Underpants-type absorbent article

Abstract

To provide an underpants-type absorbent article which can achieve both separation prevention in a wearing motion and during the wearing, and easiness of tearing in the disposal.SOLUTION: An underpants-type absorbent article includes an absorbent body, an exterior body, and a side joining part. The exterior body is constituted by laminating a plurality of thermoplastic sheets. The side joining part includes a waist region of 25 mm or less in a longitudinal direction from a waist end part and a plurality of seal parts arranged to be separated in a longitudinal direction and in a lateral direction. The side joining part includes a joining strength lowering agent provided linearly between the thermoplastic sheets. The plurality of the seal parts arranged in the waist region include a first seal part that is positioned at the n-th row (n is an integer equal to 1 or more) and is overlapped with a virtual line and a second seal part positioned at the (n+1)-th row in drawing the virtual line inclined at 45 degrees relative to the longitudinal direction and the lateral direction including components to a longitudinal direction leg side and components to the laterally inside. At least one of the first seal part and the second seal part is overlapped with the joining strength lowering agent.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to pants-type absorbent articles such as disposable diapers. [Background technology]

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

[0003] From this perspective, Patent Document 1 discloses a pants-type absorbent article having a strength-reduced region where a bond strength reducing agent that reduces the bond strength is disposed at the joints on both side ends of the ventral and dorsal parts of the exterior body, and a non-strength-reduced region where no bond strength reducing agent is disposed. In this document, the joints are disposed continuously in the longitudinal direction, and the strength-reduced region is disposed, for example, on the inner side and / or outer side in the width direction of the joints. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2011-72577 A Summary of the Invention [Problem to be solved by the invention]

[0005] The technology of Patent Document 1 adjusts the bond strength of the side bond by using a bond strength reducer, but there is room for further improvement in terms of preventing peeling during the putting on and wearing motion, and ease of tearing when discarding.

[0006] An object of the present invention is to provide a pants-type absorbent article which is capable of preventing peeling during the putting action and wearing and is also easily tearable when discarded. [Means for solving the problem]

[0007] A pants-type absorbent article according to one embodiment of the present invention includes an absorbent main body, an exterior body, and a pair of side joining portions. The exterior body is disposed on the non-skin facing side of the absorbent main body, includes a ventral region and a dorsal region located on both sides in the longitudinal direction, and is constructed by laminating a plurality of thermoplastic sheets. The pair of side joints join the ventral region and the dorsal region of the exterior body at side edges in a lateral direction perpendicular to the longitudinal direction. The pair of side joints have a waist end and a leg end which constitute both ends in the vertical direction, a waist region within 25 mm in the vertical direction from the waist end, and a plurality of seal portions arranged at a distance along the vertical direction and the horizontal direction. At least one of the pair of side joints further includes a bond strength reducer provided linearly between the thermoplastic sheets. The multiple sealed portions arranged in the waist region of the side joint include a first sealed portion and a second sealed portion that overlap with an imaginary line drawn at an angle of 45 degrees to the vertical and horizontal directions, the imaginary line including a component toward the vertical leg side and a component toward the inside of the horizontal direction. The first sealed portion is located in the nth row (n is an integer equal to or greater than 1) from the waist end side, and the second sealed portion is located in the n+1th row. At least one of the first seal portion and the second seal portion overlaps the bond strength reducing agent. Effect of the Invention

[0008] According to the pants-type absorbent article of the present invention, it is possible to achieve both prevention of peeling during the action of putting on and while wearing, and ease of tearing when discarding. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic perspective view showing a pants-type absorbent article according to a first embodiment of the present invention. [Diagram 2] 1 is a schematic plan view showing the skin-facing side of the pants-type absorbent article, and shows the pants-type absorbent article unfolded and the elastic members of each part stretched to spread out flat. FIG. [Diagram 3] FIG. 2 is a schematic plan view showing a side joining portion of the pants-type absorbent article. [Figure 4] FIG. 4 is a partially enlarged view of a waist region of the side joint, illustrating the positional relationship between the seal portion and the joint strength reducing agent. [Diagram 5] FIG. 2 is a schematic cross-sectional view of the side joint portion, showing an aspect in which the ventral region and the dorsal region are separated. [Figure 6] FIG. 13 is a partially enlarged view of a waist region of a side joint portion of a pants-type absorbent article according to a second embodiment, illustrating the positional relationship between the seal portion and a joint strength reducing agent. [Figure 7] FIG. 13 is a partially enlarged view of a waist region of a side joint portion of a pants-type absorbent article according to a third embodiment, illustrating the positional relationship between the seal portion and a joint strength reducing agent. [Figure 8] FIG. 13 is a partially enlarged view of a waist region of a side joint portion of a pants-type absorbent article according to a fourth embodiment, illustrating the positional relationship between the seal portion and a joint strength reducing agent. [Figure 9] FIG. 13 is a partially enlarged view of a waist region of a side joint portion of a pants-type absorbent article according to a fifth embodiment, illustrating the positional relationship between the seal portion and a joint strength reducing agent. [Figure 10]FIG. 13 is a partially enlarged view of a waist region of a side joint portion of a pants-type absorbent article according to a sixth embodiment, illustrating the positional relationship between the seal portion and a joint strength reducing agent. [Figure 11] FIG. 13 is a partially enlarged view of a waist region of a side joint portion of a pants-type absorbent article according to a seventh embodiment, illustrating the positional relationship between the seal portion and a joint strength reducing agent. [Figure 12] FIG. 23 is a partially enlarged view of a waist region of a side joint portion of a pants-type absorbent article according to an eighth embodiment, illustrating the positional relationship between the seal portion and a joint strength reducing agent. [Figure 13] FIG. 13 is a partially enlarged view of a waist region of a side joint portion of a pants-type absorbent article according to a ninth embodiment, illustrating the positional relationship between the seal portion and a joint strength reducing agent. [Figure 14] FIG. 23 is a partially enlarged view of a waist region of a side joint portion of a pants-type absorbent article according to a tenth embodiment, illustrating the positional relationship between the seal portion and a joint strength reducing agent. [Figure 15] FIG. 23 is a partially enlarged view of a waist region of a side joint portion of a pants-type absorbent article according to an eleventh embodiment, illustrating the positional relationship between the seal portion and a joint strength reducing agent. [Figure 16] FIG. 23 is a partially enlarged view of a waist region of a side joint portion of a pants-type absorbent article according to a twelfth embodiment, illustrating the positional relationship between the seal portion and a joint strength reducing agent. [Figure 17] FIG. 23 is a schematic plan view showing a side joining portion of a pants-type absorbent article according to a thirteenth embodiment. [Figure 18] FIG. 23 is a schematic cross-sectional view of a side joining portion of a pants-type absorbent article according to a fourteenth embodiment, showing an aspect in which the ventral region and the rear region are separated. [Figure 19] FIG. 23 is a schematic cross-sectional view of a side joining portion of a pants-type absorbent article according to a fifteenth embodiment, showing an aspect in which the ventral region and the dorsal region are separated. [Figure 20]FIG. 23 is a schematic cross-sectional view of a side joining portion of a pants-type absorbent article according to a sixteenth embodiment, showing a state in which the ventral region and the rear region are separated. [Figure 21] This is a schematic diagram showing a microscopic image of the seal portion of the above-mentioned side joint magnified approximately 500 times, where (A) shows the fibers of the seal portion of the first laminate region T1 and (B) shows the fibers of the seal portion of the second laminate region T2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0011] First Embodiment [Overall configuration of pants-type disposable diapers] 1 and 2 show a pants-type disposable diaper 1 as a pants-type absorbent article according to a first embodiment of the present invention. The pants-type disposable diaper 1 will be referred to as diaper 1 hereinafter.

[0012] As shown in FIG. 1, the diaper 1 has a waist opening 1W and a pair of leg openings IL, and is worn around the waist and crotch of a wearer. The waist opening 1W has a waist opening end Wa. The diaper 1 has a longitudinal direction X and a lateral direction Y. The longitudinal direction X extends from the wearer's abdominal side through the crotch to the back side. The lateral direction Y is perpendicular to the longitudinal direction X and corresponds to the left-right direction of the wearer. Furthermore, as shown in FIG. 2 etc., the direction perpendicular to the longitudinal direction X and the lateral direction Y of the diaper 1 is defined as a thickness direction Z. In this specification, the "waist side" means the side approaching the waist opening end Wa of the waist opening 1W in the vertical direction X, and the "leg side" means the side away from the waist opening end Wa in the vertical direction X. In this specification, "the inner side in the lateral direction Y" means the side in the lateral direction Y that is closer to the vertical center line CL that divides the pants-type absorbent article (diaper 1) in half in the lateral direction Y, and "the outer side in the lateral direction Y" means the side that is away from the vertical center line CL. In this specification, with respect to the thickness direction Z, the side closer to the wearer's skin when the pant-type absorbent article (diaper 1) is worn may be referred to as the skin side, and the side closer to the clothing may be referred to as the non-skin side. Furthermore, the "skin-facing side" refers to the side of the pant-type absorbent article (diaper 1) or its constituent members that faces the wearer's skin, i.e., the side that is relatively closer to the wearer's skin. The "non-skin-facing side" refers to the side of the pant-type absorbent article (diaper 1) or its constituent members that faces the opposite side to the skin-facing side (clothing side), i.e., the side that is relatively farther from the wearer's skin.

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

[0014] As shown in Figs. 1 and 2, the diaper 1 includes an absorbent body 4 and an exterior body 5 arranged on the non-skin-facing side of the absorbent body 4. 2 shows the diaper 1 unfolded and stretched in a plane to achieve the design dimensions with all the elastic members stretched and free from any influence of the elastic members. This state is also referred to as the "unfolded and stretched state" of the diaper 1. Unfolding the diaper 1 means separating the ventral region 5a and the dorsal region 5b of the side joint portion 8, which will be described later.

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

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

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

[0018] Furthermore, the exterior body 5 has a pair of side joints 8 in which a side edge 5d in the lateral direction Y of the ventral region 5a and a side edge 5e in the lateral direction Y of the dorsal region 5b are joined together. That is, the right side joint 8 has a configuration in which the right side edge 5d of the ventral region 5a and the right side edge 5e of the dorsal region 5b are overlapped and joined together in the thickness direction Z. The left side joint 8 has a configuration in which the left side edge 5d of the ventral region 5a and the left side edge 5e of the dorsal region 5b are overlapped and joined together in the thickness direction Z. As will be described in detail later, the side joints 8 are preferably joined by heat sealing, ultrasonic sealing or the like.

[0019] [Side joint configuration] As shown in FIG. 2, the pair of side joining portions 8 each have a waist end portion 8a and a leg end portion 8b which constitute both ends in the longitudinal direction X, respectively. The waist end portion 8a is the end portion of the side joint portion 8 on the waist side. The leg end 8b is the end of the side joint portion 8 on the leg side. Each side joint portion 8 generally extends in the longitudinal direction X from a waist end portion 8a to a leg end portion 8b.

[0020] A pair of side joints 8 each extending from the waist end 8a to the leg end 8b make the abdominal region 5a and the dorsal region 5b into a tubular shape conforming to the wearer's waist circumference, thereby forming a waist opening 1W and a leg opening 1L of the diaper 1. It is preferable that the side joints 8 maintain the abdominal region 5a and the dorsal region 5b in a joined state without peeling them off during the putting on action and when the diaper is worn. In this specification, the term "peeling off" refers to unintentional separation of the abdominal region 5a and the dorsal region 5b of the side joint portion 8 during the donning action and while the diaper 1 is being worn. On the other hand, when changing the diaper 1 after wearing, from the standpoint of hygienically disposing of excrement adhering to the diaper 1, a caregiver or the like may separate the ventral region 5a and the dorsal region 5b of the side joint portion 8, unfold the diaper 1, and then discard it. In this specification, 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 when disposing of the diaper 1 is referred to as "tearing." In this way, it is preferable that the side joint parts 8 have a structure that can prevent peeling during the putting action and while the garment is being worn, and can be easily torn when discarded.

[0021] From the above viewpoint, in this embodiment, as shown in Fig. 3, each of the pair of side joints 8 includes a plurality of seal portions S and a joint strength reducing agent 9. It is preferable that the pair of side joints 8 have the same configuration. The configuration of one of the side joints 8 will be described in detail below. In this specification, the dimensions and angles of each part are measured in their natural state without stretching the elastic members of each part, unless otherwise specified.

[0022] The sealed portion S is a portion where the thermoplastic sheets 50 of both the ventral region 5a and the dorsal region 5b are fused and joined together. The sealed portion S is joined by, for example, a pressurizing means and / or a heating means, specifically, by heat sealing or ultrasonic sealing. In this specification, the sealed area in the waist region 8c of the side joint portion 8 is a rectangular area surrounding the outline of the entirety of the multiple sealed portions S located in the waist region 8c. More specifically, in the waist region 8c, the rectangular sealed area has a side passing through a waist side end in the longitudinal direction X of the sealed portion S closest to the waist end 8a, a side passing through a leg side end in the longitudinal direction X of the sealed portion S closest to the leg end 8b, a side passing through an outer end in the lateral direction Y of the sealed portion S located on the outermost side in the lateral direction Y, and a side passing through an inner end in the lateral direction Y of the sealed portion S located on the innermost side in the lateral direction Y.

[0023] 3, the multiple sealed portions S are intermittently arranged along the vertical direction X and the horizontal direction Y. In describing the positions of the sealed portions S, they are referred to as the first row, second row, third row, etc. from the waist end portion 8a toward the leg end portion 8b, and as the first column, second column, third column, etc. from the outside to the inside in the horizontal direction Y.

[0024] The multiple seal portions S are arranged in multiple rows. The multiple seal portions S are arranged such that multiple seal rows SL, each consisting of multiple seal portions S spaced apart along the vertical direction X, are positioned in the horizontal direction. In the example shown in Fig. 3, the side joint portion 8 is composed of four seal rows SL1 to SL4. The seal row SL1 is located in the first row, the seal row SL2 in the second row, the seal row SL3 in the third row, and the seal row SL4 in the fourth row. In the example shown in Fig. 3, each seal portion S has the same size and shape, and is rectangular. In each seal row SL, the multiple seal portions S are arranged at equal intervals in the vertical direction X. The arrangement intervals of the seal portions S in the seal row SL are the same in each seal row. The seal rows SL1 and SL3 are configured to be shifted from the seal rows SL2 and SL4 in the vertical direction X by half a pitch (half the distance between two adjacent seal parts in the same seal row). This results in a staggered arrangement of the multiple seal parts S. By arranging them in a staggered pattern, the apparent distance between the seal parts in the vertical direction becomes narrower (it appears to be half the distance between two adjacent seal parts in the same seal row), and the distance between the seal parts does not increase significantly, so that when tearing, force is likely to be applied continuously to the side joints, making it easier to tear. The seal portions S belonging to the seal row SL1 (SL2) and the seal portions S belonging to the seal row SL3 (SL4) are positioned at intervals along the horizontal direction Y and are located in the same row. In two adjacent seal rows (SL1 and SL2, SL2 and SL3, SL3 and SL4), the seal portions S located in each seal row are not positioned next to each other along the horizontal direction Y and are not located in the same row.

