to the widthwise center of the side seal portion, wherein the number of sheets stacked at the stacking number changing portion changes as it moves from the waist opening side toward the leg opening side.

[0026] A slit is formed on the sheet layer forming at least one of the front body portion and the back body portion, the slit being adjacent to the center side in the width direction of the side seal portion and vertically extending through the lamination number changing portion.

[0027] The pant-type disposable wearing article does not have a perforated line for cutting from the waist opening to the leg openings.

[0028] (Effect)

[0029] In this shorts-type disposable wearable article, even if a transverse tear begins at a position where the number of layers of the sheet changes while the side seals are being torn from the waist opening to the leg openings from top to bottom or from bottom to top, the tear continues in the longitudinal direction because the transverse tear changes direction when it reaches the slit. This effectively prevents transverse tearing when the side seals are torn.

[0030] <Method 2>

[0031] The shorts-type disposable wearing article according to the first aspect, wherein

[0032] The slit has a shape extending so as to approach the side seal portions as it moves toward both sides in the longitudinal direction.

[0033] (Effect)

[0034] If the slit is in a shape such as the one in the present embodiment, for example, a "ㄑ" shape or a semicircular shape, then no matter whether the side seal portion is torn from the top or the bottom, a transverse tear occurs at the portion where the number of layers changes and when the transverse tear reaches the slit, its direction will be guided toward the side seal portion, making it easier to continue tearing in the longitudinal direction along the side seal portion.

[0035] <Third Method>

[0036] The shorts-type disposable wearing article according to the first or second aspect, wherein:

[0037] The slits are formed by leaving at least one layer of the multi-layer sheet material layers forming the front body portion and the back body portion and penetrating the other sheet material layers.

[0038] (Effect)

[0039] In this embodiment, not only does leakage due to the incision not occur, but also the wearer's skin is not visible through the incision when the wearer is worn, so the incision is not conspicuous and the aesthetics are improved.

[0040] <Method 4>

[0041] The shorts-type disposable wearing article according to any one of the first to third aspects, wherein:

[0042] A recessed portion is formed at a side edge of the side seal portion on the center side in the width direction so as to vertically penetrate the lamination number changing portion. The recessed portion is recessed laterally, and the slit is formed in the recessed portion.

[0043] (Effect)

[0044] The slits in the recessed portions of the side seals are located over the entire width of the side seals, so that the slits are less likely to come into contact with the wearer's skin and the feel of the garment becomes less likely to deteriorate. Furthermore, the slits become less noticeable, and thus the aesthetics of the garment when worn also improve.

[0045] Effects of the Invention

[0046] According to the present invention, the portion where the number of sheet layers is changed is less likely to be torn transversely, and it is not necessary to form perforated lines for cutting from the waist opening to the leg opening. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 It is a top view (inner surface side) showing the underpants-type disposable diaper in the unfolded state.

[0048] Figure 2 It is a top view (outer surface side) showing the underpants-type disposable diaper in the unfolded state.

[0049] Figure 3 It is along Figure 1 Cross-sectional view of line 4-4.

[0050] Figure 4 It is along Figure 1 Cross-sectional view of line 5-5.

[0051] Figure 5 It is along Figure 1 Cross-sectional view along line 6-6.

[0052] Figure 6 This is a perspective view of a pants-type disposable diaper in a worn state.

[0053] Figure 7 It is a schematic diagram of the cut of method 1, (a) is a sectional view along line 7-7, (b) is a view of the vicinity of the cut of the shorts-type disposable diaper viewed from the ventral side, and (c) is an enlarged cross-sectional view of the vicinity of the cut in the sectional view along line 7-7.

[0054] Figure 8 Schematic diagram of the slit of embodiment 2, (a) is a cross-sectional view taken along line 7-7, and (b) is a diagram showing the vicinity of the slit of the underpants-type disposable diaper as viewed from the ventral side.

[0055] Figure 9 Schematic diagram of the slit of method 3, (a) is a cross-sectional view taken along line 7-7, and (b) is an enlarged cross-sectional view of the vicinity of the slit in the cross-sectional view taken along line 7-7.

