Absorbent panty-type items

Abstract

To provide an underpants-type absorbent article which can achieve both separation prevention in a wearing motion and during the wearing, and easiness of tearing in the disposal.SOLUTION: An underpants-type absorbent article includes an absorbent body, an exterior body, and a pair of side joining parts. The pair of the side joining part are configured to join an abdominal side region of the exterior body and a back side region at a side edge part in a lateral direction perpendicular to a longitudinal direction. The pair of the side joining parts include a longitudinal direction end part region in which a waist end part and / or a leg end part is a longitudinal direction end part, a longitudinal direction central region, and a plurality of seal parts. A position of an inner end part of the seal part in an outermost end part that is arranged to be the closest to the longitudinal direction end part is arranged to be laterally inside the seal part in the longitudinal direction central region. At least in the seal part in the outermost end part, seal strength in an inner region is higher than that of an outer region, and in the seal part in a boundary part in the longitudinal direction central region, a difference of seal strength between the inner region and the outer region is smaller than the seal part of the outermost end part.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a pant-type absorbent article such as a disposable diaper.

Background Art

[0002] Pant-type absorbent articles generally include an absorbent body, an outer cover, and a side joining portion (side seal portion) that joins the ventral outer cover and the dorsal outer cover at the side end portions. By joining the ventral outer cover and the dorsal outer cover with the side joining portion, a waist opening and a leg opening of the pant-type absorbent article are formed. On the other hand, after wearing a pant-type absorbent article, from a hygienic perspective or the like, the side joining portion may be torn and discarded. Therefore, the side joining portion is required to have a function that it does not peel off during the wearing operation (when putting on the pant-type absorbent article) and during wearing, and can be easily torn at the time of disposal.

[0003] From such a perspective, Patent Document 1 discloses a pant-type absorbent article provided with a seal portion that joins the lateral end portions of the ventral portion and the dorsal portion of the outer cover to each other. In the pant-type absorbent article, the seal portion includes a plurality of fusion portions that are spaced apart from each other in the longitudinal direction and aligned, and at least two adjacent fusion portions among the fusion portions each include a relatively thin portion with a small thickness and a relatively thick portion with a large thickness, and all of these thin portions are located inside the fusion portion in the lateral direction.

[0004] Further, Patent Document 2 discloses a pant-type absorbent article having a strength reduction region portion in which a joining strength reducing agent is disposed at a joining portion on both side ends of the ventral portion and the dorsal portion of the outer cover, and a non-strength reduction region portion in which the joining strength reducing agent is not disposed. In the same document, the joining portion is continuously arranged in the longitudinal direction, and the strength reduction region portion is disposed, for example, inside and / or outside the width direction of the joining portion.

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] Japanese Patent Publication No. 2020-99618 [Patent Document 1] Japanese Patent Publication No. 2011-72577 [Overview of the project] [Problems that the invention aims to solve]

[0006] In the aforementioned Patent Documents 1 and 2, the absorbent pant-type article is made easier to peel off by providing a section with different joining strengths when joining the ventral and dorsal sides of the outer casing. However, depending on the strength and arrangement of the section joining the ventral and dorsal sides of the outer casing, it is possible that a point of peeling may occur or lateral tearing may occur, leaving room for further improvement.

[0007] The object of the present invention is to provide a pant-type absorbent article that can achieve both prevention of peeling during wear and during the wearing process, and ease of tearing when discarded. [Means for solving the problem]

[0008] One embodiment of the present invention comprises an absorbent pant-type article, an outer casing, and a pair of side joints. The outer casing is positioned on the non-skin-facing side of the absorbent body and includes ventral and dorsal regions located on both sides in the longitudinal direction, and is constructed by laminating a plurality of thermoplastic sheets. The pair of side joints connect the ventral region and the dorsal region of the outer casing at the transverse side edges perpendicular to the longitudinal direction. The pair of side joints have a waist end, which is the end on the waist side in the longitudinal direction, and / or a leg end, which is the end on the leg side in the longitudinal direction, as longitudinal ends, a longitudinal end region within 25 mm in the longitudinal direction from the longitudinal end, a longitudinal central region adjacent to the longitudinal end region, and a plurality of sealing portions spaced apart along the longitudinal direction. Each of the plurality of sealing portions has an inner region located laterally inward and including an inner end, and an outer region located laterally outward and including an outer end. Of the plurality of sealing portions, the position of the inner end of the outermost sealing portion located closest to the vertical end is positioned laterally inward than the position of the inner end of the sealing portion located in the vertical central region. Of the plurality of sealing portions, at least the sealing portion at the outermost end has a higher sealing strength in the inner region than in the outer region. Of the plurality of sealing portions, the sealing portion at the boundary located in the vertical central region and closest to the vertical end region has a smaller difference in sealing strength between the inner region and the outer region than the sealing portion at the outermost end. [Effects of the Invention]

[0009] The absorbent pant-type article of the present invention makes it possible to achieve both prevention of peeling during wearing and during the wearing process, and ease of tearing when disposing of the article. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic perspective view showing a pant-type absorbent article according to the first embodiment of the present invention. [Figure 2] This is a schematic plan view showing the skin-facing side of the above-mentioned absorbent pant-type article, and is a diagram showing the absorbent pant-type article unfolded and the elastic members of each part stretched out to form a flat surface. [Figure 3] This is a schematic plan view showing the side seam of the above-mentioned pant-type absorbent material. [Figure 4] This figure schematically shows a microscope image of the cross-section of the above-mentioned side joint, magnified approximately 300 times. [Figure 5] This figure schematically shows a microscope image of the seal portion of the side joint described above, magnified approximately 500 times, where (A) shows the fibers in the outer region and (B) shows the fibers in the inner region. [Figure 6] This is a schematic plan view showing the side joint of a pant-type absorbent article according to a modified example of the above embodiment. [Figure 7] (A) and (B) are each a schematic plan view showing a side joint portion of a pant-type absorbent article according to a modified example of the above embodiment. [Figure 8] It is a schematic cross-sectional view of the side joint portion, and is a view showing a state in which the ventral region and the dorsal region are separated. [Figure 9] It is a schematic plan view of a side joint portion of a pant-type absorbent article according to a second embodiment of the present invention. [Figure 10] It is a schematic plan view of a side joint portion of a pant-type absorbent article according to a third embodiment of the present invention. [Figure 11] It is a schematic plan view of a side joint portion of a pant-type absorbent article according to a fourth embodiment of the present invention.

Mode for Carrying Out the Invention

[0011] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0012] <First Embodiment> [Overall Configuration of Pant-Type Disposable Diaper] In FIGS. 1 and 2, a pant-type disposable diaper 1 is shown as a pant-type absorbent article according to a first embodiment of the present invention. The pant-type disposable diaper 1 is hereinafter referred to as the diaper 1. As shown in FIG. 1, the diaper 1 includes a waist opening 1W and a pair of leg openings 1L, and is worn around the wearer's torso and groin when worn. The waist opening 1W has a waist opening edge Wa. The diaper 1 has a longitudinal direction X and a lateral direction Y. The longitudinal direction X extends from the ventral side of the wearer through the groin to the dorsal side. The lateral direction Y is orthogonal to the longitudinal direction X and corresponds to the left-right direction of the wearer. Further, as shown in FIG. 2 and the like, the direction orthogonal to the longitudinal direction X and the lateral direction Y of the diaper 1 is defined as the thickness direction Z. In this specification, the "waist side" means the side approaching the waist opening edge Wa of the waist opening 1W in the longitudinal direction X, and the "leg side" means the side moving away from the waist opening edge Wa in the longitudinal direction X. In this specification, "inside of transverse direction Y" means the side of the pant-type absorbent article (diaper 1) that is closer to the vertical center line CL that divides the transverse direction Y into two equal parts, and "outside of transverse direction Y" means the side that is further away from the vertical center line CL. In this specification, with respect to the thickness direction Z, the side of the absorbent pant-type article (diaper 1) closer to the wearer's skin when worn may be referred to as the skin side, and the side closer to the clothing may be referred to as the non-skin side. Furthermore, the "skin-facing surface" of the absorbent pant-type article (diaper 1) or its components means the surface that is relatively closer to the wearer's skin. The "non-skin-facing surface" of the absorbent pant-type article (diaper 1) or its components means the surface that is relatively further away from the wearer's skin. Furthermore, in this specification, unless otherwise specified, the dimensions and area of ​​each part shall be measured in their natural state without stretching the elastic members of each part.

[0013] When a wearer puts on diaper 1, they first put their legs through the pair of leg openings 1L, pull diaper 1 up towards their torso, and position diaper 1 around their waist and groin. In this specification, this series of actions is referred to as the "wearing action." The wearing action may also be performed by a caregiver rather than the wearer of diaper 1. Furthermore, in this specification, the state in which the diaper 1 is positioned in the position where it is normally expected to be worn by the wearer is referred to as "when worn".

[0014] As shown in Figures 1 and 2, the diaper 1 comprises an absorbent body 4 and an outer casing 5 positioned on the non-skin-facing side of the absorbent body 4. Figure 2 shows the diaper 1 unfolded, with the elastic members of each part stretched, and spread out into a flat shape to achieve the design dimensions, completely eliminating the influence of the elastic members. This form is also referred to as the "unfolded and stretched form" of the diaper 1. Unfolding the diaper 1 means separating the ventral region 5a and the dorsal region 5b of the side joint 8, which will be described later.

[0015] The absorbent body 4 is fixed to the skin-facing side of the outer casing 5. The absorbent body 4 has at least an absorbent 40 and may further have a surface sheet 2, a back sheet (not shown), etc. For example, the absorbent body 4 has a configuration in which the back sheet, absorbent 40 and surface sheet 2 are laminated in the thickness direction Z. The absorbent 40 includes a liquid-retaining absorbent core and may further include a core wrap sheet covering the absorbent core. The materials used in each component of the absorbent body 4 (back sheet, absorbent material 40, surface sheet 2, etc.) can be any material used in the relevant art without any particular limitations.

[0016] The outer casing 5 includes a plurality of thermoplastic sheets 50. The outer casing 5 is configured, for example, as a laminate of a plurality of thermoplastic sheets 50. The thermoplastic sheet 50 is a sheet material mainly composed of thermoplastic resin. Preferably, the thermoplastic sheet 50 contains 90% by mass or more of thermoplastic resin, and more preferably, is composed of 100% by mass of thermoplastic resin. Examples of thermoplastic resins include polyolefins such as polyethylene and polypropylene; polyesters such as polyethylene terephthalate; polyamides such as nylon 6 and nylon 66; polyacrylic acid, polyalkyl methacrylate, polyvinyl chloride, and polyvinylidene chloride. These can be used individually or in combination of two or more. The thermoplastic fibers may be short or long fibers. As thermoplastic fibers, composite fibers such as core-sheath type or side-by-side type, split fibers, irregularly shaped cross-section fibers, and heat-shrinkable fibers can also be used.

[0017] The outer garment 5 comprises at least an ventral region 5a positioned on the wearer's abdominal side and a dorsal region 5b positioned on the wearer's dorsal side. The outer garment 5 of this embodiment further includes a crotch region 5c located between the ventral region 5a and the dorsal region 5b and positioned in the wearer's crotch area. In this example, the ventral region 5a, the crotch region 5c, and the dorsal region 5b are arranged along the longitudinal direction X. The outer garment 5 also has a shape that is constricted inward in the lateral direction Y at the crotch region 5c. This forms a leg opening 1L (see Figure 1) that follows the wearer's leg opening. The outer edge of the exterior body 5 is preferably constructed to be symmetrical (left-right symmetrical) with respect to the vertical center line CL.