[0025] In the side joint 8 of this embodiment and each embodiment described later, in two adjacent seal rows, the inner end in the lateral direction Y of the seal portion S belonging to the seal row SL located more outward in the lateral direction Y and the outer end in the lateral direction Y of the seal portion S belonging to the seal row SL located more inward in the lateral direction Y are located on the same imaginary vertical line (the dashed line in FIG. 4) parallel to the vertical direction X. In other words, the interval between the seal rows is 0 mm. That is, in the seal area in the waist region 8c of the side joint 8, the seal portion S is located over its entire width in the lateral direction Y. On the other hand, in the sealing region, the sealed portions S are not positioned over the entire length in the vertical direction X, and are positioned at a distance in the vertical direction X. In other words, the vertical leg side end of the sealed portion S positioned in the nth (n is an integer of 1 or more) row and the vertical waist side end of the sealed portion S positioned in the n+1th row are positioned at an interval greater than 0 mm in the vertical direction X.

[0026] In the above configuration, the multiple sealed portions S are arranged in multiple rows, spaced apart in the vertical direction X and the horizontal direction Y. This makes it difficult for the influence of peeling of one sealed portion S during putting on and during the putting action to spread to other sealed portions S. Therefore, by arranging the multiple sealed portions S in multiple rows, peeling of the side joint portion 8 during the putting action and while wearing can be effectively prevented.

[0027] The bond strength reducing agent 9 is disposed between the thermoplastic sheets 50 of the exterior body 5 and has a configuration extending linearly. The bond strength reducing agent 9 is disposed between the thermoplastic sheets 50 of the exterior body 5 at a position overlapping a part of the seal portion S, for example, before the sealing step for forming the seal portion S. The bond strength reducing agent 9 has the function of inhibiting fusion of the thermoplastic resin in this sealing step and reducing the bond strength of the seal portion S. Specific examples of the bond strength reducing agent 9 will be described later. The bond strength reducer 9 may be disposed between the thermoplastic sheets 50 included in the ventral region 5a, or may be disposed between the thermoplastic sheets 50 included in the dorsal region 5b. Alternatively, the bond strength reducer 9 may be disposed between the thermoplastic sheet 50 closest to the skin in the ventral region 5a and the thermoplastic sheet 50 closest to the skin in the dorsal region 5b, which face each other at the side joint portion 8. The phrase "the bond strength reducing agent 9 extends linearly" means that the bond strength reducing agent 9 extends in a straight line and / or a curved line.

[0028] [Positional relationship between the seal and the adhesive strength reducer] When the diaper 1 is to be disposed of, the side joint portion 8 may be torn, the ventral region 5a and the dorsal region 5b of the side joint portion 8 may be separated, and the diaper 1 may be unfolded and disposed of. According to the findings of the present inventors, when starting the tearing action of the side joint portion 8, the caregiver's fingers are likely to be placed on both the left and right sides (the ventral and dorsal sides) of the side joint portion 8 between the waist end portion 8a and a point about 25 mm to 30 mm away in the vertical direction X. When the wearer is in an upright position, the caregiver's fingers are likely to be placed on the waist side. Therefore, in the side joint portion 8, the region to which an external force for tearing (also referred to as "tear force") is particularly likely to be applied is defined as the waist region 8c within 25 mm in the vertical direction X from the waist end portion 8a.

[0029] 3, at the start of tearing, an oblique force F is applied, which includes a component toward the leg in the longitudinal direction X and a component toward the outside in the transverse direction Y. The direction of the force F is inclined at approximately 45° to the longitudinal direction X and the transverse direction Y. The tear in the waist region 8c on the tear initiation side progresses along the direction of this force F, so the peel interface moves along a direction perpendicular to the force F. In other words, the peel interface is formed on an imaginary line L along a direction including a component toward the leg side in the longitudinal direction X and a component toward the inside in the transverse direction Y. The imaginary line L is inclined at approximately 45° with respect to the longitudinal direction X and the transverse direction Y.

[0030] In the waist region 8c of the side joint portion 8, when the garment is torn, the imaginary line L (peeling interface) moves in parallel from the waist end portion 8a toward the leg end portion 8b. When multiple sealed portions S are arranged in multiple rows, multiple sealed portions S tend to be arranged on one imaginary line L when the garment is torn, as shown in Figures 3 and 4.

[0031] Here, with reference to FIG. 4, two seal portions S that simultaneously overlap one imaginary line L are referred to as a first seal portion S1 and a second seal portion S2, respectively. The first sealed portion S1 is a sealed portion located in the nth row. The second sealed portion S2 is a sealed portion located in the n+1th row, that is, the row immediately below the row to which the first sealed portion S1 belongs. The first seal portion S1 is located outboard in the lateral direction Y relative to the second seal portion S2.

[0032] 4 and in Figures 6 to 15 showing other embodiments described later, imaginary lines L that overlap the first sealed portion and / or the second sealed portion when torn are labeled with symbols L1 to L4. When the side joint portion 8 is torn from the waist end portion 8a toward the leg end portion 8b, the peel interface moves in the order of L1, L2, L3, and L4. 16 showing another embodiment described later, imaginary lines L1 and L2 are added to the imaginary line L. When the side joint portion 8 is torn from the waist end portion 8a toward the leg end portion 8b, the peel interface moves in the order of L1 and L2. In addition, when there is no need to particularly distinguish between the virtual lines L1 to L4, they will be referred to as virtual line L.

[0033] As described above, when multiple seal portions S are arranged in multiple rows, multiple seal portions S are likely to be arranged on one imaginary line L. In such a case, when tearing, multiple seal portions S arranged on the same imaginary line L will be torn simultaneously. In other words, when tearing, a force greater than or equal to the total seal strength of these multiple seal portions S is definitely required.

[0034] In contrast to this, in this embodiment, the positional relationship between the seal portion S and the bond strength reducing agent 9 in the waist region 8c is as follows. That is, as shown in Fig. 4, in the waist region 8c of the side joint portion 8, at least one of the first seal portion S1 and the second seal portion S2 located on the same imaginary line L is positioned so as to overlap the bond strength reducing agent 9. In the example shown in Fig. 4, the bond strength reducing agent 9 overlaps the first seal portion S1. By overlapping the bond strength reducing agent 9 on the first sealed portion S1 and / or the second sealed portion S2, the total seal strength of the two sealed portions S (the first sealed portion S1 and the second sealed portion S2) is weakened compared to a configuration in which the bond strength reducing agent 9 does not overlap. In other words, when the two sealed portions S (the first sealed portion S1 and the second sealed portion S2) are torn apart at the same time, they can be torn apart with a weak force, and the load applied to the exterior body 5 is suppressed. As a result, in the side joint portion 8, the exterior body 5 breaks at a portion adjacent to the sealed portion S, and further, so-called lateral tearing, in which the breakage of the exterior body 5 progresses outward in the lateral direction Y, can be effectively prevented. By suppressing the occurrence of lateral tearing of the exterior body 5, interruption of the tearing action due to each lateral tear is reduced, and stress on the caregiver and the wearer can be reduced.

[0035] In this manner, a plurality of sealed portions S are arranged at intervals in the vertical direction X and the horizontal direction Y to form a multi-row arrangement structure, and at least one of the first sealed portion S1 and the second sealed portion S2 in the waist region 8c is configured to overlap with the bond strength reducing agent 9, thereby preventing tearing when worn and during the wearing action, while facilitating tearing when discarding.

[0036] The positional relationship between the seal portion S and the bonding strength reducing agent 9 will be described in more detail below. 4, in the waist region 8c, the distance in the vertical direction X between a waist-side end SF1 in the vertical direction X of the first sealed portion S1 and a waist-side end SF2 in the vertical direction X of the second sealed portion S2 is defined as a distance D1. The distance in the horizontal direction Y between an inner end SC1 in the horizontal direction Y of the first sealed portion S1 and an inner end SC2 in the horizontal direction Y of the second sealed portion S2 is defined as a distance D2.

[0037] In this embodiment, as shown in FIG. 4, in the waist region 8c, the first sealed portion S1 and the second sealed portion S2 are arranged to satisfy the relationship D1>D2. With this arrangement, when the side joint portion 8 is torn from the waist end portion 8a toward the leg end portion 8b, focusing on the first sealed portion S1 and the second sealed portion S2, the first sealed portion S1 starts to tear first, and only a portion of the first sealed portion S1 is torn. Then, both the first sealed portion S1 and the second sealed portion S2 are torn. Then, the tearing of the first sealed portion S1 finishes, and only a portion of the second sealed portion S2 is torn. In Fig. 4, the imaginary line L1 corresponds to the location where the tearing of the first sealed portion S1 starts. The imaginary line L2 corresponds to the location where the tearing of the second sealed portion S2 starts while the tearing of the first sealed portion S1 continues. The imaginary line L3 corresponds to the location where the tearing of the first sealed portion S1 ends while the tearing of the second sealed portion S2 continues. The imaginary line L4 corresponds to the location where the tearing of the second sealed portion S2 ends.

[0038] 4, the first sealed portion S1 has a first region 11 and a third region 13. The second sealed portion S2 has a second region 12 and a fourth region 14. The first region 11 and the second region 12 correspond to the regions of the first seal portion S1 and the second seal portion S2 that are sandwiched between the imaginary line L2 and the imaginary line L3. The third region 13 corresponds to a region sandwiched between the imaginary lines L1 and L2 in the first seal portion S1. The fourth region 14 corresponds to the region between the imaginary lines L3 and L4 in the second seal portion S2.

[0039] The first region 11 is a region through which the imaginary line L passes when the imaginary line L is moved in parallel from the waist end 8a toward the leg end 8b (in the order of L1, L2, L3, L4) and overlaps with both the first sealed portion S1 and the second sealed portion S2. In the figure, the first region 11 of the first sealed portion S1 is marked with a thick diagonal line slanting downward to the right. The second region 12 is a region through which the imaginary line L passes when the imaginary line L is moved in parallel from the waist end 8a toward the leg end 8b in the second sealed portion S2 and overlaps both the first sealed portion S1 and the second sealed portion S2. In the figure, the second region 12 of the second sealed portion S2 is marked with a thick diagonal line slanting downward to the right.

[0040] The third region 13 is a region through which the imaginary line L passes when the imaginary line L is moved in parallel from the waist end 8a toward the leg end 8b in the first sealed portion S1 and overlaps only the first sealed portion S1. In the figure, a thin diagonal line is drawn in the second region 12 of the second sealed portion S2, slanting upward to the right. The fourth region 14 is a region through which the imaginary line L passes when the imaginary line L is moved in parallel from the waist end 8a toward the leg end 8b in the second sealed portion S2 and overlaps only the second sealed portion S2. In the figure, a thin diagonal line is drawn in the fourth region 14 of the second sealed portion S2, slanting upward to the right.

[0041] In the example shown in Figure 4, when torn, in the first seal portion S1 and the second seal portion S2, the imaginary line L corresponding to the peel interface passes only through the third region 13 of the first seal portion S1, then simultaneously passes through both the first region 11 of the first seal portion S1 and the second region 12 of the second seal portion S2, and then passes only through the fourth region 14 of the second seal portion S2.

[0042] In order to facilitate easier tearing during disposal, it is more preferable that the bonding strength reducing agent 9 overlaps at least one of the first region 11 and the second region 12 where both the first sealed portion S1 and the second sealed portion S2 are torn simultaneously when torn. In this embodiment, the bond strength reducing agent 9 overlaps the first region 11 of the first seal portion S1. In this way, by overlapping the first region 11 and the bond strength reducing agent 9, the total seal strength of the first region 11 and the second region 12 is weaker than in a configuration in which the bond strength reducing agent 9 does not overlap. In other words, when the first region 11 of the first sealed portion S1 and the second region 12 of the second sealed portion S2 are torn apart simultaneously, they can be torn apart with a weak force. In addition, it is possible to prevent a large force from being locally applied to the exterior body 5, and it is possible to more effectively prevent lateral tearing of the exterior body 5. This makes it easier to tear the exterior body 5 when it is disposed of.

[0043] Furthermore, it is more preferable that the bond strength reducing agent 9 be disposed in the third region 13 as well as in the first region 11 of the first seal portion S1. By overlapping the third region 13 and the bond strength reducing agent 9, the seal strength of the third region 13 becomes weaker than in a state where the bond strength reducing agent 9 does not overlap. During tearing, the third region 13 of the first sealed portion S1 is torn first, and then the first region 11 of the first sealed portion S1 and the second region 12 of the second sealed portion S2 are torn. With the above configuration, the third region 13 and the first region 11 and second region 12 can all be torn with a weak force, and the difference between the force required to tear the third region 13 and the force required to tear the first region 11 and second region 12 is not too large. This makes it possible to reduce the change in the force required to tear between the virtual line L1 and the virtual line L3, and allows the tearing operation to be performed stably and smoothly.

[0044] Furthermore, it is more preferable that the bonding strength reducing agent 9 passes continuously across both the first region 11 and the third region of the first seal portion S1 as in this embodiment. This allows the tearing of the third region 13 and the subsequent tearing of the first region 11 and the second region 12 to be carried out continuously, stably and smoothly.

[0045] In order to prevent peeling during the putting on and wearing of the mask, it is preferable that other sealants located in the same row as the seal portion S overlapped by the bond strength reducing agent 9 not overlap with the bond strength reducing agent 9. In the example shown in FIG. 3, the first seal portion S1 (located in the first column, second row) that overlaps with the bonding strength reducing agent 9 and another seal portion S (located in the third column, second row) located in the same row do not overlap with the bonding strength reducing agent 9.