[0056] Figure 10Schematic diagram of the slit of embodiment 4, (a) is a cross-sectional view taken along line 7-7, and (b) is a diagram showing the vicinity of the slit of the underpants-type disposable diaper as viewed from the ventral side. DETAILED DESCRIPTION

[0057] Hereinafter, a pants-type disposable diaper as an example of an absorbent article will be described in detail with reference to the drawings.

[0058] Figures 1 to 6 The figure shows a shorts-type disposable diaper. This shorts-type disposable diaper (hereinafter also referred to as a diaper) comprises: an outer body 20 extending from the front body F to the back body B; and an inner body 10 fixed to the inner surface of the outer body 20 in a manner extending from the front body F to the back body B. The inner body 10 is formed by interposing an absorbent body 13 between a liquid-permeable top sheet 11 and a liquid-impermeable sheet 12. During manufacturing, after the back surface of the inner body 10 is joined to the inner surface (upper surface) of the outer body 20 by a joining means such as a hot melt adhesive ( Figure 2 The inner body 10 and outer body 20 are folded at the boundary between the front body portion F and the back body portion B, that is, at the center in the front-to-back direction (longitudinal direction), and the two sides of the front body portion F and the back body portion B are joined together by welding to form side seals 21. This creates a shorts-type disposable diaper with a waist opening and a pair of left and right leg openings. The side seals 21 are formed by arranging dot-shaped or rectangular welded portions 21m in a predetermined pattern.

[0059] (Structural example of inner body)

[0060] like Figure 3 As shown, the inner body 10 has a structure in which an absorbent body 13 is interposed between the top sheet 11 and the liquid-impermeable sheet 12, and the excretion liquid that has passed through the top sheet 11 is absorbed and retained by the absorbent body 13. The planar shape of the inner body 10 is not particularly limited, but is generally set to be a substantially rectangular shape as shown in the figure.

[0061] The absorbent body 13 may be Figures 3 to 5 The single-layer structure shown may also be a multi-layer structure. As the absorbent body 13, a known absorbent may be used, for example, one primarily composed of a pulp fiber mass, an aggregate of filaments such as cellulose acetate, or a nonwoven fabric, mixed and fixed with a superabsorbent polymer as needed. To maintain the shape and polymer retention, the absorbent body 13 may be wrapped with a liquid-permeable and liquid-retaining wrapping sheet 14, such as crepe paper, as needed. The absorbent body 13 is formed into an hourglass shape with a narrowed portion in the crotch area that is narrower than the front and rear sides, but may also have a suitable rectangular shape.

[0062] As the top sheet 11 covering the front side (skin contact surface side) of absorbent body 13, preferably use porous or non-porous nonwoven fabrics or porous plastic sheets etc. The material fiber constituting the nonwoven fabric can also be natural fibers such as regenerated fibers, cotton, etc. of rayon, cuprammonium fiber, in addition to synthetic fibers such as olefin systems, polyester systems, polyamide systems, etc. such as polyethylene or polypropylene, and can use the nonwoven fabric obtained by suitable processing methods such as spunlace, spunbond, hot rolling, meltblown, needle punching. In these processing methods, spunlace is excellent in terms of flexibility and drape, and hot rolling is excellent in terms of bulkiness and softness. When a plurality of through-holes are formed on the top sheet 11, urine etc. are rapidly absorbed.

[0063] The liquid-impermeable sheet 12 covering the back side (non-skin-contacting side) of the absorbent body 13 can be made of a liquid-impermeable plastic sheet such as polyethylene or polypropylene. However, in recent years, moisture-permeable sheets have become preferred for preventing dampness. This water-blocking / moisture-permeable sheet can be preferably a microporous sheet obtained by, for example, melt-kneading inorganic microparticles such as calcium carbonate with an olefin resin such as polyethylene or polypropylene to form a sheet, followed by uniaxial or biaxial stretching. In the illustrated embodiment, the liquid-impermeable sheet 12 is folded back toward the back side along both sides of the absorbent body 13 in the width direction, along with the top sheet 11. However, this is not limited to this structure, and other known structures may be employed.

