Underpants-type absorbent article

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 pants-type absorbent articles such as disposable diapers. [Background technology]

[0002] A pants-type absorbent article generally includes an absorbent main body, an exterior body, and a side joint portion (side seal portion) that joins the ventral exterior body and the rear exterior body at their side edges. The waist opening and leg openings of the pants-type absorbent article are formed by joining the ventral exterior body and the rear exterior body by the side joint portion. On the other hand, after wearing a pant-type absorbent article, the side joints may be torn off and discarded from the viewpoint of hygiene, etc. For this reason, the side joints are required to have a function that does not come off during the wearing action (when putting on the pant-type absorbent article) or while wearing the article, but can be easily torn off when discarding the article.

[0003] From this perspective, Patent Document 1 discloses a pants-type absorbent article having a seal part that joins the lateral ends of the ventral side part and the rear side part of the exterior body to each other. In this pants-type absorbent article, the seal part includes a plurality of fused parts aligned and spaced apart from each other in the vertical direction, and at least two of the fused parts adjacent to each other each include a relatively thin part and a relatively thick part, and both of these thin parts are located on the lateral inner side of the fused parts.

[0004] Patent Document 2 discloses a pants-type absorbent article having a strength-reduced region where a bond strength reducing agent that reduces the bond strength is disposed at the joints on both side ends of the ventral and dorsal parts of the exterior body, and a non-strength-reduced region where no bond strength reducing agent is disposed. In this document, the joints are disposed continuously in the longitudinal direction, and the strength-reduced region is disposed, for example, on the inner side and / or outer side in the width direction of the joints. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2020-99618 A [Patent Document 1] JP 2011-72577 A Summary of the Invention [Problem to be solved by the invention]

[0006] In the above-mentioned Patent Documents 1 and 2, when joining the ventral side and the rear side of the exterior body, a portion with different joining strength is provided to make the pants-type absorbent article easier to peel off. However, depending on the strength and arrangement of the portion joining the ventral side and the rear side of the exterior body, peeling points may occur or horizontal tears may occur, leaving room for further improvement.

[0007] An object of the present invention is to provide a pants-type absorbent article that is capable of preventing peeling during the putting action and wearing and is also easily tearable when discarded. [Means for solving the problem]

[0008] A pants-type absorbent article according to one embodiment of the present invention includes an absorbent main body, an exterior body, and a pair of side joining portions. The exterior body is disposed on the non-skin facing side of the absorbent main body, includes a ventral region and a dorsal region located on both sides in the longitudinal direction, and is constructed by laminating a plurality of thermoplastic sheets. The pair of side joints join the ventral region and the dorsal region of the exterior body at lateral side edges perpendicular to the vertical direction. The pair of side joints have longitudinal ends, which are waist ends, which are the ends on the waist side in the longitudinal direction, and / or leg ends, which are the ends on the leg side in the longitudinal direction, and have longitudinal end regions within 25 mm in the longitudinal direction from the longitudinal ends, a longitudinal central region adjacent to the longitudinal end regions, and a plurality of seal portions arranged at a distance along the longitudinal direction. Each of the plurality of seal portions has an inner region located on the inner side in the laterally direction and including an inner end, and an outer region located on the outer side in the laterally direction and including an outer end. Of the multiple seal portions, the position of the inner end of the endmost seal portion located closest to the vertical end portion is located laterally more inward than the position of the inner end of the seal portion located in the vertical central region. Of the plurality of seal portions, at least the outermost seal portion has a higher seal strength in the inner region than in the outer region. Of the multiple seal portions, the boundary seal portion located in the longitudinal central region and closest to the longitudinal end region has a smaller difference in seal strength between the inner region and the outer region than the seal portion at the extreme end. Effect of the Invention

[0009] According to the pants-type absorbent article of the present invention, it is possible to achieve both prevention of peeling during the action of putting on and while wearing, and ease of tearing when discarding. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic perspective view showing a pants-type absorbent article according to a first embodiment of the present invention. [Diagram 2] 1 is a schematic plan view showing the skin-facing side of the pants-type absorbent article, and shows the pants-type absorbent article unfolded and the elastic members of each part stretched to spread out flat. FIG. [Diagram 3] FIG. 2 is a schematic plan view showing a side joining portion of the pants-type absorbent article. [Figure 4] FIG. 2 is a schematic diagram showing a microscope image of the cross section of the side joint portion magnified approximately 300 times. [Diagram 5] FIG. 1 is a schematic diagram showing a microscope image of the seal portion of the side joint at approximately 500 times magnification, where (A) shows the fibers in the outer region and (B) shows the fibers in the inner region. [Figure 6] FIG. 11 is a schematic plan view showing a side joining portion of a pants-type absorbent article according to a modified example of the above embodiment. [Figure 7] 13(A) and 13(B) are schematic plan views showing side joining portions of a pants-type absorbent article according to a modified example of the above embodiment. [Figure 8] FIG. 2 is a schematic cross-sectional view of the side joint portion, showing an aspect in which the ventral region and the dorsal region are separated. [Figure 9] FIG. 5 is a schematic plan view of a side joining portion of a pants-type absorbent article according to a second embodiment of the present invention. [Figure 10] FIG. 11 is a schematic plan view of a side joining portion of a pants-type absorbent article according to a third embodiment of the present invention. [Figure 11] FIG. 11 is a schematic plan view of a side joining portion of a pants-type absorbent article according to a fourth embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

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

[0012] First Embodiment [Overall configuration of pants-type disposable diapers] 1 and 2 show a pants-type disposable diaper 1 as a pants-type absorbent article according to a first embodiment of the present invention. The pants-type disposable diaper 1 will be referred to as diaper 1 hereinafter. As shown in FIG. 1, the diaper 1 has a waist opening 1W and a pair of leg openings 1L, and is worn around the waist and crotch of a wearer. The waist opening 1W has a waist opening end Wa. The diaper 1 has a longitudinal direction X and a lateral direction Y. The longitudinal direction X extends from the wearer's abdominal side through the crotch to the back side. The lateral direction Y is perpendicular to the longitudinal direction X and corresponds to the left-right direction of the wearer. Furthermore, as shown in FIG. 2 etc., the direction perpendicular to the longitudinal direction X and the lateral direction Y of the diaper 1 is defined as a thickness direction Z. In this specification, the "waist side" means the side approaching the waist opening end Wa of the waist opening 1W in the vertical direction X, and the "leg side" means the side away from the waist opening end Wa in the vertical direction X. In this specification, "the inner side in the lateral direction Y" means the side in the lateral direction Y that is closer to the vertical center line CL that divides the pants-type absorbent article (diaper 1) in half in the lateral direction Y, and "the outer side in the lateral direction Y" means the side that is away from the vertical center line CL. In this specification, with regard to the thickness direction Z, the side closer to the wearer's skin when the pant-type absorbent article (diaper 1) is 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 side" of the pant-type absorbent article (diaper 1) or its constituent members means the side relatively closer to the wearer's skin. The "non-skin-facing side" of the pant-type absorbent article (diaper 1) or its constituent members means the side relatively farther from the wearer's skin. In this specification, unless otherwise specified, the values ​​of the dimensions, area, etc. of each part are measured in a natural state with the elastic member of each part not stretched.

[0013] When a wearer puts on the diaper 1, first, the wearer puts his / her legs through the pair of leg openings 1L, pulls the diaper 1 up towards the wearer's torso, and places the diaper 1 around the wearer's waist and crotch area. In this specification, this series of actions is referred to as the "putting on action." The putting on action may be performed by a caregiver, rather than by the wearer of the diaper 1 himself / herself. In this specification, the state in which the diaper 1 is placed in a position normally assumed for wearing by a wearer is referred to as "when worn."

[0014] As shown in Figs. 1 and 2, the diaper 1 includes an absorbent body 4 and an exterior body 5 arranged on the non-skin-facing side of the absorbent body 4. 2 shows the diaper 1 unfolded and laid out flat to achieve the design dimensions with the elastic members of each portion stretched and free from any 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 portion 8, which will be described later.

[0015] The absorbent main body 4 is fixed to the skin-facing surface side of the exterior body 5. The absorbent main body 4 has at least an absorbent body 40, and may further have a top sheet 2, a back sheet (not shown), etc. For example, the absorbent main body 4 has a configuration in which the back sheet, the absorbent body 40, and the top sheet 2 are laminated in the thickness direction Z. The absorbent body 40 includes a liquid-retaining absorbent core, and may further include a core wrap sheet that covers the absorbent core. Materials used for each component included in the absorbent body 4 (back sheet, absorbent body 40, top sheet 2, etc.) may be any material used in the relevant technical field without any particular restrictions.

[0016] The exterior body 5 includes a plurality of thermoplastic sheets 50. The exterior body 5 is configured as a laminate of a plurality of thermoplastic sheets 50, for example. The thermoplastic sheet 50 is a sheet material mainly made of a thermoplastic resin. The thermoplastic sheet 50 preferably contains 90% by mass or more of a thermoplastic resin, and more preferably is made of 100% by mass of a thermoplastic resin. Examples of the thermoplastic resin include polyolefins such as polyethylene and polypropylene; polyesters such as polyethylene terephthalate; polyamides such as nylon 6 and nylon 66; polyacrylic acid, polymethacrylic acid alkyl esters, polyvinyl chloride, polyvinylidene chloride, etc., and these can be used alone or in combination of two or more. The thermoplastic fibers can be short or long fibers. Examples of the thermoplastic fibers that can be used include composite fibers such as core-sheath type or side-by-side type, split fibers, modified cross-section fibers, and heat-shrinkable fibers.

[0017] The exterior body 5 has at least a ventral region 5a arranged on the ventral side of the wearer and a dorsal region 5b arranged on the dorsal side of the wearer. The exterior body 5 of this embodiment further includes a crotch region 5c located between the ventral region 5a and the dorsal region 5b and arranged in the crotch area of ​​the wearer. In this example, the ventral region 5a, the crotch region 5c, and the dorsal region 5b are arranged along the vertical direction X. Furthermore, the exterior body 5 has a shape in which the crotch region 5c is narrowed on the inside in the horizontal direction Y. This forms leg openings 1L (see FIG. 1) that follow the wearer's leg openings. The outer edge of the exterior body 5 is preferably configured to be line-symmetric (bilaterally symmetric) with respect to the vertical center line CL.