[0046] 3, the first seal portion S1 overlapped by the bonding strength reducing agent 9 is located in the second row and first column, but is not limited thereto. For example, the first seal portion S1 may be located in the first row, or the first seal portion S1 may be located in the third row or later. In waist region 8c, there may be at least one configuration in which at least one of a first seal portion S1 located in an nth (n is an integer of 1 or more) row and a second seal portion S2 located in an n+1th row, which simultaneously overlap one virtual line L, overlaps with the bond strength reducing agent 9. Also, there may be a plurality of such configurations in waist region 8c. In order to further prevent tearing during wearing and wearing movements, it is preferable that the first row of sealed portions S located closest to the waist end portion 8a and the bond strength reducing agent 9 do not overlap.

[0047] [Example of exterior body configuration] 5, the exterior body 5 preferably includes, as the multiple thermoplastic sheets 50, an outer layer sheet 51 and an inner layer sheet 52, for example. The outer layer sheet 51 is disposed on the non-skin side of the inner layer sheet 52, and forms the non-skin facing surface of the exterior body 5. Between the inner layer sheet 52 and the outer layer sheet 51, an elastic member 10, which will be described later, is preferably disposed. In this embodiment, at least a portion of the exterior body 5 is folded back from the waist opening end Wa to the skin side, so that the exterior body 5 has a folded back structure. In the example shown in Fig. 5, only the outer layer sheet 51 is folded back from the waist end portion 8a to the skin side. In the cross-sectional view of FIG. 5, for the sake of explanation, the ventral region 5a and the dorsal region 5b of the side joint portion 8 are shown in a separated state.

[0048] In the example shown in FIG. 5, the waist region 8c is disposed in a region of the exterior body 5 that includes the folded-back structure. In this case, in the waist region 8c, among the multiple thermoplastic sheets 50 of the outer body 5, the skin-side sheet P that constitutes the skin-facing surface is the folded outer layer sheet 51, and the adjacent sheet Q adjacent to the skin-side sheet P is the inner layer sheet 52. The skin side sheet P is the sheet located closest to the skin in the waist region 8c of each of the ventral region 5a and the dorsal region 5b. The skin side sheet P of the ventral region 5a and the skin side sheet P of the dorsal region 5b are in contact with each other in an opposing state and are sealed. In other words, the skin-facing surface of the skin side sheet P becomes the joining interface of the side joining portion 8.

[0049] [Example of placement of adhesive strength reducer] From the viewpoint of reducing the bonding strength of the seal portion S more effectively, the bonding strength reducer 9 is preferably arranged as follows. As shown in Fig. 5, the bond strength reducing agent 9 is preferably disposed in the waist region 8c between the skin side sheet P and the adjacent sheet Q. In the example shown in Fig. 5, the bond strength reducing agent 9 is disposed in the ventral region 5a, but may also be disposed in the dorsal region 5b, or may be disposed in both the ventral region 5a and the dorsal region 5b. As a result, the bond strength reducer 9 is disposed between the skin side sheet P, which forms the bonding interface when sealed, and the adjacent sheet Q adjacent thereto. This makes it easier for the bond strength reducer 9 to exert its effect of inhibiting fusion between the ventral region 5a and the dorsal region 5b, effectively reducing the bond strength of the region where the sealed portion S and the bond strength reducer 9 overlap. As a result, the ease of tearing can be further improved.

[0050] From the viewpoint of further improving the ease of tearing, it is preferable that the penetration depth of the bond strength reducing agent 9 in the skin side sheet P is deeper than the penetration depth of the bond strength reducing agent 9 in the adjacent sheet Q. The penetration depth means the depth to which the bonding strength reducing agent 9 has penetrated from the applied surface in the sheet thickness direction. The penetration depth can be measured as follows.

[0051] (Method of measuring penetration depth of adhesive strength reducing agent) The side joint 8 to be measured is cut in the vertical direction X and the horizontal direction Y to prepare a measurement piece on which the cross section of the bond strength reducing agent 9 appears. Next, an enlarged image of the cross section of the side joint 8 in the measurement piece is taken at a magnification of 200 times using a microscope VHX1000 manufactured by KEYENCE Corporation, and an image of the observation field is obtained. In the observation field, the part permeated with the bond strength reducing agent 9 is observed as a transparent shiny part, so the outline of the part is identified, and the area of ​​the region surrounded by the outline is measured. This measurement is performed at five points in the waist region 8c, and the average value of these measurements is regarded as the permeation depth of the bond strength reducing agent 9 in the waist region 8c.

[0052] This allows the bonding strength reducer 9 to migrate more easily from the non-skin facing surface of the skin side sheet P to the skin facing surface which forms the bonding interface, and the bonding strength reducer 9 can more effectively inhibit fusion. Therefore, the ease of tearing can be more effectively improved.

[0053] [Example of seal dimensions] The following are examples of dimensions of the sealed portion S from the viewpoint of preventing peeling during donning and wearing and easiness of tearing. Note that the following dimensions are measured in a natural state with the elastic member not stretched. The dimension (maximum dimension) of the seal portion S in the lateral direction Y is preferably 0.15 mm or more, more preferably 0.2 mm or more, and is preferably 7 mm or less, more preferably 5 mm or less. The dimension (maximum dimension) of the seal portion S in the vertical direction X is preferably 0.1 mm or more, more preferably 0.3 mm or more, and is preferably 2 mm or less, more preferably 0.6 mm or less.

[0054] The pitch in the lateral direction Y between the multiple seal portions S belonging to the same row is preferably 0.4 mm or more, more preferably 0.7 mm or more, and is preferably 7 mm or less, more preferably 4 mm or less. The pitch in the horizontal direction Y of multiple seal portions S belonging to the same row means the distance in the horizontal direction Y between the lines that bisect each seal portion S in the horizontal direction Y in adjacent seal portions S in the horizontal direction Y. If the pitch is not constant, the pitch in the horizontal direction Y is measured at five locations, and the average value is taken as the pitch in the horizontal direction Y. In the examples shown in Fig. 4 and Figs. 6 to 16 described later, the pitch in the horizontal direction Y of multiple seal portions S belonging to the same row is the same as the dimension in the horizontal direction Y of the seal portion S. However, this is not limited to this, and the pitch in the horizontal direction Y of multiple seal portions S belonging to the same row may be smaller or larger than the dimension in the horizontal direction Y of the seal portion S. Furthermore, in the example shown in Fig. 17 described later, the pitch in the horizontal direction Y of multiple seal portions S belonging to the same row is twice the dimension in the horizontal direction Y of the seal portion S.

[0055] 4 and the examples shown in Figures 6 to 17 described later, the distance between adjacent seal rows is 0 mm, but it may be greater than 0 mm, or two seal portions belonging to each of two adjacent seal rows may be positioned so as to overlap in the horizontal direction Y. From the viewpoint of narrowing the dimension of the seal area in the horizontal direction Y to make it difficult to disperse the tearing force and to make it easier to tear, it is more preferable that the distance between adjacent seal rows is 2 mm or less.

[0056] The pitch in the longitudinal direction X of the plurality of seal portions S in each seal row SL is preferably 1.5 mm or more, more preferably 1.7 mm or more, and is preferably 5.0 mm or less, more preferably 4 mm or less. The pitch in the longitudinal direction X of the multiple seal portions S means the distance in the longitudinal direction X between the lines that bisect each seal portion S in the longitudinal direction X in adjacent seal portions S in the longitudinal direction X. If the pitch is not constant, the pitch in the longitudinal direction X is measured at five locations, and the average value is taken as the pitch in the longitudinal direction X.

[0057] The distance D1 between the waist side end in the longitudinal direction X of the first sealed portion S1 located in the nth row and the waist side end in the longitudinal direction X of the second sealed portion S2 located in the n+1th row, which simultaneously overlap one virtual line L, is preferably 0.7 mm or more, more preferably 0.8 mm or more, and is preferably 2.5 mm or less, more preferably 2 mm or less. The distance D2 between the lateral Y inner end of the first seal portion S1 and the lateral Y inner end of the second seal portion S2, which simultaneously overlap a certain virtual line L, is preferably 0.5 mm or more, more preferably 1 mm or more, and is preferably 8 mm or less, more preferably 6 mm or less.

[0058] [Example of the configuration of the adhesive strength reducing agent in plan view] In order to achieve a more stable tearing action, it is preferable that the bonding strength reducing agent 9 has a uniform line width in plan view, as shown in FIG.

[0059] Furthermore, the bond strength reducer 9 is not limited to a configuration that extends mainly linearly, and may be curved. For example, the bond strength reducer 9 may be provided in a spiral or wavy curved shape in at least one of the ventral region 5a and the dorsal region 5b. The spiral or wavy curve that forms the bond strength reducer 9 has a shape in which multiple unit shapes are repeatedly arranged in one direction. The spiral shape referred to here means a shape in which a plurality of unit shapes, each of which is a shape close to a circle or an ellipse, are repeatedly arranged in one direction. One unit shape may be formed as a closed ring, or a portion of one unit shape may be connected to an adjacent unit shape to form a plurality of unit shapes in a continuous manner. The above-mentioned wavy shape means a shape in which a shape that protrudes and undulates in one direction and the opposite direction is regarded as one unit shape, and a plurality of unit shapes are repeatedly arranged in another direction.

[0060] In this case, it is preferable that the dimension of the unit shape in the vertical direction X is larger than the dimension in the horizontal direction Y. This makes the unit shape longer in the vertical direction X. The dimension of this unit shape is the dimension of a unit shape that at least partially overlaps with the side joint portion 8 or an adjacent unit shape. Moreover, the dimension in the vertical direction X means the maximum dimension of the unit shape in the vertical direction X, and the dimension in the horizontal direction Y means the maximum dimension of the unit shape in the horizontal direction Y.

[0061] In this embodiment and in each embodiment described later, in the seal region in the waist region 8c of the side joint 8, the seal portion S is located over the entire width in the horizontal direction Y. Therefore, by making the unit shape of the bond strength reducing agent 9 elongated in the vertical direction X, it is possible to easily overlap the bond strength reducing agent 9 and the seal portion S. Furthermore, it is more preferable to make the length dimension in the vertical direction X of the unit shape of the bonding strength reducing agent 9 larger than the distance in the vertical direction X between the leg side end in the vertical direction X of the sealing portion S located in the nth row and the waist side end in the vertical direction X of the sealing portion S located in the n+1th row. This makes it easier to control so that the bonding strength reducing agent 9 and the sealing portion S overlap more reliably.

[0062] [Specific examples of adhesive strength reducing agents] The bonding strength reducing agent 9 can be any substance that can suppress the influence of heat applied during the sealing process, which is a process for forming the seal portion S. The bonding strength reducing agent 9 preferably contains, as such a substance, for example, an oil agent, a high-melting point resin having a higher melting point than the thermoplastic sheet 50, a hot melt adhesive, or the like. From the viewpoint of reducing heat generated in the sealing process and bonding the sheets together, it is preferable that the bonding strength reducing agent 9 contains a hot melt adhesive. As the hot melt adhesive, for example, a styrene-based (SIS, SBS, SEBS) or polyolefin-based material can be used. The method for disposing the bonding strength reducing agent 9 can be any commonly used method without any particular limitation, but a method of applying the bonding strength reducing agent 9 using a coater gun is preferred. This makes it possible to easily control the application shape and basis weight of the bonding strength reducing agent 9, and therefore the bonding strength.

[0063] [Example of configuration when the number of layers of the exterior body at the side joint is different] In this embodiment, as shown in FIG. 5, the exterior body 5 constituting the side joint 8 has a folded structure, and the side joint 8 has multiple regions with different numbers of thermoplastic sheets 50 laminated therein. That is, in this embodiment, the side joint portion 8 has a first laminated region T1 in which six thermoplastic sheets 50 are laminated, and a second laminated region T2 in which a smaller number of thermoplastic sheets 50 than in the first laminated region T1 are laminated. The first laminated region T1 includes, as the thermoplastic sheets 50, a first skin-side sheet P1 constituting the skin-facing surface. The second laminated region T2 includes, as the thermoplastic sheets 50, a second skin-side sheet P2 constituting the skin-facing surface. In this embodiment, the first laminated region T1 corresponds to the region where the exterior body 5 is folded back, and the skin-side sheet P in the waist region 8c corresponds to the first skin-side sheet P1.

[0064] In the example shown in Fig. 5, the first laminated region T1 in the ventral region 5a is composed of three layers: an outer layer sheet 51 that is not folded, an inner layer sheet 52 that is not folded, and a folded outer layer sheet 51. The first laminated region T1 in the dorsal region 5b is also composed of the same three layers. As a result, the first laminated region T1 is composed of a total of six layers. In the first laminated region T1, the first skin side sheet P1 is composed of the folded outer layer sheet 51. In the example shown in Fig. 5, the second laminated region T2 in the ventral region 5a is composed of two layers, an outer layer sheet 51 that is not folded back, and an inner layer sheet 52 that is not folded back. The second laminated region T2 in the dorsal region 5b is also composed of the same two layers. As a result, the second laminated region T2 is composed of a total of four layers. In the second laminated region T2, the second skin side sheet P2 is composed of the inner layer sheet 52 that is not folded back.

[0065] In the above configuration, the first lamination region T1 has a larger number of layers of the thermoplastic sheet 50 than the second lamination region T2, and therefore has a larger amount of thermoplastic resin. Therefore, the first lamination region T1 has a larger amount of resin that is heat-sealed than the second lamination region T2, and the bonding strength of the seal portion S tends to be high. In response to this, the bonding strength between the first laminated region T1 and the second laminated region T2 can be adjusted and the tear stability can be improved by adopting at least one of the following configurations 1 to 5. Note that two or more of the following configurations 1 to 5 may be combined.

[0066] (1. Fluctuations in seal strength) When the side joint 8 has multiple laminated regions with different numbers of laminated thermoplastic sheets 50, as described above, the bonding strength of the seal portion S is likely to be higher in the region with a relatively larger number of laminated layers than in the region with a smaller number of laminated layers. In contrast, from the standpoint of improving tear stability while preventing tearing when worn and during wearing movements, it is preferable that the fluctuation (variation) in the seal strength of multiple sealed parts located in areas with a relatively small number of layers is smaller than the fluctuation in the seal strength of multiple sealed parts located in areas with a relatively large number of layers.

[0067] 5, the first lamination region T1 has a larger number of thermoplastic sheets 50 laminated therein than the second lamination region T2, which tends to increase the bonding strength of the seal portion S. In the configuration shown in Fig. 5, it is preferable that the variation in seal strength of the plurality of seal portions S located in the second lamination region T2 is smaller than the variation in seal strength of the plurality of seal portions S located in the first lamination region T1. This configuration can better prevent unintended tearing during wearing and wearing action. Also, this configuration can reduce the difference in force required for tearing between the first stacked region T1 and the second stacked region T2 when tearing, making the tearing action stable and smooth.