[0064] Three-dimensional pleats BS, which primarily fit around the legs, are formed on both sides of the inner body 10. These three-dimensional pleats BS are formed by folding a pleat sheet 15 into a double-layered sheet. The fixed portion is fixed to the side of the inner body 10's back, while the main portion extends from the fixed portion through the inner body's sides to the front side of the inner body. The collapsed portion is formed by securing the front and rear ends of the main portion to the inner body's front side in a collapsed state. The free portion is formed by leaving the collapsed portions unattached. Slender pleat elastic members 16 are positioned between the two layers, at the ends of the free portion. This structure allows the free portion of the three-dimensional pleats BS, which protrudes from the side edges of the absorbent body due to the contraction of the pleat elastic members 16, to stand upright in the product. A water-repellent nonwoven fabric is preferably used as the pleat sheet 15.

[0065] The gathering elastic members 16 can be made of commonly used materials such as styrene rubber, olefin rubber, polyurethane rubber, ester rubber, polyurethane, polyethylene, polystyrene, styrene-butadiene rubber, silicone, and polyester. To prevent visibility from the outside, the gathering elastic members 16 can be arranged with a thickness of 925 dtex or less, a tension of 150-350%, and a spacing of 7.0 mm or less. Furthermore, in addition to the linear form shown in the illustration, the gathering elastic members 16 can also be strip-shaped members of a certain width.

[0066] The material fibers constituting the pleated sheet 15 are the same as those for the top sheet 11. In addition to synthetic fibers such as olefins such as polyethylene and polypropylene, polyesters, and polyamides, regenerated fibers such as rayon and cuprammonium, and natural fibers such as cotton can also be used. Nonwoven fabrics produced by appropriate processing methods such as spunbonding, hot rolling, meltblowing, and needle punching can be used. In particular, to prevent dampness, it is preferable to use a nonwoven fabric that has a low weight per unit area and excellent breathability. Furthermore, to prevent urine and other substances from penetrating while also preventing rashes and improving the feel (dryness) to the skin, it is preferable to use a water-repellent nonwoven fabric coated with a silicone-based, paraffin-based, metal-based, or alkylchromium chloride-based water-repellent.

[0067] (Example of the structure of the outer casing)

[0068] Figures 3 to 5 The outer body 20 shown has a pressing sheet 20A and a back sheet 20B, each of which is made of a non-woven fabric, etc. Elastic components 24 to 28 are arranged between the pressing sheet 20A and the back sheet 20B and between the sheets of the folded portion 20C, wherein the folded portion 20C is formed by folding the back sheet 20B toward the inner surface side at the edge of the waist opening. The outer body 20 shrinks in its natural length state with the help of the contractile force of the elastic components, thereby giving it elasticity. Regarding the planar shape, the whole body has a roughly hourglass shape with the help of the concave leg circumference line 29 formed to form the leg openings on both sides of the middle.

[0069] In the outer body 20 of the illustrated embodiment, an elastic member 24 and a plurality of waist elastic members 25 are provided as elastic members. Figures 1 and 2 In the expanded configuration shown, the elastic member 24 is positioned near the waist opening 23. Multiple below-the-waist elastic members 25 are spaced apart in the longitudinal direction and arranged widthwise in the front and back sections F and B. In addition to the set of below-the-waist elastic members 25, the front and back sections F and B each include multiple curved elastic members 26 and 28 spaced apart and arranged without intersecting each other. These curved elastic members 26 and 28 are curved and extend in a pattern that runs from one side seal 21 along one leg opening toward the crotch, then across the crotch and along the other leg opening to the other side seal 21. These elastic members 24-28 are each secured in a state of being stretched at a predetermined rate along their extension direction. Furthermore, the outer body 20 does not include any elastic members extending continuously from the side seals of the front section F to the back section B along the leg lines 29.

[0070] The waist elastic members 24 are elongated elastic members, such as multiple rubber threads, spaced longitudinally near the edges of the waist opening within the side seals 21 formed by the front and back body sections F and B. These elastic members are used to apply a stretching force to tighten the waist when the diaper is worn. In the illustrated example, rubber threads are used for the waist elastic members 24, but belt-shaped stretchable members, for example, may also be used. In the illustrated embodiment, the waist elastic members 24 are sandwiched between the nonwoven fabric of the folded portion 20C of the back sheet 20B at the waist, but they may also be sandwiched between the pressure sheet 20A and the back sheet 20B.

