JP2024010342A - Underpants-type absorbent article - Google Patents

Abstract

PROBLEM TO BE SOLVED: 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

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present invention relates to pants-type absorbent articles such as disposable diapers.

Pants-type absorbent articles generally include an absorbent main body, an exterior body, and a side joint portion (side seal portion) that joins the ventral exterior body and the dorsal exterior body at side ends. There is. The waist opening and leg openings of the pants-type absorbent article are formed by joining the ventral side exterior body and the dorsal side exterior body at the side joints.
On the other hand, after wearing a pants-type absorbent article, the side joints may be torn off and discarded for reasons of hygiene. For this reason, the side joints are required to have a function that does not peel off during the donning operation (when putting on a pants-type absorbent article) and when worn, and allows it to be easily torn when discarded.

From this point of view, Patent Document 1 discloses a pants-type absorbent article that includes a seal portion that joins the lateral ends of the ventral side portion and the dorsal side portion of the exterior body to each other. In the pants-type absorbent article, the seal portion includes a plurality of fused portions arranged spaced apart from each other in the longitudinal direction, and at least two fused portions adjacent to each other among the fused portions are each includes a thin part with a small thickness and a thick part with a relatively large thickness, and both of these thin parts are located laterally inside the fused part.

Further, Patent Document 2 discloses that a strength reducing region in which a joint strength reducing agent is arranged to reduce the joint strength is arranged at the joints at both ends of the ventral part and the dorsal part of the exterior body; A pant-type absorbent article is disclosed that has a non-strength-reduced region where the absorbent material has a non-reduced strength region. In this document, the joint part is arranged continuously in the longitudinal direction, and the strength reduction region part is arranged, for example, on the inside and/or outside of the joint part in the width direction.

JP2020-99618A Japanese Patent Application Publication No. 2011-72577

In Patent Document 1 and Patent Document 2 described above, when the ventral side and the dorsal side of the exterior body are joined, a portion with different joining strengths is provided to make the pants-type absorbent article easier to peel off. On the other hand, depending on the strength and arrangement of the part that joins the ventral side and the dorsal side of the exterior body, peeling starting points or lateral tears may occur, so there is room for further improvement.

An object of the present invention is to provide a pants-type absorbent article that is capable of preventing peeling during the wearing operation and wearing, and is easy to tear when discarded.

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 joints.
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 configured 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 side edges in a lateral direction perpendicular to the longitudinal direction.
The pair of side joints have 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 as longitudinal ends. A longitudinal end region within 25 mm in the longitudinal direction from the direction end, a longitudinal center region adjacent to the longitudinal end region, and a plurality of seal parts spaced apart along the longitudinal direction. has.
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 portion, and an outer region located on the outer side in the lateral direction and includes an outer end portion.
Among the plurality of seal parts, the position of the inner end of the end seal part disposed closest to the longitudinal end is the same as the inner end of the seal part disposed in the longitudinal center area. It is arranged on the inner side in the lateral direction than the position of the end portion.
Among the plurality of seal portions, at least the seal portion at the endmost portion 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 portion located 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 equal to smaller than the seal section.

According to the pants-type absorbent article of the present invention, it is possible to achieve both prevention of peeling during the wearing operation and wearing, and ease of tearing at the time of disposal.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic perspective view showing a pants-type absorbent article according to a first embodiment of the present invention. FIG. 2 is a schematic plan view showing the skin-facing side of the pants-type absorbent article, and is a diagram showing a state in which the pants-type absorbent article is unfolded and stretched into a flat shape by stretching the elastic members of each part. . FIG. 3 is a schematic plan view showing a side joint of the pants-type absorbent article. FIG. 3 is a diagram schematically showing a microscopic image of the cross section of the side joint portion enlarged approximately 300 times. FIG. 2 is a diagram schematically showing a microscopic image of the sealed portion of the side joint section enlarged approximately 500 times, in which (A) shows fibers in the outer region, and (B) shows fibers in the inner region. FIG. 7 is a schematic plan view showing a side joint of a pants-type absorbent article according to a modification of the above embodiment. (A) and (B) are each a schematic plan view showing a side joint of a pants-type absorbent article according to a modification of the above embodiment. It is a typical sectional view of the above-mentioned side junction part, and is a figure showing a mode where a ventral side field and a dorsal side field were separated. FIG. 7 is a schematic plan view of a side joint of a pants-type absorbent article according to a second embodiment of the present invention. FIG. 7 is a schematic plan view of a side joint of a pants-type absorbent article according to a third embodiment of the present invention. FIG. 7 is a schematic plan view of a side joint of a pants-type absorbent article according to a fourth embodiment of the present invention.

Embodiments of the present invention will be described below with reference to the drawings.

<First embodiment>
[Overall structure of pants-type disposable diaper]
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 is hereinafter referred to as a diaper 1.
As shown in FIG. 1, the diaper 1 includes a waist opening 1W and a pair of leg openings 1L, and is worn around the wearer's waist and crotch area when worn. The waist opening 1W has a waist opening end Wa. The diaper 1 has a vertical direction (X) and a horizontal direction (Y). The longitudinal direction X extends from the ventral side of the wearer through the groin region to the back side. The horizontal direction Y is perpendicular to the vertical direction X and corresponds to the left and right direction of the wearer. Furthermore, as shown in FIG. 2 and the like, a direction perpendicular to the longitudinal direction X and the lateral direction Y of the diaper 1 is defined as the thickness direction Z.
In this specification, the "waist side" means the side that approaches the waist opening end Wa of the waist opening 1W in the vertical direction X, and the "leg side" means the side that approaches the waist opening end Wa of the waist opening 1W in the vertical direction It means the side that goes away.
As used herein, the term "inner side in the lateral direction Y" means the side approaching the vertical center line CL that equally divides the pants-type absorbent article (diaper 1) into two in the lateral direction Y; The term "outside in direction Y" means the side moving away from the longitudinal center line CL.
In this specification, with respect to the thickness direction Z, when the pants-type absorbent article (diaper 1) is worn, the side closer to the wearer's skin may be referred to as the skin side, and the side closer to clothing may be referred to as the non-skin side. Further, the "skin-facing surface" of the pants-type absorbent article (diaper 1) or its constituent members means a surface relatively close to the wearer's skin. The "non-skin facing surface" of the pants-type absorbent article (diaper 1) or its constituent members means a surface relatively far from the wearer's skin.
Further, in this specification, unless otherwise specified, numerical values such as dimensions and areas of each part are measured in a natural state in which the elastic member of each part is not stretched.

When a wearer puts on the diaper 1, the wearer first puts his or her legs through the pair of leg openings 1L, pulls up the diaper 1 toward the body, and places the diaper 1 around the wearer's torso and crotch area. In this specification, this series of operations is referred to as a "wearing operation." The donning operation may be performed not by the wearer of the diaper 1 himself but by an assistant.
Furthermore, in this specification, a state in which the diaper 1 is placed in a wearing position that is normally assumed by a wearer is referred to as "when worn."

As shown in FIGS. 1 and 2, the diaper 1 includes an absorbent main body 4 and an exterior body 5 disposed on the side of the non-skin facing surface of the absorbent main body 4.
Note that FIG. 2 shows a form in which the diaper 1 is unfolded, the elastic members of each part are stretched, and the diaper 1 is spread out in a planar shape so as to have the designed dimensions without any influence of the elastic members. This mode is also referred to as the "deployed and stretched mode" of the diaper 1. Developing the diaper 1 means separating the ventral region 5a and the dorsal region 5b of the side joints 8, which will be described later.

The absorbent main body 4 is fixed to the skin-facing side of the exterior body 5. The absorbent main body 4 includes at least an absorbent core 40, and may further include a top sheet 2, a back sheet (not shown), and the like. For example, the absorbent main body 4 has a structure in which a back sheet, an absorbent core 40, and a 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 covering the absorbent core.
As materials used for each component included in the absorbent main body 4 (back sheet, absorbent body 40, top sheet 2, etc.), materials used in the technical field can be used without particular limitation.

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 thermoplastic resin. The thermoplastic sheet 50 preferably contains 90% by mass or more of a thermoplastic resin, more preferably 100% by mass of a thermoplastic resin.
Examples of thermoplastic resins include polyolefins such as polyethylene and polypropylene; polyesters such as polyethylene terephthalate; polyamides such as nylon 6 and nylon 66; polyacrylic acid, polymethacrylic acid alkyl ester, polyvinyl chloride, polyvinylidene chloride, etc. One of these may be used alone or two or more may be used in combination. The thermoplastic fibers may be short fibers or long fibers. As the thermoplastic fibers, core-sheath type or side-by-side type composite fibers, split fibers, irregular cross-section fibers, heat-shrinkable fibers, etc. can also be used.

The exterior body 5 has at least a ventral region 5a disposed on the ventral side of the wearer and a dorsal region 5b disposed 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 wearer's crotch region. In this example, the ventral region 5a, the crotch region 5c, and the dorsal region 5b are arranged along the longitudinal direction X. Furthermore, the exterior body 5 has a shape that is narrowed inward in the lateral direction Y in the crotch region 5c. Thereby, leg openings 1L (see FIG. 1) are formed along the leg openings of the wearer.
It is preferable that the outer edge of the exterior body 5 is configured to be line symmetrical (left-right symmetrical) with respect to the longitudinal center line CL.

Furthermore, the exterior body 5 has a pair of side joints 8, in which a side edge 5d of the ventral region 5a in the lateral direction Y and a side edge 5e of the dorsal region 5b in the lateral direction Y are joined. . The right side joint portion 8 has a structure in which a right side edge 5d of the ventral region 5a and a right side edge 5e of the dorsal region 5b are overlapped and joined in the thickness direction Z. The left side joint portion 8 has a configuration in which a left side edge 5d of the ventral region 5a and a left side edge 5e of the dorsal region 5b are joined together in the thickness direction Z.
The pair of side joints 8 make the ventral region 5a and the dorsal region 5b into a cylindrical shape along the wearer's waist, forming the waist opening 1W and leg opening 1L of the diaper 1.
The side joint portions 8 are preferably joined by heat sealing, ultrasonic sealing, or the like, as will be described in detail later.