[0018] Furthermore, the exterior body 5 has a pair of side joints 8 in which a side edge 5d in the lateral direction Y of the ventral region 5a and a side edge 5e in the lateral direction Y of the dorsal region 5b are joined together. The right side joint 8 has a configuration in which the right side edge 5d of the ventral region 5a and the right side edge 5e of the dorsal region 5b are overlapped and joined together in the thickness direction Z. The left side joint 8 has a configuration in which the left side edge 5d of the ventral region 5a and the left side edge 5e of the dorsal region 5b are overlapped and joined together in the thickness direction Z. The pair of side joining portions 8 connect the abdominal region 5a and the dorsal region 5b into a tubular shape that conforms to the wearer's waist circumference, thereby forming a waist opening 1W and leg openings 1L of the diaper 1. As will be described in detail later, the side joints 8 are preferably joined by heat sealing, ultrasonic sealing or the like.

[0019] [Side joint configuration] It is preferable that the side joint parts 8 maintain the joined state between the abdominal region 5a and the dorsal region 5b without peeling them off during the putting action and while the garment is being worn. On the other hand, when changing the diaper 1 after wearing, from the standpoint of hygienically disposing of excrement adhering to the diaper 1, a caregiver or the like may separate the ventral region 5a and the dorsal region 5b of the side joint portion 8, unfold the diaper 1, and then discard it. In this way, it is preferable that the side joint parts 8 have a structure that can prevent peeling during the putting action and while the garment is being worn, and can be easily torn when discarded. In this specification, the term "peeling" refers to unintentional separation of the ventral region 5a and the dorsal region 5b of the side joint portion 8 when putting on and wearing the diaper 1. In contrast, the term "tearing" refers to intentional separation of the ventral region 5a and the dorsal region 5b of the side joint portion 8 by applying an external force to the side joint portion 8 and / or its surroundings when discarding the diaper 1. Moreover, the person who tears the side seam 8 when disposing of the diaper 1 is referred to as a "disposer."

[0020] In this embodiment, the pair of side joints 8 are preferably configured substantially symmetrically with respect to the vertical center line CL, and have the same configuration. The configuration of one of the side joints 8 will be described in detail below. In the side joint portion 8, the end side in the longitudinal direction X means the side approaching the waist end portion 8a or the leg end portion 8b, and the central side in the longitudinal direction X means the side away from the waist end portion 8a or the leg end portion 8b.

[0021] 2 and 3, the side joint portion 8 has a waist end region 8c within 25 mm in the longitudinal direction X from a waist end 8a, which is the end on the waist side in the longitudinal direction X, a leg end region 8d within 25 mm in the longitudinal direction X from a leg end 8b, which is the end on the leg side in the longitudinal direction X, and a longitudinal central region 8e adjacent to the waist end region 8c and the leg end region 8d. It has a plurality of sealed portions S. In FIG. 3, a boundary line 7a 25 mm in the longitudinal direction x from the waist end 8a and a boundary line 7b 25 mm in the longitudinal direction X from the leg end 8b are diagrammatically illustrated by dotted lines.

[0022] The waist end 8a and the leg end 8b constitute both ends in the longitudinal direction X of the side joint portion 8. The side joint portion 8 extends in the longitudinal direction X as a whole 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 disposed adjacent to one another in this order along the longitudinal direction X. Therefore, the longitudinal central region 8e is a region sandwiched between the boundary line 7a and the boundary line 7b. In this embodiment, the waist end region 8a and the leg end region 8b correspond to longitudinal ends, and the waist end region 8c and the leg end region 8d correspond to longitudinal end regions.

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

[0024] As shown in FIG. 3, the multiple seal portions S are disposed in the longitudinal direction X at intervals. The planar shape of the seal portion S is not particularly limited, and may be a shape selected from a rectangular shape, other polygonal shapes, a circular shape, an elliptical shape, shapes similar to these, and other shapes. As shown in FIG. 3, from the viewpoint of ensuring sufficient area for each seal portion S while maintaining a sufficient spacing, the planar shape of the seal portion S is preferably rectangular, and more preferably rectangular with a long side in the lateral direction Y. The end of each seal portion S on the inside in the lateral direction Y is referred to as an inner end portion Sc, and the end on the outside in the lateral direction Y is referred to as an outer end portion Sd.

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

[0026] In this embodiment, an example will be described in which the inner region S11 and the outer region S12 meet at a boundary line, that is, the sealed portion S is divided into two regions, the inner region S11 and the outer region S12. The boundary line between the inner region S11 and the outer region S12 passes through approximately the center of each sealed portion S in the lateral direction Y. The boundary line between the inner region S11 and the outer region S12 does not necessarily have to be set at approximately the center in the lateral direction Y. Also, the boundary line between the inner region S11 and the outer region S12 may be set for each seal portion S.

[0027] Here, according to the findings of the present inventors, at the start of the tearing action of the side joint portion 8, the discarder's fingers are likely to be placed on both the left and right sides (ventral and dorsal sides) of the side joint portion 8, about 25 mm to 30 mm away from the waist end portion 8a or the leg end portion 8b in the vertical direction X. For example, when the wearer is in an upright position, the discarder's fingers are likely to be placed on the waist side, and when the wearer is in a lying position, the discarder's fingers are likely to be placed on the leg side. Therefore, in the side joint portion 8, the areas to which an external force for tearing (also referred to as "tear force F") is particularly likely to be applied are defined as the waist end region 8c and the leg end region 8d, which are within 25 mm in the vertical direction X from the waist end region 8a and the leg end region 8b, respectively. From the viewpoint of preventing tearing during wearing and the wearing action while facilitating tearing at the time of disposal, the arrangement and seal strength of the seal portion S in the waist end region 8c and / or the leg end region 8d are configured as follows. In this specification, the seal strength refers to the peel strength measured by a measuring device such as a Tensilon, etc. In contrast, the bond strength refers to the strength of the bond felt by the disposer when tearing the side bond portion 8.

[0028] In the following, an example will be mainly described in which the area where the sealed portion S has a characteristic arrangement and seal strength is provided from the waist end region 8c to the longitudinal central region 8e. Note that the present invention is also effective in the case where the area where the sealed portion S has a characteristic arrangement and seal strength is provided from the leg end region 8d to the longitudinal central region 8e, or in the case where the area is provided over the entire area including the waist end region 8c, the longitudinal central region 8e, and the leg end region 8d. Therefore, the following description of the waist end region 8c can be appropriately interpreted as a description of the leg end region 8d.

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

[0030] In the example shown in FIG. 3, four rows of sealed portions S are arranged in the waist end region 8c, with the most end sealed portion Sp being the first row. Of these, the second and third rows of sealed portions S have their inner ends Sc positioned in the lateral direction Y in the same position as the most end sealed portion Sp. The inner end Sc of the fourth row of sealed portion S, which is closest to the boundary line 7a, is positioned more inward in the lateral direction Y than the most end sealed portion Sp. The number of sealed portions S provided in the waist end region 8c is not limited, and for example, five or more rows of sealed portions S may be provided. Also, a sealed portion S may be provided whose inner end Sc is positioned more inward in the lateral direction Y than the most end sealed portion Sp.

[0031] Further, a plurality of sealed portions S are provided in the longitudinal central region 8e, but here, two sealed portions S are illustrated. The positions of the inner ends Sc of these sealed portions S are set at least further inward in the lateral direction Y than the outermost sealed portion Sp. Here, the positions of the inner ends Sc of the sealed portions S in the longitudinal central region 8e are set similarly to the fourth-stage sealed portion S in the waist end region 8c, but are not limited thereto and may be set arbitrarily within a range that is further inward in the lateral direction Y than the outermost sealed portion Sp. Moreover, the positions of the inner ends Sc of the sealed portions S in the longitudinal central region 8e do not need to be aligned vertically.

[0032] In general, when the tearing action of the diaper 1 starts, a tearing force F having both a central component in the longitudinal direction X and an outer component in the transverse direction Y is applied from the inside of the waist end region 8c (or the leg end region 8d). As shown in Fig. 3, this tearing force F is an outward force inclined at an angle of approximately 45° to the longitudinal direction X and the transverse direction Y.

[0033] Furthermore, the tearing in the waist end region 8c (or leg end region 8d) progresses along the direction of this force F, so the peel interface moves along a direction perpendicular to this. In other words, the peel interface is formed on a line L along a direction that includes a component toward the center in the longitudinal direction X and a component toward the inside in the lateral direction Y. For example, if there are multiple seal portions S on the line L, those seal portions S will be torn simultaneously, increasing the force required for tearing. In Fig. 3, the tearing operation starts from the waist end 8a side. In this case, line L is a line inclined 45 degrees outward in the horizontal direction Y on the side of the waist end 8a where the tearing operation starts, which is a straight line along the vertical direction X.

[0034] As described above, the position of the inner end Sc of the endmost sealed portion Sp is set to be more inward (to the right in the figure) than any of the sealed portions S in the longitudinal center region 8e. Therefore, for example, when peeling of the endmost sealed portion Sp is started, the sealed portion S in the longitudinal center region 8e does not overlap on the line L, and peeling of the endmost sealed portion Sp and the sealed portion S in the longitudinal center region 8e does not start at the same time. This makes it possible to easily tear the sealed portion S in the waist end region 8c including the endmost sealed portion Sp.

[0035] Furthermore, in this embodiment, among the multiple seal portions S, at least the seal portion Sp at the outermost end has a higher seal strength in the inner region S11 than in the outer region S12. 3, an inner region S11 and an outer region S12 are separated by a boundary line that divides the outermost seal portion Sp in half at the center in the horizontal direction Y. 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 in the outermost seal portion Sp is greater than the force required to peel off the outer region S12.

[0036] For example, the inner region S11 of the seal part Sp at the outermost end is a part that is likely to be subjected to force when worn or during the wearing action. By increasing the seal strength of the inner region S11 where force is likely to be applied in this way, it becomes difficult for starting points of peeling (hereinafter, may be referred to as peeling starting points) to occur when worn or during the wearing action, and it becomes possible to prevent tearing when worn or during the wearing action. In addition, the outer region S12 of the seal portion Sp at the outermost end has a smaller seal strength than the inner region S11 and is easier to peel off. This allows the seal portion Sp to be torn apart more easily with less force than, for example, when the seal strengths of the inner region S11 and the outer region S12 are both strong.