[0068] The fluctuation in seal strength can be adjusted by the degree of melting of the fibers. When the degree of melting is low, some areas have melted fibers and some do not, resulting in large fluctuations in strength. On the other hand, when the degree of melting is high, the fibers are completely melted in all seal areas, resulting in a uniform degree of melting, high strength, and small fluctuations in strength. The degree of melting of the fibers can be adjusted by the conditions of the sealing step, such as heat, pressure and / or time, the area of ​​the sealed portion, the composition of the fibers, and the like.

[0069] (2. Degree of melting of the seal) When the side joint 8 has multiple laminated regions with different numbers of laminated thermoplastic sheets 50, as described above, the bonding strength of the seal portion S is likely to be higher in regions with a relatively larger number of laminated layers than in regions with a smaller number of laminated layers. In contrast, from the standpoint of improving tear stability while preventing tearing when worn and during wearing movements, it is preferable that the degree of melting of the fibers in the sealed portion located in an area with a relatively small number of layers is higher than the degree of melting of the fibers in the sealed portion located in an area with a relatively large number of layers. The sealed portion S is a portion formed by fusing fibers of a plurality of thermoplastic sheets 50 of the exterior body 5. For this reason, the more fully the fibers are melted in a portion, the more the fibers will adhere to each other after cooling, and the seal strength will tend to be higher.

[0070] 5, the first lamination region T1 has a larger number of thermoplastic sheets 50 laminated therein than the second lamination region T2, which tends to increase the bonding strength of the seal portion S. In the configuration shown in Fig. 5, it is preferable that the degree of melting of the fibers of the seal portion S located in the second lamination region T2 is higher than the degree of melting of the fibers of the seal portion S located in the first lamination region T1. In this way, by configuring the seal portion S to have a high degree of melting in the region with fewer layers where the bonding strength is likely to be low, unintended tearing during wearing and wearing can be more effectively prevented. Also, by configuring in this way, the difference in the force required for tearing between the first layered region T1 and the second layered region T2 can be reduced, and the tearing action can be performed more stably and smoothly.

[0071] ((Method of calculating the degree of melting)) First, the side joint 8 is cut to prepare a measurement sample including an XZ cross section (a cross section of the seal S in the longitudinal direction X) of the seal portion S in the first stacking region T1 and the second stacking region T2. ​​After fixing the measurement sample by a known method, the XZ cross section of the measurement sample is imaged at 500 times magnification using a scanning electron microscope (SEM). In each image, the outer edge of the fiber is detected using image analysis software, and the length of the detected line is calculated as the fiber circumference. For each of the first stacking region T1 and the second stacking region T2, the average value of the fiber circumference calculated from the images of five or more sheets (five or more seal portions S) is calculated, and the average value is regarded as the fiber circumference of the seal portion S in each region. The circumferential length of the fibers in the sealed portion S in each of the first lamination region T1 and the second lamination region T2 is compared, and it is determined that the longer the circumferential length of the fibers, the lower the degree of melting.

[0072] FIG. 21(A) shows an example of an enlarged view of the XZ cross section of the seal portion S in the first stack region T1, and FIG. 21(B) shows an example of an enlarged view of the XZ cross section of the seal portion S in the second stack region T2. 21(A) has many irregularities on its outer edge 55a and a long perimeter, that is, the fiber 55 is not melted very much, and the original irregularities of the fiber 55 remain on the outer edge 55a, which is the surface. On the other hand, fiber 55 in Fig. 21(B) has a relatively smooth outer edge 55a and is shorter in circumference than fiber 55 in Fig. 21(A). In other words, fiber 55 is sufficiently melted, and the irregularities of outer edge 55a are smoothed. In this case, the degree of melting of the fibers 55 of the sealed portion S in the second lamination region T2 in FIG. 21(B) is determined to be higher than the degree of melting of the fibers 55 of the sealed portion S in the first lamination region T1 in FIG. 21(A).

[0073] The degree of melting of the fibers can be adjusted by the conditions of the sealing step, such as heat, pressure and / or time, the area of ​​the sealed portion, the composition of the fibers, and the like.

[0074] (3. Type of nonwoven fabric constituting skin side sheet and embossed area ratio) In the waist region 8c, the skin-side sheet P constituting the skin-facing surface of the exterior body 5 is preferably made of a spunbond nonwoven fabric from the viewpoint of improving tearability. From the viewpoint of sheet formability, the spunbond nonwoven fabric preferably contains a polyolefin such as polyethylene or polypropylene from among the above-mentioned thermoplastic resins, and more preferably contains polypropylene. Examples of polypropylene include α-olefins.

[0075] The spunbond nonwoven fabric used in the skin side sheet P includes a plurality of embossed portions (not shown) from the viewpoint of reliably fusing the fibers together to form a sheet. The embossed portions are portions where the fibers are fused by pressure bonding. Examples of the embossed portions include those formed intermittently by thermocompression bonding using an embossing roll and a flat roll, those formed by ultrasonic fusing, and those formed by partial fusion by intermittently applying hot air. From the viewpoints of high productivity and low equipment costs, the embossed portions are preferably formed by thermocompression bonding. The planar shape of the embossed portion may be any shape, such as a circle, an ellipse, a polygon, or a shape similar to these. The embossed portions are preferably formed in a regular pattern, but may be formed in a random pattern. For example, the embossed portions are arranged at approximately regular intervals (pitch) in the vertical direction X and the horizontal direction Y, and each row in the horizontal direction Y is shifted from the adjacent rows by half a pitch.

[0076] Here, in the exterior body, if the number of layers is large, the amount of resin in the seal increases, and the seal strength increases. Therefore, in the side joint 8, the seal strength changes depending on the number of layers, and when tearing from the waist end to the leg end, the force required to tear changes, and it becomes difficult to tear with a weak force. In contrast, it is preferable that the embossed area ratio of the skin side sheet P1 in the region with a larger number of laminations (first lamination region T1) is higher than the embossed area ratio of the skin side sheet P2 in the region with a smaller number of laminations (second lamination region T2). In this way, by configuring the area ratio of the embossed portion to be high in the first lamination region T1 where the number of layers is relatively large, it is possible to suppress an increase in the bonding strength of the seal portion S in the first lamination region T1, which is caused by the fibers being easily cut by the heat treatment and / or processing during formation, and it is possible to tear with a weak force even in an area where the number of layers is large. Therefore, when tearing from the waist end to the leg end, the change in the force required for tearing can be made small, making it easier to tear. In this way, by adjusting the embossed area ratio of the skin side sheet in areas where the number of thermoplastic sheet layers is different, the bonding strength in the first layered region T1 and the second layered region T2 can be adjusted, thereby improving tear stability.

[0077] ((Area ratio of embossed part on skin side sheet)) The area ratio of the embossed portion in the spunbonded nonwoven fabric is measured in an area including a sufficient number of embossed portions, for example, in a square area of ​​20 mm x 20 mm of the spunbonded nonwoven fabric. The area occupied by each embossed portion can be recognized as a series of areas where thermal fusion of fibers is observed. The above distance is measured in the expanded and stretched state.

[0078] The area ratio of the embossed portion of the first skin side sheet P1 is preferably 5% or more, more preferably 7% or more, and is preferably 20% or less, more preferably 17% or less. The area ratio of the embossed portion of the second skin side sheet P2 is preferably 3% or more, more preferably 5% or more, and is preferably 17% or less, more preferably 15% or less.

[0079] (4. Melting point of skin side sheet) When the side joint 8 has multiple laminated regions with different numbers of laminated thermoplastic sheets 50, as described above, the bonding strength of the seal portion S is likely to be higher in regions with a relatively larger number of laminated layers than in regions with a smaller number of laminated layers. In contrast, from the standpoint of improving tear stability while preventing tearing when worn and during wearing movements, it is preferable that the melting point of the first skin side sheet P1 included in the first laminate region T1, which has a relatively large number of layers, is higher than the melting point of the second skin side sheet P2 included in the second laminate region T2, which has a relatively small number of layers. A thermoplastic sheet 50 with a high melting point is less likely to be thermally fused and the bonding strength is more likely to decrease when a sealing process is performed under the same conditions as a thermoplastic sheet 50 with a low melting point. Therefore, in the first lamination region T1 having a large number of layers, by increasing the melting point of the first skin side sheet P1, it is possible to suppress an increase in the bonding strength of the seal portion S in the first lamination region T1. This makes it possible to reduce the difference in bonding strength between the first lamination region T1 and the second lamination region T2, and to further stabilize the bonding strength in the entire side joint portion 8. Therefore, it is possible to increase the ease of tearing the side joint portion 8.

[0080] The melting point of the first skin side sheet P1 is preferably 125°C or higher, more preferably 155°C or higher, and is preferably 260°C or lower, more preferably 250°C or lower. The melting point of the second skin side sheet P2 is preferably 123° C. or higher, more preferably 125° C. or higher, and is preferably 180° C. or lower, more preferably 170° C. or lower.

[0081] (5. Basis weight of skin side sheet) When the side joint 8 has multiple laminated regions with different numbers of laminated thermoplastic sheets 50, as described above, the bonding strength of the seal portion S is likely to be higher in regions with a relatively larger number of laminated layers than in regions with a smaller number of laminated layers. In contrast, from the standpoint of improving tear stability while preventing tearing when worn and during wearing movements, it is preferable that the basis weight of the first skin side sheet P1 included in the first stacking region T1, which has a relatively large number of layers, is lower than the basis weight of the second skin side sheet P2 included in the second stacking region T2, which has a relatively small number of layers. In a thermoplastic sheet 50 with a high basis weight, the amount of thermoplastic resin is also large, and the bonding strength at the seal portion S is likely to be high. Therefore, in the first lamination region T1 having a large number of layers, by lowering the basis weight of the first skin side sheet P1, it is possible to prevent the bonding strength of the seal portion S in the first lamination region T1 from increasing. This makes it possible to reduce the difference in bonding strength between the first lamination region T1 and the second lamination region T2, and to further stabilize the bonding strength in the entire side joint portion 8. Therefore, the tear stability of the side joint portion 8 can be improved.

[0082] The basis weight of the first skin side sheet P1 is preferably 10 g / m 2 More preferably, 12 g / m 2 More preferably, it is 30 g / m 2 Less than or equal to 25 g / m 2 The following is the result. The basis weight of the second skin side sheet P2 is preferably 12 g / m 2 More preferably, 14 g / m 2 More preferably, it is 40 g / m 2 Less than or equal to 30 g / m 2 The following is the result.

[0083] [Example of elastic member configuration] As shown in FIG. 2, the ventral region 5a and the dorsal region 5b of the exterior body 5 include a plurality of elastic members 10 extending in the lateral direction Y. The multiple elastic members 10 are disposed between the multiple thermoplastic sheets 50 of the exterior body 5. In the example shown in FIG. These elastic members 10 provide stretchability around the waist of the diaper 1, making it easier to put on and maintaining a snug fit when worn. Note that "the elastic member 10 extends in the horizontal direction Y" means that the elastic member 10 extends in the horizontal direction Y in the expanded and stretched state. However, the above expression is not limited to the state in which the elastic member 10 is parallel to the horizontal direction Y in the expanded and stretched state, but includes the state in which the elastic member 10 extends in the horizontal direction Y as a whole. Furthermore, as shown in FIG. 2, the exterior body 5 may include, in addition to the elastic members 10, leg elastic members 61 arranged around the leg openings 1L.

[0084] The elastic members 60, 61 can preferably be thread-shaped (such as rubber thread) or string-shaped (such as flat rubber) with a rectangular, square, circular, or polygonal cross section, or multifilament type thread-shaped material, etc. The material of the elastic members 60, 61 can be any material that is conventionally used for absorbent articles such as disposable diapers, etc., without any particular restrictions, and examples of such materials include synthetic rubbers such as styrene-butadiene, butadiene, isoprene, and neoprene, natural rubber, EVA, elastic polyolefin, and polyurethane.

[0085] From the viewpoint of ensuring stretchability around the entire waist, it is preferable that the outer ends in the lateral direction Y of the elastic members 10 in each of the ventral region 5a and the dorsal region 5b are located at or near the side joints 8. Specifically, it is preferable that the distance between the ends and the side joints 8 in the lateral direction Y is 10 mm or less, and it is more preferable that the distance is 0 mm and the ends are located within the side joints 8. The elastic member 10 is generally arranged in or near the area where force is applied when tearing, and this tends to affect ease of tearing when discarding. Therefore, from the viewpoint of improving ease of tearing when discarding, it is preferable to adjust the elongation rate of the elastic member as follows.

[0086] As shown in FIG. 2, the abdominal region 5a and the dorsal region 5b each have a stretchable region divided into a waist stretchable region 5f and a leg side stretchable region 5g. These regions are divided by an imaginary boundary line extending parallel to the horizontal direction Y at a position 25 mm in the vertical direction X from the waist opening end Wa. That is, the waist stretchable region 5f is located within 25 mm in the vertical direction X from the waist opening end Wa. Both side edges in the horizontal direction Y of the waist stretchable region 5f correspond to the above-mentioned waist region 8c. The leg side stretchable region 5g is located closer to the leg in the vertical direction X than the waist stretchable region 5f. The boundary line dividing the waist stretchable region 5f and the leg side stretchable region 5g extends parallel to the horizontal direction Y at a position 25 mm in the vertical direction X from the waist opening end Wa in the unfolded and stretched state.

[0087] The waist elasticated region 5f includes a plurality of elastic members 10 extending in the lateral direction Y. Similarly, the leg elasticated region 5g includes a plurality of elastic members 10 extending in the lateral direction Y. It is preferable that the average extensibility of the plurality of elastic members 10 in the waist elasticated region 5f is lower than the average extensibility of the plurality of elastic members 10 in the leg elasticated region 5g. The elongation rate of the elastic member 10 means the ratio of the length of the elastic member stretched in the expanded and stretched state of the pant-type absorbent article to the length of the elastic member in its natural length when taken out of the pant-type absorbent article. In other words, the lower the elongation rate, the smaller the elastic force tends to be when the elastic member 10 is pulled. The elongation rate of the elastic member 10 can be adjusted during manufacturing by adjusting the degree of elongation of the elastic member 10 placed in the exterior body 5. During manufacturing, for example, the elastic member 10 is elongated to a predetermined length, adhesive is applied to the elastic member 10 with a comb or the like, and the elastic member 10 is fixed to the thermoplastic sheet 50 of the exterior body 5.