[0071] The lower waist elastic members 25 are elongated elastic members, such as rubber threads, arranged longitudinally and spaced apart within the front-to-back direction of the side seals 21. They are used to apply a widthwise stretching force to the waist areas of the front and back sections F and B, respectively, thereby ensuring a close fit to the body. Furthermore, the boundary between the waist elastic members 24 and the lower waist elastic members 25 need not be clearly defined. For example, even if the number of elastic members arranged longitudinally and spaced apart along the width of the front and back sections F and B is uncertain, it is sufficient that a few elastic members on the upper side function as waist elastic members, while the remaining elastic members function as lower waist elastic members.

[0072] In addition to the waist elastic member 25, the back curved elastic member 26 provided in the back section B is a slender elastic member such as a rubber string, and is arranged along a predetermined curve. While a single back curved elastic member 26 is possible, preferably multiple members are used. In the illustrated example, four such slender elastic members are used. These back curved elastic members 26 do not intersect with one another and are spaced apart. These back curved elastic members 26 are not a combination of two or three closely spaced elastic members arranged as a bundle. Instead, three or more, preferably four or more, are spaced apart to form a predetermined stretch zone.

[0073] In addition to the waist elastic member 25, the front portion F of the outer body 20 is provided with a slender elastic member 28, such as a rubber thread, arranged along a predetermined curve. While a single elastic member 28 is possible, preferably multiple members are used. In the illustrated example, four linear elastic members are used. These elastic members 28 do not intersect with each other and are spaced apart. These elastic members 28 are not arranged in a bundle of two or three closely spaced elastic members. Instead, three or more elastic members, preferably four or more, are arranged at intervals of 3 to 20 mm, preferably approximately 6 to 16 mm, to form a predetermined stretch zone.

[0074] In addition, if Figure 2 As shown, the elastic components 25 and the curved elastic components 26 and 28 below the waist arranged in the front body portion F and the back body portion B are continuously fixed relative to the outer body 20 during manufacturing. Then, the middle portion in the width direction of the portion overlapping with the absorbent body 13 (the portion surrounded by the double-dotted line in the figure) can be finely cut with a predetermined cutting pattern to serve as a non-shrinkage portion where the shrinkage force does not act, and the portion extending laterally than the non-shrinkage portion can be used as a shrinkage portion where the shrinkage force acts (i.e., the portion where the elastic components 25 and the curved elastic components 26 and 28 below the waist remain continuously). In this way, unnecessary shrinkage in the width direction of the inner body (especially the absorbent body 13) can be prevented. Of course, as Figure 6 As shown, the waist lower elastic member 25 and the curved elastic members 26 and 28 may be continuously arranged across the inner body 10 .

[0075] The outer body 20 can be manufactured using the techniques described in, for example, Japanese Patent Application Laid-Open Nos. 4-28363 and 11-332913. Furthermore, to discontinuously cut the curved elastic members 26 and 28 on the inner body 10, it is preferable to use the cutting methods described in Japanese Patent Application Laid-Open Nos. 2002-35029, 2002-178428, and 2002-273808.

[0076] Unlike the illustrated example, the curved elastic members 26 and 28 may be provided on only one of the front section F and the back section B. Furthermore, when the curved elastic members 26 and 28 are provided on both the front section F and the back section B, a configuration (not shown) may be employed in which part or all of the group of curved elastic members 28 disposed on the front section F side intersects with part or all of the group of curved elastic members 26 disposed on the back section B side. However, as shown in the illustrated example, it is preferred that the group of curved elastic members 28 disposed on the front section F side and the group of curved elastic members 26 disposed on the back section B side do not intersect with each other, but are separated in the longitudinal direction at an intermediate position in the front-to-back direction, particularly preferably at a position slightly offset from the front section F.

[0077] The elongation of the elastic parts 24 to 28 when fixed can be appropriately determined. In the case of a typical adult product, the elongation of the waist elastic part 24 can be set to approximately 160 to 320%, the elongation of the elastic part 25 below the waist can be set to approximately 160 to 320%, and the elongation of the curved elastic parts 26 and 28 can be set to approximately 230 to 320%.