[0037] In particular, the seal portion Sp at the end tends to peel off along a line L inclined at 45° to the longitudinal direction X (lateral direction Y). Therefore, the outer region S12 of the seal portion Sp at the end is likely to peel off simultaneously with the seal portion S (the second-stage seal portion S) adjacent to the seal portion Sp at the end. For this reason, for example, if the seal strength of the outer region S12 is also set to be strong, two seal portions S located close to each other may be torn almost simultaneously, which may locally apply an excessive load to the exterior body 5. As a result, in the side joint portion 8, the exterior body 5 may break at a portion adjacent to the seal portion S, and the break of the exterior body 5 may further progress outward in the lateral direction Y along the longitudinal direction of the seal portion S, which is called a lateral tear. When a lateral tear occurs in the exterior body 5, the tearing operation is interrupted each time, which causes great stress to the disposer and the wearer.

[0038] In contrast, in the seal portion Sp at the outermost portion, the seal strength is relatively low in the outer region S12 compared to the inner region S11. As a result, even if the tearing action progresses and the seal portion Sp at the outermost portion and the adjacent seal portion S are peeled off at the same time, they can be sufficiently peeled off with a relatively weak force. This makes it possible to avoid a situation in which an excessive load is applied locally, and to sufficiently suppress the occurrence of horizontal tears, etc.

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

[0040] As described above, at the start of the tearing action, the tearing force F acts obliquely outward at an angle of 45° to the longitudinal direction X and the transverse direction Y. On the other hand, as the tearing action progresses, the tearing force F acts along the longitudinal direction X. For example, when a disposer tears the vicinity of the part being held down with his / her fingers, it is considered that the tearing force F will be along the longitudinal direction X. Therefore, for example, while tearing the sealed portion S of the waist end region 8c (or the leg end region 8d) and then starting to tear the sealed portion S of the longitudinal central region 8e, the direction of the tearing force F changes from a direction inclined at 45° to the longitudinal direction X to a direction substantially parallel to the longitudinal direction X. In this case, the line L representing the peel interface becomes substantially parallel to the transverse direction Y.

[0041] Therefore, for example, in the seal portion Sq at the boundary, the inner region S11 and the outer region S12 are peeled off at approximately the same time along the line L approximately parallel to the lateral direction Y. When peeling two regions at approximately the same time in this manner, there is a risk that a difference in the force required to peel each region will result in a force acting in an unintended direction different from the tearing force F, causing horizontal tearing, etc.

[0042] Therefore, in the seal portion Sq at the boundary, the difference in seal strength between the inner region S11 and the outer region S12 is set smaller than that of the seal portion Sp at the end. This makes the magnitude of the force required to peel the inner region S11 and the outer region S12 closer than when there is a difference in seal strength, for example, as in the seal portion Sp at the end. As a result, it is possible to prevent a situation in which a force acts in a direction different from the tearing force F, causing horizontal tearing, etc.

[0043] In this way, in the side joint portion 8, the arrangement and seal strength of each seal portion S are set by assuming a change in the direction of the tear force F (line L representing the peel interface) that accompanies the progress of the tearing action. In other words, at the start of the tearing operation, the position of the inner end Sc of the endmost seal portion Sp is made to protrude inward further than the seal portion S in the longitudinal central region 8e, making it possible to selectively apply a tearing force F inclined at 45° from the longitudinal direction X to the endmost seal portion Sp. Furthermore, in the seal portion Sp at the very end, since the seal strength of the outer region S12 is lower than that of the inner region S11, even if the tearing action progresses and the adjacent seal portion S is peeled off, there is no need to make the tearing force F extremely large. Furthermore, as the tearing action progresses, a tearing force F acts along the vertical direction X. In the seal portion Sq at the boundary where such a tearing force F acts, by setting the difference in seal strength between 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 horizontal tearing and continue the tearing action smoothly. In addition, in the seal portion Sp at the outermost end, the seal strength of the inner region S11 is higher than that of the outer region S12, so that the inner region S11 is less likely to peel off even if force is applied when wearing the garment or during wearing movements, and peeling starting points are less likely to occur. This makes it possible for the side joints 8 to be both prevented from coming apart during the putting on and wearing action, and easy to tear when discarding.

[0044] [Seal strength setting example] Here, the seal strength of each seal portion S will be described. In the above, a case has been described in which the seal strength of the inner region S11 is set higher than the seal strength of the outer region S12 in the seal portion Sp at the outermost end. Of course, in other seal portions S, the seal strength may be different between the inner region S11 and the outer region S12. For example, in Fig. 3, in the second and third rows of sealed portions S in the waist end region 8c, which are arranged on the inside in the lateral direction Y like the most end sealed portion Sp, the seal strength of the inner region S11 is set higher than that of the outer region S12 like the most end sealed portion Sp. This makes it possible to sufficiently prevent peeling during donning and wearing. Also, since the seal strength of the outer region S12 is weak, even if adjacent sealed portions S are peeled off at the same time, parts with strong seal strength are unlikely to overlap on the line L representing the peeling interface, making it possible to easily perform the tearing operation with a weak force. The seal strength of the fourth seal portion S may be set to be the same as that of the outermost seal portion Sp, or may be set to be the same as that of the outermost seal portion Sq described below.

[0045] In the longitudinal center region 8e, the boundary seal portion Sq is set to have a weaker seal strength than the edge seal portion Sp in both the inner region S11 and the outer region S12. That is, the seal strength of the inner region S11 of the boundary seal portion Sq is set lower than the seal strength of the inner region S11 of the edge seal portion Sp, and the seal strength of the outer region S12 of the boundary seal portion Sq is set lower than the seal strength of the outer region S12 of the edge seal portion Sp.

[0046] The boundary seal portion Sq is a portion where external forces that would peel off the side joint portion 8 during wearing or wearing action are less likely to concentrate compared to, for example, the endmost seal portion Sp. Therefore, even if the seal strength of the inner region S11 and the outer region S12 is somewhat low, peeling can be sufficiently prevented. In addition, in the seal portion Sq at the boundary, the direction of the tearing force F is along the vertical direction X, so the inner region S11 and the outer region S12 are peeled off at approximately the same time. Therefore, if the seal strength of the inner region S11 and the outer region S12 is too strong, a strong force is required to tear them apart. In contrast, by making the seal strength of the inner region S11 and the outer region S12 of the seal portion Sq at the boundary 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 vertical direction X.

[0047] Typically, the seal strength of the seal portion S arranged in the longitudinal center region 8e, the inner region S11, and the outer region S12 are set to be approximately the same. This makes it possible to sufficiently prevent the tearing force F acting along the longitudinal direction X from acting in an unintended direction, and makes it possible to easily tear the portion subsequent to the longitudinal center region 8e without causing horizontal tearing or the like. For example, each seal portion S arranged in the longitudinal center region 8e is set to have a uniform seal strength for the inner region S11 and the outer region S12. This allows the tearing action to be performed with a constant force, making the tearing feel easy.

[0048] <Method of measuring seal strength> A method for measuring and comparing the seal strength between the inner region S11 and the outer region S12 of each seal portion S will be described. 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 portion 8. This rectangular piece is cut along the vertical direction X to obtain two types of measurement samples, one on the outside and one on the inside in the horizontal direction Y. The cutting position is a position that divides the seal portion S into two equal parts in the horizontal direction Y. The multiple cut-out measurement samples have the same number of laminated thermoplastic sheets 50. Next, the horizontal direction Y end of each measurement sample is fixed to a Tensilon universal testing machine (RTC-1210A) manufactured by Orientec Co., Ltd., and one exterior body 5 is peeled off from the other exterior body 5. If the end of each measurement sample is difficult to fix to the Tensilon, tape or the like is attached to the end to ensure a length that allows the Tensilon to be fixed. The measurement sample is peeled off in the horizontal direction Y at a speed of, for example, 10 mm / min, and the peel strength is measured over time. The maximum peel strength measured is then regarded as the seal strength of that measurement sample. For the seal portion S provided at the same position, about 10 measurement samples are prepared corresponding to the inside and outside in the lateral direction Y, and the above-mentioned 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] A specific example of the seal strength of the seal portion S will be given. The seal strength of the inner region S11 of the outermost seal portion Sp is preferably 0.5 N or more, more preferably 0.7 N or more, and is preferably 5 N or less, more preferably 4 N or less, from the viewpoint of preventing peeling during wearing and wearing movements. The seal strength of the outer region S12 of the outermost sealed portion Sp is preferably 0.1 N or more, more preferably 0.12 N or more, and is preferably 2 N or less, more preferably 1.8 N or less, from the viewpoint of facilitating tearing during disposal. In addition, 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, and preferably 80% or less, more preferably 70% or less, from the viewpoint of achieving both peel prevention and ease of tearing.

[0050] [Example of how to adjust seal strength] The seal strength of the seal portion S can be adjusted, for example, by changing the conditions of the sealing process for forming the seal portion S, such as temperature, pressure and / or time. The seal strength can also be adjusted by changing the area of ​​the sealed portion S, which is the fused portion of the fibers. The seal strength can also be adjusted by changing the fiber composition of the thermoplastic sheet 50. Below, a specific example will be given for explanation.

[0051] (Example of adjustment by the degree of fiber melting) The sealed portion S is a portion formed by fusing fibers of a plurality of thermoplastic sheets 50 of the exterior body 5. For this reason, the more fully the fibers are melted in a portion, the more the fibers will adhere to each other after cooling, and the seal strength will tend to be higher. In this embodiment, the degree of melting of the inner region S11 of the endmost seal portion Sp is higher than the degree of melting of the outer region S12 of the endmost seal portion Sp, and is also higher than the degree of melting of the inner regions S11 of the other seal portions S arranged in the waist end region 8c. As a result, the seal strength of the inner region S11 of the outermost sealed portion Sp is the greatest among the inner region S11 and the outer region S12 of each sealed portion S included in the waist end region 8c. In addition, by controlling the degree of melting and creating differences in seal strength, it is possible to finely set the seal strength, which allows for smooth changes in seal strength and makes tearing feel easier.

[0052] <Method of calculating the degree of melting of the inner and outer regions> First, the side joint portion 8 is cut to prepare two types of measurement samples including the XZ cross sections (cross sections crossing 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 have the same number of laminated thermoplastic sheets 50. After fixing the measurement samples by a known method, the XZ cross sections of the measurement samples are imaged at, for example, 500 times magnification using a scanning electron microscope (SEM). In each image, the outer edge of the fibers is detected using image analysis software, and the length of the detected line is calculated as the perimeter of the fibers. For each of the inner region S11 and the outer region S12, the average value of the perimeter of the fibers calculated from five or more images is calculated, and the average value is taken as the perimeter of the fibers of the seal portion S. The circumferential length of the fibers in the inner region S11 and the outer region S12 are compared, and it is determined that the longer the circumferential length of the fibers, the lower the degree of melting.