[0088] As described above, the waist region 8c is likely to be directly subjected to a force in the lateral direction Y during the tearing action. In the above configuration, the average elongation rate of the elastic member 10 in the waist stretch region 5f is low, and therefore the elastic force of the elastic member 10 acting as a resistance to the tearing force is low. This makes it difficult for the energy related to the tearing force to be consumed by the elongation of the elastic member 10, and the garment can be efficiently torn even with a weaker force. Therefore, the above configuration enables a stable tearing action and prevents problems such as tearing of the exterior body 5 caused by an excessively strong tearing force.

[0089] (Method of measuring average elongation of elastic material) The side joints 8 of the pants-type absorbent article are separated to remove the absorbent main body 4, and the ventral region 5a and the dorsal region 5b of the exterior body 5 are cut out. Furthermore, the ventral region 5a and the dorsal region 5b are cut in parallel to the transverse direction Y at a position 25 mm in the longitudinal direction X from the waist opening end Wa, to cut out the waist stretchable region 5f and the leg side stretchable region 5g. Then, the length of the elastic members 10 in each cut-out region is measured when the pants-type absorbent article is in an expanded and stretched state. From these measurements, the average length of all the elastic members 10 in each of the regions 5f and 5g when in the maximum stretched state is calculated. All of the elastic members 10 fixed to each of the regions 5f, 5g by adhesive or the like are removed from the other components of the exterior body 5 using an appropriate solvent such as ethyl acetate, and the natural length of the elastic members 10 in each of the regions 5f, 5g is measured. From the measured values, the average length of all the elastic members 10 in the natural length in each of the regions 5f, 5g is calculated. Then, in each region 5f, 5g, the ratio of the average length of the elastic members 10 in the expanded, stretched state to the average length of the elastic members 10 in their natural lengths is calculated, and this is regarded as the average elongation rate of the elastic members 10 in each region 5f, 5g.

[0090] The average elongation percentage of the plurality of elastic members 10 in the waist stretch region 5f is preferably 120% or more, more preferably 130% or more, and is preferably 500% or less, more preferably 450% or less. The average elongation rate of the plurality of elastic members 10 in the leg side elasticated regions 5g is preferably 150% or more, more preferably 180% or more, and is preferably 550% or less, more preferably 500% or less. In order to effectively obtain the above-mentioned effects, the ratio of the average elongation rate of the multiple elastic members 10 in the waist stretch region 5f to the average elongation rate of the multiple elastic members 10 in the leg side stretch region 5g is preferably 20% or more, more preferably 30% or more, and is preferably 90% or less, more preferably 80% or less.

[0091] <Other embodiments> In the first embodiment, an example has been given in which the bonding strength reducing agent 9 overlaps the first region 11 and the third region 13 of the first seal portion S1, but the present invention is not limited to this. In the first embodiment, an example has been given in which the distance D1 between the first seal portion S1 and the second seal portion S2 in the vertical direction X and the distance D2 between the first seal portion S1 and the second seal portion S2 in the horizontal direction Y satisfy D1>D2. However, the present invention is not limited to this. <D2であってもよいし、D1=D2であってもよい。 Further, in the first embodiment, an example in which two sealed portions S are positioned in one row has been given, but three or more sealed portions S may be positioned in one row. Further, in the first embodiment, an example in which the seal portions S are arranged in four rows has been given, but the seal portions S may be arranged in five or more rows. These other forms will be described below as the second to thirteenth embodiments. In these embodiments, as in the first embodiment, an example is given in which the multiple seal portions S are rectangular and have the same size and shape, and the multiple seal portions S constituting each seal row SL are disposed at equal intervals.

[0092] The second to ninth embodiments are different from the first embodiment only in that the position of the bonding strength reducing agent 9 is different, and in all the embodiments, the first seal portion S1 and the second seal portion S2 have a positional relationship that satisfies D1>D2. In the second to ninth embodiments, like the first embodiment, two seal portions are positioned in one row, and are arranged in four columns. In the tenth embodiment, compared with the first embodiment, the first seal portion S1 and the second seal portion S2 have a positional relationship satisfying D1 < D2, and the positional relationship between the bonding strength reducing agent 9 and the first seal portion S1 and the second seal portion S2 is different. Similar to the first embodiment, in the tenth embodiment, two seal portions are located in one row and are arranged in four columns. In the eleventh embodiment, compared with the first embodiment, in the first seal portion S1 and the second seal portion S2, a positional relationship satisfying D1 < D2 and a positional relationship satisfying D1 > D2 coexist. Three seal portions S are located in one row and are arranged in six columns, and the positional relationship between the bonding strength reducing agent 9 and the first seal portion S1 and the second seal portion S2 is different. The twelfth embodiment is mainly different from the first embodiment in that the first seal portion S1 and the second seal portion S2 have a positional relationship satisfying D1 = D2. The thirteenth embodiment is mainly different from the first embodiment in that two seal portions are located in one row and are arranged in six columns.

[0093] In the description of each of the following embodiments, the description will focus on the points different from the first embodiment. For the same configurations, the same reference numerals will be used and the description may be omitted. Also, in each of the following embodiments, similar to the first embodiment, in the waist region 8c of the side joint portion 8, the two seal portions S overlapping the virtual line L are referred to as the first seal portion S1 and the second seal portion S2, respectively. The first seal portion S1 is the seal located in the nth row, and the second seal portion S2 is located in the (n + 1)th row (the row immediately below the row to which the first seal portion S1 belongs). In any of the first to thirteenth embodiments below, similar to the first embodiment, a plurality of seal portions S are arranged in a multi-column arrangement structure with a plurality of them spaced apart in the vertical direction X and the horizontal direction Y, and at least one of the first seal portion S1 and the second seal portion S2 in the waist region 8c overlaps with the bonding strength reducing agent 9. Thereby, while preventing tearing during wearing and wearing operations, tearing during disposal can be facilitated. Hereinafter, each embodiment will be described.

[0094] <Second embodiment> In the first embodiment, an example has been given in which the bonding strength reducing agent 9 overlaps the first region 11 and the third region 13 of the first seal portion S1. In contrast, as in the present embodiment shown in Fig. 6, the bonding strength reducing agent 9 may overlap only the first region 11 of the first seal portion S1. As shown in FIG. 6, in this embodiment, the bond strength reducing agent 9 overlaps the first region 11, which is one of the first region 11 and the second region 12 that are torn at the same time when torn. By overlapping the first region 11 and the bond strength reducing agent 9, the total seal strength of the first region 11 and the second region 12 is weakened compared to a configuration in which the bond strength reducing agent 9 does not overlap. In other words, when the first region 11 and the second region 12 are torn apart at the same time, they can be torn apart with a weak force, making the tearing easier.

[0095] <Third embodiment> In the first embodiment, an example has been given in which the bonding strength reducing agent 9 overlaps the first region 11 and the third region 13 of the first seal portion S1. In contrast, as in the present embodiment shown in Fig. 7, the bonding strength reducing agent 9 may overlap only the second region 12 of the second seal portion S2. As shown in FIG. 7, in this embodiment, the bond strength reducing agent 9 overlaps the second region 12, which is one of the first region 11 and the second region 12 that are torn at the same time when torn. By overlapping the second region 12 and the bond strength reducing agent 9, the total seal strength of the first region 11 and the second region 12 is weakened compared to a configuration in which the bond strength reducing agent 9 does not overlap. In other words, when the first region 11 and the second region 12 are torn apart at the same time, they can be torn apart with a weak force, making the tearing easier.

[0096] <Fourth embodiment> In the first embodiment, an example has been given in which the bonding strength reducing agent 9 overlaps the first region 11 and the third region 13 of the first seal portion S1. In contrast, as in the present embodiment shown in Fig. 8, the bonding strength reducing agent 9 may overlap the first region 11 of the first seal portion S1 and the second region of the second seal portion S2. As shown in FIG. 8, in this embodiment, both the first region 11 and the second region 12, which are torn at the same time when torn, overlap with the bond strength reducing agent 9. By overlapping the first region 11 and the second region 12 with the bond strength reducing agent 9, the total seal strength of the first region 11 and the second region 12 is weakened compared to a configuration in which the bond strength reducing agent 9 does not overlap. In other words, when the first region 11 and the second region 12 are torn apart at the same time, they can be torn apart with a weak force, making the tearing easier.

[0097] <Fifth embodiment> In the first embodiment, an example has been given in which the bonding strength reducing agent 9 overlaps the first region 11 and the third region 13 of the first seal portion S1. In contrast, as in the present embodiment shown in Fig. 9, the bonding strength reducing agent 9 may overlap the first region 11 and the third region 13 of the first seal portion S1 and the second region 12 of the second seal portion S2. As shown in FIG. 9, in this embodiment, the bond strength reducing agent 9 overlaps both the first region 11 and the second region 12 that are torn at the same time when torn. By overlapping the first region 11 and the second region 12 with the bond strength reducing agent 9, the total seal strength of the first region 11 and the second region 12 is weakened compared to a configuration in which the bond strength reducing agent 9 does not overlap. In other words, when the first region 11 and the second region 12 are torn apart at the same time, they can be torn apart with a weak force. Furthermore, since the bond strength reducing agent 9 overlaps not only the first region 11 and the second region 12 but also the third region 13, the third region 13 can be torn apart with a weak force. As a result, when tearing, first the third region 13 of the first sealed portion S1 is torn, followed by the first region 11 of the first sealed portion S1 and the second region 12 of the second sealed portion S2.However, since the difference between the force required to tear the third region 13 and the force required to tear the first region 11 and the second region 12 is not too large, the tearing operation can be performed stably and smoothly.

[0098] Sixth embodiment In the first embodiment, an example has been given in which the bonding strength reducing agent 9 overlaps the first region 11 and the third region 13 of the first seal portion S1. In contrast, as in the present embodiment shown in Fig. 10, the bonding strength reducing agent 9 may overlap the first region 11 and the third region 13 of the first seal portion S1 and the fourth region 14 of the second seal portion S2. As shown in FIG. 10, in this embodiment, the bond strength reducing agent 9 overlaps the first region 11, which is one of the first region 11 and the second region 12 that are torn at the same time when torn. By overlapping the first region 11 and the bond strength reducing agent 9, the total seal strength of the first region 11 and the second region 12 is weakened compared to a configuration in which the bond strength reducing agent 9 does not overlap. In other words, when the first region 11 and the second region 12 are torn apart at the same time, they can be torn apart with a weak force. Furthermore, since the bonding strength reducing agent 9 overlaps not only the first region 11 but also the third region 13 and the fourth region 14, the third region 13 and the fourth region 14 can be torn apart with a weak force. As a result, when tearing, the third region 13 is torn, then the first region 11 of the first sealed portion S1 and the second region 12 of the second sealed portion S2 are torn, and then the fourth region 14 is torn. However, since the difference between the force required to tear the third region 13 and the fourth region 14 and the force required to tear the first region 11 and the second region 12 is not too large, the tearing operation can be performed more stably and smoothly.

[0099] Seventh embodiment In the first embodiment, an example has been given in which the bonding strength reducing agent 9 overlaps the first region 11 and the third region 13 of the first seal portion S1. In contrast, as in the present embodiment shown in Fig. 11, the bonding strength reducing agent 9 may overlap the first region 11 of the first seal portion S1 and the second region 12 and the fourth region 14 of the second seal portion S2. As shown in FIG. 11, in this embodiment, the bond strength reducing agent 9 overlaps both the first region 11 and the second region 12 that are torn at the same time when torn. By overlapping the first region 11 and the second region 12 with the bond strength reducing agent 9, the total seal strength of the first region 11 and the second region 12 is weakened compared to a configuration in which the bond strength reducing agent 9 does not overlap. In other words, when the first region 11 and the second region 12 are torn apart at the same time, they can be torn apart with a weak force. Furthermore, since the bonding strength reducing agent 9 overlaps not only the first region 11 and the second region 12 but also the fourth region 14, the fourth region 14 can be torn apart with a weak force. As a result, when tearing, the first region 11 of the first sealed portion S1 and the second region 12 of the second sealed portion S2 are torn, and then the fourth region 14 is torn. However, since the difference between the force required to tear the first region 11 and the second region 12 and the force required to tear the fourth region 14 is not too large, the tearing operation can be performed stably and smoothly.

[0100] Eighth embodiment In the first embodiment, an example was given in which the bonding strength reducing agent 9 overlaps the first region 11 and the third region 13 of the first seal portion S1. In contrast, as in the present embodiment shown in Fig. 12, the bonding strength reducing agent 9 may overlap the first region 11 and the third region 13 of the first seal portion S1 and the second region 12 and the fourth region 14 of the second seal portion S2. As shown in FIG. 12, in this embodiment, the bond strength reducing agent 9 overlaps both the first region 11 and the second region 12 that are torn at the same time when torn. By overlapping the first region 11 and the second region 12 with the bond strength reducing agent 9, the total seal strength of the first region 11 and the second region 12 is weakened compared to a configuration in which the bond strength reducing agent 9 does not overlap. In other words, when the first region 11 and the second region 12 are torn apart at the same time, they can be torn apart with a weak force. Furthermore, since the bond strength reducing agent 9 overlaps not only the first region 11 and the second region 12 but also the third region 13 and the fourth region 14, the third region 13 and the fourth region 14 can be torn apart with a weak force. As a result, when tearing, the third region 13 of the first seal portion S1 is torn, then the first region 11 of the first seal portion S1 and the second region 12 of the second seal portion S2 are torn, and then the fourth region 14 is torn.However, since the difference between the force required to tear the first region 11 and the second region 12 and the force required to tear the third region 13 and the fourth region 14 is not too large, the tearing operation can be performed stably and smoothly.