[0078] (cover piece)

[0079] like Figure 1 and Figure 3 As shown, cover sheets 50 and 60 may be provided to cover the front and rear ends of the inner body 10 attached to the inner surface of the outer body 20 and to prevent leakage from the front and rear edges of the inner body 10. To further detail the illustrated embodiment, the front cover sheet 50 extends across the entire width of the diaper from the inner surface of the waist-side folded portion 20C on the inner surface of the front body F to a position overlapping the front end of the inner body 10. The rear cover sheet 60 extends across the entire width of the diaper from the inner surface of the waist-side folded portion 20C on the inner surface of the back body B to a position overlapping the rear end of the inner body 10. Alternatively, the folded portion 20C, formed by folding the outer body 20 toward the inner surface of the diaper, may be extended to a portion overlapping the inner body 10, thereby forming portions equivalent to the cover sheets 50 and 60 shown in the illustrated example. Alternatively, the cover sheets 50 and 60 may be positioned outside the waist-side folded portion 20C, that is, between the press sheet 20A and the folded portion 20C.

[0080] (About the Sheet Layers Constituting the Exterior Body)

[0081] like Figure 3 as well as Figure 7 As shown in FIG10 (a) to FIG10 (a), the number of layers of the outer body 20 is different depending on the location. Specifically, Figure 7 The number of layers of the outer body 20 shown in (a) varies in the longitudinal direction in the manner of 3 layers at the portion p, 4 layers at the portion q, 3 layers at the portion r, and 2 layers at the portion s, and the boundary where the number of layers changes is the layer number changing portion 62. Figure 7 At position q in (a), the sheet located on the outermost side (non-skin contact side) is the back sheet 20B, and the inner side thereof has, in order, a pressing sheet 20A and a folded portion 20C formed by extending the back sheet 20B toward the inner surface side at the edge of the waist opening. At the innermost side (skin contact side), there is a front cover sheet 50 located at the front body portion F and a back cover sheet 60 located at the back body portion B, with a total of four layers. Thus, in the outer body 20 of the illustrated example, from the waist opening toward the leg opening, the number of sheet layers changes from position p to 3 layers, from position q to 4 layers, from position r to 3 layers, and from position s to 2 layers. The number of layer change portions 62 are located at the following three locations: between positions p and q, between positions q and r, and between positions r and s. However, as long as there is at least one number of layer change portion 62, the number and order of sheets forming the layers of the outer body 20 can be appropriately changed without being limited to the illustrated example.

[0082] (About the structure of the slit)

[0083] Figures 7 to 10 (a) is a cross-sectional view of the shorts-type disposable diaper along line 7-7, Figures 7 to 10 (b) is a diagram showing the vicinity of the slit of the shorts-type disposable diaper as viewed from the ventral side.

[0084] Below, refer to Figures 7 to 10 The slit 61 will be described.

[0085] Figure 7 The slit of the first example is shown. Figure 7 As shown in (b), the slit 61 is a slit 61 extending in the longitudinal direction, adjacent to the center side of the side seal portion 21 in the width direction, and vertically passes through the stacking number change portion 62 of the outer body 20. Figure 7 In the example shown in (a), as described above, the number of sheets stacked at locations p, q, r, and s in the front body F or back body B changes to 3, 4, 3, and 2, respectively, as the length of the sheet moves downward from the waist opening toward the leg openings. The outer body 20 has three stacking number changing portions 62 located between locations p and q, between locations q and r, and between locations r and s. As a result, the force used to tear the side seals 21 longitudinally from these locations tends to propagate laterally, making transverse tearing more likely. Therefore, by pre-cutting all the sheets in the thickness direction of each stacking number changing portion 62 longitudinally, tearing and peeling proceed longitudinally, making transverse tearing less likely and facilitating the smooth longitudinal tearing of the side seals 21.