[Side joint configuration]
It is preferable that the side joint portion 8 maintains the state in which the ventral region 5a and the dorsal region 5b are joined together without peeling off during the wearing operation and the time of wearing.
On the other hand, when changing the diaper 1 after wearing, a caregiver or the like should clean the ventral area 5a and the dorsal area 5b of the side joint 8 in order to hygienically dispose of excrement adhering to the diaper 1. The diaper 1 may be separated and disposed of after being unfolded.
As described above, it is preferable that the side joint portion 8 has a structure that can prevent peeling during the wearing operation and when being worn, and can be easily torn when discarded.
In addition, in this specification, unintentional separation of the ventral region 5a and the dorsal region 5b of the side joint portion 8 during the operation and wearing of the diaper 1 is expressed as "peeling off." On the other hand, when disposing of the diaper 1, the action of intentionally separating the ventral region 5a and the dorsal region 5b of the side joint 8 by applying an external force to the side joint 8 and/or its surroundings is referred to as " It is expressed as "tearing apart."
Furthermore, the person who tears the side joint 8 when disposing of the diaper 1 is referred to as a "disposer".

In this embodiment, it is preferable that the pair of side joint portions 8 are configured substantially axisymmetrically with respect to, for example, the longitudinal center line CL, and have the same configuration. Below, the structure of one side joint part 8 will be explained in detail.
In the side joint portion 8, the end side in the vertical direction X means the side approaching the waist end 8a or the leg end 8b, and the center side in the vertical direction means the side approaching the waist end 8a or the leg end 8b. It means the side moving away from.

As shown in FIGS. 2 and 3, the side joint portion 8 has a waist end region 8c within 25 mm in the vertical direction X from the waist end 8a, which is the end on the waist side in the vertical direction It has a leg end region 8d within 25 mm in the longitudinal direction X from the leg end 8b, which is the end on the leg side, and a longitudinal center region 8e adjacent to the waist end region 8c and the leg end region 8d. It has a plurality of seal parts S. In addition, in FIG. 3, a boundary line 7a that is 25 mm in the vertical direction x from the waist end 8a and a boundary line 7b that is 25 mm in the vertical direction X from the leg end 8b are schematically illustrated by dotted lines.

The waist end portion 8a and the leg end portion 8b constitute both ends of the side joint portion 8 in the longitudinal direction X. The side joint portion 8 as a whole has a configuration extending in the longitudinal direction X from the waist end 8a to the leg end 8b.
The waist end region 8c, the longitudinal center region 8e, and the leg end region 8d are regions arranged adjacent to each other in this order along the longitudinal direction X. Therefore, the vertical center region 8e is a region sandwiched between the boundary line 7a and the boundary line 7b.
In this embodiment, the waist end 8a and the leg end 8b correspond to longitudinal ends. Further, the waist end region 8c and the leg end region 8d correspond to longitudinal end regions.

The seal 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. The seal portion S is joined by, for example, a pressure means and/or a heating means, and specifically, by heat sealing, ultrasonic sealing, or the like.
As shown in FIG. 4, when enlarging the XZ cross section (cut surface in the longitudinal direction is observed as a thinner area.

As shown in FIG. 3, the plurality of seal parts S are spaced apart from each other along the longitudinal direction X.
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, circular shapes, elliptical shapes, shapes similar to these, and other shapes.
As shown in FIG. 3, from the viewpoint of ensuring a sufficient area for each seal portion S while leaving an interval, the planar shape of the seal portion S is preferably rectangular. preferable.
The end of each seal portion S on the inner side in the lateral direction Y is called an inner end Sc, and the end on the outer side in the lateral direction Y is called an outer end Sd.

Each seal portion S has an inner end Sc serving as an inner end in the lateral direction Y, and an outer end Sd serving as an outer end in the lateral direction Y. Further, in the seal portion S, a region located on the inner side in the lateral direction Y and including the inner end portion Sc is described as an inner region S11, and a region located on the outer side in the lateral direction Y and including the outer end portion Sd is described as an outer region S12.
The inner region S11 and the outer region S12 are regions in which, for example, the seal strengths described below are set to different values. In addition, in all the seal parts S provided in the side joint part 8, it is not necessary that the seal strengths of the inner region S11 and the outer region S12 are different, and for example, the seal strengths of the inner region S11 and the outer region S12 are set to be the same. A seal portion S may also be included.

In this embodiment, a case where the inner region S11 and the outer region S12 are in contact with each other at a boundary line, that is, a case where the seal portion S is divided into two, the inner region S11 and the outer region S12, will be described as an example. Further, it is assumed that the boundary line between the inner region S11 and the outer region S12 passes through approximately the center of each seal portion S in the lateral direction Y.
Note that the boundary line between the inner region S11 and the outer region S12 does not necessarily need to be set approximately at the center in the horizontal direction Y. Further, a boundary line between the inner region S11 and the outer region S12 may be set for each seal portion S.

Here, according to the findings of the present inventors, at the start of the tearing operation of the side joint portion 8, the discarder's fingers are approximately 25 mm to 30 mm away from the waist end 8a or the leg end 8b in the vertical direction X. They are likely to be arranged on both the left and right sides (ventral side and dorsal side) of the side joint portion 8. For example, when the wearer is in a standing position, the discarder's fingers are likely to be placed on the waist side, and when the wearer is in a supine position, the discarder's fingers are likely to be placed on the leg side.
Therefore, in the side joint part 8, the area where external force for tearing (also referred to as "tearing force F") is particularly likely to be applied is defined as the waist end within 25 mm in the longitudinal direction X from the waist end 8a and the leg end 8b, respectively. These are defined as a leg end region 8c and a leg end region 8d. The arrangement and seal strength of the seal portion S in the waist end region 8c and/or leg end region 8d are determined from the viewpoint of preventing tearing during wearing and wearing operations, and facilitating tearing during disposal. Configure as below.
In this specification, seal strength refers to peel strength measured by a measuring device such as Tensilon. On the other hand, the bonding strength refers to the bonding strength felt by the discarder when the side bonding portion 8 is torn.

Below, an example will be mainly described in which a region in which the seal portion S has a characteristic arrangement and seal strength is provided from the waist end region 8c to the longitudinally central region 8e. In addition, in the present invention, a region where the seal portion S has a characteristic arrangement and sealing strength is provided from the leg end region 8d to the longitudinal center region 8e, or between the waist end region 8c and the longitudinal center region 8e. It is also effective when provided over the entire region including the leg end region 8d. Therefore, the description of the waist end region 8c described below can be read as a description of the leg end region 8d as appropriate.

As shown in FIG. 3, in this embodiment, among the plurality of seal parts S, the inner end Sc of the end seal part Sp disposed closest to the waist end 8a is located at the center in the vertical direction. It is arranged inward in the lateral direction Y from the position of the inner end Sc of the seal portion S arranged in the region 8e.
Here, "the seal part S disposed in the vertically central region 8e" is a sealing part S at least partially included in the vertically central region 8e. For example, the seal part S disposed on the boundary line 7a 25 mm from the waist end 8a in the longitudinal direction becomes.

In the example shown in FIG. 3, four stages of seal parts S are arranged in the waist end region 8c, with the seal part Sp at the end being the first stage. Among these, the positions of the inner end portions Sc of the second and third seal portions S in the lateral direction Y are set in the same manner as the end seal portion Sp. The position of the inner end Sc of the fourth seal portion S closest to the boundary line 7a is set to the inner side in the lateral direction Y than the endmost seal portion Sp. Note that the number of seal parts S provided in the waist end region 8c is not limited, and for example, five or more stages of seal parts S may be provided. Further, a seal portion S may be provided in which the position of the inner end portion Sc is located on the inner side in the lateral direction Y than the seal portion Sp at the endmost portion.

Further, a plurality of seal portions S are provided in the longitudinal center region 8e, but two seal portions S are illustrated here. The positions of the inner end portions Sc of these seal portions S are set at the inner side in the lateral direction Y than at least the endmost seal portion Sp. Here, the position of the inner end Sc of the seal part S in the longitudinal center region 8e is set in the same manner as the fourth stage seal part S in the waist end region 8c, but the position is not limited thereto. It may be set arbitrarily within a range that is on the inner side in the lateral direction Y than the end seal portion Sp. Further, the positions of the inner end portions Sc of the seal portion S in the longitudinally central region 8e do not need to be aligned vertically.

Generally, at the start of the tearing operation of the diaper 1, a tearing force F having both components on the center side in the longitudinal direction X and on the outside in the lateral direction Y is applied from inside the waist end region 8c (or leg end region 8d). As shown in FIG. 3, this tearing force F is an oblique outward force inclined at approximately 45 degrees with respect to the longitudinal direction X and the lateral direction Y.

Furthermore, since tearing in the waist end region 8c (or leg end region 8d) progresses along the direction of this force F, the peeling interface moves along a direction perpendicular to this direction. That is, the peeling interface is formed on a line L along a direction including a component toward the center in the vertical direction (X) and a component toward the inside in the horizontal direction (Y). For example, if there are a plurality of seal parts S on the line L, those seal parts S will be torn at the same time, and the force required for tearing will increase.
In FIG. 3, the tearing operation is started from the waist end 8a side. In this case, the line L is a straight line along the longitudinal direction X, inclined at 45 degrees outward in the lateral direction Y on the side of the waist end 8a where the tearing operation starts.

As described above, the position of the inner end Sc of the endmost seal portion Sp is set to the inner side (on the right side in the figure) of any seal portion S in the longitudinally central region 8e. Therefore, for example, when starting to peel off the endmost seal part Sp, the seal part S of the vertically central region 8e does not overlap on the line L, and the endmost seal part Sp and the vertically central region 8e do not overlap. Peeling of the seal portion S does not start at the same time. Thereby, it becomes possible to easily tear the seal portion S of the waist end region 8c including the seal portion Sp at the endmost portion.

Furthermore, in this embodiment, among the plurality of seal parts S, at least in the endmost seal part Sp, the seal strength of the inner region S11 is higher than that of the outer region S12.
In the example shown in FIG. 3, an inner region S11 and an outer region S12 are divided by a boundary line that bisects the endmost seal portion Sp at the center in the horizontal direction Y. Among these, the seal strength of the inner region S11 is set higher than the seal strength of the outer region S12. By increasing the seal strength, the force required to peel off the inner region S11 becomes larger than the force required to peel off the outer region S12 at the endmost seal portion Sp.

For example, the inner region S11 of the seal portion Sp at the end is a portion that is likely to be subjected to force during wearing or during a donning operation. In this way, by increasing the sealing strength of the inner region S11 where force is easily applied, the starting point of peeling (hereinafter sometimes referred to as the peeling starting point) is less likely to occur during wearing or during the wearing operation. It is possible to prevent tearing during the wearing operation.
Further, the outer region S12 of the seal portion Sp at the end has a smaller seal strength than the inner region S11 and is easier to peel off. As a result, during the tearing operation, it is possible to tear easily with a smaller force than, for example, when the seal strengths of both the inner region S11 and the outer region S12 are increased.