[0101] <Ninth embodiment> In the first embodiment, an example has been given in which the bonding strength reducing agent 9 overlaps the first region 11 and the third region 13 of the first seal portion S1. In contrast, as in the present embodiment shown in Fig. 13, the bonding strength reducing agent 9 may overlap the third region 13 of the first seal portion S1 and the second region 12 and the fourth region 14 of the second seal portion S2. As shown in FIG. 13, in this embodiment, the bond strength reducing agent 9 overlaps the second region 12, which is one of the first region 11 and the second region 12 that are torn at the same time when torn. By overlapping the second region 12 and the bond strength reducing agent 9, the total seal strength of the first region 11 and the second region 12 is weakened compared to a configuration in which the bond strength reducing agent 9 does not overlap. In other words, when the first region 11 and the second region 12 are torn apart at the same time, they can be torn apart with a weak force. Furthermore, since the bond strength reducing agent 9 overlaps not only the second region 12 but also the third region 13 and the fourth region 14, the third region 13 and the fourth region 14 can be torn apart with a weak force. As a result, when tearing, the third region 13 is torn, then the first region 11 of the first sealed portion S1 and the second region 12 of the second sealed portion S2 are torn, and then the fourth region 14 is torn. However, since the difference between the force required to tear the third region 13 and the fourth region 14 and the force required to tear the first region 11 and the second region 12 is not too large, the tearing operation can be performed more stably and smoothly.

[0102] Tenth embodiment In the first embodiment, an example where the positional relationship between the first seal portion and the second seal portion is D1 > D2 was given. On the other hand, as in the present embodiment shown in FIG. 14, the positional relationship between the first seal portion and the second seal portion may be such that D1 < D2. In the present embodiment, the bonding strength reducing agent 9 is in a form that overlaps with the third region 13 of the first seal portion S1, the second region 12 and the fourth region 14 of the second seal portion S2. However, the positional relationship between the first seal portion S1 and the second seal portion S2 and the bonding strength reducing agent 9 in each of the above-described embodiments can also be applied.

[0103] As shown in FIG. 14, in the present embodiment, in the waist region 8c, the first seal portion S1 and the second seal portion S2 are arranged so as to satisfy the relationship D1 < D2. By adopting such an arrangement, when the side joint portion 8 is torn from the waist end portion 8a toward the leg end portion 8b, focusing on the first seal portion S1 and the second seal portion S2, first, the second seal portion S2 starts to be torn, and only a part of the second seal portion S2 is torn. Subsequently, both the first seal portion S1 and the second seal portion S2 are torn. Subsequently, the tearing of the second seal portion S2 ends, and only a part of the first seal portion S1 is torn. In FIG. 14, the virtual line L1 corresponds to the location where the tearing of the second seal portion S2 starts. The virtual line L2 corresponds to the location where the tearing of the first seal portion S1 starts while the tearing of the second seal portion S2 continues. The virtual line L3 corresponds to the location where the tearing of the second seal portion S2 ends while the tearing of the first seal portion S1 continues. The virtual line L4 corresponds to the location where the tearing of the first seal portion S1 ends.

[0104] In FIG. 14, the first seal portion S1 has a first region 11 and a third region 13. The second seal portion S2 has a second region 12 and a fourth region 14. The first region 11 and the second region 12 correspond to the regions sandwiched between the virtual line L2 and the virtual line L3 in the first seal portion S1 and the second seal portion S2. The third region 13 corresponds to the region sandwiched between the virtual line L3 and the virtual line L4 in the first seal portion S1. The fourth region 14 corresponds to the region between the imaginary lines L1 and L2 in the second seal portion S2.

[0105] The first region 11 is a region through which the imaginary line L passes when the imaginary line L is moved in parallel from the waist end 8a toward the leg end 8b (in the order of L1, L2, L3, L4) and overlaps with both the first sealed portion S1 and the second sealed portion S2. In the figure, the first region 11 of the first sealed portion S1 is marked with a thick diagonal line slanting downward to the right. The second region 12 is a region through which the imaginary line L passes when the imaginary line L is moved in parallel from the waist end 8a toward the leg end 8b in the second sealed portion S2 and overlaps both the first sealed portion S1 and the second sealed portion S2. In the figure, the second region 12 of the second sealed portion S2 is marked with a thick diagonal line slanting downward to the right.

[0106] The third region 13 is a region through which the imaginary line L passes when the imaginary line L is moved in parallel from the waist end 8a toward the leg end 8b in the first sealed portion S1 and overlaps only the first sealed portion S1. In the figure, a thin diagonal line is drawn slanting upward to the right in the third region 13 of the first sealed portion S1. The fourth region 14 is a region through which the imaginary line L passes when the imaginary line L is moved in parallel from the waist end 8a toward the leg end 8b in the second sealed portion S2 and overlaps only the second sealed portion S2. In the figure, a thin diagonal line is drawn in the fourth region 14 of the second sealed portion S2, slanting upward to the right.

[0107] In the example shown in Figure 14, when torn, in the first seal portion S1 and the second seal portion S2, the imaginary line L corresponding to the peel interface passes only through the fourth region 14 of the second seal portion S2, then simultaneously passes through both the first region 11 of the first seal portion S1 and the second region 12 of the second seal portion S2, and then passes only through the third region 13 of the first seal portion S1.

[0108] In the present embodiment, when tearing, the joint strength reducing agent 9 overlaps with the second region 12, which is one of the first region 11 and the second region 12 that are torn simultaneously. When the second region 12 and the joint strength reducing agent 9 overlap, the total seal strength of the first region 11 and the second region 12 becomes weaker than in the form where the joint strength reducing agent 9 does not overlap. That is, when the first region 11 and the second region 12 are torn simultaneously, they can be torn with a weak force. Furthermore, in addition to the second region 12, the fourth region 14 also overlaps with the joint strength reducing agent 9, so that the fourth region 14 can be torn with a weak force. As a result, when tearing, after the fourth region 14 is torn, the first region 11 of the first seal portion S1 and the second region 12 of the second seal portion S2 are torn. However, since the difference between the force required to tear the fourth region 14 and the force required to tear the first region 11 and the second region 12 does not become too large, the tearing operation can be performed stably and more smoothly.

[0109] <The 11th Embodiment> In the first embodiment, an example of the positional relationship between the first seal portion and the second seal portion is D1 > D2, and a four-column arrangement structure in which two seal portions S are located in one row is given. In contrast, as in the present embodiment shown in FIG. 15, a form in which the positional relationship of D1 < D2 and the positional relationship of D1 > D2 coexist and a six-column arrangement structure in which three seal portions S are located in one row may be used. In the present embodiment, an example in which the positional relationship of D1 < D2 and the positional relationship of D1 > D2 coexist is given, but two or more positional relationships selected from D1 < D2, D1 > D2, and D1 = D3 may coexist.

[0110] In the present embodiment, three seal portions S are located in one row. As a result, one first seal portion may overlap with different second seal portions on different virtual lines L. Also, three seal portions may overlap on a certain virtual line L. Even in such a form, by configuring at least one of the seal portions S, namely the first seal portion S1 located in the n-th row and the second seal portion S2 located in the (n + 1)-th row, which overlap on a single virtual line L, to overlap with the bonding strength reducing agent 9, it is possible to facilitate tearing during disposal while preventing tearing during wearing and wearing operations.

[0111] As shown in FIG. 15, during the movement from the virtual line L2 to the virtual line L3, the seal portion S1 (corresponding to the first seal portion) located at the first column of the n-th row and the seal portion S2 (corresponding to the second seal portion) located at the fourth column of the (n + 1)-th row overlap on the same virtual line. The seal portion S1 and the seal portion S2 satisfy the positional relationship of D1 < D2. During the movement from the virtual line L3 to the virtual line L4, the seal portion S1 (corresponding to the first seal portion) located at the first column of the n-th row and the seal portion S2' (corresponding to the second seal portion) located at the second column of the (n + 1)-th row overlap on the same virtual line. The seal portion S1 and the seal portion S2' satisfy the positional relationship of D1 > D2. Thus, in the example shown in FIG. 15, one first seal portion S1 overlaps with different second seal portions S2 and S2' on different virtual lines L respectively.

[0112] Furthermore, in the example shown in FIG. 15, during the movement from the virtual line L2 to the virtual line L3, on a single virtual line, the seal portion S1, the seal portion S2, and the seal portion S3 located at the fifth column of the (n + 2)-th row overlap. In the seal portion S1 and the seal portion S2, the seal portion S1 corresponds to the first seal portion, and the seal portion S2 corresponds to the second seal portion. In the seal portion S2 and the seal portion S3, the seal portion S2 corresponds to the first seal portion, and the seal portion S3 corresponds to the second seal portion. The seal portion S2 and the seal portion S3 satisfy the positional relationship of D1 > D2. Also, during the movement from the virtual line L3 to the virtual line L4, on one virtual line L, the seal part S1, the seal part S2', and the seal part S3 overlap. In the seal part S1 and the seal part S2', the seal part S1 corresponds to the first seal part, and the seal part S2' corresponds to the second seal part. In the seal part S2' and the seal part S3, the seal part S2' corresponds to the first seal part, and the seal part S3 corresponds to the second seal part. The seal part S2' and the seal part S3 satisfy the positional relationship of D1 < D2. In addition, in the present embodiment, in the seal part S1 and the seal part S3, an example is given where the longitudinal X distance between the longitudinal X waist-side end of the seal part S1 and the longitudinal X waist-side end of the seal part S3 and the lateral Y distance between the lateral Y inner end of the seal part S1 and the lateral Y inner end of the seal part S3 are the same, but it is not limited to this. In this way, in the example shown in FIG. 15, three seal parts overlap on one virtual line L.

[0113] In the example shown in FIG. 15, when focusing on the seal parts S1, S2, S2', and S3, first, only a part of the seal part S2 is torn, and then the seal part S2, the seal part S1, and the seal part S3 are torn simultaneously. Next, after the seal part S2 has finished tearing, the seal part S1, the seal part S3, and the seal part S2' are torn simultaneously. Next, after the seal part S1 and the seal part S3 have finished tearing, a part of the seal part S2' is torn.

[0114] Also in the present embodiment, by overlapping the joint strength reducing agent 9 on at least one of the plurality of seal parts S located on one virtual line L, the total seal strength of the plurality of seal parts S becomes weak, and it can be torn with a weak force. In addition, it is possible to suppress the application of a locally large force to the exterior body 5, and effectively prevent the lateral cracking of the exterior body 5.

[0115] <The 12th Embodiment> In the first embodiment, an example where the positional relationship between the first seal part and the second seal part is D1 > D2 is given. In contrast, as in the present embodiment shown in FIG. 16, a form in which the positional relationship between the first seal part and the second seal part is D1 = D2 may also be used. In this embodiment, the bond strength reducer 9 overlaps only the first region 11 of the first seal portion S1, but it may overlap only the second region 12 of the second seal portion S2, or it may overlap both the first region 11 and the second region 12.

[0116] As shown in FIG. 16, in the present embodiment, in the waist region 8c, the first sealed portion S1 and the second sealed portion S2 are arranged to satisfy the relationship D1=D2. With this arrangement, when the side joint portion 8 is torn from the waist end portion 8a toward the leg end portion 8b, focusing on the first sealed portion S1 and the second sealed portion S2, both the first sealed portion S1 and the second sealed portion S2 are torn simultaneously. 16, the imaginary line L1 corresponds to the location where the tearing of the first sealed portion S1 and the second sealed portion S2 begins, and the imaginary line L2 corresponds to the location where the tearing of the first sealed portion S1 and the second sealed portion S2 ends.

[0117] The first region 11 is a region through which the imaginary line L passes when the imaginary line L is moved in parallel from the waist end 8a toward the leg end 8b (moving in parallel in the order of L1 and L2) and overlaps with both the first sealed portion S1 and the second sealed portion S2. In the figure, the first region 11 of the first sealed portion S1 is marked with a thick diagonal line slanting downward to the right. The second region 12 is a region through which the imaginary line L passes when the imaginary line L is moved in parallel from the waist end 8a toward the leg end 8b in the second sealed portion S2 and overlaps both the first sealed portion S1 and the second sealed portion S2. In the figure, the second region 12 of the second sealed portion S2 is marked with a thick diagonal line slanting downward to the right.

[0118] In the example shown in Figure 16, when the first seal portion S1 and the second seal portion S2 are torn apart, the imaginary line L corresponding to the peel interface passes through both the first region 11 of the first seal portion S1 and the second region 12 of the second seal portion S2 simultaneously. In the example shown in FIG. 16, the bond strength reducing agent 9 overlaps the first region 11, which is one of the first region 11 and the second region 12 that are torn at the same time when torn. By overlapping the first region 11 and the bond strength reducing agent 9, the total seal strength of the first region 11 and the second region 12 is weaker than in a configuration in which the bond strength reducing agent 9 does not overlap. In other words, when the first region 11 and the second region 12 are torn apart at the same time, they can be torn apart with a weak force. In addition, it is possible to prevent a large force from being locally applied to the exterior body 5, and it is possible to effectively prevent lateral tearing of the exterior body 5.

[0119] <Thirteenth embodiment> In the first embodiment, an example was given of a four-row structure in which two seal portions S are located in one row, but it may also be a six-row structure in which two seal portions S are located in one row, as in the present embodiment shown in Figure 17. 17, the multiple seal portions S are arranged such that multiple seal rows SL, each consisting of multiple seal portions S spaced apart along the vertical direction X, are positioned in the horizontal direction. In this embodiment, the side joint portion 8 is composed of six seal rows SL1 to SL6. The seal row SL1 is located in the first row, the seal row SL2 in the second row, the seal row SL3 in the third row, the seal row SL4 in the fourth row, the seal row SL5 in the fifth row, and the seal row SL6 in the sixth row. Adjacent seal rows SL are offset by 1 / 3 pitch (1 / 3 the distance between two adjacent seal sections in the same seal row) in the vertical direction X. As a result, the seal section S in seal row SL1 and the seal section S in seal row SL4 are spaced apart along the horizontal direction and are in the same row. The seal section S in seal row SL2 and the seal section S in seal row SL5 are spaced apart along the horizontal direction and are in the same row. The seal section S in seal row SL3 and the seal section S in seal row SL6 are spaced apart along the horizontal direction and are in the same row. In two adjacent seal rows (SL1 and SL2, SL2 and SL3, SL3 and SL4, SL4 and SL5, SL5 and SL6), the seal sections S in each seal row are not aligned side by side along the horizontal direction and are not in the same row.

[0120] Furthermore, fourteenth to sixteenth embodiments will be described as other embodiments.

[0121] <Fourteenth embodiment> In the above-described first embodiment, the folded-back structure of the exterior body 5 is described as being configured such that only the outer layer sheet 51 is folded back, but the present invention is not limited to this. As in the present embodiment shown in FIG. 18, both the outer sheet 51 and the inner sheet 52 may be folded back. In the following fourteenth to sixteenth embodiments, the same components as those in the above-described first embodiment are denoted by the same reference numerals and the description thereof will be omitted.