[0053] FIG. 5(A) shows an example of an enlarged view of the XZ cross section of the outer region S12, and FIG. 5(B) shows an example of an enlarged view of the XZ cross section of the inner region S11. 5A has many irregularities on its outer edge 55a and a long perimeter, that is, the fiber 55 is 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, fiber 55 in Fig. 5(B) has a relatively smooth outer edge 55a and is shorter in circumference than fiber 55 in Fig. 5(A). In other words, fiber 55 is sufficiently melted, and the irregularities of outer edge 55a are smoothed. In this case, the degree of melting of the fibers 55 in the inner region S11 in FIG. 5(B) is determined to be higher than the degree of melting of the fibers 55 in the outer region S12 in FIG. 5(A).

[0054] The degree of melting of the fibers can be adjusted by conditions such as heat, pressure and / or time during the sealing process. By adjusting the sealing strength by the degree of melting of the fibers, the sealing strength can be adjusted without significantly changing the planar shapes (e.g., dimensions in the vertical direction X) or thicknesses of the inner region S11 and the outer region S12. By making the planar shapes of the inner region S11 and the outer region S12 uniform, each sealed portion S can be torn one after another at approximately regular intervals when torn. Therefore, the tearing operation can be performed stably and smoothly, reducing the stress of the disposer. Furthermore, the degree of melting of the fibers can be changed without changing the fiber composition of the thermoplastic sheet 50 for each of the inner region S11 and the outer region S12. This allows the seal strength to be adjusted relatively easily and accurately.

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

[0056] (Example of adjusting the thickness of the seal part) In general, by greatly compressing the overlapped thermoplastic sheets 50 in the thickness direction Z during the sealing process, the molten fibers are strongly compressed, thereby increasing the seal strength of the seal portion S. In other words, the thinner the seal portion S, the higher the seal strength. On the other hand, there is a possibility that the seal strength may be extremely different between the thin and thick regions. For example, if the inner region S11 is thin and the outer region S12 is thick, the force required to peel the inner region S11 may be extremely large. In this case, immediately after peeling the inner region S11, an excessive tearing force F acts on the outer region S12, and the force is applied in an unintended direction, which may result in horizontal tearing or the like.

[0057] In this embodiment, among the seal portions S arranged in the waist end region 8c, at least the seal portion Sp at the outermost end is set to have a thickness in the inner region S11 that is substantially the same as that in the outer region S12. In this case, for example, by adjusting the degree of melting described above, the thicknesses of the inner region S11 and the outer region S12 can be made substantially the same while the seal strengths are made different. This makes it possible to avoid a situation in which the difference in seal strength between the inner region S11 and the outer region S12 becomes extremely large, and to prevent the occurrence of horizontal tears, etc. In this disclosure, "approximately the same thickness" means "substantially the same." For example, if the thickness of one piece is within a range of ±20% of the thickness of the other piece, the thicknesses are considered to be approximately the same.

[0058] <Method of measuring the thickness of the inner and outer regions> Two types of measurement samples including XZ cross sections (cross sections across the seal portion S in the longitudinal direction X) of the inner region S11 and the outer region S12 of the seal portion S are prepared. The cut-out measurement samples have the same number of laminated thermoplastic sheets 50. After fixing the measurement sample by a known method, the XZ cross section of the measurement sample is imaged by a SEM or the like at a magnification of, for example, 500 times. Then, as shown in FIG. 4, a recessed portion in the image is defined as the seal portion S (the outer region S12 or the inner region S11). Using image analysis software, the thickness Ds (see FIG. 4) in the thickness direction Z of the portion that divides the seal portion S in half 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 the outer region S12, the average value of the thicknesses calculated from five or more images is calculated, and the average value is defined as the thickness of the inner region S11 and the outer region S12 of the seal portion S.

[0059] [Example of seal strength in inner area] As described above, the inner region S11 is the region that is torn before the outer region S12 when the tearing action starts. 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 the force applied by the disposer during the tearing action, for example. The following describes the seal strength set in each inner region S11 of the multiple seal portions S provided in the side joint portion 8. Here, as in Fig. 3, a configuration is described assuming a case in which the garment is torn from the waist end portion 8a, but the description of the waist end portion 8a can be interpreted as a description of the leg end portion 8b.

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

[0061] In this case, the seal strength of the inner region S11 is highest at the seal portion Sp at the extreme end, and decreases toward the predetermined position. The seal strength may be configured to decrease linearly, or may decrease so as to converge to a constant value. This allows the seal strength of the inner region S11, which is more likely to be subjected to force, to change continuously (smoothly) toward the predetermined position during the tearing operation. This prevents, for example, a situation in which force is applied in an unintended direction during the tearing operation, and allows the diaper 1 to be easily torn without causing horizontal tears or the like.

[0062] Specifically, the degree of melting of the inner region S11 of the sealed portion S is set to decrease from the waist end portion 8a toward a predetermined position of the longitudinal center region 8e. In this way, by controlling the degree of melting of the fibers, the seal strength on the inner side in the lateral direction Y changes more smoothly. This makes it possible to sufficiently prevent breakage during tearing, and improves ease of tearing.

[0063] The seal strength of the outer region S12 may be set to match the seal strength of the inner region S11. For example, when the ratio of the seal strength of the outer region S12 to the inner region S11 is determined, the seal strength of the outer region S12 is appropriately set according to the ratio. The seal strength of the outer region S12 may be set to a constant value. In this case, the seal strength is typically set to a value lower than the seal strength of the corresponding inner region S11. There are no other limitations on the method of setting the seal strength of the outer region S12. The seal strength of the inner region S11 and the outer region S12 of each seal portion S can be measured based on the procedure described above in the section "Method of measuring seal strength."

[0064] [Example of seal placement] Here, as shown in FIG. 3, an example of the arrangement of the seal portions S will be described, taking as an example a case in which the size (width in the vertical direction X and horizontal direction Y) of each seal portion S provided in the side joint portion 8 is constant. (Example of arrangement of inner ends of the seal part Sp at the outermost end and the seal part Sq at the boundary) In this embodiment, the position of the inner end Sc of the outermost seal portion Sp is set inside in the lateral direction Y from the position of the inner end Sc of the boundary seal portion Sq within a range of 0.7 mm to 5 mm. In this case, for example, if the sealed portion S is torn from the waist end region 8c to the longitudinal center region 8e, the position of the sealed portion moves about 25 mm in the longitudinal direction X, but changes by no more than about 5 mm in the lateral direction Y. In this way, the position of the inside of each sealed portion S in the lateral direction Y does not change drastically. This makes it possible to avoid the occurrence of lateral tears and the like, while reducing the discomfort felt when peeling off the garment.

[0065] Furthermore, when starting to tear, the fingers are often used to pinch the inside of the waist end region 8c in the horizontal direction Y and apply force. On the other hand, when subsequently tearing in the vertical direction X, the fingers are often moved to the vicinity of the tearing point. This finger movement is preferably along the vertical direction X so that there is as little unnecessary movement (in the horizontal direction Y) as possible. From this perspective, by arranging the inner ends of the endmost seal portion Sp and the boundary seal portion Sq within the above-mentioned range, it is possible to provide a side joint portion 8 that is easy to tear as a whole.

[0066] The shift amount of the central positions of the plurality of seal portions S in the lateral direction Y is set in the range of 5 mm to 15 mm. Here, the "shift amount of the central positions of the plurality of seal portions S in the lateral direction Y" refers to the relative shift amount of the central positions of the respective seal portions S in the lateral direction Y. For example, the distance (shift amount) of the central positions in the lateral direction Y when comparing the seal portion S whose central position is the innermost in the lateral direction Y (for example, the seal portion Sp at the end in FIG. 3) with the seal portion S whose central position is the outermost in the lateral direction Y (for example, the seal portion S closest to the leg end 8b in FIG. 3) is set in the above-mentioned range. As a result, the position in the lateral direction Y does not change extremely over the entire area of ​​the side joint portion 8, so that it is possible to sufficiently reduce the sense of incongruity when peeling while avoiding the occurrence of lateral tearing and the like.

[0067] [Example dimensions for sealing parts] The following are examples of dimensions of the sealed portion S from the viewpoint of preventing peeling during donning and wearing and easiness of tearing at the same time. Note that the following dimensions are measured in a natural state with the elastic member not stretched. The dimension (maximum dimension) of the seal portion S in the lateral direction Y is preferably 0.5 mm or more, more preferably 1 mm or more, and is preferably 10 mm or less, more preferably 4 mm or less. The dimension (maximum dimension) of the seal portion S in the vertical direction X is preferably 0.1 m or more, more preferably 0.3 mm or more, and is preferably 2 mm or less, more preferably 0.6 mm or less. The pitch of the seal portions S in the longitudinal direction X is preferably 1.5 mm or more, more preferably 2 mm or more, and is preferably 5.0 mm or less, more preferably 4 mm or less. The pitch in the longitudinal direction X of the multiple seal portions S means the distance in the longitudinal direction X between the lines dividing each seal portion S in two equal parts in the longitudinal direction X, in the seal portions S adjacent to each other in the longitudinal direction X. If the pitch is not constant, the pitch in the longitudinal direction X is measured at five locations, and the average value is taken as the pitch in the longitudinal direction X.

[0068] [Example of placement of fusion inhibitors] The local peel strength of the seal portion S can also be adjusted by arranging a melting inhibitor that inhibits melting of the resin between the thermoplastic sheets 50. For example, by arranging a linear melting inhibitor so as to intersect with the seal portion S, it is possible to provide a locally easy-to-tear portion in the seal portion S.

[0069] From this viewpoint, as shown in Fig. 6, it is preferable that the waist end region 8c and / or the leg end region 8d in which the plurality of seal portions S are arranged have a fusion inhibitor 9 provided linearly between the thermoplastic sheets 50. In this case, it is preferable that each of the plurality of seal portions S, excluding at least the seal portion S closest to the end in the longitudinal direction X, constitutes a cross seal portion having an intersection portion 9s that intersects with the fusion inhibitor 9. Since the sealed portion S closest to the end in the longitudinal direction X does not overlap the fusion inhibitor 9, peeling starting points are unlikely to form at the end in the longitudinal direction X when the diaper 1 is worn or during the wearing action. On the other hand, since the multiple sealed portions S at the center in the longitudinal direction X intersect with the linear fusion inhibitor 9, the intersections 9s become tearing starting points when the diaper 1 is disposed of, and the side joint portions 8 are easier to tear.