[0018] Furthermore, the outer casing 5 has a pair of side joints 8 to which the lateral edge 5d of the ventral region 5a in the lateral direction Y and the lateral edge 5e of the dorsal region 5b in the lateral direction Y are joined. The right side joint 8 has a configuration in which the right lateral edge 5d of the ventral region 5a and the right lateral edge 5e of the dorsal region 5b are joined by overlapping them in the thickness direction Z. The left side joint 8 has a configuration in which the left lateral edge 5d of the ventral region 5a and the left lateral edge 5e of the dorsal region 5b are joined by overlapping them in the thickness direction Z. The pair of side joints 8 form a tubular shape that conforms to the wearer's waist, with the ventral region 5a and the dorsal region 5b following the wearer's waist, and the waist opening 1W and leg openings 1L of the diaper 1 are formed. The side joint 8 is preferably joined by a heat seal or ultrasonic seal, as will be described in detail later.

[0019] [Configuration of the side joint] It is preferable that the side joint 8 maintains a joined state without the ventral region 5a and the dorsal region 5b separating during the wearing process and while wearing the garment. On the other hand, when changing diaper 1 after wearing it, from the standpoint of hygienically disposing of the excrement attached to diaper 1, caregivers may separate the ventral region 5a and the dorsal region 5b of the side joint 8, unfold diaper 1, and then dispose of it. Thus, it is preferable that the side joint portion 8 has a structure that prevents peeling during the wearing process and while wearing the garment, and that can be easily torn when discarded. In this specification, the unintentional separation of the ventral region 5a and the dorsal region 5b of the side joint 8 during the putting-on process and while wearing the diaper 1 is described as "peeling off." In contrast, the action of intentionally separating the ventral region 5a and the dorsal region 5b of the side joint 8 by applying external force to the side joint 8 and / or its surroundings when disposing of the diaper 1 is described as "tearing." Furthermore, the entity that tears the side seam 8 when disposing of diaper 1 is referred to as the "disposer."

[0020] In this embodiment, it is preferable that the pair of side joints 8 are configured substantially symmetrically with respect to a vertical center line CL, for example, and that each has a similar configuration. The configuration of one of the side joints 8 will be described in detail below. In the side joint 8, the vertical X end side refers to the side that approaches the waist end 8a or the leg end 8b, and the vertical X center side refers to the side that moves away from the waist end 8a or the leg end 8b.

[0021] As shown in Figures 2 and 3, the side joint 8 has a waist end region 8c within 25 mm in the vertical direction X from the waist end 8a, which is the waist end in the vertical direction X; a leg end region 8d within 25 mm in the vertical direction X from the leg end 8b, which is the leg end in the vertical direction X; and a vertical central region 8e adjacent to the waist end region 8c and the leg end region 8d. It also has a plurality of seal portions S. In Figure 3, the boundary line 7a, which is 25 mm in the vertical direction x from the waist end 8a, and the boundary line 7b, which is 25 mm in the vertical direction X from the leg end 8b, are schematically shown by dotted lines.

[0022] The waist end 8a and the leg end 8b constitute both ends of the side joint 8 in the longitudinal direction X. The side joint 8 as a whole has a configuration that extends in the longitudinal direction X from the waist end 8a to the leg end 8b. The waist end region 8c, the longitudinal central region 8e, and the leg end region 8d are regions arranged adjacent to each other in this order along the longitudinal direction X. Therefore, the longitudinal central region 8e is the region enclosed by boundary lines 7a and 7b. In this embodiment, the waist end 8a and leg end 8b correspond to the longitudinal ends. Also, the waist end region 8c and leg end region 8d correspond to the longitudinal end regions.

[0023] The seal portion S is the part where the thermoplastic sheets 50 of both the ventral region 5a and the dorsal region 5b are fused and joined together. The seal portion S is joined, for example, by pressurizing means and / or heating means, specifically by heat sealing or ultrasonic sealing. As shown in Figure 4, when the XZ cross-section (cross-section in the longitudinal direction X) of the side joint 8 is magnified, the seal portion S is observed as a part where the fibers 55 of the thermoplastic sheet 50 have fused together, resulting in a thinner thickness than the surrounding area.

[0024] As shown in Figure 3, the multiple sealing portions S are arranged spaced apart along the vertical direction X. The planar shape of the sealing portion S is not particularly limited and may be a rectangular shape, other polygonal shapes, circular shapes, elliptical shapes, similar shapes, or other shapes selected from among them. As shown in Figure 3, from the viewpoint of ensuring sufficient area for each sealing portion S while maintaining spacing, the planar shape of the sealing portion S is preferably rectangular, and more preferably a rectangular shape that is elongated in the lateral direction Y. The end of each seal portion S on the inside in the lateral direction Y is defined as the inner end Sc, and the end on the outside in the lateral direction Y is defined as the outer end Sd.

[0025] Each seal portion S has an inner end portion Sc, which is the inner end in the lateral direction Y, and an outer end portion Sd, which is the outer end in the lateral direction Y. In the seal portion S, the region located on the inner side in the lateral direction Y and including the inner end portion Sc is described as the inner region S11, and the region located on the outer side in the lateral direction Y and including the outer end portion Sd is described as the outer region S12. The inner region S11 and the outer region S12 are regions where the seal strength, as described later, is set to a different value. Note that the seal strengths of the inner region S11 and the outer region S12 do not need to be different in all seal portions S provided in the side joint 8; for example, some seal portions S may have the same seal strength in both the inner region S11 and the outer region S12.

[0026] In this embodiment, we will explain using as an example the case where the inner region S11 and the outer region S12 are in contact at a boundary line, that is, the seal portion S is divided into two parts, the inner region S11 and the outer region S12. Furthermore, the boundary line between the inner region S11 and the outer region S12 is assumed to pass approximately through the center of the lateral direction Y of each seal portion S. Note that the boundary line between the inner region S11 and the outer region S12 does not necessarily have to be set approximately in the center of the lateral direction Y. Alternatively, the boundary line between the inner region S11 and the outer region S12 may be set for each seal portion S.

[0027] Here, our findings indicate that at the start of the tearing motion of the side joint 8, the discarder's fingers are likely to be positioned on both sides (ventral and dorsal) of the side joint 8, approximately 25mm to 30mm in the longitudinal direction X from the waist end 8a or leg end 8b. For example, if the wearer is standing, the discarder's fingers are likely to be positioned on the waist side, and if the wearer is lying down, the discarder's fingers are likely to be positioned on the leg side. Therefore, in the side joint 8, the areas where an external force for tearing (also referred to as "tear force F") is particularly likely to be applied are defined as the waist end area 8c and the leg end area 8d, which are within 25 mm in the vertical direction X from the waist end 8a and leg end 8b, respectively. Then, from the viewpoint of preventing tearing during wear and movement while facilitating tearing at disposal, the arrangement and seal strength of the seal portion S in the waist end area 8c and / or leg end area 8d are configured as follows. In this specification, seal strength refers to the peel strength measured by a measuring device such as Tensilon. In contrast, bond strength refers to the strength of the bond felt by the disposer when tearing the side joint 8.

[0028] The following description will primarily focus on an example in which the region in which the seal portion S has a distinctive arrangement and seal strength extends from the waist end region 8c to the longitudinal central region 8e. The present invention is also effective when the region in which the seal portion S has a distinctive arrangement and seal strength extends from the leg end region 8d to the longitudinal central region 8e, or when it extends across the entire region encompassing the waist end region 8c, the longitudinal central region 8e, and the leg end region 8d. Therefore, the description of the waist end region 8c below can be appropriately interpreted as a description of the leg end region 8d.

[0029] As shown in Figure 3, in this embodiment, among the multiple sealing portions S, the position of the inner end Sc of the outermost sealing portion Sp located closest to the waist end 8a is positioned laterally Y-inward than the position of the inner end Sc of the sealing portion S located in the vertical central region 8e. Here, "seal portion S located in the vertical central region 8e" refers to a seal portion S that is at least partially included in the vertical central region 8e. For example, a seal portion S located on a boundary line 7a 25 mm in the vertical direction X from the waist end 8a is partially included in the vertical central region 8e and is therefore considered a seal portion S located in the vertical central region 8e.

[0030] In the example shown in Figure 3, the waist end region 8c has four stages of sealing sections S, with the outermost sealing section Sp being the first stage. Of these, the lateral Y position of the inner ends Sc of the second and third stages of sealing sections S is set to be the same as that of the outermost sealing section Sp. The inner end Sc of the fourth stage of sealing section S, which is closest to the boundary line 7a, is set to be laterally inward in the Y direction than the outermost sealing section Sp. Note that the number of sealing sections S provided in the waist end region 8c is not limited, and for example, five or more stages of sealing sections S may be provided. Also, sealing sections S may be provided in which the position of the inner end Sc is laterally inward in the Y direction than that of the outermost sealing section Sp.

[0031] Furthermore, multiple sealing portions S are provided in the vertical central region 8e, but two sealing portions S are shown in this illustration. The position of the inner end portion Sc of these sealing portions S is set to be at least inward in the lateral direction Y than the outermost sealing portion Sp. Here, the position of the inner end portion Sc of the sealing portion S in the vertical central region 8e is set in the same way as the fourth sealing portion S in the waist end region 8c, but it is not limited to this and may be set arbitrarily within the range of being inward in the lateral direction Y than the outermost sealing portion Sp. Also, the positions of the inner end portion Sc of the sealing portion S in the vertical central region 8e do not need to be aligned vertically.

[0032] Generally, at the start of the tearing motion of diaper 1, a tearing force F is applied from the inside of the waist end region 8c (or leg end region 8d), having components from the longitudinal X (center side) and the transverse Y (outside side). As shown in Figure 3, this tearing force F is an oblique outward force tilted at approximately 45° with respect to the longitudinal X and transverse Y directions.

[0033] Furthermore, since the tearing in the waist end region 8c (or leg end region 8d) proceeds along the direction of this force F, the delamination interface moves along a direction perpendicular to this. In other words, the delamination interface is formed on a line L along a direction that includes a component toward the center in the vertical direction X and a component toward the inside in the horizontal direction Y. For example, if there are multiple sealing portions S on line L, these sealing portions S will be torn simultaneously, increasing the force required for tearing. In Figure 3, the tearing operation begins from the waist end 8a. In this case, line L is a straight line along the vertical direction X, tilted 45 degrees outward in the horizontal direction Y on the waist end 8a where the tearing operation begins.

[0034] As described above, the inner end Sc of the outermost seal portion Sp is positioned inside (to the right in the figure) of any of the seal portions S in the longitudinal central region 8e. Therefore, for example, when peeling of the outermost seal portion Sp is initiated, the seal portions S of the longitudinal central region 8e do not overlap with line L, and the peeling of the outermost seal portion Sp and the seal portions S of the longitudinal central region 8e do not begin simultaneously. This makes it possible to easily tear the seal portion S of the waist end region 8c, including the outermost seal portion Sp.

[0035] Furthermore, in this embodiment, of the multiple sealing portions S, at least the outermost sealing portion Sp has a higher sealing strength in the inner region S11 than in the outer region S12. In the example shown in Figure 3, the outermost seal portion Sp is divided into an inner region S11 and an outer region S12 by a boundary line that bisects it at the center of the lateral Y direction. Of these, the seal strength of the inner region S11 is set higher than that of the outer region S12. By increasing the seal strength, the force required to peel off the inner region S11 at the outermost seal portion Sp becomes greater than the force required to peel off the outer region S12.

[0036] For example, the inner region S11 of the outermost seal portion Sp is a part that is prone to force during wear and wearing. By increasing the seal strength of this inner region S11, which is prone to force, it becomes less likely for a point where peeling begins (hereinafter sometimes referred to as the peeling point) to occur during wear and wearing, and it becomes possible to prevent tearing during wear and wearing. Furthermore, the outer region S12 of the outermost seal area Sp has a weaker seal strength than the inner region S11 and is easier to peel off. As a result, during tearing operations, it is possible to tear it easily with less force compared to, for example, when both the inner region S11 and the outer region S12 have strong seal strengths.