[0122] 18, the outer sheet 51 and the inner sheet 52 are folded back from the waist opening end Wa toward the skin. The leg side ends of the outer sheet 51 and the inner sheet 52 in the folded back areas are positioned at approximately the same position in the longitudinal direction X.

[0123] In the waist region 8c, among the multiple thermoplastic sheets 50 of the outer body 5, the skin-side sheet P that constitutes the skin-facing surface is a folded outer layer sheet 51, and the adjacent sheet Q adjacent to the skin-side sheet P is a folded inner layer sheet 52. In this case, similarly to the first embodiment, the bond strength reducing agent 9 is preferably disposed in the waist region 8c between the skin side sheet P and the adjacent sheet Q. In the example shown in Fig. 18, the bond strength reducing agent 9 is disposed between the folded outer layer sheet 51 and the adjacent folded inner layer sheet 52. This allows the bond strength reducing agent 9 to be disposed near the bonding interface of the side bonding portion 8, effectively reducing the bond strength of the region where the seal portion S and the bond strength reducing agent 9 overlap. From the viewpoint of further improving the ease of tearing, it is preferable that the penetration depth of the bond strength reducing agent 9 in the skin side sheet P is deeper than the penetration depth of the bond strength reducing agent 9 in the adjacent sheet Q. In the example shown in FIG. 18, the bond strength reducing agent 9 is arranged in the dorsal region 5b, but as described above, it may be arranged in the ventral region 5a, or in both the ventral region 5a and the dorsal region 5b.

[0124] Also, in the same manner as in the first embodiment, in this embodiment, the side joint portion 8 has a first laminated region T1 including a first skin side sheet P1 and six or more thermoplastic sheets 50 laminated therein, and a second laminated region T2 including a second skin side sheet P2 and having a smaller number of thermoplastic sheets 50 laminated therein than in the first laminated region T1. In this example, the first laminated region T1 corresponds to the region where the exterior body 5 is folded back, and the skin side sheet P in the waist region 8c corresponds to the first skin side sheet P1.

[0125] In the example shown in Fig. 18, the first laminated region T1 in the ventral region 5a is composed of four layers: an unfolded outer layer sheet 51, an unfolded inner layer sheet 52, a folded inner layer sheet 52, and a folded outer layer sheet 51. The first laminated region T1 in the dorsal region 5b is also composed of the same four layers. As a result, the first laminated region T1 is composed of a total of eight layers. In the first laminated region T1, the first skin side sheet P1 is composed of the folded outer layer sheet 51. In the example shown in Fig. 18, the second laminated region T2 in the ventral region 5a is composed of two layers, an outer layer sheet 51 that is not folded back, and an inner layer sheet 52 that is not folded back. The second laminated region T2 in the dorsal region 5b is also composed of the same two layers. As a result, the second laminated region T2 is composed of a total of four layers. In the second laminated region T2, the second skin side sheet P2 is composed of the inner layer sheet 52 that is not folded back.

[0126] In this embodiment as well, from the viewpoint of further stabilizing the joint strength in the entire side joint portion 8, the following configuration may be adopted. For example, it is preferable that the variation in the seal strength of the multiple seal portions located in the second stacking region T2, where the number of thermoplastic sheet layers is relatively small, is smaller than the variation in the seal strength of the multiple seal portions located in the first stacking region T1, where the number of thermoplastic sheet layers is relatively large. For example, it is preferable that the degree of melting of the fibers of the seal portion located in the second lamination region T2, where the number of thermoplastic sheet layers is relatively small, is higher than the degree of melting of the fibers of the seal portion located in the first lamination region T1, where the number of thermoplastic sheet layers is relatively large.

[0127] Also in this embodiment, from the viewpoint of further stabilizing the joint strength in the entire side joint portion 8, the first skin side sheet P1 and the second skin side sheet P2 may each be configured as follows. For example, it is preferable that the first skin side sheet P1 and the second skin side sheet P2 are each composed of a spunbond nonwoven fabric including a plurality of embossed portions, and it is preferable that the area ratio of the embossed portions in the first skin side sheet P1 is larger than the area ratio of the embossed portions in the second skin side sheet P2. For example, in this embodiment as well, the melting point of the first skin side sheet P1 is preferably higher than the melting point of the second skin side sheet P2. For example, also in this embodiment, the basis weight of the first skin side sheet P1 is preferably lower than the basis weight of the second skin side sheet P2.

[0128] In addition to the above configuration, in the pants-type absorbent article having the side joint 8 of this embodiment, the positional relationship between the first and second seal portions and the joint strength reducer 9 can be configured in the same manner as in any of the first to thirteenth embodiments, thereby making it possible to prevent peeling during the putting on and wearing action and to easily tear the article when discarding it.

[0129] <Fifteenth embodiment> The configuration of the exterior body 5 having a folded-back structure is not limited to the above example. For example, the folded-back end 51a, which is the end of the folded-back region of the outer layer sheet 51, and the folded-back end 52a, which is the end of the folded-back region of the inner layer sheet 52, may be positioned at different positions in the longitudinal direction X. In the example shown in FIG. 19, the folded end 52a of the inner sheet 52 is located closer to the waist in the longitudinal direction X than the folded end 51a of the outer sheet 51.

[0130] 19, in the waist region 8c, both the outer sheet 51 and the inner sheet 52 are folded back. In this case, the skin-facing sheet P is the folded outer sheet 51, and the adjacent sheet Q adjacent to the skin-facing sheet P is the folded inner sheet 52. In this case, similarly to the first embodiment, the bond strength reducing agent 9 is preferably disposed in the waist region 8c between the skin side sheet P and the adjacent sheet Q. In the example shown in Fig. 19, the bond strength reducing agent 9 is disposed between the folded outer layer sheet 51 and the adjacent folded inner layer sheet 52. From the viewpoint of further improving the ease of tearing, it is preferable that the penetration depth of the bond strength reducing agent 9 in the skin side sheet P is deeper than the penetration depth of the bond strength reducing agent 9 in the adjacent sheet Q. In the example shown in Figure 19, the bond strength reducing agent 9 is placed in the ventral region 5a, but as described above, it may be placed in the dorsal region 5b, or it may be placed in both the ventral region 5a and the dorsal region 5b.

[0131] Also, in the same manner as in the fourteenth embodiment, in this embodiment, the side joint portion 8 has a first lamination region T1 in which six or more thermoplastic sheets 50 including the first skin side sheet P1 are laminated, and a second lamination region T2 in which a smaller number of thermoplastic sheets 50 than the first lamination region T1 are laminated, including the second skin side sheet P2. In this example, the first lamination region T1 corresponds to the region where the exterior body 5 is folded back, and the skin side sheet P in the waist region 8c corresponds to the first skin side sheet P1. Furthermore, in this embodiment, the first lamination region T1 includes regions having different numbers of laminated thermoplastic sheets 50. That is, the first lamination region T1 includes a leg-side laminate region T12 adjacent to the second lamination region T2 and having a greater number of laminated thermoplastic sheets 50 than the second lamination region T2, and a waist-side laminate region T11 in which a greater number of laminated thermoplastic sheets 50 than the leg-side laminate region T12 is laminated. In the example shown in FIG. 19, the waist region 8c is included in the waist-side layered region T11.

[0132] In the example shown in Fig. 19, the waist side laminated region T11 in the abdominal region 5a is composed of four layers: an unfolded outer layer sheet 51, an unfolded inner layer sheet 52, a folded inner layer sheet 52, and a folded outer layer sheet 51. The waist side laminated region T11 in the dorsal region 5b is also composed of the same four layers. As a result, the waist side laminated region T11 is composed of a total of eight layers. The leg side laminated region T12 of the ventral region 5a is composed of three layers: an unfolded outer layer sheet 51, an unfolded inner layer sheet 52, and a folded outer layer sheet 51. The leg side laminated region T12 of the dorsal region 5b is also composed of the same three layers. As a result, the leg side laminated region T12 is composed of a total of six layers. In both the waist side laminated region T11 and the leg side laminated region T12, the first skin side sheet P1 is formed of an outer layer sheet 51 that is folded back. In the example shown in Fig. 19, the second laminated region T2 in the ventral region 5a is composed of two layers, an outer layer sheet 51 that is not folded back, and an inner layer sheet 52 that is not folded back. The second laminated region T2 in the dorsal region 5b is also composed of the same two layers. As a result, the second laminated region T2 is composed of a total of four layers. In the second laminated region T2, the second skin side sheet P2 is composed of the inner layer sheet 52 that is not folded back.

[0133] In this embodiment as well, from the viewpoint of further stabilizing the joint strength in the entire side joint portion 8, the following configuration may be adopted. For example, it is preferable that the variation in the seal strength of the plurality of seal parts located in the region with a relatively small number of thermoplastic sheet layers is smaller than the variation in the seal strength of the plurality of seal parts located in the region with a relatively large number of thermoplastic sheet layers. In this embodiment, the waist side laminated region T11 has the largest number of layers, the leg side laminated region T12 has the next largest number of layers, and the second laminated region T2 has the smallest number of layers. It is preferable that the second laminated region T2 has the smallest variation in seal strength, the leg side laminated region T12 has the next smallest variation in seal strength, and the waist side laminated region T11 has the largest variation in seal strength. In this way, the number of thermoplastic sheet layers decreases stepwise from the waist end to the leg end, and the variation in seal strength becomes smaller in the region with fewer layers, thereby making it possible to reduce the difference in the force required for tearing in each of the three regions, the waist side laminated region T11, the leg side laminated region T12, and the second laminated region T2, and to perform the tearing operation stably and smoothly. For example, it is preferable that the melting degree of the fibers of the sealed portion located in the region where the number of layers of the thermoplastic sheet is relatively small is higher than that of the sealed portion located in the region where the number of layers of the thermoplastic sheet is relatively large. In this embodiment, the waist side laminated region T11 has the largest number of layers, the leg side laminated region T12 has the next largest number of layers, and the second laminated region T2 has the smallest number of layers. It is preferable that the melting degree of the fibers of the sealed portion S of the second laminated region T2 is the highest, the melting degree of the fibers of the sealed portion S of the leg side laminated region T12 is the next highest, and the melting degree of the fibers of the sealed portion S of the waist side laminated region T11 is the lowest. In this way, the number of layers of the thermoplastic sheet is gradually decreased from the waist end to the leg end, and the melting degree of the fibers is increased in the region where the number of layers is smaller, so that the difference in the required tearing force in each of the three regions of the waist side laminated region T11, the leg side laminated region T12, and the second laminated region T2 can be reduced, and the tearing operation can be performed stably and smoothly.

[0134] In this embodiment as well, from the viewpoint of further stabilizing the joint strength in the entire side joint portion 8, the first skin side sheet P1 and the second skin side sheet P2 may each be configured as follows. For example, it is preferable that the first skin side sheet P1 and the second skin side sheet P2 are each composed of a spunbond nonwoven fabric including a plurality of embossed portions, and it is preferable that the area ratio of the embossed portions in the first skin side sheet P1 is larger than the area ratio of the embossed portions in the second skin side sheet P2. For example, in this embodiment as well, the melting point of the first skin side sheet P1 is preferably higher than the melting point of the second skin side sheet P2. For example, also in this embodiment, the basis weight of the first skin side sheet P1 is preferably lower than the basis weight of the second skin side sheet P2.

[0135] In addition to the above configuration, in the pants-type absorbent article having the side joint 8 of this embodiment, the positional relationship between the first and second seal portions and the joint strength reducer 9 can be configured in the same manner as in any of the first to thirteenth embodiments, thereby making it possible to prevent peeling during the putting on and wearing action and to easily tear the article when discarding it.

[0136] <16th embodiment> The pants-type absorbent article of the present invention is not limited to the examples in which the exterior body 5 has a folded-back structure as in the above-mentioned respective embodiments, and the exterior body 5 does not necessarily have to have a folded-back structure. In this embodiment, as shown in FIG. 20, neither the outer layer sheet 51 nor the inner layer sheet 52 may be folded back, and the ends of these sheets may coincide with the waist opening end Wa. That is, in this example, the exterior body 5 is entirely composed of the same number of layers, and for example, the ventral region 5a and the dorsal region 5b are each composed of two layers, an outer layer sheet 51 and an inner layer sheet 52.

[0137] In other words, in the waist region 8c of the side joint 8, among the multiple thermoplastic sheets 50 of the outer body 5, the skin-side sheet P that constitutes the skin-facing surface is the inner layer sheet 52, and the adjacent sheet Q adjacent to the skin-side sheet P is the outer layer sheet 51. In this case, similarly to the first embodiment, the bond strength reducing agent 9 is preferably disposed in the waist region 8c between the skin side sheet P and the adjacent sheet Q, from the viewpoint of effectively reducing the bond strength in the region where the sealed portion S and the bond strength reducing agent 9 overlap. In the example shown in Fig. 20, the bond strength reducing agent 9 is disposed between the inner layer sheet 52 and the outer layer sheet 51 adjacent thereto. In addition, from the viewpoint of more effectively reducing the bonding strength in the area where the seal portion S and the bonding strength reducing agent 9 overlap, it is preferable that the penetration depth of the bonding strength reducing agent 9 in the skin side sheet P is deeper than the penetration depth of the bonding strength reducing agent 9 in the adjacent sheet Q. In the example shown in FIG. 20, the bond strength reducing agent 9 is placed in both the ventral region 5a and the dorsal region 5b, but as described above, it may be placed in either the ventral region 5a or the dorsal region 5b.

[0138] In this embodiment, from the viewpoint of further stabilizing the bonding strength in the entire side joint portion 8, it is preferable that the skin side sheet P is made of the same nonwoven fabric in the entire side joint portion 8. For example, the skin side sheet P is preferably made of a spunbond nonwoven fabric containing a plurality of embossed portions, and the area ratio of the embossed portions is preferably substantially constant throughout the entire side joint portion 8. Here, "the area ratio of the embossed portions is substantially constant throughout the entire side joint portion 8" means that, when comparing the area ratios of 10 or more embossed portions in the side joint portion 8, the highest area ratio is 110% or less, with the lowest area ratio being 100%. For example, in this embodiment, it is preferable that the melting point of the skin side sheet P is substantially constant throughout the entire side joint 8. "The melting point of the skin side sheet P is substantially constant throughout the entire side joint 8" means that when comparing the melting points of the skin side sheet P at 10 or more locations in the side joint 8, if the lowest melting point is set to 100%, the highest melting point is 110% or less. For example, in this embodiment, it is preferable that the basis weight of the skin side sheet P is substantially constant throughout the entire side joint 8. "The basis weight of the skin side sheet P is substantially constant throughout the entire side joint 8" means that when comparing the basis weights of the skin side sheet P at 10 or more locations in the side joint 8, the highest basis weight is 110% or less when the lowest basis weight is 100%.