In particular, the seal portion Sp at the end tends to peel off along a line L inclined at 45 degrees with respect to the vertical direction X (horizontal direction Y). Therefore, there is a high possibility that the outer region S12 of the endmost seal portion Sp is peeled off at the same time as the seal portion S (second stage seal portion S) adjacent to the endmost seal portion Sp. For this reason, for example, if the seal strength of the outer region S12 is also set to be strong, the two seal portions S located close to each other will be torn at almost the same time, causing an excessive load to be locally applied to the exterior body 5. There is. As a result, in the side joint portion 8, the exterior body 5 breaks at a portion adjacent to the seal portion S, and the fracture of the exterior body 5 further progresses outward in the lateral direction Y along the longitudinal direction of the seal portion S. Tears may occur. When horizontal tearing of the exterior body 5 occurs, the tearing operation is interrupted each time, causing great stress to the discarder and the wearer.

On the other hand, in the seal portion Sp at the end, the sealing strength of the outer region S12 is relatively lower than that of the inner region S11. As a result, even if the tearing operation progresses and the endmost seal part Sp and the adjacent seal part S are peeled off at the same time, it is possible to sufficiently peel them off with a relatively weak force. Therefore, a situation in which an excessive load is applied locally can be avoided, and it is possible to sufficiently suppress the occurrence of horizontal tearing.

Furthermore, in the present embodiment, among the plurality of seal parts S, in the seal part Sq located in the longitudinal center region 8e and closest to the waist end region 8c, the seal strength between the inner region S11 and the outer region S12 is lowered. The difference in strength is smaller than that of the seal portion Sp at the extreme end.
Here, the boundary seal part Sq is the seal part S that is closest to the boundary line 7a (closest to the waist end 8a) among the seal parts S that are at least partially arranged in the longitudinal center region 8e. . In FIG. 3, the fifth seal portion S from the top is the boundary seal portion Sq.

As described above, at the start of the tearing operation, an oblique outward tearing force F that is inclined at 45 degrees in the vertical direction X and the horizontal direction Y acts. On the other hand, as the tearing operation progresses, the tearing force F acts along the longitudinal direction X.
For example, when a discarder tears near the part that is being held down with his or her fingers, the tearing force F is thought to be along the vertical direction X. Therefore, for example, the direction of the tearing force F is in the longitudinal direction The direction changes from a direction tilted by 45 degrees to a direction substantially parallel to the vertical direction X. In this case, the line L representing the peeling interface is approximately parallel to the lateral direction Y.

For this reason, for example, in the seal portion Sq at the boundary, the inner region S11 and the outer region S12 are peeled off substantially simultaneously along a line L substantially parallel to the lateral direction Y.
When peeling two areas almost simultaneously like this, there is a difference in the force required to peel each area, so force acts in an unintended direction different from the tearing force F, resulting in horizontal tearing, etc. there is a possibility.

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 to be smaller than that in the seal portion Sp at the end. As a result, the magnitude of the force required to peel off the inner region S11 and the outer region S12 becomes closer to each other, compared to a case where there is a difference in seal strength as in the seal portion Sp at the end, for example. As a result, it becomes possible to suppress a situation in which a force acts in a direction deviating from the tearing force F, resulting in horizontal tearing or the like.

In this way, the arrangement and seal strength of each seal part S are set in the side joint part 8, assuming a change in the direction of the tearing force F (line L representing the peeling interface) as the tearing operation progresses. .
That is, at the start of the tearing operation, by making the position of the inner end Sc of the seal part Sp at the end protrude more inward than the seal part S in the longitudinally central region 8e, the tearing operation is performed at an angle of 45 degrees from the longitudinal direction X. It becomes possible to selectively apply the force F to the seal portion Sp at the extreme end.
In addition, in the seal portion Sp at the end, since the seal strength of the outer region S12 is lower than that of the inner region S11, even if the tearing operation progresses and the adjacent seal portion S is peeled off, the tearing force F is extremely high. It doesn't need to be big.
Furthermore, as the tearing operation progresses, a tearing force F along the longitudinal direction X acts. In the seal portion Sq at the boundary where such tearing force F acts, the difference in seal strength between the inner region S11 and the outer region S12 is set to be smaller than that of the seal portion Sp at the end, thereby preventing horizontal tearing, etc. It is possible to suppress this and continue the tearing operation smoothly.
In addition, in the seal portion Sp at the end, the seal strength of the inner region S11 is higher than that of the outer region S12, so the inner region S11 is difficult to peel off even if force is applied during wearing or wearing operation, and the starting point of peeling does not occur. Hateful.
Thereby, in the side joint portion 8, it is possible to achieve both prevention of peeling during the wearing operation and wearing, and ease of tearing at the time of disposal.

[Seal strength setting example]
Here, the seal strength of each seal portion S will be explained.
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 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 waist end region 8c, in the second and third tier seal parts S arranged on the inner side in the lateral direction Y, similarly to the seal part Sp at the end, the seal part Sp at the end Similarly, the seal strength of the inner region S11 is set higher than the seal strength of the outer region S12. Thereby, it is possible to sufficiently prevent peeling during the wearing operation and the wearing operation. In addition, since the sealing strength of the outer region S12 is weak, even if adjacent sealing parts S are peeled off at the same time, parts with strong sealing strength are unlikely to overlap on the line L representing the peeling interface, and a weak force However, it becomes possible to perform tearing operations easily.
Note that the seal strength of the fourth stage seal portion S may be set in the same manner as the endmost seal portion Sp, or may be set in the same manner as the endmost seal portion Sq described below. good.

In the longitudinal center region 8e, the seal portion Sq at the boundary is set to have a weaker seal strength than the seal portion Sp at the end 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 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 lower than the seal strength of the inner region S11 of the edge seal portion Sp. is set lower than the seal strength of the outer region S12 of the seal portion Sp at the end.

The seal portion Sq at the boundary is a portion where external forces, etc. that tend to peel off the side joint portion 8 during wearing or during a donning operation are less likely to concentrate, compared to, for example, the seal portion Sp at the extreme end. Therefore, even if the seal strength of the inner region S11 and the outer region S12 is somewhat low, peeling can be sufficiently prevented.
Further, in the seal portion Sq at the boundary portion, since the direction of the tearing force F is along the longitudinal direction X, the inner region S11 and the outer region S12 are peeled off almost simultaneously. Therefore, if the sealing strength of the inner region S11 and the outer region S12 is too strong, a strong force will be required to tear it. On the other hand, by making the seal strength of the inner region S11 and outer region S12 of the seal portion Sq at the boundary smaller than that of the seal portion Sp at the end, the tearing operation can be easily performed with a weak force along the longitudinal direction X. It becomes possible to do this.

Typically, the seal strength of the inner region S11 and the seal strength of the outer region S12 of the seal portion S disposed in the longitudinal center region 8e are set to be substantially the same. As a result, it is possible to sufficiently avoid a situation in which the tearing force F acting along the longitudinal direction X acts in an unintended direction. Can be easily torn.
For example, each seal portion S arranged in the longitudinally central region 8e is set to have a uniform sealing strength for the inner region S11 and the outer region S12. This allows the tearing operation to be performed with a constant force, making the tearing feel easier.

<Seal strength measurement method>
A method of measuring and comparing the seal strength between the inner region S11 and the outer region S12 of each seal portion S will be explained.
First, it is cut out into a rectangular shape with a length that includes the seal portion S to be measured in the vertical direction X and a length that includes the entire width of the side joint portion 8 in the horizontal direction Y. This rectangular piece is cut along the longitudinal direction X to obtain two types of samples for measurement, one on the outside and one on the inside in the transverse direction. Note that the cutting position is a position that divides the seal portion S into two equal parts in the horizontal direction Y. The plurality of cut out measurement samples have the same number of laminated thermoplastic sheets 50.
Subsequently, the lateral 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 it is difficult to fix the end of each measurement sample to the Tensilon, attach tape or the like to the end to ensure a length that allows the Tensilon to be fixed. The sample for measurement is peeled off in the lateral direction Y at a speed of, for example, 10 mm/min, and the peel strength is measured over time. Then, the measured maximum peel strength is taken as the seal strength of the measurement sample.
Regarding the seal portion S provided at the same location, about 10 measurement samples corresponding to the inside and outside in the lateral direction Y are prepared, and the above-mentioned measurements are performed on 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.

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 seal portion Sp at the end is preferably 0.5N or more, more preferably 0.7N or more, and preferably 5N from the viewpoint of preventing peeling during wearing and wearing operations. It is more preferably 4N or less.
The seal strength of the outer region S12 of the seal portion Sp at the end is preferably 0.1 N or more, more preferably 0.12 N or more, and preferably 2 N or less, more preferably 0.1 N or more, from the viewpoint of easy tearing at the time of disposal. Preferably it is 1.8N or less.
In addition, in the seal portion Sp at the end, 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%, from the viewpoint of achieving both prevention of peeling and ease of tearing. % or more, preferably 80% or less, more preferably 70% or less.

[Example of how to adjust seal strength]
The seal strength of the seal portion S can be adjusted, for example, by changing conditions such as temperature, pressure, and/or time during the sealing process for forming the seal portion S.
Moreover, the sealing strength can also be adjusted by changing the area of the sealing part S, which is the fused part of the fibers.
Further, the sealing strength can also be adjusted by changing the composition of the fibers of the thermoplastic sheet 50.
A specific example will be described below.

(Example of adjustment depending on the degree of melting of fiber)
The seal portion S is a portion formed by fusing fibers of a plurality of thermoplastic sheets 50 of the exterior body 5. Therefore, in a portion where the fibers are sufficiently melted, the fibers tend to stick to each other after cooling, and the sealing strength tends to be higher.
In this embodiment, the degree of melting of the inner region S11 of the seal portion Sp at the end is higher than the degree of melting of the outer region S12 of the seal portion Sp at the end, and The degree of melting is higher than that of the inner region S11 of the other seal portions S.
Thereby, the sealing strength of the inner region S11 of the seal portion Sp at the endmost portion becomes the maximum among the inner region S11 and outer region S12 of each seal portion S included in the waist end region 8c.
Further, by controlling the degree of melting and creating a difference in seal strength, it is possible to finely set the seal strength. This makes it possible to smoothly change the seal strength, making tearing easier.

<How to calculate the melting degree of the inner region and outer region>
First, the side joint portion 8 is cut to prepare two types of measurement samples including the XZ cross section (cross section 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. prepare. The plurality of 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 using a scanning electron microscope (SEM) at a magnification of, for example, 500 times. In each captured image, the outer edge of the fiber is detected using image analysis software, and the length of the detected line is calculated as the circumference of the fiber. For each of the inner region S11 and the outer region S12, an average value of the circumferential lengths of the fibers calculated from five or more images is calculated, and the average value is set as the circumferential length of the fibers of the seal portion S.
The circumferential lengths 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.