[0037] In particular, the outermost seal portion Sp tends to peel off along a line L that is inclined at 45° with respect to the vertical direction X (horizontal direction Y). Therefore, the outer region S12 of the outermost seal portion Sp is highly likely to peel off simultaneously with the adjacent seal portion S (second seal portion S). For this reason, if the seal strength of the outer region S12 is set to be strong, for example, the two close-located seal portions S may be torn almost simultaneously, resulting in an excessive load being applied locally to the outer casing 5. As a result, at the side joint 8, the outer casing 5 may break in the portion adjacent to the seal portion S, and further, a so-called transverse tear may occur in the outer casing 5, where the tear progresses outward in the transverse direction Y along the longitudinal direction of the seal portion S. Each time a transverse tear occurs in the outer casing 5, the tearing operation is interrupted, which causes significant stress to the person disposing of the product and the person wearing it.

[0038] In contrast, at the outermost seal portion Sp, the sealing strength of the outer region S12 is relatively lower than that of the inner region S11. As a result, even if tearing progresses and the outermost seal portion Sp and the adjacent seal portion S are separated simultaneously, separation can be sufficiently achieved with relatively weak force. Therefore, situations where excessive load is applied locally are avoided, and the occurrence of lateral cracks and other damage can be sufficiently suppressed.

[0039] Furthermore, in this embodiment, among the multiple sealing portions S, the sealing portion Sq at the boundary located in the vertical central region 8e and closest to the waist end region 8c has a smaller difference in sealing strength between the inner region S11 and the outer region S12 than the sealing portion Sp at the outermost end. Here, the boundary seal portion Sq is the seal portion S that is closest to the boundary line 7a (closest to the waist end 8a) among the seal portions S that are located in at least a portion of the vertical central region 8e. In Figure 3, the fifth seal portion S from the top is the boundary seal portion Sq.

[0040] As described above, at the start of the tearing motion, a tearing force F acts diagonally outward, tilted at 45° in both the vertical X and horizontal Y directions. However, as the tearing motion progresses, the tearing force F begins to act along the vertical X direction. For example, when tearing near the part being held down by the disposer's fingers, the tearing force F is thought to align with the longitudinal direction X. Therefore, for example, when tearing the seal portion S in the waist end region 8c (or leg end region 8d) and then beginning to tear the seal portion S in the longitudinal central region 8e, the direction of the tearing force F changes from a direction inclined at 45° with respect to the longitudinal direction X to a direction approximately parallel to the longitudinal direction X. In this case, the line L representing the delamination interface becomes approximately parallel to the transverse direction Y.

[0041] Therefore, for example, in the sealing portion Sq at the boundary, the inner region S11 and the outer region S12 are separated almost simultaneously by a line L that is approximately parallel to the lateral direction Y. When two regions are separated almost simultaneously in this way, the difference in the force required to separate each region can cause a force to act in an unintended direction different from the tearing force F, potentially leading to lateral tearing or other problems.

[0042] Therefore, at the boundary seal portion Sq, the difference in seal strength between the inner region S11 and the outer region S12 is set to be smaller than that of the seal portion Sp at the outermost end. As a result, the magnitude of the force required to separate the inner region S11 and the outer region S12 becomes closer to that of a case where, for example, there is a difference in seal strength similar to that at the outermost seal portion Sp. As a result, it becomes possible to suppress situations where a force acts in a direction away from the tearing force F, causing lateral cracks or the like.

[0043] In this way, the arrangement of each seal portion S and the seal strength of the side joint portion 8 are set based on the assumption that the direction of the tearing force F (the line L representing the delamination interface) will change as the tearing operation progresses. In other words, at the start of the tearing operation, the position of the inner end Sc of the outermost seal portion Sp is made to protrude inward from the seal portion S in the longitudinal central region 8e, thereby making it possible to selectively apply a tearing force F tilted at 45° from the longitudinal direction X to the outermost seal portion Sp. Furthermore, at the outermost seal portion Sp, the seal strength of the outer region S12 is lower than that of the inner region S11. Therefore, even if the tearing operation progresses and the adjacent seal portion S is peeled off, it is not necessary to increase the tearing force F to an extremely large degree. Furthermore, as the tearing motion progresses, a tearing force F acts along the longitudinal direction X. At the seal portion Sq at the boundary where such a tearing force F acts, by setting the strength difference between the seal strength of the inner region S11 and the outer region S12 to be smaller than that of the seal portion Sp at the outermost end, it is possible to suppress lateral tearing and other issues and continue the tearing motion smoothly. Furthermore, at the outermost seal portion Sp, the seal strength of the inner region S11 is higher than that of the outer region S12. Therefore, even if force is applied during wear or wearing, the inner region S11 is less likely to peel off, and a point of peeling is less likely to occur. This makes it possible to achieve both prevention of peeling during wear and during the wearing process at the side joint 8, and ease of tearing when discarding.

[0044] [Example of setting seal strength] Here, we will explain the sealing strength of each sealing section S. The above describes the case where, at the outermost seal portion Sp, the seal strength of the inner region S11 is set higher than the seal strength of the outer region S12. Of course, in other seal portions S, the seal strength may also be different between the inner region S11 and the outer region S12. For example, in Figure 3, in the waist end region 8c, the second and third sealing sections S, which are located inward in the lateral direction Y, similar to the outermost sealing section Sp, have a sealing strength in the inner region S11 that is higher than that of the outer region S12, similar to the outermost sealing section Sp. This effectively prevents peeling during and after wearing. Furthermore, because the sealing strength of the outer region S12 is weak, even if adjacent sealing sections S are peeled off simultaneously, the areas with strong sealing strength are less likely to overlap on the line L representing the peeling interface, making it possible to easily tear the garment with weak force. The sealing strength of the fourth sealing section S may be set in the same way as the outermost sealing section Sp, or it may be set in the same way as the outermost sealing section Sq described below.

[0045] In the vertical central region 8e, the sealing strength of the boundary seal portion Sq is set to be weaker than that of the outermost seal portion Sp in both the inner region S11 and the outer region S12. That is, the sealing strength of the inner region S11 of the boundary seal portion Sq is lower than that of the inner region S11 of the outermost seal portion Sp, and the sealing strength of the outer region S12 of the boundary seal portion Sq is set to be lower than that of the outer region S12 of the outermost seal portion Sp.

[0046] The sealing portion Sq at the boundary is a part where external forces attempting to peel off the side joint 8 during wear or wearing are less likely to concentrate compared to, for example, the sealing portion Sp at the outermost end. Therefore, even if the sealing strength of the inner region S11 and the outer region S12 is somewhat low, peeling can be sufficiently prevented. Furthermore, at the boundary seal portion Sq, the direction of the tearing force F is along the longitudinal direction X, so the inner region S11 and the outer region S12 are separated almost simultaneously. Therefore, if the seal strength of the inner region S11 and the outer region S12 is too strong, a strong force will be required to tear them apart. In contrast, by making the seal strength of the inner region S11 and the outer region S12 of the boundary seal portion Sq smaller than that of the seal portion Sp at the outermost end, it becomes possible to easily perform the tearing operation with a weak force along the longitudinal direction X.

[0047] Typically, the seal strength of the inner region S11 and the outer region S12 of the seal portion S located in the longitudinal central region 8e are set to be approximately the same. This makes it possible to avoid situations where the tearing force F acting along the longitudinal direction X acts in an unintended direction, and allows the portion beyond the longitudinal central region 8e to be easily torn without causing transverse tears or other damage. For example, each sealing portion S located in the vertical central region 8e is set to a uniform sealing strength for both the inner region S11 and the outer region S12. This allows for tearing with a constant force, making tearing feel easier.

[0048] <Method for measuring seal strength> The method for measuring and comparing the sealing strength between the inner region S11 and the outer region S12 of each sealing portion S will be described below. First, a rectangular piece is cut out with a length in the vertical direction X that includes the seal portion S to be measured, and a length in the horizontal direction Y that includes the entire width of the side joint 8. This rectangular piece is then cut along the vertical direction X to obtain two types of measurement samples, one for the outer side and one for the inner side in the horizontal direction Y. The cutting position is such that the seal portion S is divided into two equal parts in the horizontal direction Y. The multiple measurement samples cut out are all made of the same number of layers of thermoplastic sheet 50. Next, the lateral Y-end of each measurement sample is fixed to a Tensilon universal tester (RTC-1210A) manufactured by Orientec Co., Ltd., and the outer casing 5 is peeled from one casing 5 to the other. If it is difficult to fix the end of each measurement sample to the Tensilon, tape or the like is attached to the end to ensure that there is enough length for the Tensilon to fix it. The measurement sample is peeled in the lateral Y direction at a speed of, for example, 10 mm / min, and the peel strength is measured over time. The maximum peel strength measured is then taken as the seal strength of that measurement sample. For the seal portion S provided in the same area, approximately 10 measurement samples are prepared for both the inner and outer sides in the lateral direction Y, and the above-described measurements are performed for each measurement sample. If the maximum peel strength of the inner measurement sample is higher than the maximum peel strength of the outer measurement sample, it is determined that the seal strength of the inner region S11 is higher than the seal strength of the outer region S12.

[0049] Let's give a specific example of the sealing strength of the sealing part S. The sealing strength of the inner region S11 of the outermost sealing portion Sp is preferably 0.5N or more, more preferably 0.7N or more, preferably 5N or less, and more preferably 4N or less, from the viewpoint of preventing peeling during wear and wearing operations. The sealing strength of the outer region S12 of the outermost sealing portion Sp is preferably 0.1N or more, more preferably 0.12N or more, preferably 2N or less, and more preferably 1.8N or less, from the viewpoint of facilitating tearing during disposal. Furthermore, in the outermost seal portion Sp, the ratio of the seal strength of the outer region S12 to the seal strength of the inner region S11 is preferably 10% or more, more preferably 15% or more, preferably 80% or less, and more preferably 70% or less, from the viewpoint of achieving both peel prevention and ease of tearing.

[0050] [Examples of methods for adjusting seal strength] The sealing strength of the seal portion S can be adjusted, for example, by changing conditions such as temperature, pressure, and / or time during the sealing process that forms the seal portion S. Furthermore, the seal strength can also be adjusted by changing the area of ​​the seal portion S, which is the fused portion of the fibers. Furthermore, the sealing strength can also be adjusted by changing the fiber composition of the thermoplastic sheet 50. The following will provide specific examples to illustrate this point.

[0051] (Example of adjustment based on the degree of fiber melting) The seal portion S is a part formed by the fusion of fibers from multiple thermoplastic sheets 50 of the outer casing 5. Therefore, the more thoroughly the fibers are fused together in a given area, the more firmly the fibers adhere to each other after cooling, resulting in a higher seal strength. In this embodiment, the degree of melting of the inner region S11 of the outermost seal portion Sp is higher than the degree of melting of the outer region S12 of the outermost seal portion Sp, and is also higher than the degree of melting of the inner region S11 of other seal portions S located in the waist end region 8c. As a result, the sealing strength of the inner region S11 of the outermost sealing portion Sp is the greatest among the inner region S11 and outer region S12 of each sealing portion S included in the waist end region 8c. Furthermore, by controlling the degree of melting to create differences in seal strength, it becomes possible to finely adjust the seal strength. This allows for smooth changes in seal strength, making it feel easier to tear.

[0052] <Method for calculating the degree of melting in the inner and outer regions> First, the side joint 8 is cut to prepare two types of measurement samples, each containing an XZ cross-section (a cross-section that crosses the seal portion S in the longitudinal direction X) of the inner region S11 and the outer region S12 of the seal portion S. The cut-out measurement samples shall have the same number of layers of thermoplastic sheet 50. After fixing the measurement samples by a known method, the XZ cross-section of the measurement samples is imaged using a scanning electron microscope (SEM) at, for example, 500x magnification. In each image captured, the outer edge of the fibers is detected using image analysis software, and the length of the detected line is calculated as the circumference of the fiber. For each of the inner region S11 and the outer region S12, the average value of the fiber circumference calculated from five or more images is calculated, and this average value is taken as the circumference of the fibers in the seal portion S. The circumferences of the fibers in the inner region S11 and the outer region S12 are compared, and it is determined that the longer the fiber circumference, the lower the degree of melting.