[0086] The characteristic of tearing or peeling at the ply count change portion 62 is that, even at the location where the number of sheets changes from a smaller number to a larger number, the tearing force acting longitudinally along the side seal 21 tends to propagate transversely along the ply count change portion, thus easily causing transverse tearing at the ply count change portion 62. When tearing longitudinally downward from the waist opening toward the leg opening, transverse tearing is particularly likely to occur at the ply count change portion 62, the boundary between p and q, where the number of sheets changes from three to four. When tearing longitudinally upward from the leg opening toward the waist opening, transverse tearing is particularly likely to occur at the boundary between r and q, the ply count change portion 62. The presence of the slits 61 at the ply count change portion 62, where transverse tearing is more likely to occur, facilitates smooth longitudinal tearing of the side seal 21. Longitudinal tearing of the side seal 21 can occur longitudinally downward from the waist opening toward the leg opening, or longitudinally upward from the leg opening toward the waist opening.

[0087] Furthermore, the outer body 20 of the first example does not have perforations extending from the waist opening to the leg openings near the side seals 21. Instead, slits 61 are formed only at the various ply-number changing portions 62, which are susceptible to transverse tearing. Slits 61 are not formed outside the ply-number changing portions (there are no slits that do not longitudinally cut through the ply-number changing portions 62). Therefore, compared to shorts-type disposable diapers with perforations, the number of slits that come into contact with the skin is reduced, resulting in a better wearing feel and a lower likelihood of leakage through the slits. Furthermore, when multiple ply-number changing portions 62 are provided, slits 61 do not need to be provided at all of them. Slits 61 may be omitted from a portion of the ply-number changing portions 62 (e.g., where transverse tearing is less likely to occur). Figure 7 The longitudinal length 61L of the slit 61 shown in (b) is preferably 2 mm to 10 mm, more preferably 4 mm to 8 mm, but can be determined as appropriate. In addition, the distance 61W in the width direction from the side seal 21 to the slit 61 is preferably 0 mm to 5 mm, more preferably 1 mm to 3 mm, but can be determined as appropriate. From the perspective of transverse fracture resistance, Figure 7 As shown in (c) of FIG. 8 , it is preferable that the slit 61 penetrates all the layers constituting the exterior body 20 .

[0088] exist Figures 7 to 10 The example in which the number of stacked sheets changes to 3 layers at position p, changes to 4 layers at position q, changes to 3 layers at position r, and changes to 2 layers at position s is shown, but as mentioned above, it is not limited to this. Even if the number of stacked sheets is different, it is possible to prevent transverse rupture by providing a slit 61 that runs vertically through the stacking number change portion 62 in the same manner as in the first example.

[0089] If a pair of slits 61 are respectively provided on the front body portion F and the back body portion B, it is preferred because, for example, when the wearer tears the side seal of the shorts-type disposable diaper, the transverse rupture can be prevented regardless of which side of the ventral side or the dorsal side the transverse rupture occurs.

[0090] However, the slits 61 may be provided only in the front body portion F or only in the back body portion B. In this case, the slits 61 may be provided on either side of the front body portion F or the back body portion B. Furthermore, when the slits 61 are provided separately in the front body portion F and the back body portion B, it is preferred that the slits 61 in the front body portion F and the slits 61 in the back body portion B are provided at overlapping positions, as this facilitates manufacturing. However, the slits 61 may be provided at different positions in the longitudinal or transverse directions.

[0091] Figure 8This is a schematic diagram showing a second example of a slit 61. The slit 61 has a shape extending so as to approach the side seals 21 as it moves toward both sides in the longitudinal direction. Therefore, even if the tearing force or peeling force in the longitudinal direction of the side seals 21 advances in the transverse direction at the lamination number changing portion 62 and causes a transverse break, the force is guided back toward the side seals 21 along the slit 61, making it easier to continue tearing the side seals 21.

[0092] Furthermore, whether the side seals 21 are torn longitudinally downward from the waist opening toward the leg openings or, conversely, upward from the leg openings toward the waist openings, the tearing force is directed toward the side seals 21 via the slits 61 because both ends of the slits 61 face the side seals 21. Therefore, whether the side seals 21 are torn longitudinally downward from the waist opening toward the leg openings or, conversely, upward from the leg openings toward the waist openings, the tearing can proceed smoothly.