[0139] In addition to the above configuration, in the pants-type absorbent article having the side joint 8 of this embodiment, the positional relationship between the first and second seal portions and the joint strength reducer 9 can be configured in the same manner as in any of the first to thirteenth embodiments, thereby making it possible to prevent peeling during the putting on and wearing action and to easily tear the article when discarding it.

[0140] <Other embodiments> Although the embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and it goes without saying that various modifications can be made without departing from the spirit of the present invention.

[0141] For example, in the above embodiment, the exterior body 5 has been described as having the ventral region 5a, the dorsal region 5b, and the crotch region 5c, but is not limited thereto. For example, the exterior body 5 may have a configuration in which the ventral region and the dorsal region are separated without having a crotch region.

[0142] Also, for example, in the above-mentioned embodiment, the sealed portions S are arranged in four or six rows, but preferably three to seven rows. By adopting a multi-row structure with three or more rows, even if there is a large fluctuation (variation in strength) in the strength of each sealed portion S, when one sealed portion S peels off, the other sealed portions S can maintain the joint at the side joint portion 8, and peeling of the side joint portion 8 during the putting action and when worn can be effectively prevented. Also, by adopting seven or less rows, the width of the sealed area of ​​the side joint portion 8 is less likely to become wide, so that the force at the time of tearing is less likely to disperse, making it easier to tear the side joint portion.

[0143] In addition, for example, in the above embodiment, the seal portions S are rectangular in shape and of the same size, but the seal portions S may have different shapes and sizes. In the above embodiment, the seal portions S are equally spaced in the vertical direction X, but they may be different. In such a case, by distributing multiple sealed areas S at the side joint 8 so that the highest sealed area rate is 150% or less when the lowest sealed area rate is 100%, it is easy to tear with the same force from the waist end to the leg end.

[0144] The pants-type absorbent article according to the present invention does not have to be a disposable diaper for infants, and may be, for example, a disposable diaper for adults or children. Furthermore, the pants-type absorbent article according to the present invention does not have to be a disposable diaper as long as it is an absorbent article of the type worn on the lower body. Examples of such pants-type absorbent articles include pants-type sanitary napkins.

[0145] The present invention can also have the following configuration. <1> A pants-type absorbent article comprising: an absorbent body; an exterior body arranged on a non-skin-facing side of the absorbent body, including a ventral region and a dorsal region located on both sides in a longitudinal direction, the exterior body being constructed by laminating a plurality of thermoplastic sheets; and a pair of side joining portions joining the ventral region and the dorsal region of the exterior body at side edges in a lateral direction perpendicular to the longitudinal direction, The pair of side joints each have a waist end and a leg end constituting both ends in the longitudinal direction, a waist region within 25 mm in the longitudinal direction from the waist end, and a plurality of seal portions arranged at a distance along the longitudinal direction and the lateral direction, At least one of the pair of side joints further has a bond strength reducer provided linearly between the thermoplastic sheets, The plurality of sealed portions arranged in the waist region of the side joint portion include a first sealed portion and a second sealed portion that overlap with a virtual line drawn at an angle of 45 degrees with respect to the longitudinal direction and the lateral direction, the virtual line including a component directed toward the leg side in the longitudinal direction and a component directed toward the inner side in the lateral direction; The first sealed portion is located in the nth row (n is an integer equal to or greater than 1) from the waist end portion side, and the second sealed portion is located in the n+1th row, At least one of the first seal portion and the second seal portion overlaps with the bonding strength reducing agent. Pants-type absorbent article. <2> When the virtual line is moved in parallel from the waist end portion toward the leg end portion and overlapped with respect to the first sealed portion and the second sealed portion, the first sealed portion has a first region through which the virtual line passes between where the virtual line overlaps with both the first sealed portion and the second sealed portion, and the second sealed portion has a second region through which the virtual line passes between where the virtual line overlaps with both the first sealed portion and the second sealed portion, The bond strength reducing agent overlaps at least one of the first region and the second region. The above <1> The pants-type absorbent article according to claim 1. <3> When the virtual line is moved in parallel from the waist end portion to the leg end portion and overlapped with the first sealed portion and the second sealed portion, the first sealed portion has the first region and a third region through which the virtual line passes while the virtual line overlaps only with the first sealed portion, The third region and the bonding strength reducing agent overlap each other. The above <2> The pants-type absorbent article according to claim 1. <4> When the virtual line is moved in parallel from the waist end portion to the leg end portion and overlapped with the first sealed portion and the second sealed portion, the second sealed portion has the second region and a fourth region through which the virtual line passes while the virtual line overlaps only with the second sealed portion, The fourth region and the bonding strength reducing agent overlap each other. The above <2> or <3> The pants-type absorbent article according to claim 1. <5> When the vertical distance between the vertical waist side end of the first sealed portion and the vertical waist side end of the second sealed portion is D1, and the horizontal distance between the horizontal inner end of the first sealed portion and the horizontal inner end of the second sealed portion is D2, D1>D2, When the virtual line is moved in parallel from the waist end portion toward the leg end portion to overlap the first sealed portion and the second sealed portion, the first sealed portion has a first region through which the virtual line passes while the virtual line overlaps both the first sealed portion and the second sealed portion, and a third region through which the virtual line passes while the virtual line overlaps only the first sealed portion, The third region and the bonding strength reducing agent overlap each other. The above <1> or <2> The pants-type absorbent article according to claim 1. <6> When the vertical distance between the vertical waist side end of the first sealed portion and the vertical waist side end of the second sealed portion is D1, and the horizontal distance between the horizontal inner end of the first sealed portion and the horizontal inner end of the second sealed portion is D2, D1 <D2であり、 When the virtual line is moved in parallel from the waist end portion toward the leg end portion to overlap the first sealed portion and the second sealed portion, the second sealed portion has a second region through which the virtual line passes while the virtual line overlaps both the first sealed portion and the second sealed portion, and a fourth region through which the virtual line passes while the virtual line overlaps only the second sealed portion, The fourth region and the bonding strength reducing agent overlap each other. The above <1> or <2> The pants-type absorbent article according to claim 1. <7> The bond strength reducing agent includes a hot melt adhesive. The above <1> from <6> 13. The pants-type absorbent article according to claim 12 . <8> The plurality of thermoplastic sheets include a skin-side sheet constituting a skin-facing surface of the exterior body in the waist region and an adjacent sheet adjacent thereto, The bond strength reducing agent is disposed between the skin side sheet and the adjacent sheet. The above <1> from <7> 13. The pants-type absorbent article according to claim 12 . <9> The side joint portion has regions where the number of layers of the thermoplastic sheets is different from each other, The degree of melting of the fibers in the sealed portion located in the region where the number of layers of the thermoplastic sheet is relatively small is higher than the degree of melting of the fibers in the sealed portion located in the region where the number of layers of the thermoplastic sheet is relatively large. The above <1> from <8> 13. The pants-type absorbent article according to claim 12 . <10> The side joint portion has three regions in which the number of layers of the thermoplastic sheet is different from each other so that the number of layers of the thermoplastic sheet decreases in sequence from the waist end portion to the leg end portion. The above <9> The pants-type absorbent article according to claim 1. <11> The side joint portion is a first laminated region in which six or more of the thermoplastic sheets are laminated, including a first skin-side sheet constituting a skin-facing surface; a second lamination region in which a smaller number of the thermoplastic sheets than in the first lamination region are laminated, the second lamination region including a second skin-side sheet constituting a skin-facing surface; the first skin side sheet and the second skin side sheet are each made of a spunbond nonwoven fabric including a plurality of embossments; The first skin side sheet has a higher area ratio occupied by the plurality of embossed portions than the second skin side sheet. The above <1> from <10> 13. The pants-type absorbent article according to claim 12 . <12> The side joint portion is a first laminated region in which six or more of the thermoplastic sheets are laminated, including a first skin-side sheet constituting a skin-facing surface; a second lamination region in which a smaller number of the thermoplastic sheets than in the first lamination region are laminated, the second lamination region including a second skin-side sheet constituting a skin-facing surface; The melting point of the first skin side sheet is higher than the melting point of the second skin side sheet. The above <1> from <11> 13. The pants-type absorbent article according to claim 12 . <13> The side joint portion is a first laminated region in which six or more of the thermoplastic sheets are laminated, including a first skin-side sheet constituting a skin-facing surface; a second laminated region in which a smaller number of the thermoplastic sheets than the first laminated region are laminated, the second laminated region including a second skin-side sheet constituting a skin-facing surface; The first skin side sheet has a basis weight lower than the basis weight of the second skin side sheet. The above <1> from <12> 13. The pants-type absorbent article according to claim 12 . [Explanation of symbols]

[0146] 1...Pants-type absorbent articles (disposable diapers, diapers) 4…Absorbent body 5…Exterior body 5a...ventral region 5b...Dorsal region 50…Thermoplastic sheet 8…Side joint 8a…Waist end 8b…Leg end 9…Bond strength reducing agent S…Seal part S1: First seal S2: Second seal section L, L1~L4...Virtual lines

Claims

1. A pant-type absorbent article comprising: an absorbent body; an outer casing disposed on the non-skin-facing side of the absorbent body and comprising a plurality of thermoplastic sheets laminated together, including a ventral region and a dorsal region located on both sides in the longitudinal direction; and a pair of side joints joining the ventral region and the dorsal region of the outer casing at the lateral edge perpendicular to the longitudinal direction, The pair of side joints comprises a waist end and a leg end that constitute both ends in the vertical direction, a waist region within 25 mm in the vertical direction from the waist end, and a plurality of sealing portions spaced apart along the vertical and horizontal directions. At least one of the pair of side joints further comprises a bonding strength reducing agent provided linearly between the thermoplastic sheets, The plurality of sealing portions arranged in the waist region of the side joint include a first sealing portion and a second sealing portion that overlap with a virtual line that is inclined at 45° with respect to the vertical and horizontal directions, which includes a component toward the vertical leg side and a component toward the horizontal inward, The first sealing portion is located in the nth row (where n is an integer of 1 or more) from the waist end side, and the second sealing portion is located in the n+1th row. At least one of the first sealing portion and the second sealing portion overlaps with the bonding strength reducing agent. Absorbent pants.

2. When the imaginary line is superimposed on the first seal portion and the second seal portion by moving it parallel from the waist end to the leg end, the first seal portion has a first region through which the imaginary line passes while the imaginary line overlaps both the first seal portion and the second seal portion, and the second seal portion has a second region through which the imaginary line passes while the imaginary line overlaps both the first seal portion and the second seal portion. The bonding strength reducing agent overlaps with at least one of the first region and the second region. The pant-type absorbent article according to claim 1.

3. Let D1 be the vertical distance between the vertical waist-side end of the first seal portion and the vertical waist-side end of the second seal portion, and let D2 be the horizontal distance between the horizontal inner end of the first seal portion and the horizontal inner end of the second seal portion. Then, D1 > D2. When the imaginary line is superimposed on the first seal portion and the second seal portion by moving it parallel from the waist end to the leg end, the first seal portion has a first region through which the imaginary line passes while the imaginary line overlaps both the first seal portion and the second seal portion, and a third region through which the imaginary line passes while the imaginary line overlaps only the first seal portion. The third region and the bonding strength reducing agent overlap. The pant-type absorbent article according to claim 1 or 2.

4. When the vertical distance between the vertical waist-side end of the first seal portion and the vertical waist-side end of the second seal portion is D1, and the horizontal distance between the horizontal inner end of the first seal portion and the horizontal inner end of the second seal portion is D2, then D1 < D2, When the imaginary line is superimposed on the first seal portion and the second seal portion by moving it parallel from the waist end to the leg end, the second seal portion has a second region through which the imaginary line passes while the imaginary line overlaps both the first seal portion and the second seal portion, and a fourth region through which the imaginary line passes while the imaginary line overlaps only the second seal portion. The fourth region and the bonding strength reducing agent overlap. The pant-type absorbent article according to claim 1 or 2.

5. The aforementioned bonding strength reducing agent includes a hot melt adhesive. The pant-type absorbent article according to claim 1 or 2.

6. The plurality of thermoplastic sheets in the waist region include a skin-side sheet that constitutes the skin-facing surface of the exterior body and adjacent sheets adjacent thereto. The bonding strength reducing agent is placed between the skin-side sheet and the adjacent sheet. The pant-type absorbent article according to claim 1 or 2.

7. The side joint portion has regions where the number of layers of the thermoplastic sheet differs from each other. The degree of melting of fibers in the sealing portion located in a region with a relatively small number of layers of the thermoplastic sheet is higher than the degree of melting of fibers in the sealing portion located in a region with a relatively large number of layers of the thermoplastic sheet. The pant-type absorbent article according to claim 1 or 2.

8. The side joint has three regions with different numbers of layers, such that the number of layers of the thermoplastic sheet decreases sequentially from the waist end to the leg end. The pant-type absorbent article according to claim 7.

9. The aforementioned side joint portion is A first laminated region in which six or more thermoplastic sheets, including a first skin-side sheet constituting the skin-facing surface, are laminated, It has a second laminated region in which fewer thermoplastic sheets than the first laminated region are laminated, including a second skin-side sheet that constitutes the skin-facing surface, The first skin-side sheet and the second skin-side sheet are each composed of a spunbond nonwoven fabric containing multiple embossings. The area ratio occupied by the multiple embossed portions is higher in the first skin-side sheet than in the second skin-side sheet. The pant-type absorbent article according to claim 1 or 2.

10. The aforementioned side joint portion is A first laminated region in which six or more thermoplastic sheets, including a first skin-side sheet constituting the skin-facing surface, are laminated, It has a second laminated region in which fewer thermoplastic sheets than the first laminated region are laminated, including a second skin-side sheet that constitutes the skin-facing surface, The melting point of the first skin-facing sheet is higher than that of the second skin-facing sheet. The pant-type absorbent article according to claim 1 or 2.

11. The aforementioned side joint portion is A first laminated region in which six or more thermoplastic sheets, including a first skin-side sheet constituting the skin-facing surface, are laminated, It has a second laminated region in which fewer thermoplastic sheets than the first laminated portion are laminated, including a second skin-side sheet that constitutes the skin-facing surface, The basis weight of the first skin-side sheet is lower than the basis weight of the second skin-side sheet. The pant-type absorbent article according to claim 1 or 2.

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