[0053] Figure 5(A) shows an example of an enlarged view of the XZ cross-section of the outer region S12, and Figure 5(B) shows an example of an enlarged view of the XZ cross-section of the inner region S11. The fiber 55 in Figure 5(A) has many irregularities on its outer edge 55a and a long circumference. In other words, the fiber 55 was not melted very much, and the original irregularities of the fiber 55 remain on the outer edge 55a, which is the surface. On the other hand, the fiber 55 in Figure 5(B) has a relatively smooth outer edge 55a and a shorter circumference than the fiber 55 in Figure 5(A). In other words, the fiber 55 has been sufficiently melted, and the irregularities on the outer edge 55a have been smoothed out. In this case, the degree of melting of the fibers 55 in the inner region S11 of Figure 5(B) is determined to be higher than the degree of melting of the fibers 55 in the outer region S12 of Figure 5(A).

[0054] The degree of fiber melting can be adjusted by conditions such as heat, pressure, and / or time during the sealing process. By adjusting the seal strength by the degree of fiber melting, the seal strength can be adjusted without significantly changing the planar shape (e.g., the dimension in the vertical direction X) or thickness of the inner region S11 and the outer region S12. By aligning the planar shapes of the inner region S11 and the outer region S12, each sealed portion S can be torn sequentially at approximately constant intervals during tearing. Therefore, the tearing operation can be performed stably and smoothly, reducing stress on the disposer. Furthermore, the degree of fiber melting can be changed without changing the fiber composition of the thermoplastic sheet 50 in each of the inner region S11 and outer region S12. This makes it possible to adjust the seal strength relatively easily and accurately.

[0055] The ratio of the circumference of the fibers in the sealing portion S of the outer region S12 to the circumference of the fibers in the sealing portion S of the inner region S11 is preferably 105% or more, more preferably 110% or more, preferably 300% or less, and more preferably 200% or less.

[0056] (Example of adjusting the thickness of the seal) Generally, by compressing the stacked thermoplastic sheets 50 in the thickness direction Z during the sealing process, the molten fibers are strongly compressed, thereby increasing the sealing strength of the sealed portion S. In other words, the thinner the sealing portion S, the higher the sealing strength. On the other hand, the seal strength may differ drastically between thin and thick areas. For example, if the inner region S11 is thin and the outer region S12 is thick, the force required to peel off the inner region S11 may become extremely large. In this case, an excessive tearing force F may act on the outer region S12 immediately after peeling off the inner region S11, causing force in an unintended direction and potentially resulting in lateral tearing or other damage.

[0057] In this embodiment, of the seal portions S located in the waist end region 8c, at least the outermost seal portion Sp is set so that the thickness of the inner region S11 and the thickness of the outer region S12 are approximately the same. In this case, by adjusting, for example, the degree of melting as described above, it is possible to make the thickness of the inner region S11 and the outer region S12 roughly the same while making the seal strength different. This prevents situations where the difference in seal strength between the inner region S11 and the outer region S12 becomes extremely large, and makes it possible to prevent the occurrence of lateral cracks and the like. In this disclosure, "thicknesses are approximately the same" means "substantially the same." For example, if the thickness of one is within ±20% of the thickness of the other, the thicknesses will be considered approximately the same.

[0058] <Method for measuring the thickness of the inner and outer regions> Two types of measurement samples are prepared, each containing an XZ cross-section (a cross-section traversing the seal portion S in the longitudinal direction X) of the inner region S11 and the outer region S12 of the seal portion S. Multiple cut-out measurement samples are made up of the same number of layers of thermoplastic sheet 50. After fixing the measurement samples by a known method, the XZ cross-section of the measurement samples is imaged using an SEM or the like, magnified, for example, 500 times. Then, as shown in Figure 4, the concave portion in the captured image is defined as the seal portion S (outer region S12 or inner region S11). Using image analysis software, the thickness Ds (see Figure 4) in the thickness direction Z of the portion that divides the seal portion S in the width direction (longitudinal direction X) is calculated as the thickness of the seal portion S. For each of the inner region S11 and outer region S12, the average value of the thickness calculated from five or more images is calculated, and this average value is taken as the thickness of the inner region S11 and outer region S12 of the seal portion S.

[0059] [Example of seal strength in the inner region] As described above, the inner region S11 is the part that is torn before the outer region S12 at the start of the tearing operation. Also, even when the tearing force is approximately parallel to the longitudinal direction X, the force acts more easily on the inner region S11 than on the outer region S12. Therefore, by controlling the seal strength of the inner region S11, it is possible to control, for example, the force applied by the user during the tearing operation. The following describes the seal strength set in each inner region S11 of the multiple seal portions S provided in the side joint 8. Here, as in Figure 3, we will describe a configuration assuming tearing from the waist end 8a, but the description regarding the waist end 8a can be read as a description regarding the leg end 8b.

[0060] For example, the sealing strength of the inner region S11 of the sealing portion S may be set to decrease as it approaches a predetermined position in the longitudinal central region 8e from the waist end 8a. Here, the predetermined position in the longitudinal central region 8e is, for example, the central position in the longitudinal direction X within the longitudinal central region 8e, but is not limited to this. For example, positions such as 30 mm, 40 mm, 50 mm, 60 mm, 70 mm, etc., in the longitudinal direction X from the waist end 8a (or leg end 8b) may be set as predetermined positions.

[0061] In this case, the sealing strength of the inner region S11 is highest at the outermost sealing portion Sp and decreases as it approaches the predetermined position. The sealing strength may be configured to decrease linearly, or it may decrease so as to converge to a constant value. As a result, during the tearing operation, the sealing strength of the inner region S11, which is prone to force, changes continuously (smoothly) toward the predetermined position. This prevents situations such as force being applied in an unintended direction during the tearing operation, and allows the diaper 1 to be easily torn without causing lateral tears or the like.

[0062] Specifically, the degree of melting in the inner region S11 of the seal portion S is set to decrease as it approaches a predetermined position in the longitudinal central region 8e from the waist end 8a. By controlling the degree of melting of the fibers in this way, the seal strength on the transverse Y side changes more smoothly. This makes it possible to sufficiently avoid tearing during tearing operations and improve ease of tearing.

[0063] The sealing strength of the outer region S12 may be set to match the sealing strength of the inner region S11. For example, if the ratio of the sealing strength of the outer region S12 to that of the inner region S11 is predetermined, the sealing strength of the outer region S12 will be set appropriately according to that ratio. Alternatively, the sealing strength of the outer region S12 may be set to a constant value. In this case, it is typically set to a lower sealing strength than that of the corresponding inner region S11. The method for setting the sealing strength of the outer region S12 is not limited to these methods. The sealing strength of the inner region S11 and outer region S12 of each sealing portion S can be measured according to the procedure described in the "Method for Measuring Sealing Strength" section above.

[0064] [Example of seal placement] Here, we will explain an example of the arrangement of each seal portion S, using the case where the size of each seal portion S provided in the side joint portion 8 (width in the vertical direction X and the horizontal direction Y) is constant, as shown in Figure 3. (Example of arrangement of the inner end portion in the outermost seal portion Sp and the boundary seal portion Sq) In this embodiment, the position of the inner end Sc of the outermost seal portion Sp is set to be 0.7 mm to 5 mm inward in the lateral direction Y from the position of the inner end Sc of the boundary seal portion Sq. In this case, for example, if the seal portion S is torn from the waist end region 8c to the longitudinal central region 8e, the position of the seal portion will move by about 25 mm in the longitudinal direction X, but will only change by about 5 mm at most in the lateral direction Y. In this way, the position of each seal portion S on the inside of the lateral direction Y does not change drastically. This makes it possible to avoid the occurrence of lateral tears and other damage while minimizing any discomfort when peeling it off.

[0065] Furthermore, at the start of tearing, force is often applied by pinching the inside of the waist end region 8c in the lateral direction Y with the fingers. On the other hand, when tearing in the subsequent longitudinal direction X, the fingers are often moved near the area to be torn while tearing. It is preferable that this finger movement follows the longitudinal direction X to minimize unnecessary movement (in the lateral direction Y). From this viewpoint as well, by positioning the inner ends of the outermost seal portion Sp and the boundary seal portion Sq within the above-described range, a side joint 8 can be provided that is easy to tear overall.

[0066] Furthermore, the amount of displacement in the lateral direction Y of the central positions of the multiple sealing parts S is set within the range of 5 mm to 15 mm. Here, "amount of displacement in the lateral direction Y of the central positions of the multiple sealing parts S" refers to the relative shift amount in the lateral direction Y of the central positions of each sealing part S. For example, when comparing the sealing part S whose central position is furthest inward in the lateral direction Y (for example, the outermost sealing part Sp in Figure 3) with the sealing part S whose central position is furthest outward in the lateral direction Y (for example, the sealing part S closest to the leg end 8b in Figure 3), the distance (amount of displacement) of the central positions in the lateral direction Y is set within the range described above. As a result, the position in the lateral direction Y does not change drastically throughout the entire side joint 8, making it possible to avoid the occurrence of lateral tears and other damage while sufficiently minimizing any discomfort when peeling it off.

[0067] [Example dimensions for the seal portion] The dimensions of the sealing portion S are as follows, taking into consideration both preventing peeling during wear and ease of tearing. Note that the following dimensions are measured in the natural state when the elastic member is not stretched. The lateral dimension Y of the seal portion S (maximum dimension) is preferably 0.5 mm or more, more preferably 1 mm or more, and also preferably 10 mm or less, more preferably 4 mm or less. The vertical dimension (maximum dimension) of the seal portion S is preferably 0.1 m or more, more preferably 0.3 mm or more, and also preferably 2 mm or less, more preferably 0.6 mm or less. The pitch of the sealing portion S in the vertical direction X is preferably 1.5 mm or more, more preferably 2 mm or more, and also preferably 5.0 mm or less, more preferably 4 mm or less. The pitch in the vertical direction X of multiple seal portions S refers to the distance in the vertical direction X between lines that divide each seal portion S in the vertical direction X for adjacent seal portions S in the vertical direction X. If this pitch is not constant, the pitch in the vertical direction X is measured at five locations and the average value is taken as the pitch in the vertical direction X.

[0068] [Example of fusion inhibitor placement] The local peel strength of the seal portion S can also be adjusted by placing a melt inhibitor between the thermoplastic sheets 50 to inhibit the melting of the resin. For example, by placing a linear melt inhibitor so as to intersect with the seal portion S, a locally easily tearable area can be created in the seal portion S.

[0069] From this viewpoint, as shown in Figure 6, it is preferable that the waist end region 8c and / or leg end region 8d, where multiple seal portions S are arranged, have a fusion inhibitor 9 provided linearly between the thermoplastic sheets 50. In this case, it is preferable that at least the seal portion S on the longitudinal X end side, excluding the seal portion S on the longest longitudinal X end, each constitute a cross seal portion having an intersection 9s that intersects with the fusion inhibitor 9. By ensuring that the seal portion S closest to the vertical X end does not overlap with the fusion inhibitor 9, it becomes less likely for a point of peeling to form at the vertical X end during wear and during the wearing process. On the other hand, as the multiple seal portions S on the central side of the vertical X intersect with the linear fusion inhibitor 9, the intersection 9s becomes the starting point for tearing when the diaper 1 is disposed of, resulting in a side joint 8 that is easier to tear.

[0070] The fusion inhibitor 9 is placed, for example, between the thermoplastic sheets 50 of the outer casing 5 before the sealing step for forming the seal portion S. The fusion inhibitor 9 can be any substance that can suppress the effects of heat applied during the sealing process, without any particular limitations. Examples of such substances include hot melt adhesives, polyurethane-based materials, and petroleum-based resins. In addition to reducing the heat generated during the sealing process, the fusion inhibitor 9 is preferably a hot-melt adhesive from the viewpoint of joining sheets together. As the hot-melt adhesive, for example, styrene-based (SIS, SBS, SEBS) or polyolefin-based materials can be used. The method for applying the fusion inhibitor 9 can be any commonly used method without particular limitations, but a method of coating the fusion inhibitor 9 using a coater gun is preferred. This allows for easy control of the coating shape and basis weight of the fusion inhibitor 9.