[0093] exist Figure 8 (b) shows a semicircular slit 61 , but the present invention is not limited to this form and may also be in a “ㄑ” shape with both ends facing the side seal portion 21 .

[0094] Figure 9 The structure of the slit 61 of the third example is shown. From the perspective of preventing transverse fracture, the slit 61 preferably penetrates all the sheets of the outer body 20 in the thickness direction, but it is also possible to retain at least one layer (i.e., there is no slit on this sheet) as in the third example, and only penetrate the other sheets. Figure 9 In the example shown in (b), only the innermost (skin contacting side) front cover sheet 50 and rear cover sheet 60 are not slit, and all other sheet layers are slit at the lamination number change portion 62.

[0095] The sheet layers that are not slit can be determined as appropriate. For example, of the four-layer sheet forming portion q of the outer body 20, the two inner layers can be retained while the two outer layers are cut. In other words, the front cover sheet 50, the rear cover sheet 60, and the folded portion 20C can be cut while the pressing sheet 20A and the back sheet 20B are cut. Alternatively, of the four-layer sheet forming portion q of the outer body 20, the three inner layers can be retained while the one outer layer is cut. In other words, the front cover sheet 50, the rear cover sheet 60, the folded portion 20C, and the pressing sheet 20A can be cut while only the back sheet 20B is cut.

[0096] By forming the slits 61 so that at least one sheet of the outer body 20 remains, as in the third example, the exposed skin is not visible through the slits 61 of the outer body 20, thereby improving the aesthetic appearance when worn. Furthermore, as shown in the illustrated example, if the slits 61 are not formed on the innermost (skin-contacting) sheet, then since the slits 61 are completely absent on the sheet that directly contacts the wearer's skin, the wearing feel is improved compared to a case where the slits 61 do not contact the skin. In the illustrated example, all the slits 61 are covered by the innermost sheet, but only a portion of the slits 61 may be covered by the innermost sheet.

[0097] Figure 10 : is a schematic diagram showing the slit 61 of the fourth example. That is, in the fourth example, a recessed portion 21U is formed at the side edge of the side seal portion 21 near the center side in the width direction WD so as to vertically penetrate the stacking number changing portion 62, and a slit is formed in the recessed portion. More specifically, Figure 10 In the example shown in (b), the width of the horizontally long rectangular weld 21m located in the lamination number varying portion 62 of the exterior body 20 is formed shorter than the weld 21m in other portions, thereby forming a recess 21U having a longitudinal slit 61 therein. The longitudinal length 61L of the slit 61 is preferably 2 mm to 10 mm, more preferably 4 mm to 8 mm, but can be determined as appropriate. Furthermore, the widthwise distance 61W from the side seal 21 to the slit 61 is preferably 0 mm to 5 mm, more preferably 1 mm to 3 mm, but can be determined as appropriate. The longitudinal length 21L of the recess 21U is 100% to 150% of the length 61L of the slit 61, and the widthwise length 21W of the recess 21U is 100% to 200% of the widthwise distance 61W from the side seal 21 to the slit 61, but can be determined as appropriate.

[0098] In this example, since the slits 61 extend across the entire width of the side seals 21, the appearance of the garment is good when worn, and since the slits 61 do not directly contact the skin when worn, the garment feels comfortable when worn. Furthermore, transverse tearing is less likely to occur toward the center of the width of the outer body 20, allowing for smooth and continuous longitudinal tearing.

[0099] In the first to fourth examples, adjacent auxiliary slits can be provided on the central side of the slit 61 in the width direction (i.e., a plurality of slits can be provided at intervals in the width direction). The auxiliary slits can be slits that pass through the stacking number changing portion 62 vertically. They can be longitudinally straight lines as in the first example, or semicircular or "ㄑ"-shaped with both ends facing the side sealing portion 21 as in the second example. In addition, the auxiliary slits can be slits that pass through all the sheets constituting the outer body 20, or they can be slits that retain at least one sheet. When the transverse rupture that occurs at the stacking number changing portion 62 does not stop at the slit 61, but further advances along the stacking number changing portion 62 toward the central side in the width direction of the outer body 20, since the auxiliary slits are located in the direction of advancement of the transverse rupture, they can assist by preventing the transverse rupture and returning the tearing force to the side sealing portion 21. From such a viewpoint, preferably the auxiliary slit is not too far from the slit closest to the side seal portion side (e.g., the separation distance in the width direction is below 3 mm). In addition, preferably, the longitudinal dimension of the auxiliary slit is longer than the longitudinal dimension of the slit closest to the side seal portion side.