[0070] The fusion inhibitor 9 is disposed between the thermoplastic sheets 50 of the exterior body 5, for example, prior to a sealing step for forming the seal portion S. Any substance capable of suppressing the influence of heat applied during the sealing process can be used as the fusion inhibitor 9 without any particular limitation. Examples of such substances include hot melt adhesives, polyurethane-based materials, and petroleum-based resins. From the viewpoint of reducing heat generated in the sealing process and bonding the sheets together, it is preferable that the fusion inhibitor 9 is a hot melt adhesive. As the hot melt adhesive, for example, a styrene-based (SIS, SBS, SEBS) or polyolefin-based material can be used. The method for disposing the fusion inhibitor 9 can be any commonly used method without any particular limitation, but a method of applying the fusion inhibitor 9 using a coater gun is preferred. This makes it possible to easily control the coating shape, basis weight, etc. of the fusion inhibitor 9.

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

[0072] In the example shown in Fig. 6, each seal portion S provided in the waist end region 8c is arranged so that the fusion inhibitor 9 intersects with the seal portions S, except for at least the seal portion Sp at the outermost end. Here, the seal portions S in the second, third, and fourth rows from the top in the figure are the cross seal portions St1, St2, and St3, respectively. This is not limiting, and for example, only the seal portions S in the second and third rows (cross seal portions St1 and St2) may intersect with the fusion inhibitor 9, or the seal portions S in the fifth row and onward may intersect with the fusion inhibitor 9.

[0073] The intersecting portion 9s refers to a portion of the intersecting seal portions St1, St2, and St3 that intersects with the fusion inhibitor 9 in a plan view. Here, in the intersecting seal portions St1, St2, and St3, if the end portion on the waist end portion 8a side and extending in the horizontal direction Y is defined as the upper end portion Sa, and the end portion on the leg end portion 8b side and extending in the horizontal direction Y is defined as the lower end portion Sb, then the intersecting portion 9s is formed linearly from the lower end portion Sb to the upper end portion Sa. It is preferable that each of the cross seal portions St1, St2, and St3 has one cross portion 9s. Furthermore, it is more preferable that in the side joint portion 8, one fusion inhibitor 9 crosses each of the multiple cross seal portions St1, St2, and St3 at one location.

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

[0075] In addition, from the viewpoint of improving the ease of tearing in the vertical direction X, it is preferable that the multiple seal portions S have n cross seal portions St1, St2, ..., Stn, which are 3 or more, including the first cross seal portion St1 and the second cross seal portion St2. In the example shown in FIG. 6, the multiple seal portions S include a first cross seal portion St1, a second cross seal portion St2, and a third cross seal portion St3. In the following description, each of the intersecting seal portions St1, St2, ... will also be referred to as Stn, where n is an integer of 2 or more.

[0076] From the viewpoint of further improving the ease of tearing, it is preferable that the intersecting seal portion Stn intersects with the fusion inhibitor 9 at a position other than the outer end portion Sd and the inner end portion Sc on both sides in the transverse direction Y, and that the intersecting distance a(n) between the inner end portion Sc and the intersecting portion 9s monotonically decreases from the end portion side in the longitudinal direction X toward the center side in the longitudinal direction X. Here, the intersection distance a(n) is, for example, the distance in the lateral direction Y from the inner end Sc of the outermost seal portion Sp to the innermost point of the intersection portion 9s in the lateral direction Y. Furthermore, "monotonically decreasing" means that the intersection distance a(n) is longer than the intersection distance a(n-1). That is, in the above configuration, when n is an integer of 2 or more, the following formula (1) holds. a(n)>a(n-1) …(1) For example, in the example shown in FIG. 6, the cross distances a1, a2, and a3 of the first cross seal portion St1, the second cross seal portion St2, and the third cross seal portion St3 satisfy the following relationship. a1>a2>a3

[0077] In this way, the intersection 9s, which serves as the tear guide portion, is disposed on the outer side in the horizontal direction Y at the end portion in the vertical direction X where force is likely to be applied when the garment is worn or during the wearing action. This makes it difficult for force to be applied to the intersection 9s, which is relatively prone to peeling, at the end portion in the vertical direction X. This makes it possible to prevent the occurrence of peeling starting points. In addition, the intersecting portion 9s is disposed further inward in the horizontal direction Y as it approaches the center in the vertical direction X. This allows the tearing operation to be started and, after the seal portion Sp at the outermost end is peeled off, the seal portion S on the center side in the vertical direction X can be peeled off smoothly by being guided by the intersecting portion 9s. This makes it possible to realize a side joint portion 8 that is less likely to tear when worn or during the wearing action, and that can be easily torn.

[0078] In order to achieve a more stable tearing operation, it is preferable that the widths of the intersections 9s of the multiple intersecting seal portions St1, St2 in the lateral direction Y are substantially the same, as shown in FIG. In the example shown in Figure 6, the width b1 in the horizontal direction Y of the intersection 9s between the first cross seal St1 and the fusion inhibitor 9 is substantially identical to the width b2 in the horizontal direction Y of the intersection 9s between the second cross seal St2 and the fusion inhibitor 9.

[0079] The widths b1 and b2 of each intersection 9s in the horizontal direction Y can be set to, for example, the average value of the width in the horizontal direction Y of the intersection 9s at the upper end Sa and the width in the horizontal direction Y of the intersection 9s at the lower end Sb. Alternatively, the width in the horizontal direction Y of each intersection 9s at the center position in the vertical direction X of each seal portion S may be set to the widths b1 and b2. The width being "substantially the same" means that the width of each intersection 9s is within 150% or less when the smallest width among all the intersections 9s is taken as 100%. In the above configuration, the variation in the widths b1 and b2 of the intersection 9s can be suppressed, and the variation in the peel strength of each intersection seal portion St1 and St2 can be suppressed. This prevents a person who disposes of the pants-type absorbent article from feeling uncomfortable while tearing the article. This prevents a person who disposes of the pants-type absorbent article from applying a stronger tearing force than necessary, which may cause the exterior body 5 to tear. Furthermore, by stabilizing the widths b1, b2 of the intersection 9s, a significant decrease in the seal strength of the intersection seal portions St1, St2 can be suppressed, and peeling of the side joint portion 8 during the putting action and when worn can be more reliably prevented.

[0080] Specifically, the width of the intersection 9s in the horizontal direction Y is preferably 5% or more, more preferably 10% or more, and preferably 60% or less, more preferably 50% or less, of the length of the intersection seal portion Stk in the horizontal 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, and is preferably 1.5 mm or less, more preferably 1.2 mm or less. The dimensions of the intersection portion 9s and the intersection seal portion Stk are measured in the maximum stretched state.

[0081] 7(A) and 7(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 as a whole inward in the lateral direction Y of the side joint 8, and the overall planar shape thereof is preferably a spiral or wavy curve. Also, it is preferable that the fusion inhibitor 9 has at least a part of its spiral or wavy curve disposed in the side joint 8, thereby satisfying the above formula (1) and the like.

[0082] The spiral or wavy curve forming the fusion inhibitor 9 has a shape in which a plurality of unit shapes 9a, 9b are repeatedly arranged in one direction. FIG. 7(A) shows an example in which the curve of the fusion inhibitor 9 is spiral-shaped. The spiral shape here means a shape in which a plurality of unit shapes 9a, each of which is a shape close to a circle or an ellipse, are repeatedly arranged in one direction. In FIG. 7(A), unit shapes 9a close to an ellipse are repeatedly arranged in the horizontal direction Y. Note that, although each unit shape 9a is formed in a closed ring shape in FIG. 7(A), a portion of one unit shape 9a may be connected to an adjacent unit shape 9a, and a plurality of unit shapes 9a may be continuously formed. 7(B) shows an example in which the curve of the fusion inhibitor 9 is wavy. Wavy means that a shape that is undulating in one direction and the opposite direction is taken as one unit shape 9b, and multiple unit shapes 9b are repeatedly arranged along the other direction.

[0083] The fusion inhibitor 9 is configured in a curved shape as described above, which allows for smooth tearing and prevents the tearing force from concentrating locally. This prevents the discomfort that may occur during tearing of the side joint 8 and prevents the waste disposal user from applying a stronger tearing force than necessary, which may cause the exterior body 5 to break.

[0084] Furthermore, the spiral or wavy curve of the fusion inhibitor 9 preferably extends along the lateral direction Y. That is, in the curve, the plurality of unit shapes 9a, 9b are preferably arranged along the lateral direction Y. This makes it possible to realize a fusion inhibitor 9 having a smooth curve.

[0085] In this case, it is preferable that the unit shapes 9a, 9b have a larger dimension in the vertical direction X than in the horizontal direction Y. The dimensions of the unit shapes 9a, 9b are the dimensions of the unit shapes 9a, 9b that at least partially overlap the side joint portion 8 or the unit shapes 9a, 9b adjacent thereto. The dimension in the vertical direction X means the maximum dimension in the vertical direction X of the unit shapes 9a, 9b, and the dimension in the horizontal direction Y means the maximum dimension in the horizontal direction Y of the unit shapes 9a, 9b. For example, in the spiral curve shown in FIG. 7(A), the dimension c1 in the vertical direction X of a unit shape 9a is larger than the dimension c2 in the horizontal direction Y. Similarly, for example, in the wavy curve shown in FIG. 7(B), the dimension d1 in the vertical direction X of the unit shape 9b is larger than the dimension d2 in the horizontal direction Y. This makes the unit shapes 9a and 9b elongated in the longitudinal direction X, which makes it easier to induce tearing in the longitudinal direction X, thereby further improving the ease of tearing.

[0086] (Example of placement of adhesion inhibitor in thickness direction) In order for the fusion inhibitor 9 to efficiently exert its fusion-inhibiting effect, it is more preferable that it be disposed in the vicinity of the interface to be joined. From this viewpoint, as shown in FIG. 8, the fusion inhibitor 9 is preferably disposed between the skin side sheet P of the thermoplastic sheet 50 and the adjacent sheet Q adjacent thereto. The skin side sheet P is a thermoplastic sheet 50 which constitutes the skin-facing surface of the exterior body 5 in at least one of the waist end region 8c and / or the 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 with each other in an opposing state and sealed. In the above configuration, the fusion inhibitor 9 is disposed near the joint interface, so that the fusion inhibitor 9 is more likely to exert its fusion inhibition 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 Fig. 8, the skin side sheet P is formed of the inner layer sheet 52 of the exterior body 5. Also, the adjacent sheet Q is formed of the outer layer sheet 51 of the exterior body 5. For the purpose of explanation, the cross-sectional view of Fig. 8 shows the ventral region 5a and the dorsal region 5b of the side joint portion 8 in a separated state. In the example shown in FIG. 8, the fusion inhibitor 9 is placed in the ventral region 5a, but it may also be placed in the dorsal region 5b, or may be placed in both the ventral region 5a and the dorsal region 5b.