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.
The fiber 55 in FIG. 5(A) includes many irregularities on the outer edge 55a and has a long circumference. In other words, the fibers 55 are not melted very much, and the original unevenness of the fibers 55 remains on the outer edge 55a, which is the surface.
On the other hand, the fiber 55 in FIG. 5(B) has a relatively smooth outer edge 55a and has a shorter circumference than the fiber 55 in FIG. 5(A). In other words, the fibers 55 are sufficiently melted, and the irregularities on the 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).

The degree of melting of the fibers can be adjusted by adjusting conditions such as heat, pressure and/or time during the sealing process. By adjusting the seal strength depending on the degree of melting of the fibers, the seal strength can be adjusted without greatly changing the planar shape (for example, the dimension in the longitudinal direction X) or thickness of the inner region S11 and the outer region S12. By aligning the planar shapes of the inner region S11 and the outer region S12, each seal portion S can be torn one after another at approximately constant intervals during tearing. Therefore, the tearing operation can be performed stably and smoothly, and the stress on the person disposing of the product can be reduced.
Further, the degree of melting of the fibers can be changed without changing the composition of the fibers of the thermoplastic sheet 50 for each of the inner region S11 and the outer region S12. Thereby, the seal strength can be adjusted relatively easily and accurately.

The ratio of the circumferential length of the fibers in the sealing part S in the outer region S12 to the circumferential length of the fibers in the sealing part 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.

(Example of adjusting the thickness of the seal part)
Generally, by greatly compressing the stacked thermoplastic sheets 50 in the thickness direction Z during the sealing process, the molten fibers are strongly compressed and the seal strength of the seal portion S can be increased. In other words, the thinner the seal portion S is, the higher the seal strength becomes.
On the other hand, the seal strength may be extremely different between a thin region and a thick region. For example, if the inner region S11 is thin and the outer region S12 is thick, the force required to peel off the inner region S11 may become extremely large. In this case, an excessive tearing force F acts on the outer region S12 immediately after the inner region S11 is peeled off, and force is applied in an unintended direction, which may result in horizontal tearing or the like.

In the present embodiment, among the seal parts S arranged in the waist end region 8c, at least the endmost seal part Sp is set so that the thickness of the inner region S11 and the thickness of the outer region S12 are set to be substantially the same. In this case, for example, by adjusting the degree of melting described above, etc., it is possible to make the thicknesses of the inner region S11 and the outer region S12 about the same while making the seal strengths different. This avoids a situation where the difference in seal strength becomes extremely large between the inner region S11 and the outer region S12, and it becomes possible to prevent horizontal tearing and the like.
Note that in the present disclosure, having substantially the same thickness means being substantially the same. For example, if the thickness of one is within ±20% of the thickness of the other, it is assumed that the thicknesses are substantially the same.

<How to measure the thickness of the inner and outer regions>
Two types of samples for measurement are prepared, each including an XZ cross section (a cross section that crosses the seal portion S in the longitudinal direction X) of the inner region S11 and the outer region S12 of the seal portion S. The plurality of cut out measurement samples have the same number of laminated thermoplastic sheets 50. After fixing the measurement sample by a known method, an image of the XZ cross section of the measurement sample is magnified, for example, 500 times, using a SEM or the like. Then, as shown in FIG. 4, the depressed portion in the captured image is defined as the seal portion S (outer region S12 or inner region S11). Using image analysis software, the thickness Ds (see FIG. 4) in the thickness direction Z of a portion that divides this seal portion S into two in the width direction (vertical direction X) is calculated as the thickness of the seal portion S. For each of the inner region S11 and the outer region S12, an average value of the thickness calculated from five or more images is calculated, and the average value is set as the thickness of the inner region S11 and the outer region S12 of the seal portion S.

[Example of seal strength in inner area]
As described above, the inner region S11 is torn earlier than the outer region S12 at the start of the tearing operation. Further, 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 sealing strength of the inner region S11, it is possible to control the force applied by the discarder during the tearing operation, for example.
Below, the seal strength set in each inner region S11 of the plurality of seal parts S provided in the side joint part 8 will be explained. Here, similar to FIG. 3, a configuration will be described assuming a case where it is torn from the waist end 8a, but the description regarding the waist end 8a can be read as the description regarding the leg end 8b.

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

In this case, the seal strength of the inner region S11 is highest at the endmost seal portion Sp, and decreases as it approaches a predetermined position. The seal strength may be configured to decrease linearly or may decrease so as to converge to a constant value. As a result, during the tearing operation, the seal strength of the inner region S11 to which force is easily applied changes continuously (smoothly) toward a predetermined position. This avoids a situation where, for example, force is applied in an unintended direction during the tearing operation, and the diaper 1 can be easily torn without causing horizontal tearing or the like.

Specifically, the melting degree of the inner region S11 of the seal portion S is set to decrease as it approaches a predetermined position in the longitudinally central region 8e from the waist end 8a. 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 avoid tearing during the tearing operation and improve the ease of tearing.

Note that the seal strength of the outer region S12 may be set in accordance with 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. Further, the seal strength of the outer region S12 may be set constant. In this case, the seal strength is typically set to be lower than the seal strength of the corresponding inner region S11. In addition, the method of setting the seal strength of the outer region S12 is not limited.
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 in the section “Method for Measuring Seal Strength” above.

[Example of arrangement of seal part]
Here, as shown in FIG. 3, taking as an example the case where the size (width in the vertical direction X and the horizontal direction Y) of each seal part S provided in the side joint part 8 is constant, An example of the arrangement will be explained.
(Example of arrangement of inner end portions of the seal portion Sp at the end and the seal portion Sq at the boundary)
In this embodiment, the position of the inner end Sc of the seal part Sp at the end is inward in the lateral direction Y within a range of 0.7 mm or more and 5 mm or less from the position of the inner end Sc of the seal part Sq at the boundary part. Set.
In this case, for example, if the seal part S is torn from the waist end region 8c to the longitudinal center region 8e, the position of the seal part will move by about 25 mm in the vertical direction X, but by about 5 mm at most in the horizontal direction Y. only changes. In this way, the inner position of each seal portion S in the lateral direction Y does not change drastically. Thereby, it is possible to avoid the occurrence of horizontal tearing and the like, and to reduce the discomfort when peeling off.

Moreover, at the time of starting tearing, force is often applied by pinching the inner side of the waist end region 8c in the lateral direction Y with fingers. On the other hand, during the subsequent tearing in the longitudinal direction X, the fingers are often moved near the location to be torn. This movement of the finger is preferably along the vertical direction X so that there is as little unnecessary movement (in the lateral direction Y) as possible. From this point of view as well, by arranging the inner end portions of the endmost seal portion Sp and the boundary seal portion Sq within the above-mentioned range, it is possible to provide the side joint portion 8 having a structure that is easily torn as a whole.

Further, the amount of deviation of the center position of the plurality of seal portions S in the lateral direction Y is set within a range of 5 mm or more and 15 mm or less. Here, "the amount of shift in the lateral direction Y of the center position of the plurality of seal parts S" is the relative shift amount in the lateral direction Y of the center position of each seal part S. For example, a seal part S whose center position is the innermost in the lateral direction Y (for example, the seal part Sp at the end in FIG. 3) and a seal part S whose center position is the outermost in the lateral direction Y (in FIG. 3, for example, the seal part Sp at the end) The distance (shift amount) of the center position in the lateral direction Y when comparing the seal portion S) closest to the portion 8b is set within the above range. As a result, the position in the lateral direction Y does not change drastically over the entire area of the side joint portion 8, so that it is possible to sufficiently reduce the discomfort when peeling off while avoiding the occurrence of lateral tearing or the like.

[Example of dimensions regarding seal part]
As for the dimensions of the seal portion S, the following examples can be given from the viewpoint of achieving both prevention of peeling and ease of tearing during the wearing operation and wearing. Note that the following dimensions are measured in a natural state in which the elastic member is 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 preferably 10 mm or less, more preferably 4 mm or less.
The dimension (maximum dimension) of the seal portion S in the longitudinal direction X is preferably 0.1 m or more, more preferably 0.3 mm or more, and preferably 2 mm or less, more preferably 0.6 mm or less.
The pitch of the seal portion S in the longitudinal direction X is preferably 1.5 mm or more, more preferably 2 mm or more, and preferably 5.0 mm or less, more preferably 4 mm or less.
In addition, the pitch in the longitudinal direction X of the plurality of seal parts S means the distance in the longitudinal direction X between the lines that divide each seal part S into two equal parts in the longitudinal direction do. Moreover, when this pitch is not constant, the pitch in the vertical direction X is measured at five locations, and the average value thereof is taken as the pitch in the vertical direction X.

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

From this point of view, as shown in FIG. It is preferable to have a fusion inhibitor 9. In this case, it is preferable that each of the plurality of seal parts S excluding at least the seal part S closest to the end in the longitudinal direction constitute an intersecting seal part having an intersecting part 9s that intersects with the fusion inhibitor 9.
Since the seal portion S closest to the end in the vertical direction X does not overlap the fusion inhibitor 9, a starting point of peeling is less likely to be formed at the end in the vertical direction during wearing and during the wearing operation. On the other hand, since the plurality of seal parts S on the center side in the longitudinal direction can be obtained.

The fusion inhibitor 9 is placed between the thermoplastic sheets 50 of the exterior body 5, for example, before the sealing process for forming the seal portion S.
As the fusion inhibitor 9, any substance capable of suppressing the influence of heat applied during the sealing process can be used without particular limitation. Examples of such substances include hot melt adhesives, polyurethane base materials, petroleum resins, and the like.
In addition to reducing the heat generated in the sealing process, the fusion inhibitor 9 is preferably a hot melt adhesive from the viewpoint of joining the sheets together. As the hot melt adhesive, for example, styrene-based (SIS, SBS, SEBS) or polyolefin-based materials can be used.
As a method for disposing the fusion inhibitor 9, any commonly used method can be used without particular limitation, but a method of applying the fusion inhibitor 9 using a coater gun is preferred. Thereby, the coating shape, basis weight, etc. of the fusion inhibitor 9 can be easily controlled.

The fusion inhibitor 9 may be arranged between the thermoplastic sheets 50 included in the ventral region 5a, or may be arranged between the thermoplastic sheets 50 included in the dorsal region 5b. Alternatively, the fusion inhibitor 9 is 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 in the side joint portion 8. Good too.
"The fusion inhibitor 9 extends linearly" means that the fusion inhibitor 9 extends linearly and/or curvedly in plan view. The fusion inhibitor 9 traverses the cross-sealed portion in the longitudinal direction X, so it extends in a direction that includes the component in the longitudinal direction.