[0071] The fusion inhibitor 9 may be placed between the thermoplastic sheets 50 included in the ventral region 5a, or between the thermoplastic sheets 50 included in the dorsal region 5b. Alternatively, the fusion inhibitor 9 may be placed between the thermoplastic sheets 50 closest to the skin in the ventral region 5a and the thermoplastic sheets 50 closest to the skin in the dorsal region 5b, which face each other at the side joint 8. "The fusion inhibitor 9 extends linearly" means that, in a plan view, the fusion inhibitor 9 extends in a straight line and / or curved line. Since the fusion inhibitor 9 crosses the intersecting seal portion in the longitudinal direction X, it extends in a direction that includes the component of the longitudinal direction X.

[0072] In the example shown in Figure 6, each seal portion S is arranged in the waist end region 8c such that it intersects with the fusion inhibitor 9, excluding at least the outermost seal portion Sp. Here, the second, third, and fourth seal portions S from the top of the figure become the intersecting seal portions St1, St2, and St3, respectively. However, it is not limited to this; for example, only the second and third seal portions S (intersecting seal portions St1 and St2) may intersect with the fusion inhibitor 9, or the fifth and subsequent seal portions S may intersect with the fusion inhibitor 9.

[0073] The intersection 9s refers to the portion of the intersecting seal portions St1, St2, and St3 that intersects with the fusion inhibitor 9 in a plan view. In the intersecting seal portions St1, St2, and St3, if the end on the waist end 8a side that extends in the lateral direction Y is called the upper end Sa, and the end on the leg end 8b side that extends in the lateral direction Y is called the lower end Sb, then the intersecting portion 9s is formed linearly from the lower end Sb to the upper end Sa. It is preferable that there is only one intersection 9s in each of the intersecting seal portions St1, St2, and St3. Furthermore, it is even more preferable that in the side joint portion 8, one fusion inhibitor 9 intersects with multiple intersecting seal portions St1, St2, and St3 at one location each.

[0074] (Example of fusion inhibitor placement in a plan view) From the viewpoint of reducing local delamination strength and inducing tearing by the fusion inhibitor 9, the side joint 8 can adopt the following configuration. The cross seal portion located closest to the longitudinal X end (waist end 8a in Figure 6) constitutes the first cross seal portion St1. The cross seal portion adjacent to the first cross seal portion St1 constitutes the second cross seal portion St2. It is preferable that these first cross seal portion St1 and second cross seal portion St2 intersect with the fusion inhibitor 9 at positions other than the outer end Sd and inner end Sc on both sides of the lateral Y direction. Furthermore, it is preferable that the first cross seal portion St1 and second cross seal portion St2 are located in the waist end region 8c and / or the leg end region 8d. This facilitates the tearing operation at the longitudinal X end (waist end 8a and / or leg end 8b).

[0075] Furthermore, from the viewpoint of improving ease of tearing in the longitudinal direction X, it is preferable that the multiple sealing portions S have 3 or more n intersecting sealing portions St1, St2, ..., Stn, including a first intersecting sealing portion St1 and a second intersecting sealing portion St2. In the example shown in Figure 6, the multiple sealing portions S include a first intersecting sealing portion St1, a second intersecting sealing portion St2, and a third intersecting sealing portion St3. In the following explanation, each intersecting seal section St1, St2, ... will also be referred to as Stn, where n is an integer greater than or equal to 2.

[0076] Furthermore, from the viewpoint of further improving tearability, it is preferable that the intersecting seal portion Stn intersects with the fusion inhibitor 9 at positions other than the outer end Sd and inner end Sc on both sides in the lateral direction Y, and that the crossing distance a(n) between the inner end Sc and the intersecting portion 9s is provided to decrease monotonically from the end side in the longitudinal direction X towards the center side in the longitudinal direction X. Here, the intersection distance a(n) is defined as the distance in the lateral direction Y from, for example, the inner end Sc of the outermost seal portion Sp to the innermost point in the lateral direction Y of the intersection portion 9s. Monotonically decreasing means that the relationship a(n) is longer than the intersection distance a(n-1). In other words, in the above configuration, when n is an integer greater than or equal to 2, the following equation (1) holds true. a(n) > a(n-1) …(1) For example, in the example shown in Figure 6, the intersection distances a1, a2, and a3 of the first intersection seal section St1, the second intersection seal section St2, and the third intersection seal section St3 satisfy the following relationship. a1>a2>a3

[0077] Thus, the intersection 9s, which acts as a tear-inducing section, is positioned on the outward side in the lateral direction (Y) at the vertical X end, where force is easily applied during wear and wearing movements. As a result, less force is applied to the intersection 9s, which is relatively prone to peeling, at the vertical X end. Therefore, the occurrence of a peeling initiation point can be avoided. Furthermore, the intersection 9s is positioned further inward in the horizontal direction (Y) as it approaches the center in the vertical direction (X). This allows the sealing portion S on the central side in the vertical direction (X) to be smoothly peeled off after the tearing operation has started and the sealing portion Sp at the outermost end has been removed, guided by the intersection 9s. This makes it possible to create a side joint 8 that is less likely to tear during wear or movement while being worn, and that can be easily torn.

[0078] Furthermore, from the viewpoint of achieving a more stable tearing operation, it is preferable that the width of the intersection 9s of the multiple intersecting seal portions St1 and St2 in the lateral direction Y is substantially the same, as shown in Figure 6. In the example shown in Figure 6, the width b1 in the lateral direction Y of the intersection 9s between the first cross seal portion St1 and the fusion inhibitor 9 is substantially the same as the width b2 in the lateral direction Y of the intersection 9s between the second cross seal portion St2 and the fusion inhibitor 9.

[0079] The widths b1 and b2 of each intersection 9s in the lateral direction Y can be, for example, the average of the width of the intersection 9s at the upper end Sa and the width of the intersection 9s at the lower end Sb in the lateral direction Y. Alternatively, the widths b1 and b2 may be the widths b1 and b2 of each intersection 9s at the center position in the vertical direction X of each seal portion S. The above widths being "substantially identical" means that the width of each intersection 9s is 150% or less of the smallest width of all intersections 9s, when that smallest width is taken as 100%. In the above configuration, variations in the widths b1 and b2 of the intersection 9s can be suppressed, and variations in the peel strength of each intersection seal St1 and St2 can be suppressed. This prevents the person disposing of the pants-type absorbent article from feeling discomfort during the tearing process. Therefore, it is possible to prevent problems such as the outer casing 5 tearing due to the person disposing of the article applying excessively strong tearing force. Furthermore, by stabilizing the widths b1 and b2 of the intersection portion 9s, a significant decrease in the sealing strength of the intersection seal portions St1 and St2 can be suppressed, and peeling of the side joint portion 8 during the wearing operation and while wearing can be more reliably prevented.

[0080] Specifically, the width of the intersection portion 9s in the lateral direction Y is preferably 5% or more, more preferably 10% or more, preferably 60% or less, and more preferably 50% or less, relative to the length of the intersection seal portion Stk in the lateral direction Y. The width of the intersection 9s in the lateral direction Y is preferably 0.1 mm or more, more preferably 0.2 mm or more, preferably 1.5 mm or less, and more preferably 1.2 mm or less. The dimensions of the intersection 9s and the intersection seal Stk shall be measured in the maximum extended state.

[0081] Furthermore, as shown in Figures 7(A) and (B), the fusion inhibitor 9 is preferably configured in a curved shape. In this case, for example, the fusion inhibitor 9 is preferably configured in at least a part of a spiral or wavy curve. For example, the fusion inhibitor 9 may extend inward in the lateral direction Y of the side joint 8 as a whole, and it is preferable that its overall planar shape is spiral or wavy curved. Furthermore, it is preferable that at least a part of the spiral or wavy curve of the fusion inhibitor 9 is positioned on the side joint 8 so as to satisfy the above formula (1), etc.

[0082] The spiral or wavy curve forming the fusion inhibitor 9 has a shape in which multiple unit shapes 9a and 9b are repeatedly arranged in one direction. Figure 7(A) shows an example where the curve of the fusion inhibitor 9 is spiral-shaped. Here, spiral shape means a shape in which multiple unit shapes 9a, each being a circular or nearly elliptical shape, are repeatedly arranged along one direction. In Figure 7(A), nearly elliptical unit shapes 9a are repeatedly arranged in the lateral direction Y. In Figure 7(A), each unit shape 9a is formed as a closed ring, but a part of one unit shape 9a may be connected to an adjacent unit shape 9a, and multiple unit shapes 9a may be formed continuously. Figure 7(B) shows an example where the curve of the fusion inhibitor 9 is wavy. Wavy means a shape in which multiple unit shapes 9b, each convex and undulating in one direction and the opposite direction, are repeatedly arranged along other directions.

[0083] The fusion inhibitor 9 is configured in the curved shape described above, which allows for smooth tearing and prevents localized concentration of tearing force. This suppresses any discomfort that may occur during the tearing of the side joint 8, preventing the discarder from applying excessively strong tearing force and causing the outer casing 5 to tear.

[0084] Furthermore, it is preferable that the spiral or wavy curve of the fusion inhibitor 9 extends along the lateral direction Y. In other words, it is preferable that the plurality of unit shapes 9a and 9b are arranged along the lateral direction Y in the curve. This makes it possible to realize a fusion inhibitor 9 having a smooth curved shape.

[0085] In this case, it is preferable that the vertical dimension X of the above-mentioned unit shapes 9a and 9b is larger than the horizontal dimension Y. The dimensions of these unit shapes 9a and 9b are those of unit shapes 9a and 9b that overlap at least a portion of the side joint 8, or the dimensions of unit shapes 9a and 9b adjacent to them. Furthermore, the vertical dimension X refers to the maximum vertical dimension X of the unit shapes 9a and 9b, and the horizontal dimension Y refers to the maximum horizontal dimension Y of the unit shapes 9a and 9b. For example, in the spiral curve shown in Figure 7(A), the vertical dimension c1 of the unit shape 9a is larger than the horizontal dimension c2. Similarly, in the wavy curve shown in Figure 7(B), for example, the vertical dimension d1 of the unit shape 9b in the X direction is greater than the horizontal dimension d2 in the Y direction. As a result, the unit shapes 9a and 9b become elongated in the longitudinal direction X, making it easier to induce tearing in the longitudinal direction X and further improving the ease of tearing.

[0086] (Example of arrangement of fusion inhibitors in the thickness direction) In order to efficiently exert the fusion inhibitory effect of the fusion inhibitor 9, it is more preferable to place it near the interface to be joined. From this perspective, as shown in Figure 8, it is preferable that the fusion inhibitor 9 be placed between the skin-side sheet P of the thermoplastic sheet 50 and the adjacent sheet Q next to it. The skin-facing sheet P is a thermoplastic sheet 50 that constitutes the skin-facing surface of the outer casing 5 in at least one of the waist end region 8c and / or leg end region 8d. The adjacent sheet Q is a thermoplastic sheet 50 adjacent to the skin-side sheet P in the thickness direction Z. At the side joint 8, the skin-side sheet P of the ventral region 5a and the skin-side sheet P of the dorsal region 5b are in contact and sealed while facing each other. In the above configuration, the fusion inhibitor 9 is placed near the joint interface, so the fusion inhibitor 9 can easily exert its fusion-inhibiting effect between the ventral region 5a and the dorsal region 5b. Therefore, the peel strength of the intersection 9s can be effectively reduced, and the ease of tearing can be further improved.