[0088] From the viewpoint of further improving the ease of tearing, it is preferable that the penetration depth of the adhesion inhibitor 9 in the skin side sheet P is deeper than the penetration depth of the adhesion inhibitor 9 in the adjacent sheet Q. The penetration depth means the depth to which the fusion inhibitor 9 has penetrated from the applied surface in the sheet thickness direction. This allows the fusion inhibitor 9 to easily migrate from the non-skin facing surface of the skin side sheet P to the skin facing surface which is the bonding interface, and the fusion inhibitor 9 can more effectively exert its fusion inhibition effect. Therefore, the ease of tearing can be more effectively improved.

[0089] <Method for measuring penetration depth of adhesion inhibitor> The side joint 8 to be measured is cut in the vertical direction X and the horizontal direction Y to prepare a test piece on which the cross section of the fusion inhibitor 9 appears. Next, an enlarged image of the cross section of the side joint 8 in the test piece is taken at a magnification of 200 times using a microscope VHX1000 manufactured by KEYENCE Corporation, and an image of the observation field is obtained. In the observation field, the part in which the fusion inhibitor 9 has permeated is observed as a transparent and shiny part, so the outline of the part is identified, and the area of ​​the area surrounded by the outline is measured. This measurement is performed at five points 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 the end region.

[0090] [Example of elastic member configuration] 2, a plurality of elastic members 10 extending in the lateral direction Y are disposed in each of the ventral region 5a and the dorsal region 5b of the exterior body 5. Specifically, the plurality of elastic members 10 are disposed between the plurality of thermoplastic sheets 50 of the exterior body 5 (see FIG. 8). These elastic members 10 provide stretchability around the waist of the diaper 1, making it easier to put on and maintaining a snug fit when worn. Note that "the elastic member 10 extends in the horizontal direction Y" means that the elastic member 10 extends in the horizontal direction Y in the expanded and stretched state. However, the above expression is not limited to the state in which the elastic member 10 is parallel to the horizontal direction Y in the expanded and stretched state, but includes the state in which the elastic member 10 extends in the horizontal direction Y as a whole. Furthermore, as shown in FIG. 2, the exterior body 5 may include, in addition to the elastic members 10, leg elastic members 11 arranged around the leg openings 1L.

[0091] The elastic members 10, 11 can preferably be in the form of a thread (such as rubber thread) or string (such as flat rubber) having a rectangular, square, circular, polygonal, etc. cross section, or a multifilament type thread, etc. The material of the elastic members 10, 11 can be any material that is conventionally used for absorbent articles such as disposable diapers, without any particular restrictions, and examples of such materials include synthetic rubbers such as styrene-butadiene, butadiene, isoprene, and neoprene, natural rubber, EVA, elastic polyolefin, polyurethane, etc.

[0092] From the viewpoint of ensuring stretchability around the entire waist, it is preferable that the outer ends in the lateral direction Y of the elastic members 10 in each of the ventral region 5a and the dorsal region 5b are located at or near the side joints 8. Specifically, it is preferable that the distance between the ends and the side joints 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 joints 8. The elastic member 10 is generally arranged in or near the area where force is applied when tearing, and is likely to affect the ease of tearing of the side joint portion 8. Therefore, from the viewpoint of improving ease of tearing when discarding, it is preferable to adjust the elongation rate of the elastic member as follows.

[0093] In the example shown in FIG. 3, the elastic elongation rate of the multiple elastic members 10 arranged in the waist end region 8c is set lower than the elastic elongation rate of the multiple elastic members 10 arranged in the longitudinal center region 8e. Here, the elastic elongation percentage is an average elongation percentage obtained by averaging the elongation percentages of the elastic members 10 arranged in the waist end region 8c (or the longitudinal center region 8e).

[0094] The stretch rate of the elastic member 10 means the ratio of the length of the elastic member stretched in the expanded and stretched state of the pant-type absorbent article to the length of the elastic member 10 in its natural length when taken out of the pant-type absorbent article. In other words, the lower the elongation rate, the smaller the elastic force when the elastic member 10 is pulled tends to be. The stretch rate of the elastic member 10 can be adjusted during manufacturing by adjusting the degree of stretch of the elastic member 10 placed in the exterior body 5. During manufacturing, for example, the elastic member 10 is stretched to a predetermined length, adhesive is applied to the elastic member 10 with a comb or the like, and the elastic member 10 is fixed to the thermoplastic sheet 50 of the exterior body 5.

[0095] As described above, a force in the lateral direction Y may be directly applied to the waist end region 8c during the tearing action. In the above configuration, the average elongation percentage of the elastic member 10 in the waist end region 8c is low, and therefore the elastic force of the elastic member 10 acting as a resistance to the tearing force is low. This makes it difficult for the energy related to the tearing force to be consumed by the elongation of the elastic member 10, and the waist end region 8c can be efficiently torn even with a weaker force. This allows for a stable tearing action and prevents problems such as tearing of the exterior body 5 caused by an excessively strong tearing force. In the longitudinal central region 8e, the average elongation percentage of the elastic members 10 is relatively high. Therefore, even if the average elongation percentage of the elastic members 10 in the waist end regions 8c is set to be somewhat lower, the diaper 1 can still fit adequately around the waist.

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

[0097] <Method for measuring average elongation rate of elastic material> The side joints 8 of the pants-type absorbent article are separated to remove the absorbent main body 4, and the ventral region 5a and the back region 5b of the exterior body 5 are cut out. Furthermore, the ventral region 5a and the back region 5b are cut in parallel to the horizontal direction Y at positions 25 mm in the vertical direction X from the waist end portions 8a (waist opening ends Wa) and / or leg end portions 8b, and the waist end regions 8c (or leg end regions 8d) and the vertical center region 8e are separated. Then, the length of the elastic members 10 in each cut-out region is measured when the pants-type absorbent article is in an expanded and stretched state. From these measurements, the average length of all the elastic members 10 in each of the regions 8c, 8d, and 8e in the maximum stretched state is calculated. All of the elastic members 10 fixed to each of the regions 8c, 8d, and 8e by adhesive or the like are removed from the other components of the exterior body 5 using an appropriate solvent such as ethyl acetate, and the natural length of the elastic members 10 in each of the regions 8c, 8d, and 8e is measured. From these measurements, the average value of the natural length of all of the elastic members 10 in each of the regions 8c, 8d, and 8e is calculated. Then, in each region 8c, 8d, 8e, the ratio of the average length of the elastic member 10 in the expanded, stretched state to the average length of the elastic member 10 at its natural length is calculated, and this is regarded as the average elongation rate of the elastic member 10 in each region 8c, 8d, 8e.

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

[0099] [Example of exterior body configuration] 8, the exterior body 5 preferably includes, as the multiple thermoplastic sheets 50, an outer layer sheet 51 and an inner layer sheet 52, for example. The outer layer sheet 51 is disposed on the non-skin side of the inner layer sheet 52, and forms the non-skin facing surface of the exterior body 5. Between the inner layer sheet 52 and the outer layer sheet 51, for example, an elastic member 10 is disposed. In this embodiment, at least a portion of the exterior body 5 is folded back from the waist opening end Wa to the skin side, so that the exterior body 5 has a folded back structure. In the example shown in Fig. 8, only the outer layer sheet 51 is folded back from the waist end portion 8a to the skin side.

[0100] In this embodiment, as shown in FIG. 8, due to the folded-back structure of the exterior body 5, the side joint portion 8 has a plurality of regions with different numbers of layers of the thermoplastic sheet 50. That is, in this embodiment, the side joint portion 8 has a first laminated portion T1 in which six or more thermoplastic sheets 50 are laminated, and a second laminated portion T2 in which a smaller number of thermoplastic sheets 50 than the first laminated portion T1 are laminated. In this embodiment, the first laminated portion T1 corresponds to the area where the exterior body 5 is folded back. The first laminated portion T1 includes, as the thermoplastic sheets 50, a first skin-side sheet P1 constituting the skin-facing surface. The second laminated portion T2 includes, as the thermoplastic sheets 50, a second skin-side sheet P2 constituting the skin-facing surface.

[0101] In the example shown in Fig. 8, the first laminate part T1 in the ventral region 5a is composed of three layers: an outer layer sheet 51 that is not folded, an inner layer sheet 52 that is not folded, and a folded outer layer sheet 51. The first laminate part T1 in the dorsal region 5b is also composed of the same three layers. As a result, the first laminate part T1 is composed of a total of six layers. In the first laminate part T1, the first skin side sheet P1 is composed of the folded outer layer sheet 51. In the example shown in Fig. 8, the second laminate part T2 in the ventral region 5a is composed of two layers, an outer layer sheet 51 that is not folded back, and an inner layer sheet 52 that is not folded back. The second laminate part T2 in the dorsal region 5b is also composed of the same two layers. As a result, the second laminate part T2 is composed of a total of four layers. In the second laminate part T2, the second skin side sheet P2 is composed of the inner layer sheet 52 that is not folded back.

[0102] 8, the waist end region 8c on the waist end 8a side is disposed in the first laminated section T1. The leg end region 8d on the leg end 8b side is disposed in the second laminated section T2. ​​The longitudinal center region 8e between the waist end region 8c and the leg end region 8d is disposed from the first laminated section T1 to the second laminated section T2. ​​By appropriately adjusting the folding position, the leg end region 8d may be disposed in the first laminated section T1, which has a larger number of layers, or the waist end region 8c may be disposed in the second laminated section T2, which has a smaller number of layers.

[0103] The first laminated part T1 has a larger number of thermoplastic sheets 50 laminated therein than the second laminated part T2, and therefore has a larger amount of thermoplastic resin. Therefore, the first laminated part T1 has a larger amount of resin that is heat-sealed than the second laminated part T2, and the seal strength of the seal part S tends to be high. Therefore, by adjusting the arrangement of the seal portion S of the first laminate portion T1 and the second laminate portion T2, the bonding strength in the first laminate portion T1 and the second laminate portion T2 can be adjusted, thereby improving the tear stability.