In the example shown in FIG. 6, each seal part S provided in the waist end region 8c is arranged such that the fusion inhibitor 9 intersects with the seal part S excluding at least the endmost seal part Sp. S is placed. Here, the second, third, and fourth seal portions S from the top in the figure are cross seal portions St1, St2, and St3, respectively. The present invention is not limited to this, and for example, only the second and third seal parts S (intersecting seal parts St1 and St2) may intersect with the fusion inhibitor 9, or the seal parts S of the fifth and subsequent stages may intersect with the fusion inhibitor 9. The fusion inhibitor 9 may also intersect with the fusion inhibitor 9.

The intersecting portion 9s means a portion of the intersecting seal portions St1, St2, and St3 that intersects with the fusion inhibitor 9 in plan view.
Here, in the cross seal parts St1, St2, and St3, the end on the waist end 8a side and extending in the lateral direction Y is the upper end Sa, and the end on the leg end 8b side and extending in the lateral direction Y The intersection portion 9s is formed linearly from the lower end Sb to the upper end Sa.
It is preferable that each of the crossing seal parts St1, St2, and St3 have one crossing part 9s. Furthermore, in the side joint portion 8, it is more preferable that one fusion inhibitor 9 intersects each of the plurality of cross seal portions St1, St2, and St3 at one location.

(Example of arrangement of fusion inhibitor 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 portion located closest to the end in the longitudinal direction X (the waist end 8a side in FIG. 6) constitutes a first cross seal portion St1. The intersecting seal portion adjacent to the first intersecting seal portion St1 constitutes a second intersecting seal portion St2. It is preferable that these first intersecting seal parts St1 and second intersecting seal parts St2 intersect with the fusion inhibitor 9 at positions other than the outer end Sd and the inner end Sc on both sides in the lateral direction Y. Moreover, it is preferable that the first cross seal part St1 and the second cross seal part St2 are arranged in the waist end region 8c and/or the leg end region 8d. This facilitates the tearing operation at the longitudinal direction X ends (waist end 8a and/or leg end 8b).

In addition, from the viewpoint of improving the ease of tearing in the longitudinal direction ..., Stn.
In the example shown in FIG. 6, the plurality of seal parts S include a first cross seal part St1, a second cross seal part St2, and a third cross seal part St3.
In addition, in the following description, each cross|crossing seal part St1, St2,... is also called Stn. Here, n is an integer of 2 or more.

In addition, from the viewpoint of further improving tearability, the intersecting seal portion Stn intersects the fusion inhibitor 9 at a position other than the outer end Sd and the inner end Sc on both sides in the lateral direction Y, and the inner end It is preferable that the intersecting distance a(n) between Sc and the intersecting portion 9s decreases monotonically from the end 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 seal portion Sp at the end to the innermost point in the lateral direction Y of the intersection portion 9s. Furthermore, monotonically decreasing means that a relationship is satisfied in which the crossing distance a(n) is longer than the crossing distance a(n-1).
That is, in the above configuration, when n is an integer of 2 or more, the following formula (1) holds true.
a(n)>a(n-1)...(1)
For example, in the example shown in FIG. 6, the intersecting distances a1, a2, and a3 of the first intersecting seal portion St1, the second intersecting seal portion St2, and the third intersecting seal portion St3 satisfy the following relationship.
a1>a2>a3

In this way, the intersection portions 9s serving as tear guide portions are arranged on the outer side in the horizontal direction Y on the end side in the vertical direction X, where force is likely to be applied during wearing or during a donning operation. As a result, on the end side in the longitudinal direction X, force is hardly applied to the intersection portion 9s, which is relatively easy to peel off. Therefore, occurrence of peeling starting points can be avoided.
Further, the intersection portions 9s are arranged closer to the center in the vertical direction X, and further inside in the horizontal direction Y. Thereby, after starting the tearing operation and peeling off the seal part Sp at the end, the seal part S on the center side in the longitudinal direction X can be smoothly peeled off as guided by the intersection 9s. .
Thereby, it is possible to realize the side joint portion 8 that is difficult to tear during wearing or during a donning operation and is easy to tear.

Moreover, from the viewpoint of realizing a more stable tearing operation, as shown in FIG. 6, it is preferable that the widths of the intersection parts 9s of the plurality of intersecting seal parts St1 and St2 in the lateral direction Y are substantially the same.
In the example shown in FIG. 6, the width b1 in the lateral direction Y of the intersection 9s of the first intersection seal part St1 and the fusion inhibitor 9 is the width b1 of the intersection 9s of the second intersection seal part St2 and the fusion inhibitor 9. It is substantially the same as the width b2 in the lateral direction Y of .

The widths b1 and b2 in the lateral direction Y of each intersection 9s are, for example, the average value of the width in the lateral direction Y of the intersection 9s at the upper end Sa and the width in the lateral direction Y of the intersection 9s at the lower end Sb. can do. Alternatively, the widths in the horizontal direction Y of each intersection portion 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 above widths being "substantially the same" means that the width of each intersection 9s is 150% or less when the smallest width of all intersections 9s is taken as 100%. do.
With the above configuration, it is possible to suppress variations in the widths b1 and b2 of the intersection portions 9s, and to suppress variations in the peel strength of each intersection seal portion St1 and St2. This can prevent the person who discards the pants-type absorbent article from feeling uncomfortable during tearing. Therefore, it is possible to prevent the discarder from applying an unnecessarily strong tearing force and causing the exterior body 5 to tear.
In addition, by stabilizing the widths b1 and b2 of the intersection portions 9s, it is possible to suppress a significant decrease in the seal strength of the intersection seal portions St1 and St2, and more reliably prevent the side joint portions 8 from peeling off during the donning operation and when wearing. can be prevented.

Specifically, the width of the intersection portion 9s in the lateral direction Y is preferably 5% or more, more preferably 10% or more, and preferably 60% or less of the length of the intersection seal portion Stk in the lateral direction Y. , more preferably 50% or less.
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 preferably 1.5 mm or less, more preferably 1.2 mm or less.
Note that the dimensions of the intersection portion 9s and the dimensions of the intersection seal portion Stk shall be measured as the dimensions in the maximum extension state.

Moreover, as shown in FIGS. 7(A) and 7(B), it is preferable that the fusion inhibitor 9 is configured in a curved shape. In this case, for example, it is preferable that the fusion inhibitor 9 is constituted by at least a portion of a spiral or wavy curve.
For example, the fusion inhibitor 9 may extend inward in the lateral direction Y of the side joint portion 8 as a whole, and preferably has a spiral or wavy curved shape in plan view as a whole. Further, it is preferable that the fusion inhibitor 9 satisfies the above-mentioned formula (1) etc. by disposing at least a part of the spiral or wavy curve in the side joint portion 8.

The spiral or wavy curve forming the fusion inhibitor 9 has a shape in which a plurality of unit shapes 9a and 9b are repeatedly arranged in one direction.
FIG. 7(A) shows an example in which the curve of the fusion inhibitor 9 has a spiral shape. The spiral shape here means a shape in which a plurality of unit shapes 9a are repeatedly arranged along one direction, with one unit shape 9a having a shape close to a circle or an ellipse. In FIG. 7A, unit shapes 9a that are close to elliptical shapes are repeatedly arranged in the horizontal direction Y. In FIG. In addition, in FIG. 7(A), each unit shape 9a is formed in a closed ring shape, but a part of one unit shape 9a is connected to an adjacent unit shape 9a, and a plurality of unit shapes 9a are connected. It may be formed continuously.
FIG. 7(B) shows an example in which the curve of the fusion inhibitor 9 is wavy. The wavy shape means a shape in which a unit shape 9b is a convexly undulating shape in one direction and the opposite direction, and a plurality of unit shapes 9b are repeatedly arranged along the other direction.

By configuring the fusion inhibitor 9 in the above-described curved shape, tearing can be induced smoothly and tearing force can be prevented from being locally concentrated. This can suppress the discomfort that may occur during the tearing of the side joints 8, and prevent the discarder from applying an unnecessarily strong tearing force and causing the exterior body 5 to tear.

Furthermore, it is preferable that the spiral or wavy curve of the fusion inhibitor 9 extends along the lateral direction Y. That is, it is preferable that the plurality of unit shapes 9a and 9b are arranged along the horizontal direction Y in the curve. Thereby, the fusion inhibitor 9 having a smooth curved shape can be realized.

In this case, it is preferable that the unit shapes 9a and 9b have a larger dimension in the vertical direction X than in the lateral direction Y. The dimensions of the unit shapes 9a, 9b are those of the unit shapes 9a, 9b that at least partially overlap the side joint portion 8, or the unit shapes 9a, 9b adjacent thereto. Further, 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 lateral direction Y means the maximum dimension in the lateral direction Y of the unit shapes 9a, 9b.
For example, in the spiral curve shown in FIG. 7A, the dimension c1 in the vertical direction X of the 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.
As a result, the unit shapes 9a and 9b become 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.

(Example of arrangement of fusion inhibitor in thickness direction)
In order to efficiently exhibit the fusion inhibiting effect of the fusion inhibitor 9, it is more preferable to arrange it near the interface to be joined.
From this point of view, 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 that 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.
In the side joint portion 8, the skin-side sheet P of the ventral region 5a and the skin-side sheet P of the dorsal region 5b face each other and are in contact and sealed. In the above configuration, since the fusion inhibitor 9 is disposed near the bonding interface, the fusion inhibitor 9 tends to inhibit fusion between the ventral region 5a and the dorsal region 5b. Therefore, the peel strength of the intersection 9s can be effectively reduced, and the tearability can be further improved.

In the example shown in FIG. 8, the skin-side sheet P is composed of the inner layer sheet 52 of the exterior body 5. Further, the adjacent sheet Q is constituted by the outer layer sheet 51 of the exterior body 5. In addition, in the cross-sectional view of FIG. 8, the ventral region 5a and the dorsal region 5b of the side joint portion 8 are shown in a separated state for the sake of explanation.
In the example shown in FIG. 8, the fusion inhibitor 9 is placed in the ventral region 5a, but may also be placed in the dorsal region 5b, or in both the ventral region 5a and the dorsal region 5b. You can.

From the viewpoint of further improving tearability, it is preferable that the penetration depth of the fusion inhibitor 9 in the skin-side sheet P is deeper than the penetration depth of the fusion inhibitor 9 in the adjacent sheet Q.
The penetration depth means the depth to which the fusion inhibitor 9 penetrates from the coating surface in the sheet thickness direction.
This makes it easier for the fusion inhibitor 9 to migrate from the non-skin-facing surface of the skin-side sheet P to the skin-facing surface that serves as the bonding interface, making the fusion inhibiting effect of the fusion inhibitor 9 more effective. can be demonstrated. Therefore, tearability can be improved more effectively.