[0100] In addition, in each of the above examples, the structures of other examples can be combined as appropriate.

[0101] <Explanation of terms used in this manual>

[0102] When the following terms are used in the specification, unless otherwise specified in the specification, the following terms in the specification have the following meanings.

[0103] The “front-rear direction” refers to the direction (longitudinal direction) indicated by the symbol LD in the drawings, and the “width direction” refers to the direction (lateral direction) indicated by the symbol WD in the drawings. The front-rear direction is perpendicular to the width direction.

[0104] The "expanded state" refers to a state in which the garment is not contracted (including any contraction such as contraction of elastic members) and is relaxed and flatly expanded.

[0105] "Elongation" refers to a value when the natural length is 100%. For example, an elongation of 200% means the same as an elongation of 2 times.

[0106] · Unless otherwise specified, the dimensions of each part refer to the dimensions in the unfolded state, not the natural length state.

[0107] Industrial applicability

[0108] The present invention is applicable to shorts-type disposable wearing articles such as the shorts-type disposable diapers, shorts-type disposable sanitary napkins, and shorts-type disposable diaper covers as described above.

[0109] Label Description

[0110] 10: Inner body; 11: Top sheet; 12: Liquid-impermeable sheet; 13: Absorbent body; 14: Wrapping sheet; 15: Pleated sheet; 16: Pleated elastic member; 20: Outer body; 20A: Pressing sheet; 20B: Back sheet; 20C: Folded portion; 21: Side seal portion; 21m: Welded portion; 21U: Concave portion; 21L: Longitudinal length of the concave portion; 21W: Width length of the concave portion; 23: Near the waist opening; 24: Waist elastic component; 25: Elastic component below the waist; 26: Dorsal curved elastic component; 28: Ventral curved elastic component; 29: Leg circumference; 50: Front cover; 60: Back cover; 61: Slit; 61L: Longitudinal length of the slit; 61W: Distance from the side seal to the slit in the width direction; 62: Layer number change part; B: Back body part; BS: Three-dimensional pleats; F: Front body part; WD: Width direction; LD: Longitudinal direction.

Claims

1. A shorts-type disposable wearing article, characterized in that: The shorts-type disposable wearing article comprises: a front body portion and a back body portion; Side seals formed by welding the two side portions of the front body portion and the two side portions of the back body portion; a waist portion which is continuous in a tubular shape with the aid of a side seal portion; a waist opening, which is an opening on the waist side of the waist portion; and A pair of leg openings on the left and right sides are formed closer to the legs than the waist. The front body portion and the back body portion are formed by bonding multiple layers of sheets. There is at least one stacking number changing portion at the side seal portion and at a portion adjacent to the widthwise center of the side seal portion, wherein the number of sheets stacked at the stacking number changing portion changes from the waist opening side toward the leg opening side. A slit is formed on the sheet forming at least one of the front body portion and the back body portion, the slit being adjacent to the center side in the width direction of the side seal portion and vertically extending through the lamination number changing portion. The pant-type disposable wearing article does not have a perforated line for cutting from the waist opening to the leg openings.

2. The shorts-type disposable wearing article according to claim 1, wherein: The slit has a shape extending so as to approach the side seal portions as it moves toward both sides in the longitudinal direction.

3. The shorts-type disposable wearing article according to claim 1 or 2, wherein: The slits are formed by leaving at least one of the plurality of sheets forming the front body portion and the back body portion and penetrating the other sheets.

4. The shorts-type disposable wearing article according to claim 1 or 2, wherein: A concave portion is formed at a side edge of the side seal portion near the center in the width direction so as to vertically penetrate the lamination number changing portion, and the concave portion is concave laterally. The slit is formed in the recess.

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