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

[0105] (Arrangement of embossed parts on skin side sheet) In this embodiment, the first skin side sheet P1 and the second skin side sheet P2 may each be made of a spunbond nonwoven fabric including a plurality of embossments. The embossment of the spunbonded nonwoven fabric is a portion where the fibers are fused by pressure bonding. For example, the embossment may be formed by intermittently forming the embossment by thermocompression bonding using an embossing roll and a flat roll, by ultrasonic bonding, or by partially fusing the embossment by intermittently applying hot air. From the viewpoint of high productivity and low equipment cost, the embossment is preferably formed by thermocompression bonding. The planar shape of the embossment may be any shape such as a circle, an ellipse, a polygon, or shapes similar thereto. The embossment is preferably formed in a regular pattern, but may be formed in a random pattern. In the embossing, the fibers are easily broken by the heat treatment and / or processing treatment during formation, so if the embossing overlaps with the embossment of the sealed 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 having different embossed area ratios, i.e., the ratio of the total area of ​​a given region occupied by a plurality of embosses to the total area of ​​the given region. Specifically, it is preferable that the embossed area ratio of the first skin side sheet P1 is higher than that of the second skin side sheet P2. The embossed area ratio of a spunbonded nonwoven fabric is measured in an area containing a sufficient number of embosses, for example, in a square area of ​​20 mm x 20 mm of the spunbonded nonwoven fabric. The area occupied by each embossment can be recognized as a series of areas where thermal fusion of fibers is observed. The measurement of the above area ratio is performed in a spread-out and stretched state.

[0107] As described above, the seal strength may decrease in the seal portion S that overlaps with the embossment. Therefore, by increasing the area ratio of the embossment in the first laminated portion T1, which has a large number of layers, the seal portion S and the embossment in the first laminated portion T1 are more likely to overlap, and the seal strength can be prevented from increasing. 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 make the bonding strength in the entire side joint portion 8 more stable. Therefore, the tear stability of the side joint portion 8 can be improved.

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

[0109] (Melting point of skin side 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. A thermoplastic sheet 50 with a high melting point is less likely to be heat-sealed and the seal strength is more likely to decrease when a sealing process is performed under the same conditions as a thermoplastic sheet 50 with a low melting point. Therefore, in the first laminated part T1 having a large number of layers, by increasing the melting point of the first skin side sheet P1, it is possible to suppress an increase in the seal strength of the seal part S of the first laminated part T1. This makes it possible to reduce the difference in the bond strength between the first laminated part T1 and the second laminated part T2, and to make the bond strength in the entire side joint part 8 more stable. Therefore, it is possible to increase the ease of tearing the side joint part 8.

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

[0111] (Basis weight of skin side 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 a thermoplastic sheet 50 with a high basis weight, the amount of thermoplastic resin is also large, and the seal strength of the seal portion S is likely to be high. Therefore, in the first laminated portion T1 having a large number of layers, by lowering the basis weight of the first skin side sheet P1, it is possible to prevent the seal strength of the seal portion S of the first laminated portion T1 from increasing. 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 in the entire side joint portion 8. Therefore, the tear stability of the side joint portion 8 can be improved.

[0112] The basis weight of the first skin side sheet P1 is preferably 10 g / m 2 More preferably, 12 g / m 2 More preferably, it is 30 g / m 2 Less than or equal to 25 g / m 2 The following is the result. The basis weight of the second skin side sheet P2 is preferably 12 g / m 2 More preferably, 14 g / m 2 More preferably, it is 40 g / m 2 Less than or equal to 30 g / m 2 The following is the result.

[0113] <Second embodiment> Next, other embodiments will be described. In each of the following embodiments, the same or corresponding configurations as those in the first embodiment will be denoted by the same reference numerals and the description thereof will be omitted as appropriate. In addition, the configurations described in the first embodiment can be applied to the pants-type absorbent article (pants-type disposable diaper) in each embodiment to the extent possible.

[0114] As explained with reference to Fig. 3 etc., at the start of the tearing operation, an outward tearing force F inclined at 45° to the longitudinal direction X (or transverse direction Y) peels off each sealed portion S with a line L perpendicular to that direction as a peeling interface. At this time, the line L is a line obtained by inclining a straight line along the longitudinal direction X by 45° outward in the transverse direction Y on the end side of the longitudinal direction X (the waist end 8a side in Fig. 3).

[0115] In the first embodiment, an example is described in which multiple sealed portions S are arranged to overlap such a line L in the waist end region 8c and / or leg end region 8d, which are vertical end regions, but the arrangement of the sealed portions S is not limited to this example. As shown in FIG. 9, in this embodiment, the sealed portion S in the waist end region 8c is configured so that two or more sealed portions S do not overlap a line (line L) that is formed by inclining a straight line along the vertical direction by 45 degrees outward in the horizontal direction Y on the waist end 8a side.

[0116] In the side joint portion 208 shown in Fig. 9, the configuration of the sealed portion S in the waist end region 8c is different from that in Fig. 3. Note that the configurations of the sealed portions S in the longitudinal center region 8e and the leg end region 8d in Fig. 9 are the same as those of the side joint portion 8 shown in Fig. 3. 9 also shows an inner region S11 and an outer region S12 for each seal portion S. Of these, at least in the seal portion Sp at the outermost end, the seal strength of the inner region S11 is set higher than that of the outer region S12. In addition, in the seal portion Sq at the boundary, the difference in seal strength between the inner region S11 and the outer region S12 is set smaller than that of the seal portion Sp at the outermost end. In addition, the strength of the inner region S11 and the outer region S12 of each seal portion S may be set as appropriate.

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

[0118] This reduces the possibility of two or more sealed portions S being peeled off simultaneously in the waist end region 8c during a tearing operation. Also, it becomes possible to peel off each sealed portion S individually. This makes it possible to perform a tearing operation with a relatively weak force. Furthermore, since it is possible to avoid a situation in which force is applied locally to multiple positions during the tearing operation, it is possible to sufficiently prevent the occurrence of lateral tears, etc.

[0119] 9 may be applied to the leg end region 8d. That is, the sealed portion S in the leg end region 8d may be configured so that two or more sealed portions S do not overlap a line (line L) obtained by inclining a straight line along the vertical direction 45 degrees outward in the horizontal direction Y on the leg end 8b side. This makes it possible to sufficiently prevent horizontal tearing and easily tear the side joint portion 208 even when the tearing operation is performed from the leg end 8b side.

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

[0121] In the side joint portion 308 shown in Fig. 10, the arrangement of each sealed portion S in the waist end region 8c, the longitudinal central region 8e, and the leg end region 8d is different from that of the side joint portion 8 shown in Fig. 3. The size, pitch, etc. of each sealed portion S in the longitudinal direction X and the lateral direction Y may be set in the same manner as each sealed portion S shown in Fig. 3. 10 also shows an inner region S11 and an outer region S12 for each seal portion S. Of these, at least in the seal portion Sp at the outermost end, the seal strength of the inner region S11 is set higher than that of the outer region S12. In addition, in the seal portion Sq at the boundary, the difference in seal strength between the inner region S11 and the outer region S12 is set smaller than that of the seal portion Sp at the outermost end. In addition, the strength of the inner region S11 and the outer region S12 of each seal portion S may be set as appropriate.

[0122] 10, in the side joint portion 308, a reference line 7c indicating a predetermined position in the longitudinal direction X is set in the longitudinal center region 8e. The position of the reference line 7c is set, for example, to the center position in the longitudinal direction X of the longitudinal center region 8e. Note that the position of the reference line 7c is not particularly limited as long as it is within the longitudinal center region 8e. In this embodiment, the closer to the reference line 7c from the waist end 8a, the further outward in the lateral direction Y the position of the inner end Sc of the sealed portion S is. Also, the closer to the reference line 7c from the leg end 8b, the further outward in the lateral direction Y the position of the inner end Sc of the sealed portion S is. Thus, in this embodiment, the position of the inner end Sc of the sealed portion S closest to the reference line 7c (here, the seventh sealed portion S from the top in the figure) is positioned outermost among the sealed portions S.

[0123] With this configuration, the position of the inner end Sc is continuously directed outward in the lateral direction Y. For example, during a tearing operation, multiple sealed portions S are unlikely to overlap simultaneously with respect to a line L perpendicular to the tearing force F inclined at 45 degrees. This eliminates the need to simultaneously peel off multiple sealed portions S, making it possible to perform the tearing operation with a weak force and sufficiently prevent the occurrence of lateral tears. In addition, the position of the inner end Sc does not locally protrude inward or outward in the lateral direction Y. This prevents a sudden change in the force required for tearing during the tearing operation, allowing the disposer to tear the container without feeling uncomfortable. 10, whether viewed from the waist end 8a or the leg end 8b, the position of the inner end Sc of each sealed portion S gradually shifts outward in the lateral direction Y. Therefore, whether the tearing action is started from the waist end 8a or the leg end 8b, the occurrence of lateral tears can be prevented and the tearing action can be performed 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 that is closest to the reference line 7c. 10, an example in which a single reference line 7c is provided has been described, but two reference lines may be set. For example, a reference line on the waist end 8a side and a reference line on the leg end 8b side are set, and the position of the inner end Sc of the sealed portion S is shifted outward in the horizontal direction Y from each end in the vertical direction X to the reference line closest to each end. In this case, the position of the sealed portion S provided between the two reference lines is set to be aligned in the vertical direction X, for example. This makes it possible to sufficiently prevent the occurrence of horizontal tears, etc., even if the tear force F changes from a state inclined at 45° to a state parallel to the vertical direction X.

[0125] <Fourth embodiment> In the first embodiment, an example has been described in which the position in the lateral direction Y of the inner end Sc of the seal portion S is set to be shifted in the lateral direction Y for each group consisting of two or more seal portions S, but the arrangement of the seal portion S is not limited to this example, and the arrangement of each seal portion may be set individually. As shown in FIG. 11, in this embodiment, the position of the inner end Sc of the sealed portion is disposed laterally further outward from the waist end 8a toward the leg end 8b.

[0126] In the side joint portion 408 shown in Fig. 11, the arrangement of each of the sealed portions S in the waist end region 8c, the longitudinal central region 8e, and the leg end region 8d is different from that of the side joint portion 8 shown in Fig. 3. The size, pitch, etc. of each of the sealed portions S in the longitudinal direction X and the lateral direction Y may be set in the same manner as each of the sealed portions S shown in Fig. 3. 11 also shows an inner region S11 and an outer region S12 for each seal portion S. Of these, at least in the seal portion Sp at the outermost end, the seal strength of the inner region S11 is set higher than that of the outer region S12. In addition, in the seal portion Sq at the boundary, the difference in seal strength between the inner region S11 and the outer region S12 is set smaller than that of the seal portion Sp at the outermost end. In addition, the strength of the inner region S11 and the outer region S12 of each seal portion S may be set as appropriate.