<Method for measuring penetration depth of fusion inhibitor>
The side joint portion 8 to be measured is cut out in the vertical direction X and the horizontal direction Y to prepare a measurement piece in which a cross section of the fusion inhibitor 9 is exposed. Next, an enlarged image of the cross section of the side joint portion 8 in the measurement piece is photographed at a magnification of 200 times using a microscope VHX1000 manufactured by KEYENCE, and an image of the observation field is obtained. In the observation field, the part soaked with the fusion inhibitor 9 is observed as a transparently shining part, so the outline of the part is specified and the area of the area surrounded by the outline is measured. This measurement is performed at five locations in the waist end region 8c and/or leg end region 8d to be measured, and the average value thereof is taken as the penetration depth of the fusion inhibitor 9 in that end region.

[Example of configuration of elastic member]
As shown in FIG. 2, a plurality of elastic members 10 extending in the lateral direction Y are arranged in the ventral region 5a and the dorsal region 5b of the exterior body 5, respectively. Specifically, the plurality of elastic members 10 are arranged between the plurality of thermoplastic sheets 50 of the exterior body 5 (see FIG. 8).
These elastic members 10 exhibit elasticity around the waist of the diaper 1, making it easy to put on the diaper and maintain a good fit when worn.
Note that "the elastic member 10 extends in the lateral direction Y" means that the elastic member 10 extends in the lateral direction Y in the unfolded and extended state. However, the above expression is not limited to a mode in which the elastic member 10 is parallel to the lateral direction Y in the unfolded and stretched state, but includes a mode in which the elastic member 10 extends in the lateral direction Y as a whole.
Furthermore, as shown in FIG. 2, the exterior body 5 may include, in addition to the elastic member 10 described above, a leg elastic member 11 disposed around the leg opening 1L.

The elastic members 10 and 11 are preferably thread-like (thread rubber, etc.) or string-like (flat rubber, etc.) having a rectangular, square, circular, or polygonal cross section, or multifilament-type thread-like ones. can. As the material of the elastic members 10 and 11, materials conventionally used for absorbent articles such as disposable diapers can be used without particular limitation, such as synthetic rubber such as styrene-butadiene, butadiene, isoprene, and neoprene, natural rubber, and EVA. , stretchable polyolefin, polyurethane, and the like.

The outer ends of the elastic members 10 in the ventral region 5a and the dorsal region 5b in the lateral direction Y may be located at or near the side joints 8 in order to ensure elasticity around the entire waist. preferable. Specifically, the distance between the end portion and the side joint portion 8 in the lateral direction Y is preferably 10 mm or less, and the distance is 0 mm and the end portion is located within the side joint portion 8. It is more preferable.
The elastic member 10 is generally arranged at or near a region where force is applied during tearing, and tends to affect the ease with which the side joint portion 8 is torn. Therefore, from the viewpoint of improving the ease of tearing at the time of disposal, it is preferable to adjust the elongation rate of the elastic member as follows.

In the example shown in FIG. 3, the elastic body elongation rate of the plurality of elastic members 10 arranged in the waist end region 8c is lower than the elastic body elongation rate of the plurality of elastic members 10 arranged in the longitudinal center region 8e. Set.
Here, the elastic body elongation rate is an average elongation rate obtained by averaging the elongation rates of the elastic members 10 disposed in the waist end region 8c (or the longitudinal center region 8e).

The elongation rate of the elastic member 10 means the ratio of the length of the elastic member stretched in the unfolded and stretched state of the pants-type absorbent article to the length of the elastic member 10 in its natural length taken out from the pants-type absorbent article. do.
In other words, the lower the elongation rate is, the smaller the elastic force when the elastic member 10 is pulled tends to be.
Note that the elongation rate of the elastic member 10 can be adjusted by adjusting the degree of elongation of the elastic member 10 arranged in the exterior body 5 during manufacturing. During manufacturing, for example, the elastic member 10 is stretched to a predetermined length, and adhesive is applied to the elastic member 10 using a comb or the like to fix the elastic member 10 to the thermoplastic sheet 50 of the exterior body 5.

As described above, a force in the lateral direction Y may be directly applied to the waist end region 8c during the tearing operation. In the above configuration, since the average elongation rate of the elastic member 10 in the waist end region 8c is low, the elastic force of the elastic member 10 that acts as a resistance against the tearing force becomes low. Thereby, the energy related to the tearing force is less likely to be consumed by the expansion of the elastic member 10, and the waist end region 8c can be efficiently torn with a weaker force. This enables a stable tearing operation, and prevents problems such as breakage of the exterior body 5 due to too strong tearing force.
Note that in the longitudinal center region 8e, the average elongation rate of the elastic member 10 is relatively high. Therefore, even if the average elongation rate of the elastic member 10 in the waist end region 8c is set to be somewhat low, the diaper 1 can be sufficiently fitted around the waist.

Note that the elastic body elongation rate may be similarly set in the leg end region 8d. That is, the elastic body elongation rate of the plurality of elastic members 10 arranged in the leg end region 8d is set lower than the elastic body elongation rate of the plurality of elastic members 10 arranged in the longitudinal center region 8e. This makes it possible to sufficiently improve the ease of the tearing operation from the leg end 8b side.

<Method for measuring average elongation rate of elastic member>
The side joints 8 of the pants-type absorbent article are separated, the absorbent body 4 is removed, and the ventral region 5a and the dorsal region 5b of the exterior body 5 are cut out. Furthermore, a position 25 mm away from the waist end 8a (waist opening end Wa) and/or leg end 8b of the ventral region 5a and the dorsal region 5b in the vertical direction X is cut in parallel to the lateral direction Y, and the waist end The region 8c (or leg end region 8d) and the longitudinal center region 8e are separated.
Then, the length of the elastic member 10 in each cut out region is measured in the unfolded and stretched state of the pants-type absorbent article. From this measured value, the average value of the lengths of all the elastic members 10 in the maximum extension state in each region 8c, 8d, and 8e is calculated.
All the elastic members 10 fixed to each region 8c, 8d, 8e with adhesive or the like are removed from other constituent members of the exterior body 5 using an appropriate solvent such as ethyl acetate, and each region 8c, 8d, 8e Measure the natural length of the elastic member 10 at . From this measured value, the average value of the natural lengths of all the elastic members 10 in each region 8c, 8d, and 8e is calculated.
Then, in each region 8c, 8d, and 8e, the ratio of the average length of the elastic member 10 in the unfolded and stretched state to the average length of the elastic member 10 in the natural length is calculated, and this is calculated for each region 8c, 8d, and 8e. 8d and 8e are the average elongation rates of the elastic members 10.

The average elongation rate 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 preferably 500% or less, more preferably 450% or more. % 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 preferably 550% or less, more preferably 500% or less.
The ratio of the average elongation rate of the plurality of elastic members 10 in the waist end region 8c (or leg end region 8d) to the average elongation rate of the plurality of elastic members 10 in the longitudinal center region 8e effectively achieves the above effects. From the viewpoint of obtaining a high temperature, it is preferably 20% or more, more preferably 30% or more, and preferably 90% or less, more preferably 80% or less.

[Example of configuration of exterior body]
As shown in FIG. 8, the exterior body 5 preferably includes, as the plurality of 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 a non-skin facing surface of the exterior body 5. For example, an elastic member 10 is arranged between the inner layer sheet 52 and the outer layer sheet 51.
In this embodiment, at least a portion of the exterior body 5 is folded back from the waist opening end Wa toward the skin side, so that the exterior body 5 has a folded structure. In the example shown in FIG. 8, only the outer layer sheet 51 is folded back from the waist end 8a toward the skin.

In this embodiment, as shown in FIG. 8, due to the folded structure of the exterior body 5, the side joint portion 8 has a plurality of regions in which the number of laminated thermoplastic sheets 50 differs.
That is, in the present embodiment, the side joint portion 8 includes a first laminated portion T1 in which six or more thermoplastic sheets 50 are laminated, and a first laminated portion T1 in which a smaller number of thermoplastic sheets 50 than the first laminated portion T1 are laminated. 2 laminated portion T2. In this embodiment, the first laminated portion T1 corresponds to a region where the exterior body 5 is folded back. The first laminated portion T1 includes, as the thermoplastic sheet 50, a first skin-side sheet P1 that constitutes a skin-facing surface. The second laminated portion T2 includes, as the thermoplastic sheet 50, a second skin-side sheet P2 that constitutes a skin-facing surface.

In the example shown in FIG. 8, the first laminated portion T1 of the ventral region 5a is composed of three layers: an unfolded outer sheet 51, an unfolded inner sheet 52, and a folded outer sheet 51. be done. The first laminated portion T1 of the back region 5b is also composed of three similar layers. As a result, the first stacked portion T1 is composed of six layers in total. In the first laminated portion T1, the first skin-side sheet P1 is composed of a folded outer layer sheet 51.
In the example shown in FIG. 8, the second laminated portion T2 of the ventral region 5a is composed of two layers: an unfolded outer layer sheet 51 and an unfolded inner layer sheet 52. The second laminated portion T2 of the back region 5b is also composed of two similar layers. Thereby, the second laminated portion T2 is composed of a total of four layers. In the second laminated portion T2, the second skin-side sheet P2 is composed of an inner layer sheet 52 that is not folded back.

In the example shown in FIG. 8, the waist end region 8c on the side of the waist end 8a is arranged in the first laminated portion T1. The leg end region 8d on the side of the leg end 8b is arranged in the second laminated portion T2. A longitudinal center region 8e between the waist end region 8c and the leg end region 8d is arranged from the first laminated portion T1 to the second laminated portion T2. Note that the folding position may be adjusted as appropriate to arrange the leg end region 8d in the first laminated portion T1 having a large number of layers, or to arrange the waist end region 8c in a second laminated portion T2 having a small number of layers. You can.

Since the first laminated portion T1 has a greater number of laminated thermoplastic sheets 50 than the second laminated portion T2, the amount of thermoplastic resin is also greater. Therefore, the first laminated portion T1 has a larger amount of heat-sealed resin than the second laminated portion T2, and the sealing strength of the seal portion S tends to be higher.
Therefore, by adjusting the arrangement of the seal parts S of the first laminated part T1 and the second laminated part T2, the bonding strength in the first laminated part T1 and the second laminated part T2 is adjusted, and the tearing stability is improved. be able to.

[Example of configuration of skin-side sheet in first laminated part and second laminated part]
From the viewpoint of adjusting the bonding strength between the first laminated portion T1 and the second laminated portion T2 and improving tearing stability, it is also possible to adopt the first skin-side sheet P1 and the second skin-side sheet P2 with different configurations. good.