[0087] In the example shown in Figure 8, the skin-side sheet P is composed of the inner layer sheet 52 of the outer casing 5. The adjacent sheet Q is composed of the outer layer sheet 51 of the outer casing 5. Note that in the cross-sectional view of Figure 8, the ventral region 5a and the dorsal region 5b of the side joint 8 are shown separated for illustrative purposes. In the example shown in Figure 8, the fusion inhibitor 9 is located in the ventral region 5a, but it may also be located in the dorsal region 5b, or in both the ventral region 5a and the dorsal region 5b.

[0088] From the viewpoint of further improving tearability, it is preferable that the penetration depth of the fusion inhibitor 9 in the skin-side sheet P is deeper than the penetration depth of the fusion inhibitor 9 in the adjacent sheet Q. Penetration depth refers to the depth to which the fusion inhibitor 9 penetrates from the coated surface in the direction of the sheet thickness. This makes it easier for the fusion inhibitor 9 to migrate from the non-skin-facing surface of the skin-side sheet P to the skin-facing surface that forms the bonding interface, allowing the fusion inhibitory effect of the fusion inhibitor 9 to be exerted more effectively. Therefore, tearability can be more effectively improved.

[0089] <Method for measuring the penetration depth of fusion inhibitors> The side joint 8 to be measured is cut in the vertical X direction and the horizontal Y direction to create a measurement piece in which the cross-section of the fusion inhibitor 9 is exposed. Next, a magnified image of the cross-section of the side joint 8 in the measurement piece is taken at a magnification of 200x using a KEYENCE VHX1000 microscope to obtain an image of the field of view. In the field of view, the area into which the fusion inhibitor 9 has permeated is observed as a transparent, luminous area, so the outline of that area is identified, and the area of ​​the region enclosed by the outline is measured. This measurement is performed at five locations in the waist end region 8c and / or leg end region 8d to be measured, and the average value of these measurements is taken as the penetration depth of the fusion inhibitor 9 in that end region.

[0090] [Example of elastic member configuration] As shown in Figure 2, multiple elastic members 10 extending in the lateral direction Y are arranged in the ventral region 5a and the dorsal region 5b of the outer casing 5, respectively. Specifically, the multiple elastic members 10 are arranged between multiple thermoplastic sheets 50 of the outer casing 5 (see Figure 8). These elastic members 10 provide elasticity to the waist of the diaper 1, making it easier to put on and maintaining a good fit when worn. Furthermore, "the elastic member 10 extends in the lateral direction Y" means that the elastic member 10 extends in the lateral direction Y when unfolded and extended. However, the above expression is not limited to the elastic member 10 being parallel to the lateral direction Y when unfolded and extended, but also includes the configuration in which the entire unit extends in the lateral direction Y. Furthermore, as shown in Figure 2, the exterior body 5 may include, in addition to the elastic member 10, a leg elastic member 11 arranged around the leg opening 1L.

[0091] The elastic members 10 and 11 can preferably be thread-like (e.g., elastic thread) or string-like (e.g., flat elastic) with a rectangular, square, circular, or polygonal cross-section, or multifilament-type thread-like material. The material of the elastic members 10 and 11 can be any material conventionally used for absorbent articles such as disposable diapers, and is not particularly limited. Examples include synthetic rubber such as styrene-butadiene, butadiene, isoprene, and neoprene, natural rubber, EVA, stretchable polyolefin, and polyurethane.

[0092] From the viewpoint of ensuring the overall elasticity of the girth, it is preferable that the outer ends of the elastic members 10 in the lateral direction Y of the ventral region 5a and the dorsal region 5b are located at or near the side joint 8. Specifically, it is preferable that the distance of such ends from the side joint 8 in the lateral direction Y is 10 mm or less, and it is more preferable that the distance is 0 mm and the ends are located within the side joint 8. The elastic member 10 is generally positioned in or near the region where force is applied during tearing, and can easily affect the ease of tearing of the side joint 8. Therefore, from the viewpoint of improving the ease of tearing during disposal, it is preferable to adjust the elongation rate of the elastic member as follows.

[0093] In the example shown in Figure 3, the elastic elongation rate of the multiple elastic members 10 located in the waist end region 8c is set lower than the elastic elongation rate of the multiple elastic members 10 located in the longitudinal central region 8e. Here, the elastic elongation rate is the average elongation rate obtained by averaging the elongation rates of each elastic member 10 located in the waist end region 8c (or the longitudinal central region 8e).

[0094] The elongation rate of the elastic member 10 refers to the ratio of the length of the elastic member when the pants-type absorbent article is unfolded and stretched to the length of the elastic member 10 when it is removed from the pants-type absorbent article at its natural length. In other words, the lower the elongation rate, the smaller the elastic force tends to be when the elastic member 10 is stretched. The elongation rate of the elastic member 10 can be adjusted during manufacturing by adjusting the degree of elongation of the elastic member 10 placed on the outer casing 5. During manufacturing, for example, the elastic member 10 is stretched to a predetermined length, adhesive is applied to the elastic member 10 using a comb or the like, and the elastic member 10 is fixed to the thermoplastic sheet 50 of the outer casing 5.

[0095] As described above, a lateral force Y may be directly applied to the waist end region 8c during the tearing operation. In the above configuration, the average elongation rate of the elastic member 10 in the waist end region 8c is low, which reduces the elastic force of the elastic member 10 that acts as a resistance to the tearing force. As a result, the energy related to the tearing force is less likely to be consumed by the elongation of the elastic member 10, and the waist end region 8c can be torn efficiently even with a weaker force. This enables a stable tearing operation and prevents problems such as tearing of the outer casing 5 due to excessive tearing force. Furthermore, the average elongation rate of the elastic member 10 is relatively high in the vertical central region 8e. Therefore, even if the average elongation rate of the elastic member 10 in the waist end region 8c is set to be somewhat lower, the diaper 1 can still be fitted sufficiently around the waist.

[0096] In addition, the elastic body elongation rate may be similarly set in the leg end region 8d. That is, the elastic body elongation rate of the multiple elastic members 10 arranged in the leg end region 8d is set lower than the elastic body elongation rate of the multiple elastic members 10 arranged in the longitudinal central region 8e. This makes it possible to significantly improve the ease of tearing from the leg end 8b side.

[0097] <Method for measuring the average elongation rate of elastic members> The side joints 8 of the pant-type absorbent article are separated to remove the absorbent body 4, and the ventral region 5a and dorsal region 5b of the outer casing 5 are cut out. Furthermore, the waist end 8a (waist opening end Wa) and / or leg end 8b of the ventral region 5a and dorsal region 5b are cut 25 mm in the longitudinal direction X, parallel to the transverse direction Y, to separate the waist end region 8c (or leg end region 8d) and the longitudinal central region 8e. Then, the length of the elastic member 10 in each cut-out region of the pant-type absorbent article is measured in its unfolded and stretched state. From these measurements, the average length of all elastic members 10 in the maximum stretched state in each region 8c, 8d, and 8e is calculated. All elastic members 10 fixed to each region 8c, 8d, and 8e with adhesive or the like are removed from the other components of the exterior body 5 using a suitable solvent such as ethyl acetate, and the natural length of the elastic members 10 in each region 8c, 8d, and 8e is measured. From these measurements, the average value of the natural length of all elastic members 10 in each region 8c, 8d, and 8e is calculated. Then, in each region 8c, 8d, and 8e, the ratio of the average length of the elastic member 10 in the unfolded and stretched state to the average length of the elastic member 10 in the natural length is calculated, and this is taken as the average elongation rate of the elastic member 10 in each region 8c, 8d, and 8e.

[0098] The average elongation rate of the multiple elastic members 10 in the waist end region 8c (or leg end region 8d) is preferably 120% or more, more preferably 130% or more, preferably 500% or less, and more preferably 450% or less. The average elongation rate of the multiple elastic members 10 in the vertical central region 8e is preferably 150% or more, more preferably 180% or more, preferably 550% or less, and more preferably 500% or less. From the viewpoint of effectively obtaining the above effects, the ratio of the average elongation rate of the multiple elastic members 10 in the waist end region 8c (or leg end region 8d) to the average elongation rate of the multiple elastic members 10 in the vertical central region 8e is preferably 20% or more, more preferably 30% or more, preferably 90% or less, and more preferably 80% or less.

[0099] [Example of exterior structure] As shown in Figure 8, the exterior body 5 preferably includes a plurality of thermoplastic sheets 50, such as an outer layer sheet 51 and an inner layer sheet 52. The outer layer sheet 51 is positioned on the non-skin side of the inner layer sheet 52 and forms the non-skin facing surface of the exterior body 5. An elastic member 10 is positioned between the inner layer sheet 52 and the outer layer sheet 51. In this embodiment, the outer casing 5 has a folded structure because at least a portion of it is folded back towards the skin from the waist opening end Wa. In the example shown in Figure 8, only the outer layer sheet 51 is folded back towards the skin from the waist end 8a.

[0100] In this embodiment, as shown in Figure 8, due to the folded structure of the outer casing 5, the side joint portion 8 has multiple regions with different numbers of layers of thermoplastic sheet 50. In other words, in this embodiment, the side joint 8 has a first laminated section T1 in which six or more thermoplastic sheets 50 are laminated, and a second laminated section T2 in which fewer thermoplastic sheets 50 than the first laminated section T1 are laminated. In this embodiment, the first laminated section T1 corresponds to the area in which the outer casing 5 is folded over. The first laminated section T1 includes a first skin-side sheet P1 which constitutes the skin-facing surface as a thermoplastic sheet 50. The second laminated section T2 includes a second skin-side sheet P2 which constitutes the skin-facing surface as a thermoplastic sheet 50.

[0101] In the example shown in Figure 8, the first laminated section T1 of the ventral region 5a is composed of three layers: an unfolded outer sheet 51, an unfolded inner sheet 52, and a folded outer sheet 51. The first laminated section T1 of the dorsal region 5b is also composed of three layers in the same manner. Thus, the first laminated section T1 is composed of a total of six layers. In the first laminated section T1, the first skin-side sheet P1 is composed of a folded outer sheet 51. In the example shown in Figure 8, the second laminated section T2 of the ventral region 5a is composed of two layers: an unfolded outer sheet 51 and an unfolded inner sheet 52. The second laminated section T2 of the dorsal region 5b is also composed of two similar layers. Thus, the second laminated section T2 is composed of a total of four layers. In the second laminated section T2, the second skin-side sheet P2 is composed of an unfolded inner sheet 52.

[0102] In the example shown in Figure 8, the waist end region 8c on the waist end 8a side is located in the first laminated section T1. The leg end region 8d on the leg end 8b side is located in the second laminated section T2. ​​The vertical central region 8e between the waist end region 8c and the leg end region 8d is located from the first laminated section T1 to the second laminated section T2. ​​Alternatively, the leg end region 8d may be placed in the first laminated section T1, which has more layers, by adjusting the folding position as appropriate, or the waist end region 8c may be placed in the second laminated section T2, which has fewer layers.

[0103] The first laminated section T1 has more layers of thermoplastic sheets 50 than the second laminated section T2, and therefore contains a larger amount of thermoplastic resin. As a result, the first laminated section T1 contains a larger amount of resin that is heat-fused than the second laminated section T2, and the sealing strength of the seal section S tends to be higher. Therefore, by adjusting the arrangement of the sealing portion S of the first laminated portion T1 and the second laminated portion T2, the bonding strength between the first laminated portion T1 and the second laminated portion T2 can be adjusted, thereby improving tear stability.

[0104] [Examples of the configuration of the skin-side sheet in the first and second laminated sections] From the viewpoint of adjusting the bonding strength between the first laminated section T1 and the second laminated section T2 and improving tear stability, the first and second skin-side sheets P1 and P2 may be made of different configurations.