[0127] As shown in FIG. 11, in the side joint portion 408, each sealed portion S is arranged such that the position of the inner end Sc of the sealed portion S shifts outward in the lateral direction Y from the waist end portion 8a toward the leg end portion 8b. There is no limitation on the method of shifting the position of the inner end Sc of each seal portion S. 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, when the tearing operation is started from the waist end portion 8a, multiple sealed portions S are unlikely to overlap simultaneously with the line L perpendicular to the tearing force F inclined at 45 degrees, as in Fig. 10. Therefore, it is not necessary to peel multiple sealed portions S simultaneously, and the tearing operation can be performed with a weak force while the occurrence of horizontal tears can be sufficiently prevented. 11, the position of the inner end Sc of the sealed portion S does not shift toward the inside in the lateral direction Y during the tearing operation. Therefore, the tearing operation can be completed with almost no change in the tearing force F until the end.

[0129] Also, a configuration in which the relationship between the waist end 8a and the leg end 8b is the opposite to that shown in Fig. 11 may be adopted. That is, the position of the inner end Sc of the sealed portion may be disposed laterally outward as it approaches the waist end 8a from the leg end 8b. This makes it possible to sufficiently prevent horizontal tears and improve the ease of the tearing operation, even when the tearing operation starts from the leg end 8b.

[0130] <Other embodiments> Although the embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and it goes without saying that various modifications can be made without departing from the spirit of the present invention.

[0131] In the above embodiment, the pair of side joint portions 8 have been described as having the same configuration, but only one of the side joint portions 8 may have a configuration including the plurality of seal portions S described above.

[0132] For example, in the above embodiment, the exterior body 5 has been described as having the ventral region 5a, the dorsal region 5b, and the crotch region 5c, but is not limited thereto. For example, the exterior body 5 may have a configuration in which the ventral region and the dorsal region are separated without having a crotch region.

[0133] The pants-type absorbent article according to the present invention does not have to be a disposable diaper for infants, and may be, for example, a disposable diaper for adults or children. Furthermore, the pants-type absorbent 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 pants-type absorbent articles include pants-type sanitary napkins.

[0134] In relation to the above-mentioned embodiment, the present invention further discloses the following pants-type absorbent article. <1> A pants-type absorbent article comprising: an absorbent body; an exterior body arranged on a non-skin-facing side of the absorbent body, including a ventral region and a dorsal region located on both sides in a longitudinal direction, the exterior body being constructed by laminating a plurality of thermoplastic sheets; and a pair of side joining portions joining the ventral region and the dorsal region of the exterior body at side edges in a lateral direction perpendicular to the longitudinal direction, The pair of side joints each have a waist end portion, which is an end portion on the waist side in the longitudinal direction, and / or a leg end portion, which is an end portion on the leg side in the longitudinal direction, as a longitudinal end portion, a longitudinal end region within 25 mm in the longitudinal direction from the longitudinal end portion, a longitudinal central region adjacent to the longitudinal end region, and a plurality of seal portions arranged at a distance along the longitudinal direction, Each of the plurality of seal portions has an inner region located on an inner side in the lateral direction and including an inner end portion, and an outer region located on an outer side in the lateral direction and including an outer end portion, a position of the inner end of an outermost seal portion that is disposed closest to the longitudinal end of the plurality of seal portions is disposed laterally inward relative to a position of the inner end of the seal portion that is disposed in the longitudinal central region; Among the plurality of seal portions, at least the seal portion at the outermost end has a seal strength higher in the inner region than in the outer region, Among the plurality of seal portions, in the seal portion at the boundary that is disposed in the longitudinal center region and closest to the longitudinal end region, the difference in seal strength between the inner region and the outer region is smaller than that of the seal portion at the outermost end. Pants-type absorbent article. <2> The ratio of the seal strength of the outer region of the outermost seal portion to the seal 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> The pants-type absorbent article according to claim 1. <3> The seal strength of the inner region of the seal portion at the outermost end is 0.5 N or more and 5 N or less, preferably 0.7 N or more and 4 N or less, The seal strength of the outer region of the seal portion at the outermost end is 0.1 N to 2 N, preferably 0.12 N to 1.8 N. <1> or <2> The pants-type absorbent article according to claim 1. <4> The seal strength of the inner region of the boundary seal portion is lower than the seal strength of the inner region of the outermost seal portion, and The seal strength of the outer region of the boundary seal portion is lower than the seal strength of the outer region of the edge seal portion. <1> from <3> 13. The pants-type absorbent article according to claim 12, <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 is also higher than the degree of melting of the inner regions of other seal portions disposed in the longitudinal end regions. <1> from <4> 13. The pants-type absorbent article according to claim 12, <6> Among the seal portions arranged in the longitudinal end regions, at least the seal portion at the outermost end has a thickness that is approximately the same as that of the inner region. <1> from <5> 13. The pants-type absorbent article according to claim 12, <7> The seal portion disposed in the longitudinal center region has a seal strength in the inner region and a seal strength in the outer region that are substantially the same. <1> from <6> 13. The pants-type absorbent article according to claim 12, <8> A plurality of elastic members extending in the lateral direction are disposed in each of the ventral region and the dorsal region, The elastic elongation of the plurality of elastic members disposed in the longitudinal end regions is lower than the elastic elongation of the plurality of elastic members disposed in the longitudinal center region. <1> from <7> 13. The pants-type absorbent article according to claim 12, <9> In the longitudinal end region, the seal portion is configured so that two or more seal portions do not overlap on a line obtained by inclining a straight line along the longitudinal direction by 45 degrees toward the outside in the lateral direction on the longitudinal end side. <1> from <8> 13. The pants-type absorbent article according to claim 12, <10> The position of the inner end of the seal portion is disposed outward in the lateral direction as it approaches a predetermined position in the longitudinal center region from the longitudinal end. <1> from <9> 13. The pants-type absorbent article according to claim 12, <11> The seal strength of the inner region of the seal portion decreases from the longitudinal end portion toward a predetermined position of the longitudinal center region. <1> from <10> 13. The pants-type absorbent article according to claim 12, <12> The degree of melting of the inner region of the seal portion decreases from the longitudinal end portion toward a predetermined position of the longitudinal center region. <11> The pants-type absorbent article according to claim 1. <13> The position of the inner end of the sealed portion is disposed on the outer side in the lateral direction as it approaches the leg end from the waist end or approaches the waist end from the leg end. <1> from <9> 13. The pants-type absorbent article according to claim 12, [Explanation of symbols]

[0135] Sc…Inner end Sd…outer end S11…Inner area S12…outer area 1. Diapers 4…Absorbent body 5…Exterior body 5a...ventral region 5b…Dorsal region 5c…Inseam area 8, 208, 308, 408…Side joint 8a…Waist end 8b…Leg end 8c…Waist end area 8d…Leg end area 8e…Vertical center area 9. Fusion inhibitors 10...Elastic member 50…Thermoplastic sheet

Claims

1. An absorbent article comprising an absorbent body, an outer wrapper disposed on the non-skin-facing side of the absorbent body and including a ventral region and a dorsal region located on both longitudinal sides, the outer wrapper being formed by laminating a plurality of thermoplastic sheets, and a pair of side joints that join the ventral region and the dorsal region of the outer wrapper at lateral side edges orthogonal to the longitudinal direction, wherein the pair of side joints has a longitudinal end region within 25 mm in the longitudinal direction from a longitudinal end, which is a waist end that is an end on the waist side in the longitudinal direction and / or a leg end that is an end on the leg side in the longitudinal direction, a longitudinal central region adjacent to the longitudinal end region, and a plurality of seal portions spaced apart along the longitudinal direction; each of the plurality of seal portions has an inner region located on the inner side in the lateral direction and including an inner end, and an outer region located on the outer side in the lateral direction and including an outer end; among the plurality of seal portions, the position of the inner end of the outermost seal portion disposed closest to the longitudinal end is disposed more inward in the lateral direction than the position of the inner end of the seal portion disposed in the longitudinal central region; among the plurality of seal portions, at least in the outermost seal portion, the seal strength of the inner region is higher than that of the outer region; among the plurality of seal portions, in the seal portion at the boundary portion disposed in the longitudinal central region and closest to the longitudinal end region, the strength difference in seal strength between the inner region and the outer region is smaller than that of the outermost seal portion A pant-type absorbent article.

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

3. The degree of melting of the inner region of the seal portion at the outermost end is higher than the degree of melting of the outer region of the seal portion at the outermost end, and is also higher than the degree of melting of the inner region of another seal portion disposed in the longitudinal end region. The pants-type absorbent article according to claim 1 or 2.

4. Among the seal portions disposed in the longitudinal end region, at least the seal portion at the outermost end has substantially the same thickness in the inner region and the outer region. The pants-type absorbent article according to claim 1 or 2.

5. The seal portion disposed in the longitudinal central region has substantially the same seal strength in the inner region and the outer region. The pants-type absorbent article according to claim 1 or 2.

6. In each of the ventral region and the dorsal region, a plurality of elastic members extending in the transverse direction are disposed. The elastic body elongation rate of the plurality of elastic members disposed in the longitudinal end region is lower than the elastic body elongation rate of the plurality of elastic members disposed in the longitudinal central region. The pants-type absorbent article according to claim 1 or 2.

7. In the longitudinal end region, the seal portion is configured such that two or more of the seal portions do not overlap a line obtained by inclining a straight line along the longitudinal direction 45 degrees outward in the transverse direction on the longitudinal end side. The pants-type absorbent article according to claim 1 or 2.

8. The position of the inner end portion of the seal portion is disposed more outward in the transverse direction as it approaches a predetermined position in the longitudinal central region from the longitudinal end. The pants-type absorbent article according to claim 1 or 2.

9. The seal strength of the inner region of the seal portion decreases as it approaches a predetermined position in the longitudinal central region from the longitudinal end. The pants-type absorbent article according to claim 1 or 2.

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

11. The position of the inner end portion of the seal portion is arranged on the outer side in the lateral direction as it approaches the leg end portion from the waist end portion or as it approaches the waist end portion from the leg end portion. The pant-type absorbent article according to claim 1 or 2.

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