(Arrangement of embossed part 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.
Embosses in spunbond nonwoven fabrics are areas where fibers are crimped and fused. Examples of embossments include those formed intermittently by thermocompression bonding using an embossing convex roll and a flat roll, those formed by ultrasonic fusion, and those formed by partial fusion by intermittently applying hot air. Examples include. From the viewpoint of high productivity and low equipment cost, the embossing is preferably formed by thermocompression bonding.
The planar shape of the embossing may be any shape such as a circular shape, an elliptical shape, a polygonal shape, or a shape similar to these. The embossing is preferably formed in a fixed pattern, but may be formed in a random pattern.
In the case of embossing, the fibers tend to break due to heat treatment and/or processing during formation, so if the fibers overlap with the embossing of the seal portion S, the sealing strength may decrease.

Therefore, the first skin-side sheet P1 and the second skin-side sheet P2 have different emboss area ratios, that is, the ratio of the total area of the area occupied by a plurality of embossments to the total area of a predetermined area. Preferably, it is made of spunbond nonwoven fabric. Specifically, it is preferable that the area ratio of the embossing is higher in the first skin-side sheet P1 than in the second skin-side sheet P2.
The area ratio of embossing in a spunbond nonwoven fabric is measured in a region containing a sufficiently large number of embossments, and can be measured, for example, in a 20 mm x 20 mm square region of the spunbond nonwoven fabric. The area occupied by each embossment can be recognized as a series of areas where thermal fusion of the fibers is observed. Note that the measurement of the area ratio is performed in the unfolded and stretched state.

As described above, the seal strength may decrease in the seal portion S that overlaps with the embossing. Therefore, by increasing the area ratio of the embossing in the first laminated portion T1 where the number of laminated layers is large, it is possible to make it easier for the seal portion S and the embossed to overlap in the first laminated portion T1, and to suppress an increase in seal strength. . Thereby, the difference in bonding strength between the first laminated portion T1 and the second laminated portion T2 can be reduced, and the bonding strength in the entire side joint portion 8 can be further stabilized. Therefore, the tearing stability of the side joint portions 8 can be improved.

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

(Melting point of skin side sheet)
As another example, the melting point of the first skin-side sheet P1 is preferably higher than the melting point of the second skin-side sheet P2.
The thermoplastic sheet 50 with a high melting point is less likely to be thermally fused and the sealing strength is more likely to decrease when a sealing process is performed under the same conditions than the thermoplastic sheet 50 with a low melting point. Therefore, by increasing the melting point of the first skin-side sheet P1 in the first laminated portion T1 having a large number of laminated layers, it is possible to suppress an increase in the seal strength of the seal portion S of the first laminated portion T1. Thereby, the difference in bonding strength between the first laminated portion T1 and the second laminated portion T2 can be reduced, and the bonding strength in the entire side joint portion 8 can be further stabilized. Therefore, the tearability of the side joint portion 8 can be improved.

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

(Basic weight of skin side sheet)
As another example, the basis weight of the first skin-side sheet P1 is preferably lower than the basis weight of the second skin-side sheet P2.
In the thermoplastic sheet 50 having a high basis weight, the amount of thermoplastic resin is also large, and the seal strength of the seal portion S tends to be high. Therefore, by lowering the basis weight of the first skin-side sheet P1 in the first laminated portion T1 where the number of laminated layers is large, it is possible to suppress an increase in the seal strength of the seal portion S of the first laminated portion T1. . Thereby, the difference in bonding strength between the first laminated portion T1 and the second laminated portion T2 can be reduced, and the bonding strength in the entire side joint portion 8 can be further stabilized. Therefore, the tearing stability of the side joint portions 8 can be improved.

The basis weight of the first skin-side sheet P1 is preferably 10 g/m ² or more, more preferably 12 g/m ² or more, and preferably 30 g/m ² or less, more preferably 25 g/m ² or less.
The basis weight of the second skin-side sheet P2 is preferably 12 g/m ² or more, more preferably 14 g/m ² or more, and preferably 40 g/m ² or less, more preferably 30 g/m ² or less.

<Second embodiment>
Next, other embodiments will be described. In each of the following embodiments, the same or corresponding configurations as those of the first embodiment described above are given the same reference numerals, and the description thereof will be omitted as appropriate. Moreover, the structure explained in 1st Embodiment can be applied to the pants-type absorbent article (pants-type disposable diaper) of each embodiment to the extent possible.

As explained with reference to FIG. 3, etc., at the start of the tearing operation, an outward tearing force F tilted at 45° with respect to the longitudinal direction Each seal portion S is peeled off as a peeling interface. At this time, the line L was a line obtained by inclining a straight line along the vertical direction X by 45° outward in the horizontal direction Y on the end side in the vertical direction X (the waist end 8a side in FIG. 3).

In the first embodiment, an example will be described in which a plurality of seal portions S are arranged to overlap with such a line L in the waist end region 8c and/or leg end region 8d, which are the longitudinal end regions. However, the arrangement of the seal portion S is not limited to this example.
As shown in FIG. 9, in the present embodiment, the seal portion S in the waist end region 8c is a line (line L) obtained by tilting a straight line along the vertical direction by 45 degrees outward in the lateral direction Y on the waist end 8a side. The structure is such that two or more seal portions S do not overlap.

In the side joint portion 208 shown in FIG. 9, the configuration of the seal portion S in the waist end region 8c is different from that in FIG. 3. In addition, in FIG. 9, the configuration of each seal portion S in the longitudinal center region 8e and the leg end region 8d is similar to the configuration of the side joint portion 8 shown in FIG. 3.
Further, in FIG. 9, for each seal portion S, an inner region S11 and an outer region S12 are illustrated. Among these, at least in the seal portion Sp at the endmost portion, the seal strength of the inner region S11 is set higher than that of the outer region S12. Further, in the seal portion Sq at the boundary portion, the difference in seal strength between the inner region S11 and the outer region S12 is set to be smaller than that in the seal portion Sp at the endmost portion. In addition, the strength of the inner region S11 and the outer region S12 of each seal portion S may be set as appropriate.

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

This reduces the possibility that two or more seal portions S will be peeled off at the same time in the waist end region 8c during the tearing operation. Further, each seal portion S can be individually peeled off. This makes it possible to perform a tearing operation even with a relatively weak force.
Moreover, since it is possible to avoid a situation in which force is locally applied to a plurality of positions during the tearing operation, it is possible to sufficiently prevent the occurrence of horizontal tears.

Note that the configuration of the side joint portion 208 shown in FIG. 9 may be applied to the leg end region 8d. That is, in the leg end region 8d, two or more seal parts S do not overlap a line (line L) obtained by tilting a straight line along the vertical direction 45 degrees outward in the lateral direction Y on the leg end 8b side. It may be configured as follows. As a result, even when the tearing operation is performed from the leg end 8b side, it is possible to sufficiently prevent the occurrence of horizontal tearing, and to easily tear the side joint portion 208.

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

In the side joint portion 308 shown in FIG. 10, the arrangement of each seal portion S in the waist end region 8c, the longitudinal center region 8e, and the leg end region 8d is different from the side joint portion 8 shown in FIG. 3. Note that the size, pitch, etc. in the vertical direction X and the horizontal direction Y of each seal portion S may be set similarly to each seal portion S shown in FIG. 3.
Further, in FIG. 10, for each seal portion S, an inner region S11 and an outer region S12 are illustrated. Among these, at least in the seal portion Sp at the endmost portion, the seal strength of the inner region S11 is set higher than that of the outer region S12. Further, in the seal portion Sq at the boundary portion, the difference in seal strength between the inner region S11 and the outer region S12 is set to be smaller than that in the seal portion Sp at the endmost portion. In addition, the strength of the inner region S11 and the outer region S12 of each seal portion S may be set as appropriate.

As shown in FIG. 10, in the side joint portion 308, a reference line 7c representing a predetermined position in the vertical direction X is set in the vertically central region 8e. The position of the reference line 7c is set, for example, to the center position in the vertical direction X of the vertical center region 8e. Note that if it is inside the vertical center area 8e. The position of the reference line 7c is not particularly limited.
In this embodiment, the closer the reference line 7c is from the waist end 8a, the further the inner end Sc of the seal portion S is disposed on the outer side in the lateral direction Y. Further, as the position of the inner end Sc of the seal portion S approaches the reference line 7c from the leg end 8b, the position of the inner end Sc of the seal portion S is disposed further outward in the lateral direction Y. As described above, in this embodiment, the position of the inner end Sc of the seal portion S closest to the reference line 7c (here, the seventh seal portion S from the top in the figure) is the closest among the seal portions S. placed on the outside.

With such a configuration, the position of the inner end portion Sc continuously moves outward in the lateral direction Y. For example, during a tearing operation, it becomes difficult for the plurality of seal portions S to overlap simultaneously with respect to a line L that is perpendicular to the tearing force F inclined at 45 degrees. Therefore, it is no longer necessary to peel off a plurality of seal portions S at the same time, and it becomes possible to perform the tearing operation with a weak force, and it is possible to sufficiently prevent the occurrence of horizontal tearing, etc.
Further, the position of the inner end portion Sc does not locally protrude inward or outward in the lateral direction Y. Therefore, a situation where the force required for tearing changes suddenly during the tearing operation is avoided, and the discarder can perform the tearing operation without feeling uncomfortable.
Further, in FIG. 10, the position of the inner end Sc of each seal portion S gradually shifts outward in the lateral direction Y when viewed from either the waist end 8a or the leg end 8b. Therefore, regardless of whether the tearing operation is started from the waist end 8a or the leg end 8b, it is possible to prevent horizontal tearing and perform the tearing operation smoothly.

Note that the method of 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 portion 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 approach the position of the inner end Sc of the seal portion S closest to the reference line 7c.
Further, in FIG. 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 side of the waist end 8a and a reference line on the side of the leg end 8b are set, and the position of the inner end Sc of the seal part S is set from each longitudinal direction X end to the reference line closest to each end. is shifted outward in the lateral direction Y. In this case, the positions of the seal portions S provided between the two reference lines are set to be aligned in the vertical direction X, for example. Thereby, even if the tearing force F changes from a state inclined at 45 degrees to a state parallel to the longitudinal direction X, it is possible to sufficiently prevent the occurrence of horizontal tearing, etc.

<Fourth embodiment>
In the first embodiment, an example has been described in which the position of the inner end Sc of the seal part S in the lateral direction Y is set to be shifted in the lateral direction Y for each group consisting of two or more seal parts S. The arrangement of the parts S is not limited to this example, and the arrangement of each seal part may be set individually.
As shown in FIG. 11, in this embodiment, the position of the inner end Sc of the seal portion is arranged laterally outward as it approaches the leg end 8b from the waist end 8a.