[0105] (Placement of embossed areas on the skin-facing sheet) In this embodiment, the first skin-side sheet P1 and the second skin-side sheet P2 may each be composed of a spunbond nonwoven fabric containing multiple embossings. The embossing on spunbond nonwoven fabric is a region where fibers are compressed and fused together. Embossing can be formed intermittently by thermal compression using, for example, an embossing convex roll and a flat roll; by ultrasonic fusion; or by intermittent application of hot air for partial fusion. From the viewpoint of high productivity and low equipment costs, embossing formed by thermal compression is preferred. The planar shape of the emboss can be any shape, such as a circle, an ellipse, a polygon, or a shape similar thereto. While it is preferable that the emboss be formed in a consistent pattern, it may also be formed in a random pattern. In embossing, the fibers are easily broken by the heat treatment and / or processing during formation, so if it overlaps with the embossing of the seal portion S, the seal strength may decrease.

[0106] Therefore, it is preferable that the first skin-side sheet P1 and the second skin-side sheet P2 are made of spunbond nonwoven fabrics in which the embossing area ratio, that is, the ratio of the total area of ​​the region occupied by multiple embossings to the total area of ​​the predetermined region, is different from that of the first skin-side sheet P1. Specifically, it is preferable that the embossing area ratio of the first skin-side sheet P1 is higher than that of the second skin-side sheet P2. The area ratio of embossing in spunbond nonwoven fabric is measured in an area containing a sufficient number of embossing patterns, for example, in a 20mm x 20mm square area of ​​the spunbond nonwoven fabric. The area occupied by each embossing pattern can be recognized as a series of areas where thermal fusion of fibers is observed. The above area ratio measurement should be performed in the unfolded and stretched state.

[0107] As described above, the seal strength may decrease in the seal portion S where the embossing overlaps. Therefore, by increasing the area ratio of the embossing in the first laminated portion T1, which has a large number of layers, the seal portion S and the embossing can overlap more easily in the first laminated portion T1, thereby suppressing an increase in seal strength. This makes it possible to reduce the difference in bonding strength between the first laminated portion T1 and the second laminated portion T2, and to further stabilize the bonding strength of the entire side joint 8. Consequently, the tear stability of the side joint 8 can be improved.

[0108] The area ratio of the embossing on the first skin-side sheet P1 is preferably 5% or more, more preferably 7% or more, preferably 20% or less, and more preferably 17% or less. The embossed area ratio of the second skin-side sheet P2 is preferably 3% or more, more preferably 5% or more, preferably 17% or less, and more preferably 15% or less.

[0109] (Melting point of the skin-facing sheet) As another example, it is preferable that the melting point of the first skin-side sheet P1 is higher than the melting point of the second skin-side sheet P2. Thermoplastic sheets 50 with a high melting point are less likely to thermally fuse when the sealing process is performed under the same conditions compared to thermoplastic sheets 50 with a low melting point, and the seal strength tends to decrease. Therefore, in the first laminated section T1, which has a large number of layers, increasing the melting point of the first skin-side sheet P1 can suppress the increase in the seal strength of the seal portion S of the first laminated section T1. This makes it possible to reduce the difference in bonding strength between the first laminated section T1 and the second laminated section T2, and to further stabilize the bonding strength of the entire side joint 8. Consequently, the ease of tearing the side joint 8 can be improved.

[0110] The melting point of the first skin-side sheet P1 is preferably 125°C or higher, more preferably 155°C or higher, preferably 260°C or lower, and more preferably 250°C or lower. The melting point of the second skin-side sheet P2 is preferably 123°C or higher, more preferably 125°C or higher, preferably 180°C or lower, and more preferably 170°C or lower.

[0111] (Basis weight of the skin-facing sheet) As another example, it is preferable that the basis weight of the first skin-side sheet P1 is lower than the basis weight of the second skin-side sheet P2. In thermoplastic sheets 50 with a high basis weight, the amount of thermoplastic resin is also high, which tends to increase the seal strength of the seal portion S. Therefore, in the first laminated section T1, which has a large number of layers, lowering the basis weight of the first skin-side sheet P1 can suppress the increase in the seal strength of the seal portion S of the first laminated section T1. This reduces the difference in bonding strength between the first laminated section T1 and the second laminated section T2, and further stabilizes the bonding strength of the entire side joint 8. Consequently, the tear stability of the side joint 8 can be improved.

[0112] The basis weight of the first skin-side sheet P1 is preferably 10 g / m². 2 More than 12g / m 2 The above is preferable, preferably 30 g / m² 2 More preferably 25 g / m 2 The following applies: The basis weight of the second skin-side sheet P2 is preferably 12 g / m². 2 More preferably, 14 g / m 2 The above is preferable to 40 g / m². 2 More preferably 30g / m 2 The following applies:

[0113] <Second Embodiment> Next, other embodiments will be described. In the following embodiments, components that are the same as or corresponding to those in the first embodiment described above will be denoted by the same reference numerals and their descriptions will be omitted as appropriate. Furthermore, the absorbent pant-type article (disposable pant-type diaper) of each embodiment can be configured to the extent possible using the configuration described in the first embodiment.

[0114] As explained with reference to Figure 3, at the start of the tearing operation, an outward tearing force F, inclined at 45° with respect to the longitudinal direction X (or transverse direction Y), causes each seal portion S to be peeled off with a line L perpendicular to that direction as the peeling interface. At this time, line L was a straight line along the longitudinal direction X, inclined at 45° outward in the transverse direction Y at the end side of the longitudinal direction X (waist end 8a side in Figure 3).

[0115] In the first embodiment, an example was described in which a plurality of sealing portions S are arranged in the waist end region 8c and / or leg end region 8d, which are longitudinal end regions, so as to overlap with such a line L. However, the arrangement of the sealing portions S is not limited to this example. As shown in Figure 9, in this embodiment, in the waist end region 8c, the seal portion S is configured such that two or more seal portions S do not overlap a line (line L) that is a straight line along the vertical direction tilted 45 degrees outward in the horizontal direction Y on the waist end 8a side.

[0116] In the side joint 208 shown in Figure 9, the configuration of the seal portion S in the waist end region 8c differs from that in Figure 3. Note that in Figure 9, the configuration of the seal portions S in the longitudinal central region 8e and the leg end region 8d is the same as that of the side joint 8 shown in Figure 3. Figure 9 also illustrates the inner region S11 and outer region S12 for each seal portion S. Of these, at least at the outermost seal portion Sp, the seal strength of the inner region S11 is set to be higher than that of the outer region S12. Furthermore, at the boundary seal portion Sq, the difference in seal strength between the inner region S11 and the outer region S12 is set to be smaller than that of the outermost seal portion Sp. In addition, the strengths of the inner region S11 and outer region S12 of each seal portion S may be set as appropriate.

[0117] As shown in Figure 9, each seal portion S in the waist end region 8c is set to have a short width in the lateral direction Y and is positioned so as not to overlap with line L. For example, for adjacent seal portions S, each seal portion S is positioned such that line L can be drawn between the lower end of the outer end Sd of the seal portion S closer to the waist end 8a and the upper end of the inner end Sc of the seal portion S further from the waist end 8a, without intersecting the seal portion S. This prevents two seal portions S from overlapping on the same line L.

[0118] This reduces the likelihood of two or more seal portions S simultaneously being peeled off in the waist end region 8c during the tearing operation. Furthermore, it becomes possible to peel off each seal portion S individually. This allows the tearing operation to be performed with relatively weak force. Furthermore, since it is possible to avoid situations where force is applied locally at multiple locations during the tearing process, it is possible to sufficiently prevent the occurrence of lateral tears and other damage.

[0119] Furthermore, the configuration of the side joint 208 shown in Figure 9 may also be applied to the leg end region 8d. That is, in the leg end region 8d, the seal portion S may be configured such that two or more seal portions S do not overlap a line (line L) that is a straight line along the vertical direction tilted 45 degrees outward in the horizontal direction Y on the leg end 8b side. This ensures that even when tearing is performed from the leg end 8b side, the occurrence of lateral tears is sufficiently prevented, and the side joint 208 can be easily torn.

[0120] <Third Embodiment> In the first embodiment, an example was described in which the lateral Y position of the inner end Sc of the seal portion S is shifted laterally Y for each group consisting of two or more seal portions S. However, the arrangement of the seal portions S is not limited to this example, and the arrangement of each seal portion may be set individually. As shown in Figure 10, in this embodiment, the position of the inner end portion Sc of the seal portion S is positioned further outward in the lateral direction Y as it approaches a predetermined position in the vertical central region 8e from the waist end portion 8a.

[0121] In the side joint 308 shown in Figure 10, the arrangement of the seal portions S in the waist end region 8c, the longitudinal central region 8e, and the leg end region 8d differs from that of the side joint 8 shown in Figure 3. The size and pitch of each seal portion S in the longitudinal X and transverse Y directions may be set in the same way as the seal portions S shown in Figure 3. Figure 10 also illustrates the inner region S11 and outer region S12 for each seal portion S. At least at the outermost seal portion Sp, the seal strength of the inner region S11 is set to be higher than that of the outer region S12. Furthermore, at the boundary seal portion Sq, the difference in seal strength between the inner region S11 and the outer region S12 is set to be smaller than that of the outermost seal portion Sp. In addition, the strengths of the inner region S11 and outer region S12 of each seal portion S may be set as appropriate.

[0122] As shown in Figure 10, in the side joint 308, a reference line 7c representing a predetermined position in the vertical direction X is set in the vertical central region 8e. The position of the reference line 7c is set, for example, at the central position in the vertical direction X of the vertical central region 8e. The position of the reference line 7c is not particularly limited as long as it is inside the vertical central region 8e. In this embodiment, the closer the seal portion S is to the reference line 7c from the waist end 8a, the further outward the inner end Sc of the seal portion S is positioned in the lateral direction Y. Similarly, the closer the leg end 8b is to the reference line 7c, the further outward the inner end Sc of the seal portion S is positioned in the lateral direction Y. Thus, in this embodiment, the inner end Sc of the seal portion S closest to the reference line 7c (here, the 7th seal portion S from the top in the figure) is positioned as the outermost of all the seal portions S.

[0123] With this configuration, the position of the inner end portion Sc continuously moves outward in the lateral direction Y. For example, during a tearing operation, multiple seal portions S are less likely to overlap simultaneously with a line L perpendicular to the tearing force F which is inclined at 45°. Therefore, it becomes unnecessary to peel off multiple seal portions S simultaneously, making it possible to perform the tearing operation with a weaker force and effectively preventing the occurrence of lateral tears. Furthermore, the position of the inner end Sc will no longer protrude locally inward or outward in the lateral direction Y. As a result, situations where the force required for tearing changes abruptly during the tearing operation are avoided, and the person disposing of the material can perform the tearing operation without any discomfort. Furthermore, in Figure 10, regardless of whether the view is taken from the waist end 8a or the leg end 8b, the position of the inner end Sc of each seal portion S gradually shifts outward in the lateral direction Y. Therefore, regardless of whether the tearing operation is started from the waist end 8a or the leg end 8b, it is possible to prevent lateral tearing and perform the tearing operation smoothly.

[0124] The method for shifting the position of the inner end Sc of each seal portion S is not limited. For example, an arrangement may be used in which the position of the inner end Sc is linearly shifted outward in the lateral direction Y toward the reference line 7c. Alternatively, the position of each seal portion S may be set so as to asymptotically approach the position of the inner end Sc of the seal portion S closest to the reference line 7c. Furthermore, although Figure 10 illustrates an example where a single reference line 7c is provided, two reference lines may also be set. For example, a reference line on the waist end 8a side and a reference line on the leg end 8b side may be set, and the position of the inner end Sc of the seal portion S is shifted outward in the lateral Y direction from each longitudinal X end to the reference line nearest to each end. In this case, the position of the seal portion S provided between the two reference lines is set to align with the longitudinal X direction, for example. This makes it possible to sufficiently prevent the occurrence of lateral tears, etc., even when the tear force F changes from a state where it is tilted at 45° to a state where it is parallel to the longitudinal X direction.

[0125] <Fourth Embodiment> In the first embodiment, an example was described in which the lateral Y position of the inner end Sc of the seal portion S is shifted laterally Y for each group consisting of two or more seal portions S. However, the arrangement of the seal portions S is not limited to this example, and the arrangement of each seal portion may be set individually. As shown in Figure 11, in this embodiment, the position of the inner end portion Sc of the seal portion is positioned laterally outward as it approaches the leg end portion 8b from the waist end portion 8a.

[0126] In the side joint 408 shown in Figure 11, the arrangement of the seal portions S in the waist end region 8c, the longitudinal central region 8e, and the leg end region 8d differs from that of the side joint 8 shown in Figure 3. The size and pitch of each seal portion S in the longitudinal X and transverse Y directions may be set in the same way as the seal portions S shown in Figure 3. Figure 11 also illustrates the inner region S11 and outer region S12 for each seal portion S. Of these, at least at the outermost seal portion Sp, the seal strength of the inner region S11 is set to be higher than that of the outer region S12. Furthermore, at the boundary seal portion Sq, the difference in seal strength between the inner region S11 and the outer region S12 is set to be smaller than that of the outermost seal portion Sp. In addition, the strengths of the inner region S11 and outer region S12 of each seal portion S may be set as appropriate.

[0127] As shown in Figure 11, in the side joint 408, each seal portion S is positioned such that as you move from the waist end 8a towards the leg end 8b, the position of the inner end Sc of the seal portion S shifts outward in the lateral direction Y. The method for shifting the position of the inner end Sc of each seal portion S is not limited. For example, an arrangement may be used in which the position of the inner end Sc is linearly shifted outward in the lateral direction Y toward the leg end 8b. Alternatively, the position of each seal portion S may be set so as to asymptotically approach the position of the inner end Sc of the seal portion S closest to the leg end 8b.

[0128] With this configuration, for example, if the tearing operation is started from the waist end 8a, the multiple seal portions S are less likely to overlap simultaneously with respect to the line L perpendicular to the tearing force F which is inclined at 45°, as shown in Figure 10. Therefore, it is no longer necessary to peel off multiple seal portions S simultaneously, making it possible to perform the tearing operation with a weaker force and effectively preventing the occurrence of lateral tears. Furthermore, unlike the example shown in Figure 11, the position of the inner end Sc of the seal portion S does not shift inward in the lateral direction Y during the tearing operation. Therefore, the tearing operation can be completed without significantly changing the tearing force F until the end.

[0129] Furthermore, a configuration in which the relationship between the waist end 8a and the leg end 8b is reversed from that shown in Figure 11 may also be adopted. That is, the position of the inner end Sc of the seal portion may be positioned laterally outward as it approaches the waist end 8a from the leg end 8b. This makes it possible to sufficiently prevent the occurrence of lateral tears and improve the ease of the tearing operation, even when the tearing operation is started from the leg end 8b.

[0130] <Other Embodiments> Although embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above, and various modifications can be made without departing from the spirit of the present invention.

[0131] In the embodiments described above, the pair of side joints 8 were described as having the same configuration, but one of the side joints 8 may have a configuration that includes the multiple sealing portions S described above.

[0132] For example, in the above-described embodiment, the outer casing 5 was described as having a ventral region 5a, a dorsal region 5b, and a crotch region 5c, but it is not limited to this. For example, the outer casing 5 may not have a crotch region and may have a configuration in which the ventral region and the dorsal region are separated.

[0133] The absorbent pant-type article according to the present invention does not have to be a disposable diaper for infants; for example, it may be a disposable diaper for adults or children. Furthermore, the absorbent pant-type article according to the present invention does not have to be a disposable diaper, as long as it is an absorbent article of the type worn on the lower body. Examples of such absorbent pant-type articles include sanitary napkins in pant form.

[0134] With regard to the embodiments described above, the present invention further discloses the following pant-type absorbent articles. <1> A pant-type absorbent article comprising: an absorbent body; an outer casing disposed on the non-skin-facing side of the absorbent body and comprising a plurality of thermoplastic sheets laminated together, including a ventral region and a dorsal region located on both sides in the longitudinal direction; and a pair of side joints joining the ventral region and the dorsal region of the outer casing at the transverse side edges perpendicular to the longitudinal direction, The pair of side joints have a waist end, which is the end on the waist side in the longitudinal direction, and / or a leg end, which is the end on the leg side in the longitudinal direction, as longitudinal ends, a longitudinal end region within 25 mm in the longitudinal direction from the longitudinal end, a longitudinal central region adjacent to the longitudinal end region, and a plurality of sealing portions spaced apart along the longitudinal direction. Each of the plurality of sealing portions has an inner region located laterally inward and including an inner end, and an outer region located laterally outward and including an outer end. Of the plurality of sealing portions, the position of the inner end of the outermost sealing portion located closest to the vertical end is positioned laterally inward than the position of the inner end of the sealing portion located in the vertical central region. Of the plurality of sealing portions, at least the sealing portion at the outermost end has a higher sealing strength in the inner region than in the outer region. Of the multiple sealing portions, the sealing portion at the boundary closest to the vertical end region, which is located in the vertical central region, has a smaller difference in sealing strength between the inner region and the outer region than the sealing portion at the outermost end. Absorbent pants. <2> The ratio of the sealing strength of the outer region of the outermost seal portion to the sealing strength of the inner region of the outermost seal portion is 10% or more and 80% or less, preferably 15% or more and 70% or less. <1> Absorbent pant-type articles as described above. <3> The sealing strength of the inner region of the seal portion at the outermost end is 0.5N or more and 5N or less, preferably 0.7N or more and 4N or less. The sealing strength of the outer region of the seal portion at the outermost end is 0.1N or more and 2N or less, preferably 0.12N or more and 1.8N or less. <1> or <2> Absorbent pant-type articles as described above. <4> The sealing strength of the inner region of the sealing portion at the boundary is lower than the sealing strength of the inner region of the sealing portion at the outermost end, The sealing strength of the outer region of the sealing portion at the boundary is lower than the sealing strength of the outer region of the sealing portion at the outermost end. <1> from <3> A pant-type absorbent article described in any one of the following. <5> The degree of melting of the inner region of the outermost seal portion is higher than the degree of melting of the outer region of the outermost seal portion, and also higher than the degree of melting of the inner region of other seal portions located in the longitudinal end region. <1> from <4> A pant-type absorbent article described in any one of the following. <6> Of the sealing portions arranged in the aforementioned vertical end region, at least the sealing portion at the outermost end has a thickness that is substantially the same as the thickness of the inner region and the thickness of the outer region. <1> from <5> A pant-type absorbent article described in any one of the following. <7> The sealing portion located in the vertical central region has substantially the same sealing strength in the inner region and the sealing strength in the outer region. <1> from <6> A pant-type absorbent article described in any one of the following. <8> Multiple elastic members extending in the transverse direction are arranged in the ventral region and the dorsal region, respectively. The elastic elongation rate of the plurality of elastic members arranged in the longitudinal end region is lower than that of the plurality of elastic members arranged in the longitudinal central region. <1> from <7> A pant-type absorbent article described in any one of the following. <9> In the aforementioned vertical end region, the sealing portion is configured such that two or more sealing portions do not overlap a line that is a straight line along the vertical direction tilted 45 degrees outward in the horizontal direction at the vertical end side. <1> from <8> A pant-type absorbent article described in any one of the following. <10> The position of the inner end of the seal portion is positioned further outward in the lateral direction as it approaches the predetermined position in the vertical central region from the vertical end. <1> from <9> A pant-type absorbent article described in any one of the following. <11> The sealing strength of the inner region of the seal decreases as it approaches a predetermined position in the central region of the vertical region from the vertical end. <1> from <10> A pant-type absorbent article described in any one of the following. <12> The degree of melting in the inner region of the seal decreases as it approaches a predetermined position in the central region of the vertical direction from the vertical end. <11> Absorbent pant-type articles as described above. <13> The position of the inner end of the sealing portion is positioned laterally outward as it approaches the leg end from the waist end, or as it approaches the waist end from the leg end. <1> from <9> A pant-type absorbent article described in any one of the following. [Explanation of symbols]

[0135] Sc…Inner end Sd…outer end S11…Inner area S12…outer area 1… Diaper 4… Absorbent body 5…Exterior 5a...ventral region 5b...Dorsal region 5c…Inseam area 8, 208, 308, 408... Side joints 8a... waist end 8b... Leg end 8c...Waist end region 8d... Leg end region 8e...Central area in the vertical direction 9… Fusion inhibitors 10...Elastic member 50… Thermoplastic sheet

Claims

1. A pant-type absorbent article comprising: an absorbent body; an outer casing disposed on the non-skin-facing side of the absorbent body and comprising a plurality of thermoplastic sheets laminated together, including a ventral region and a dorsal region located on both sides in the longitudinal direction; and a pair of side joints joining the ventral region and the dorsal region of the outer casing at the transverse side edges perpendicular to the longitudinal direction, The pair of side joints have a waist end, which is the end on the waist side in the longitudinal direction, and / or a leg end, which is the end on the leg side in the longitudinal direction, as longitudinal ends, a longitudinal end region within 25 mm in the longitudinal direction from the longitudinal end, a longitudinal central region adjacent to the longitudinal end region, and a plurality of sealing portions spaced apart along the longitudinal direction. Each of the plurality of sealing portions has an inner region located laterally inward and including an inner end, and an outer region located laterally outward and including an outer end. Of the plurality of sealing portions, the position of the inner end of the outermost sealing portion located closest to the vertical end is positioned laterally inward than the position of the inner end of the sealing portion located in the vertical central region. Of the plurality of sealing portions, at least the sealing portion at the outermost end has a higher sealing strength in the inner region than in the outer region. Of the plurality of sealing portions, the sealing portion at the boundary closest to the vertical end region, which is located in the vertical central region, has a smaller difference in sealing strength between the inner region and the outer region than the sealing portion at the outermost end. The degree of melting of the inner region of the outermost seal portion is higher than the degree of melting of the outer region of the outermost seal portion, and also higher than the degree of melting of the inner region of other seal portions located in the longitudinal end region. Absorbent pants.

2. The sealing strength of the inner region of the sealing portion at the boundary is lower than the sealing strength of the inner region of the sealing portion at the outermost end, The sealing strength of the outer region of the sealing portion at the boundary is lower than the sealing strength of the outer region of the sealing portion at the outermost end. The pant-type absorbent article according to claim 1.

3. Of the sealing portions arranged in the aforementioned vertical end region, at least the sealing portion at the outermost end has a thickness that is substantially the same as the thickness of the inner region and the thickness of the outer region. The pant-type absorbent article according to claim 1 or 2.

4. The sealing portion located in the vertical central region has substantially the same sealing strength in the inner region and the sealing strength in the outer region. The pant-type absorbent article according to claim 1 or 2.

5. Multiple elastic members extending in the transverse direction are arranged in the ventral region and the dorsal region, respectively. The elastic elongation rate of the plurality of elastic members arranged in the longitudinal end region is lower than that of the plurality of elastic members arranged in the longitudinal central region. The pant-type absorbent article according to claim 1 or 2.

6. In the aforementioned vertical end region, the sealing portion is configured such that two or more sealing portions do not overlap a line that is a straight line along the vertical direction tilted 45 degrees outward in the horizontal direction at the vertical end side. The pant-type absorbent article according to claim 1 or 2.

7. The position of the inner end of the seal portion is positioned further outward in the lateral direction as it approaches the predetermined position in the vertical central region from the vertical end. The pant-type absorbent article according to claim 1 or 2.

8. The sealing strength of the inner region of the seal decreases as it approaches a predetermined position in the central region of the vertical region from the vertical end. The pant-type absorbent article according to claim 1 or 2.

9. The degree of melting in the inner region of the seal decreases as it approaches a predetermined position in the central region of the vertical direction from the vertical end. The pant-type absorbent article according to claim 8.

10. The position of the inner end of the sealing portion is positioned laterally outward as it approaches the leg end from the waist end, or as it approaches the waist end from the leg end. The pant-type absorbent article according to claim 1 or 2.

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