In the side joint portion 408 shown in FIG. 11, the arrangement of each seal portion S in the waist end region 8c, the longitudinal center region 8e, and the leg end region 8d is different from the side joint portion 8 shown in FIG. 3. Note that the size, pitch, etc. in the vertical direction X and the horizontal direction Y of each seal portion S may be set similarly to each seal portion S shown in FIG. 3.
Further, in FIG. 11, for each seal portion S, an inner region S11 and an outer region S12 are illustrated. Among these, at least in the seal portion Sp at the endmost portion, the seal strength of the inner region S11 is set higher than that of the outer region S12. Further, in the seal portion Sq at the boundary portion, the difference in seal strength between the inner region S11 and the outer region S12 is set to be smaller than that in the seal portion Sp at the endmost portion. In addition, the strength of the inner region S11 and the outer region S12 of each seal portion S may be set as appropriate.

As shown in FIG. 11, in the side joint portion 408, each seal portion is arranged such that the position of the inner end portion Sc of the seal portion S shifts outward in the lateral direction Y as the waist end portion 8a approaches the leg end portion 8b. S is placed.
The method of shifting the position of the inner end portion Sc of each seal portion S is not limited. For example, an arrangement may be used in which the position of the inner end Sc is linearly shifted outward in the lateral direction Y toward the leg end 8b. Alternatively, the position of each seal portion S may be set so as to approach the position of the inner end Sc of the seal portion S closest to the leg end portion 8b.

With such a configuration, for example, when the tearing operation is started from the waist end 8a, the plurality of seal parts S are unlikely to overlap at the same time with respect to the line L perpendicular to the tearing force F inclined at 45 degrees, as shown in FIG. Become. Therefore, it is no longer necessary to peel off a plurality of seal portions S at the same time, and it becomes possible to perform the tearing operation with a weak force, and it is possible to sufficiently prevent the occurrence of horizontal tearing, etc.
Further, unlike the example shown in FIG. 11, the position of the inner end Sc of the seal portion S does not shift inward in the lateral direction Y during the tearing operation. Therefore, the tearing operation can be completed without substantially changing the tearing force F until the end.

Further, a configuration may be adopted in which the relationship between the waist end 8a and the leg end 8b is reversed from that shown in FIG. 11. That is, the position of the inner end Sc of the seal portion may be arranged laterally outward from the leg end 8b toward the waist end 8a. Thereby, even if the tearing operation is started from the leg end portion 8b, it is possible to sufficiently prevent the occurrence of horizontal tearing and improve the ease of the tearing operation.

<Other embodiments>
Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and it goes without saying that various changes can be made without departing from the gist of the present invention.

In the above-mentioned embodiment, it was explained that a pair of side joint parts 8 had the same composition, but only one side joint part 8 may have a composition including a plurality of seal parts S mentioned above.

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

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

Regarding the embodiments described above, the present invention further discloses the following pants-type absorbent article.
<1>
An exterior body comprising an absorbent main body, and a ventral region and a dorsal region disposed on the non-skin-facing side of the absorbent main body and located on both sides in the longitudinal direction, and configured by laminating a plurality of thermoplastic sheets. and a pair of side joints that join 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 have 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 as longitudinal ends. A longitudinal end region within 25 mm in the longitudinal direction from the direction end, a longitudinal center region adjacent to the longitudinal end region, and a plurality of seal parts spaced apart along the longitudinal direction. has
Each of the plurality of seal portions has an inner region located on the inner side in the lateral direction and includes an inner end portion, and an outer region located on the outer side in the lateral direction and includes an outer end portion,
Among the plurality of seal parts, the position of the inner end of the end seal part disposed closest to the longitudinal end is the same as the inner end of the seal part disposed in the longitudinal center area. disposed laterally inward than the end position,
Among the plurality of seal portions, at least the seal portion at the extreme 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 portion located 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 equal to Pants-shaped absorbent article that is smaller than the seal part of the part.
<2>
The ratio of the seal strength of the outer region of the endmost seal portion to the seal strength of the inner region of the endmost seal portion is 10% or more and 80% or less, preferably 15% or more and 70% or less. The pants-type absorbent article according to <1>.
<3>
The seal strength of the inner region of the seal portion at the end is 0.5N or more and 5N or less, preferably 0.7N or more and 4N or less,
The pants-type absorbent article according to <1> or <2>, wherein the seal strength of the outer region of the seal portion at the end is 0.1 N or more and 2 N or less, preferably 0.12 N or more and 1.8 N or less. .
<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 endmost seal portion, and
The pants-type absorbent according to any one of <1> to <3>, wherein the seal strength of the outer region of the boundary seal portion is lower than the seal strength of the outer region of the end seal portion. Sex items.
<5>
The melting degree of the inner region of the endmost seal portion is higher than the melting degree of the outer region of the endmost seal portion, and the other seal portions disposed in the longitudinal end region The pants-type absorbent article according to any one of <1> to <4>, wherein the melting degree of the inner region is higher than that of the inner region.
<6>
Among the seal portions arranged in the longitudinal end regions, at least the seal portion at the endmost portion has a thickness that is substantially the same in the inner region and the outer region. The pants-type absorbent article described in any one of the above.
<7>
The pants type according to any one of <1> to <6>, wherein the seal portion disposed in the longitudinal center region has substantially the same seal strength in the inner region and the seal strength in the outer region. Absorbent articles.
<8>
A plurality of elastic members extending in the lateral direction are arranged in each of the ventral region and the dorsal region,
The elastic body elongation rate of the plurality of elastic members arranged in the longitudinal direction end region is lower than the elastic body elongation rate of the plurality of elastic members arranged in the longitudinal direction center region. <1> to <7 ＞The pants-type absorbent article according to any one of ＞.
<9>
In the vertical end region, the seal portion is configured such that two or more of the seal portions do not overlap a line obtained by tilting a straight line along the vertical direction to the outside in the horizontal direction at 45 degrees on the vertical end side. The pants-type absorbent article according to any one of <1> to <8>.
<10>
Any one of <1> to <9>, wherein the position of the inner end of the sealing part is disposed further outward in the horizontal direction as it approaches a predetermined position in the vertical center area from the vertical end. The pants-type absorbent article described in .
<11>
The pants-type absorbent according to any one of <1> to <10>, wherein the seal strength of the inner region of the seal portion decreases as it approaches a predetermined position in the longitudinal center region from the longitudinal end portion. Sex items.
<12>
The pants-type absorbent article according to <11>, wherein the degree of melting in the inner region of the seal portion decreases as the distance from the longitudinal end portion approaches a predetermined position in the longitudinal center region.
<13>
The position of the inner end of the seal portion is arranged further outward in the lateral direction as the distance from the waist end approaches the leg end, or as the distance approaches the waist end from the leg end. <1> The pants-type absorbent article according to any one of <9>.

Sc...inner end Sd...outer end S11...inner region S12...outer region 1...diaper 4...absorbent main body 5...exterior body 5a...ventral region 5b...dorsal region 5c...crotch region 8, 208, 308, 408...Side joint portion 8a...Waist end 8b...Leg end 8c...Waist end region 8d...Leg end region 8e...Longitudinal center region 9...Fusion inhibitor 10...Elastic member 50...Thermoplastic sheet

Claims (11)

An exterior body comprising an absorbent main body, and a ventral region and a dorsal region disposed on the non-skin-facing side of the absorbent main body and located on both sides in the longitudinal direction, and configured by laminating a plurality of thermoplastic sheets. and a pair of side joints that join 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 have a waist end that is a waist end in the longitudinal direction and/or a leg end that is a leg end in the longitudinal direction. A longitudinal end region within 25 mm in the longitudinal direction from the direction end, a longitudinal center region adjacent to the longitudinal end region, and a plurality of seal parts spaced apart along the longitudinal direction. has
Each of the plurality of seal portions has an inner region located on the inner side in the lateral direction and includes an inner end portion, and an outer region located on the outer side in the lateral direction and includes an outer end portion,
Among the plurality of seal parts, the position of the inner end of the end seal part located closest to the longitudinal end is the inner end of the seal part arranged in the longitudinal center area. disposed laterally inward from the end position,
Among the plurality of seal portions, at least the seal portion at the extreme end has a seal strength higher in the inner region than in the outer region;
Among the plurality of seal portions, in a seal portion at a boundary portion located 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 equal to Pants-shaped absorbent article that is smaller than the seal part of the part. The seal strength of the inner region of the boundary seal portion is lower than the seal strength of the inner region of the end seal portion, and
The pants-type absorbent article according to claim 1, wherein the seal strength of the outer region of the boundary seal portion is lower than the seal strength of the outer region of the end seal portion. The melting degree of the inner region of the endmost seal part is higher than the melting degree of the outer region of the endmost seal part, and the other seal parts disposed in the longitudinal end region The pants-type absorbent article according to claim 1 or 2, wherein the melting degree of the inner region is higher than that of the inner region. Any one of claims 1 to 3, wherein at least the seal portion at the end of the seal portions arranged in the longitudinal end region has a thickness that is substantially the same in the inner region and the outer region. The pants-type absorbent article according to item 1. The pants-type absorbent according to any one of claims 1 to 4, wherein the seal portion disposed in the longitudinal center region has substantially the same seal strength in the inner region and the seal strength in the outer region. Goods. A plurality of elastic members extending in the lateral direction are arranged in each of the ventral region and the dorsal region,
The elastic body elongation rate of the plurality of elastic members arranged in the longitudinal direction end region is lower than the elastic body elongation rate of the plurality of elastic members arranged in the longitudinal direction center region. The pants-type absorbent article according to any one of the items. In the vertical end region, the seal portion is configured such that two or more of the seal portions do not overlap a line obtained by tilting a straight line along the vertical direction to the outside in the horizontal direction at 45 degrees on the vertical end side. The pants-type absorbent article according to any one of claims 1 to 6. According to any one of claims 1 to 7, the position of the inner end of the seal portion is arranged further outward in the lateral direction as it approaches a predetermined position in the longitudinal center region from the longitudinal end. pants-type absorbent article. The pants-type absorbent article according to any one of claims 1 to 8, wherein the seal strength of the inner region of the seal portion decreases as it approaches a predetermined position in the longitudinal center region from the longitudinal end portion. . The pants-type absorbent article according to claim 9, wherein the degree of melting in the inner region of the seal portion decreases as the distance from the longitudinal end portion approaches a predetermined position in the longitudinal center region. 1 . The inner end of the seal portion is positioned further outward in the lateral direction from the waist end to the leg end, or from the leg end to the waist end. 7. The pants-type absorbent article according to any one of 7.

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